fix name, add comment

remove clone
move data in term req, single doc opt for stats

.github/workflows/coverage.yml

@@ -0,0 +1,29 @@
+name: Coverage
+
+on:
+  push:
+    branches: [main]
+
+# Ensures that we cancel running jobs for the same PR / same workflow.
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  coverage:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Install Rust
+        run: rustup toolchain install nightly-2024-07-01 --profile minimal --component llvm-tools-preview
+      - uses: Swatinem/rust-cache@v2
+      - uses: taiki-e/install-action@cargo-llvm-cov
+      - name: Generate code coverage
+        run: cargo +nightly-2024-07-01 llvm-cov --all-features --workspace --doctests --lcov --output-path lcov.info
+      - name: Upload coverage to Codecov
+        uses: codecov/codecov-action@v3
+        continue-on-error: true
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }} # not required for public repos
+          files: lcov.info
+          fail_ci_if_error: true

.github/workflows/test.yml

@@ -76,9 +76,7 @@ jobs:
             profile: minimal
             override: true
 
-    - uses: taiki-e/install-action@v2
-      with:
-        tool: 'nextest'
+    - uses: taiki-e/install-action@nextest
     - uses: Swatinem/rust-cache@v2
 
     - name: Run tests

.gitignore

@@ -6,6 +6,7 @@ target
 target/debug
 .vscode
 target/release
+Cargo.lock
 benchmark
 .DS_Store
 *.bk
@@ -14,7 +15,3 @@ trace.dat
 cargo-timing*
 control
 variable
-
-# for `sample record -p`
-profile.json
-profile.json.gz

Cargo.toml

@@ -21,11 +21,11 @@ byteorder = "1.4.3"
 crc32fast = "1.3.2"
 once_cell = "1.10.0"
 regex = { version = "1.5.5", default-features = false, features = [
-  "std",
-  "unicode",
+    "std",
+    "unicode",
 ] }
 aho-corasick = "1.0"
-tantivy-fst = { git = "https://github.com/paradedb/fst.git" }
+tantivy-fst = "0.5"
 memmap2 = { version = "0.9.0", optional = true }
 lz4_flex = { version = "0.11", default-features = false, optional = true }
 zstd = { version = "0.13", optional = true, default-features = false }
@@ -38,10 +38,9 @@ levenshtein_automata = "0.2.1"
 uuid = { version = "1.0.0", features = ["v4", "serde"] }
 crossbeam-channel = "0.5.4"
 rust-stemmers = "1.2.0"
-tantivy-stemmers = { version = "0.4.0", default-features = false, features = ["polish_yarovoy"] }
 downcast-rs = "2.0.1"
 bitpacking = { version = "0.9.2", default-features = false, features = [
-  "bitpacker4x",
+    "bitpacker4x",
 ] }
 census = "0.4.2"
 rustc-hash = "2.0.0"
@@ -49,10 +48,6 @@ thiserror = "2.0.1"
 htmlescape = "0.3.1"
 fail = { version = "0.5.0", optional = true }
 time = { version = "0.3.35", features = ["serde-well-known"] }
-# TODO: We have integer wrappers with PartialOrd, and a misfeature of
-# `deranged` causes inference to fail in a bunch of cases. See
-# https://github.com/jhpratt/deranged/issues/18#issuecomment-2746844093
-deranged = "=0.4.0"
 smallvec = "1.8.0"
 rayon = "1.5.2"
 lru = "0.12.0"
@@ -74,7 +69,6 @@ hyperloglogplus = { version = "0.4.1", features = ["const-loop"] }
 futures-util = { version = "0.3.28", optional = true }
 futures-channel = { version = "0.3.28", optional = true }
 fnv = "1.0.7"
-parking_lot = "0.12.4"
 typetag = "0.2.21"
 
 [target.'cfg(windows)'.dependencies]
@@ -94,7 +88,7 @@ more-asserts = "0.3.1"
 rand_distr = "0.4.3"
 time = { version = "0.3.10", features = ["serde-well-known", "macros"] }
 postcard = { version = "1.0.4", features = [
-  "use-std",
+    "use-std",
 ], default-features = false }
 
 [target.'cfg(not(windows))'.dev-dependencies]
@@ -141,14 +135,14 @@ compare_hash_only = ["stacker/compare_hash_only"]
 
 [workspace]
 members = [
-  "query-grammar",
-  "bitpacker",
-  "common",
-  "ownedbytes",
-  "stacker",
-  "sstable",
-  "tokenizer-api",
-  "columnar",
+    "query-grammar",
+    "bitpacker",
+    "common",
+    "ownedbytes",
+    "stacker",
+    "sstable",
+    "tokenizer-api",
+    "columnar",
 ]
 
 # Following the "fail" crate best practises, we isolate

benches/agg_bench.rs

@@ -54,33 +54,33 @@ fn bench_agg(mut group: InputGroup<Index>) {
     register!(group, stats_f64);
     register!(group, extendedstats_f64);
     register!(group, percentiles_f64);
-    register!(group, terms_few);
+    register!(group, terms_7);
     register!(group, terms_all_unique);
-    register!(group, terms_many);
+    register!(group, terms_150_000);
     register!(group, terms_many_top_1000);
     register!(group, terms_many_order_by_term);
     register!(group, terms_many_with_top_hits);
     register!(group, terms_all_unique_with_avg_sub_agg);
     register!(group, terms_many_with_avg_sub_agg);
-    register!(group, terms_few_with_avg_sub_agg);
     register!(group, terms_status_with_avg_sub_agg);
-    register!(group, terms_status);
-    register!(group, terms_few_with_histogram);
     register!(group, terms_status_with_histogram);
+    register!(group, terms_zipf_1000);
+    register!(group, terms_zipf_1000_with_histogram);
+    register!(group, terms_zipf_1000_with_avg_sub_agg);
 
     register!(group, terms_many_json_mixed_type_with_avg_sub_agg);
 
     register!(group, cardinality_agg);
-    register!(group, terms_few_with_cardinality_agg);
+    register!(group, terms_status_with_cardinality_agg);
 
     register!(group, range_agg);
     register!(group, range_agg_with_avg_sub_agg);
-    register!(group, range_agg_with_term_agg_few);
+    register!(group, range_agg_with_term_agg_status);
     register!(group, range_agg_with_term_agg_many);
     register!(group, histogram);
     register!(group, histogram_hard_bounds);
     register!(group, histogram_with_avg_sub_agg);
-    register!(group, histogram_with_term_agg_few);
+    register!(group, histogram_with_term_agg_status);
     register!(group, avg_and_range_with_avg_sub_agg);
 
     // Filter aggregation benchmarks
@@ -159,10 +159,10 @@ fn cardinality_agg(index: &Index) {
     });
     execute_agg(index, agg_req);
 }
-fn terms_few_with_cardinality_agg(index: &Index) {
+fn terms_status_with_cardinality_agg(index: &Index) {
     let agg_req = json!({
         "my_texts": {
-            "terms": { "field": "text_few_terms" },
+            "terms": { "field": "text_few_terms_status" },
             "aggs": {
                 "cardinality": {
                     "cardinality": {
@@ -175,13 +175,7 @@ fn terms_few_with_cardinality_agg(index: &Index) {
     execute_agg(index, agg_req);
 }
 
-fn terms_few(index: &Index) {
-    let agg_req = json!({
-        "my_texts": { "terms": { "field": "text_few_terms" } },
-    });
-    execute_agg(index, agg_req);
-}
-fn terms_status(index: &Index) {
+fn terms_7(index: &Index) {
     let agg_req = json!({
         "my_texts": { "terms": { "field": "text_few_terms_status" } },
     });
@@ -194,7 +188,7 @@ fn terms_all_unique(index: &Index) {
     execute_agg(index, agg_req);
 }
 
-fn terms_many(index: &Index) {
+fn terms_150_000(index: &Index) {
     let agg_req = json!({
         "my_texts": { "terms": { "field": "text_many_terms" } },
     });
@@ -253,17 +247,6 @@ fn terms_all_unique_with_avg_sub_agg(index: &Index) {
     });
     execute_agg(index, agg_req);
 }
-fn terms_few_with_histogram(index: &Index) {
-    let agg_req = json!({
-        "my_texts": {
-            "terms": { "field": "text_few_terms" },
-            "aggs": {
-                "histo": {"histogram": { "field": "score_f64", "interval": 10 }}
-            }
-        }
-    });
-    execute_agg(index, agg_req);
-}
 fn terms_status_with_histogram(index: &Index) {
     let agg_req = json!({
         "my_texts": {
@@ -276,17 +259,18 @@ fn terms_status_with_histogram(index: &Index) {
     execute_agg(index, agg_req);
 }
 
-fn terms_few_with_avg_sub_agg(index: &Index) {
+fn terms_zipf_1000_with_histogram(index: &Index) {
     let agg_req = json!({
         "my_texts": {
-            "terms": { "field": "text_few_terms" },
+            "terms": { "field": "text_1000_terms_zipf" },
             "aggs": {
-                "average_f64": { "avg": { "field": "score_f64" } }
+                "histo": {"histogram": { "field": "score_f64", "interval": 10 }}
             }
-        },
+        }
     });
     execute_agg(index, agg_req);
 }
+
 fn terms_status_with_avg_sub_agg(index: &Index) {
     let agg_req = json!({
         "my_texts": {
@@ -299,6 +283,25 @@ fn terms_status_with_avg_sub_agg(index: &Index) {
     execute_agg(index, agg_req);
 }
 
+fn terms_zipf_1000_with_avg_sub_agg(index: &Index) {
+    let agg_req = json!({
+        "my_texts": {
+            "terms": { "field": "text_1000_terms_zipf" },
+            "aggs": {
+                "average_f64": { "avg": { "field": "score_f64" } }
+            }
+        },
+    });
+    execute_agg(index, agg_req);
+}
+
+fn terms_zipf_1000(index: &Index) {
+    let agg_req = json!({
+        "my_texts": { "terms": { "field": "text_1000_terms_zipf" } },
+    });
+    execute_agg(index, agg_req);
+}
+
 fn terms_many_json_mixed_type_with_avg_sub_agg(index: &Index) {
     let agg_req = json!({
         "my_texts": {
@@ -354,7 +357,7 @@ fn range_agg_with_avg_sub_agg(index: &Index) {
     execute_agg(index, agg_req);
 }
 
-fn range_agg_with_term_agg_few(index: &Index) {
+fn range_agg_with_term_agg_status(index: &Index) {
     let agg_req = json!({
         "rangef64": {
             "range": {
@@ -369,7 +372,7 @@ fn range_agg_with_term_agg_few(index: &Index) {
                 ]
             },
             "aggs": {
-                "my_texts": { "terms": { "field": "text_few_terms" } },
+                "my_texts": { "terms": { "field": "text_few_terms_status" } },
             }
         },
     });
@@ -425,12 +428,12 @@ fn histogram_with_avg_sub_agg(index: &Index) {
     });
     execute_agg(index, agg_req);
 }
-fn histogram_with_term_agg_few(index: &Index) {
+fn histogram_with_term_agg_status(index: &Index) {
     let agg_req = json!({
         "rangef64": {
             "histogram": { "field": "score_f64", "interval": 10 },
             "aggs": {
-                "my_texts": { "terms": { "field": "text_few_terms" } }
+                "my_texts": { "terms": { "field": "text_few_terms_status" } }
             }
         }
     });
@@ -475,6 +478,13 @@ fn get_collector(agg_req: Aggregations) -> AggregationCollector {
 }
 
 fn get_test_index_bench(cardinality: Cardinality) -> tantivy::Result<Index> {
+    // Flag to use existing index
+    let reuse_index = std::env::var("REUSE_AGG_BENCH_INDEX").is_ok();
+    if reuse_index && std::path::Path::new("agg_bench").exists() {
+        return Index::open_in_dir("agg_bench");
+    }
+    // crreate dir
+    std::fs::create_dir_all("agg_bench")?;
     let mut schema_builder = Schema::builder();
     let text_fieldtype = tantivy::schema::TextOptions::default()
         .set_indexing_options(
@@ -486,24 +496,44 @@ fn get_test_index_bench(cardinality: Cardinality) -> tantivy::Result<Index> {
     let text_field_all_unique_terms =
         schema_builder.add_text_field("text_all_unique_terms", STRING | FAST);
     let text_field_many_terms = schema_builder.add_text_field("text_many_terms", STRING | FAST);
-    let text_field_many_terms = schema_builder.add_text_field("text_many_terms", STRING | FAST);
-    let text_field_few_terms = schema_builder.add_text_field("text_few_terms", STRING | FAST);
     let text_field_few_terms_status =
         schema_builder.add_text_field("text_few_terms_status", STRING | FAST);
+    let text_field_1000_terms_zipf =
+        schema_builder.add_text_field("text_1000_terms_zipf", STRING | FAST);
     let score_fieldtype = tantivy::schema::NumericOptions::default().set_fast();
     let score_field = schema_builder.add_u64_field("score", score_fieldtype.clone());
     let score_field_f64 = schema_builder.add_f64_field("score_f64", score_fieldtype.clone());
     let score_field_i64 = schema_builder.add_i64_field("score_i64", score_fieldtype);
-    let index = Index::create_from_tempdir(schema_builder.build())?;
-    let few_terms_data = ["INFO", "ERROR", "WARN", "DEBUG"];
-    // Approximate production log proportions: INFO dominant, WARN and DEBUG occasional, ERROR rare.
-    let log_level_distribution = WeightedIndex::new([80u32, 3, 12, 5]).unwrap();
+    // use tmp dir
+    let index = if reuse_index {
+        Index::create_in_dir("agg_bench", schema_builder.build())?
+    } else {
+        Index::create_from_tempdir(schema_builder.build())?
+    };
+    // Approximate log proportions
+    let status_field_data = [
+        ("INFO", 8000),
+        ("ERROR", 300),
+        ("WARN", 1200),
+        ("DEBUG", 500),
+        ("OK", 500),
+        ("CRITICAL", 20),
+        ("EMERGENCY", 1),
+    ];
+    let log_level_distribution =
+        WeightedIndex::new(status_field_data.iter().map(|item| item.1)).unwrap();
 
     let lg_norm = rand_distr::LogNormal::new(2.996f64, 0.979f64).unwrap();
 
     let many_terms_data = (0..150_000)
         .map(|num| format!("author{num}"))
         .collect::<Vec<_>>();
+
+    // Prepare 1000 unique terms sampled using a Zipf distribution.
+    // Exponent ~1.1 approximates top-20 terms covering around ~20%.
+    let terms_1000: Vec<String> = (1..=1000).map(|i| format!("term_{i}")).collect();
+    let zipf_1000 = rand_distr::Zipf::new(1000, 1.1f64).unwrap();
+
     {
         let mut rng = StdRng::from_seed([1u8; 32]);
         let mut index_writer = index.writer_with_num_threads(1, 200_000_000)?;
@@ -513,8 +543,12 @@ fn get_test_index_bench(cardinality: Cardinality) -> tantivy::Result<Index> {
             index_writer.add_document(doc!())?;
         }
         if cardinality == Cardinality::Multivalued {
-            let log_level_sample_a = few_terms_data[log_level_distribution.sample(&mut rng)];
-            let log_level_sample_b = few_terms_data[log_level_distribution.sample(&mut rng)];
+            let log_level_sample_a = status_field_data[log_level_distribution.sample(&mut rng)].0;
+            let log_level_sample_b = status_field_data[log_level_distribution.sample(&mut rng)].0;
+            let idx_a = zipf_1000.sample(&mut rng) as usize - 1;
+            let idx_b = zipf_1000.sample(&mut rng) as usize - 1;
+            let term_1000_a = &terms_1000[idx_a];
+            let term_1000_b = &terms_1000[idx_b];
             index_writer.add_document(doc!(
                 json_field => json!({"mixed_type": 10.0}),
                 json_field => json!({"mixed_type": 10.0}),
@@ -524,10 +558,10 @@ fn get_test_index_bench(cardinality: Cardinality) -> tantivy::Result<Index> {
                 text_field_all_unique_terms => "coolo",
                 text_field_many_terms => "cool",
                 text_field_many_terms => "cool",
-                text_field_few_terms => "cool",
-                text_field_few_terms => "cool",
                 text_field_few_terms_status => log_level_sample_a,
                 text_field_few_terms_status => log_level_sample_b,
+                text_field_1000_terms_zipf => term_1000_a.as_str(),
+                text_field_1000_terms_zipf => term_1000_b.as_str(),
                 score_field => 1u64,
                 score_field => 1u64,
                 score_field_f64 => lg_norm.sample(&mut rng),
@@ -554,8 +588,8 @@ fn get_test_index_bench(cardinality: Cardinality) -> tantivy::Result<Index> {
                 json_field => json,
                 text_field_all_unique_terms => format!("unique_term_{}", rng.gen::<u64>()),
                 text_field_many_terms => many_terms_data.choose(&mut rng).unwrap().to_string(),
-                text_field_few_terms => few_terms_data.choose(&mut rng).unwrap().to_string(),
-                text_field_few_terms_status => few_terms_data[log_level_distribution.sample(&mut rng)],
+                text_field_few_terms_status => status_field_data[log_level_distribution.sample(&mut rng)].0,
+                text_field_1000_terms_zipf => terms_1000[zipf_1000.sample(&mut rng) as usize - 1].as_str(),
                 score_field => val as u64,
                 score_field_f64 => lg_norm.sample(&mut rng),
                 score_field_i64 => val as i64,
@@ -607,7 +641,7 @@ fn filter_agg_all_query_with_sub_aggs(index: &Index) {
                 "avg_score": { "avg": { "field": "score" } },
                 "stats_score": { "stats": { "field": "score_f64" } },
                 "terms_text": {
-                    "terms": { "field": "text_few_terms" }
+                    "terms": { "field": "text_few_terms_status" }
                 }
             }
         }
@@ -623,7 +657,7 @@ fn filter_agg_term_query_with_sub_aggs(index: &Index) {
                 "avg_score": { "avg": { "field": "score" } },
                 "stats_score": { "stats": { "field": "score_f64" } },
                 "terms_text": {
-                    "terms": { "field": "text_few_terms" }
+                    "terms": { "field": "text_few_terms_status" }
                 }
             }
         }

bitpacker/Cargo.toml

@@ -11,6 +11,9 @@ keywords = []
 documentation = "https://docs.rs/tantivy-bitpacker/latest/tantivy_bitpacker"
 homepage = "https://github.com/quickwit-oss/tantivy"
 
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
 [dependencies]
 bitpacking = { version = "0.9.2", default-features = false, features = ["bitpacker1x"] }
 

bitpacker/src/bitpacker.rs

@@ -48,7 +48,7 @@ impl BitPacker {
 
     pub fn flush<TWrite: io::Write + ?Sized>(&mut self, output: &mut TWrite) -> io::Result<()> {
         if self.mini_buffer_written > 0 {
-            let num_bytes = (self.mini_buffer_written + 7) / 8;
+            let num_bytes = self.mini_buffer_written.div_ceil(8);
             let bytes = self.mini_buffer.to_le_bytes();
             output.write_all(&bytes[..num_bytes])?;
             self.mini_buffer_written = 0;
@@ -65,16 +65,10 @@ impl BitPacker {
 
 #[derive(Clone, Debug, Default, Copy)]
 pub struct BitUnpacker {
-    num_bits: u32,
+    num_bits: usize,
     mask: u64,
 }
 
-pub type BlockNumber = usize;
-
-// 16k
-const BLOCK_SIZE_MIN_POW: u8 = 14;
-const BLOCK_SIZE_MIN: usize = 2 << BLOCK_SIZE_MIN_POW;
-
 impl BitUnpacker {
     /// Creates a bit unpacker, that assumes the same bitwidth for all values.
     ///
@@ -88,9 +82,8 @@ impl BitUnpacker {
         } else {
             (1u64 << num_bits) - 1u64
         };
-
         BitUnpacker {
-            num_bits: u32::from(num_bits),
+            num_bits: usize::from(num_bits),
             mask,
         }
     }
@@ -99,69 +92,16 @@ impl BitUnpacker {
         self.num_bits as u8
     }
 
-    /// Calculates a block number for the given `idx`.
-    #[inline]
-    pub fn block_num(&self, idx: u32) -> BlockNumber {
-        // Find the address in bits of the index.
-        let addr_in_bits = (idx * self.num_bits) as usize;
-
-        // Then round down to the nearest byte.
-        let addr_in_bytes = addr_in_bits >> 3;
-
-        // And compute the containing BlockNumber.
-        addr_in_bytes >> (BLOCK_SIZE_MIN_POW + 1)
-    }
-
-    /// Given a block number and dataset length, calculates a data Range for the block.
-    pub fn block(&self, block: BlockNumber, data_len: usize) -> Range<usize> {
-        let block_addr = block << (BLOCK_SIZE_MIN_POW + 1);
-        // We extend the end of the block by a constant factor, so that it overlaps the next
-        // block. That ensures that we never need to read on a block boundary.
-        block_addr..(std::cmp::min(block_addr + BLOCK_SIZE_MIN + 8, data_len))
-    }
-
-    /// Calculates the number of blocks for the given data_len.
-    ///
-    /// Usually only called at startup to pre-allocate structures.
-    pub fn block_count(&self, data_len: usize) -> usize {
-        let block_count = data_len / (BLOCK_SIZE_MIN as usize);
-        if data_len % (BLOCK_SIZE_MIN as usize) == 0 {
-            block_count
-        } else {
-            block_count + 1
-        }
-    }
-
-    /// Returns a range within the data which covers the given id_range.
-    ///
-    /// NOTE: This method is used for batch reads which bypass blocks to avoid dealing with block
-    /// boundaries.
-    #[inline]
-    pub fn block_oblivious_range(&self, id_range: Range<u32>, data_len: usize) -> Range<usize> {
-        let start_in_bits = id_range.start * self.num_bits;
-        let start = (start_in_bits >> 3) as usize;
-        let end_in_bits = id_range.end * self.num_bits;
-        let end = (end_in_bits >> 3) as usize;
-        // TODO: We fetch more than we need and then truncate.
-        start..(std::cmp::min(end + 8, data_len))
-    }
-
     #[inline]
     pub fn get(&self, idx: u32, data: &[u8]) -> u64 {
-        self.get_from_subset(idx, 0, data)
-    }
-
-    /// Get the value at the given idx, which must exist within the given subset of the data.
-    #[inline]
-    pub fn get_from_subset(&self, idx: u32, data_offset: usize, data: &[u8]) -> u64 {
-        let addr_in_bits = idx * self.num_bits;
-        let addr = (addr_in_bits >> 3) as usize - data_offset;
+        let addr_in_bits = idx as usize * self.num_bits;
+        let addr = addr_in_bits >> 3;
         if addr + 8 > data.len() {
             if self.num_bits == 0 {
                 return 0;
             }
             let bit_shift = addr_in_bits & 7;
-            return self.get_slow_path(addr, bit_shift, data);
+            return self.get_slow_path(addr, bit_shift as u32, data);
         }
         let bit_shift = addr_in_bits & 7;
         let bytes: [u8; 8] = (&data[addr..addr + 8]).try_into().unwrap();
@@ -173,7 +113,6 @@ impl BitUnpacker {
     #[inline(never)]
     fn get_slow_path(&self, addr: usize, bit_shift: u32, data: &[u8]) -> u64 {
         let mut bytes: [u8; 8] = [0u8; 8];
-
         let available_bytes = data.len() - addr;
         // This function is meant to only be called if we did not have 8 bytes to load.
         debug_assert!(available_bytes < 8);
@@ -189,25 +128,26 @@ impl BitUnpacker {
     // #Panics
     //
     // This methods panics if `num_bits` is > 32.
-    fn get_batch_u32s(&self, start_idx: u32, data_offset: usize, data: &[u8], output: &mut [u32]) {
+    fn get_batch_u32s(&self, start_idx: u32, data: &[u8], output: &mut [u32]) {
         assert!(
             self.bit_width() <= 32,
             "Bitwidth must be <= 32 to use this method."
         );
 
-        let end_idx = start_idx + output.len() as u32;
+        let end_idx: u32 = start_idx + output.len() as u32;
 
-        let end_bit_read = end_idx * self.num_bits;
-        let end_byte_read = (end_bit_read + 7) / 8;
+        // We use `usize` here to avoid overflow issues.
+        let end_bit_read = (end_idx as usize) * self.num_bits;
+        let end_byte_read = end_bit_read.div_ceil(8);
         assert!(
-            end_byte_read as usize <= data_offset + data.len(),
+            end_byte_read <= data.len(),
             "Requested index is out of bounds."
         );
 
         // Simple slow implementation of get_batch_u32s, to deal with our ramps.
         let get_batch_ramp = |start_idx: u32, output: &mut [u32]| {
             for (out, idx) in output.iter_mut().zip(start_idx..) {
-                *out = self.get_from_subset(idx, data_offset, data) as u32;
+                *out = self.get(idx, data) as u32;
             }
         };
 
@@ -220,24 +160,24 @@ impl BitUnpacker {
         // We want the start of the fast track to start align with bytes.
         // A sufficient condition is to start with an idx that is a multiple of 8,
         // so highway start is the closest multiple of 8 that is >= start_idx.
-        let entrance_ramp_len = 8 - (start_idx % 8) % 8;
+        let entrance_ramp_len: u32 = 8 - (start_idx % 8) % 8;
 
         let highway_start: u32 = start_idx + entrance_ramp_len;
 
-        if highway_start + BitPacker1x::BLOCK_LEN as u32 > end_idx {
+        if highway_start + (BitPacker1x::BLOCK_LEN as u32) > end_idx {
             // We don't have enough values to have even a single block of highway.
             // Let's just supply the values the simple way.
             get_batch_ramp(start_idx, output);
             return;
         }
 
-        let num_blocks: u32 = (end_idx - highway_start) / BitPacker1x::BLOCK_LEN as u32;
+        let num_blocks: usize = (end_idx - highway_start) as usize / BitPacker1x::BLOCK_LEN;
 
         // Entrance ramp
         get_batch_ramp(start_idx, &mut output[..entrance_ramp_len as usize]);
 
         // Highway
-        let mut offset = ((highway_start * self.num_bits) as usize / 8) - data_offset;
+        let mut offset = (highway_start as usize * self.num_bits) / 8;
         let mut output_cursor = (highway_start - start_idx) as usize;
         for _ in 0..num_blocks {
             offset += BitPacker1x.decompress(
@@ -249,7 +189,7 @@ impl BitUnpacker {
         }
 
         // Exit ramp
-        let highway_end = highway_start + num_blocks * BitPacker1x::BLOCK_LEN as u32;
+        let highway_end: u32 = highway_start + (num_blocks * BitPacker1x::BLOCK_LEN) as u32;
         get_batch_ramp(highway_end, &mut output[output_cursor..]);
     }
 
@@ -259,27 +199,16 @@ impl BitUnpacker {
         id_range: Range<u32>,
         data: &[u8],
         positions: &mut Vec<u32>,
-    ) {
-        self.get_ids_for_value_range_from_subset(range, id_range, 0, data, positions)
-    }
-
-    pub fn get_ids_for_value_range_from_subset(
-        &self,
-        range: RangeInclusive<u64>,
-        id_range: Range<u32>,
-        data_offset: usize,
-        data: &[u8],
-        positions: &mut Vec<u32>,
     ) {
         if self.bit_width() > 32 {
-            self.get_ids_for_value_range_slow(range, id_range, data_offset, data, positions)
+            self.get_ids_for_value_range_slow(range, id_range, data, positions)
         } else {
             if *range.start() > u32::MAX as u64 {
                 positions.clear();
                 return;
             }
             let range_u32 = (*range.start() as u32)..=(*range.end()).min(u32::MAX as u64) as u32;
-            self.get_ids_for_value_range_fast(range_u32, id_range, data_offset, data, positions)
+            self.get_ids_for_value_range_fast(range_u32, id_range, data, positions)
         }
     }
 
@@ -287,7 +216,6 @@ impl BitUnpacker {
         &self,
         range: RangeInclusive<u64>,
         id_range: Range<u32>,
-        data_offset: usize,
         data: &[u8],
         positions: &mut Vec<u32>,
     ) {
@@ -295,7 +223,7 @@ impl BitUnpacker {
         for i in id_range {
             // If we cared we could make this branchless, but the slow implementation should rarely
             // kick in.
-            let val = self.get_from_subset(i, data_offset, data);
+            let val = self.get(i, data);
             if range.contains(&val) {
                 positions.push(i);
             }
@@ -306,12 +234,11 @@ impl BitUnpacker {
         &self,
         value_range: RangeInclusive<u32>,
         id_range: Range<u32>,
-        data_offset: usize,
         data: &[u8],
         positions: &mut Vec<u32>,
     ) {
         positions.resize(id_range.len(), 0u32);
-        self.get_batch_u32s(id_range.start, data_offset, data, positions);
+        self.get_batch_u32s(id_range.start, data, positions);
         crate::filter_vec::filter_vec_in_place(value_range, id_range.start, positions)
     }
 }
@@ -402,14 +329,14 @@ mod test {
     fn test_get_batch_panics_over_32_bits() {
         let bitunpacker = BitUnpacker::new(33);
         let mut output: [u32; 1] = [0u32];
-        bitunpacker.get_batch_u32s(0, 0, &[0, 0, 0, 0, 0, 0, 0, 0], &mut output[..]);
+        bitunpacker.get_batch_u32s(0, &[0, 0, 0, 0, 0, 0, 0, 0], &mut output[..]);
     }
 
     #[test]
     fn test_get_batch_limit() {
         let bitunpacker = BitUnpacker::new(1);
         let mut output: [u32; 3] = [0u32, 0u32, 0u32];
-        bitunpacker.get_batch_u32s(8 * 4 - 3, 0, &[0u8, 0u8, 0u8, 0u8], &mut output[..]);
+        bitunpacker.get_batch_u32s(8 * 4 - 3, &[0u8, 0u8, 0u8, 0u8], &mut output[..]);
     }
 
     #[test]
@@ -418,7 +345,7 @@ mod test {
         let bitunpacker = BitUnpacker::new(1);
         let mut output: [u32; 3] = [0u32, 0u32, 0u32];
         // We are missing exactly one bit.
-        bitunpacker.get_batch_u32s(8 * 4 - 2, 0, &[0u8, 0u8, 0u8, 0u8], &mut output[..]);
+        bitunpacker.get_batch_u32s(8 * 4 - 2, &[0u8, 0u8, 0u8, 0u8], &mut output[..]);
     }
 
     proptest::proptest! {
@@ -441,7 +368,7 @@ mod test {
             for len in [0, 1, 2, 32, 33, 34, 64] {
                 for start_idx in 0u32..32u32 {
                     output.resize(len, 0);
-                    bitunpacker.get_batch_u32s(start_idx, 0, &buffer, &mut output);
+                    bitunpacker.get_batch_u32s(start_idx, &buffer, &mut output);
                     for (i, output_byte) in output.iter().enumerate() {
                         let expected = (start_idx + i as u32) & mask;
                         assert_eq!(*output_byte, expected);

columnar/Cargo.toml

@@ -16,7 +16,7 @@ stacker = { version= "0.6", path = "../stacker", package="tantivy-stacker"}
 sstable = { version= "0.6", path = "../sstable", package = "tantivy-sstable" }
 common = { version= "0.10", path = "../common", package = "tantivy-common" }
 tantivy-bitpacker = { version= "0.9", path = "../bitpacker/" }
-serde = { version = "1.0.152", features = ["derive"] }
+serde = "1.0.152"
 downcast-rs = "2.0.1"
 
 [dev-dependencies]

columnar/benches/bench_access.rs

@@ -1,6 +1,6 @@
 use binggan::{InputGroup, black_box};
 use common::*;
-use tantivy_columnar::{Column, ValueRange};
+use tantivy_columnar::Column;
 
 pub mod common;
 
@@ -46,16 +46,16 @@ fn bench_group(mut runner: InputGroup<Column>) {
     runner.register("access_first_vals", |column| {
         let mut sum = 0;
         const BLOCK_SIZE: usize = 32;
-        let mut docs = Vec::with_capacity(BLOCK_SIZE);
-        let mut buffer = Vec::with_capacity(BLOCK_SIZE);
+        let mut docs = vec![0; BLOCK_SIZE];
+        let mut buffer = vec![None; BLOCK_SIZE];
         for i in (0..NUM_DOCS).step_by(BLOCK_SIZE) {
-            docs.clear();
+            // fill docs
+            #[allow(clippy::needless_range_loop)]
             for idx in 0..BLOCK_SIZE {
-                docs.push(idx as u32 + i);
+                docs[idx] = idx as u32 + i;
             }
 
-            buffer.clear();
-            column.first_vals_in_value_range(&mut docs, &mut buffer, ValueRange::All);
+            column.first_vals(&docs, &mut buffer);
             for val in buffer.iter() {
                 let Some(val) = val else { continue };
                 sum += *val;

columnar/benches/bench_merge.rs

@@ -40,14 +40,7 @@ fn main() {
                 let columnar_readers = columnar_readers.iter().collect::<Vec<_>>();
                 let merge_row_order = StackMergeOrder::stack(&columnar_readers[..]);
 
-                merge_columnar(
-                    &columnar_readers,
-                    &[],
-                    merge_row_order.into(),
-                    &mut out,
-                    || false,
-                )
-                .unwrap();
+                merge_columnar(&columnar_readers, &[], merge_row_order.into(), &mut out).unwrap();
                 Some(out.len() as u64)
             },
         );

columnar/src/block_accessor.rs

@@ -29,12 +29,20 @@ impl<T: PartialOrd + Copy + std::fmt::Debug + Send + Sync + 'static + Default>
         }
     }
     #[inline]
-    pub fn fetch_block_with_missing(&mut self, docs: &[u32], accessor: &Column<T>, missing: T) {
+    pub fn fetch_block_with_missing(
+        &mut self,
+        docs: &[u32],
+        accessor: &Column<T>,
+        missing: Option<T>,
+    ) {
         self.fetch_block(docs, accessor);
         // no missing values
         if accessor.index.get_cardinality().is_full() {
             return;
         }
+        let Some(missing) = missing else {
+            return;
+        };
 
         // We can compare docid_cache length with docs to find missing docs
         // For multi value columns we can't rely on the length and always need to scan

columnar/src/column/mod.rs

@@ -1,7 +1,6 @@
 mod dictionary_encoded;
 mod serialize;
 
-use std::cell::RefCell;
 use std::fmt::{self, Debug};
 use std::io::Write;
 use std::ops::{Range, RangeInclusive};
@@ -20,11 +19,6 @@ use crate::column_values::monotonic_mapping::StrictlyMonotonicMappingToInternal;
 use crate::column_values::{ColumnValues, monotonic_map_column};
 use crate::{Cardinality, DocId, EmptyColumnValues, MonotonicallyMappableToU64, RowId};
 
-thread_local! {
-    static ROWS: RefCell<Vec<RowId>> = const { RefCell::new(Vec::new()) };
-    static DOCS: RefCell<Vec<DocId>> = const { RefCell::new(Vec::new()) };
-}
-
 #[derive(Clone)]
 pub struct Column<T = u64> {
     pub index: ColumnIndex,
@@ -95,6 +89,31 @@ impl<T: PartialOrd + Copy + Debug + Send + Sync + 'static> Column<T> {
         self.values_for_doc(row_id).next()
     }
 
+    /// Load the first value for each docid in the provided slice.
+    #[inline]
+    pub fn first_vals(&self, docids: &[DocId], output: &mut [Option<T>]) {
+        match &self.index {
+            ColumnIndex::Empty { .. } => {}
+            ColumnIndex::Full => self.values.get_vals_opt(docids, output),
+            ColumnIndex::Optional(optional_index) => {
+                for (i, docid) in docids.iter().enumerate() {
+                    output[i] = optional_index
+                        .rank_if_exists(*docid)
+                        .map(|rowid| self.values.get_val(rowid));
+                }
+            }
+            ColumnIndex::Multivalued(multivalued_index) => {
+                for (i, docid) in docids.iter().enumerate() {
+                    let range = multivalued_index.range(*docid);
+                    let is_empty = range.start == range.end;
+                    if !is_empty {
+                        output[i] = Some(self.values.get_val(range.start));
+                    }
+                }
+            }
+        }
+    }
+
     /// Translates a block of docids to row_ids.
     ///
     /// returns the row_ids and the matching docids on the same index
@@ -124,7 +143,7 @@ impl<T: PartialOrd + Copy + Debug + Send + Sync + 'static> Column<T> {
     #[inline]
     pub fn get_docids_for_value_range(
         &self,
-        value_range: ValueRange<T>,
+        value_range: RangeInclusive<T>,
         selected_docid_range: Range<u32>,
         doc_ids: &mut Vec<u32>,
     ) {
@@ -149,181 +168,6 @@ impl<T: PartialOrd + Copy + Debug + Send + Sync + 'static> Column<T> {
     }
 }
 
-// Separate impl block for methods requiring `Default` for `T`.
-impl<T: PartialOrd + Copy + Debug + Send + Sync + 'static + Default> Column<T> {
-    /// Load the first value for each docid in the provided slice.
-    ///
-    /// The `docids` vector is mutated: documents that do not match the `value_range` are removed.
-    /// The `values` vector is populated with the values of the remaining documents.
-    #[inline]
-    pub fn first_vals_in_value_range(
-        &self,
-        input_docs: &[DocId],
-        output: &mut Vec<crate::ComparableDoc<Option<T>, DocId>>,
-        value_range: ValueRange<T>,
-    ) {
-        match (&self.index, value_range) {
-            (ColumnIndex::Empty { .. }, value_range) => {
-                let nulls_match = match &value_range {
-                    ValueRange::All => true,
-                    ValueRange::Inclusive(_) => false,
-                    ValueRange::GreaterThan(_, nulls_match) => *nulls_match,
-                    ValueRange::GreaterThanOrEqual(_, nulls_match) => *nulls_match,
-                    ValueRange::LessThan(_, nulls_match) => *nulls_match,
-                    ValueRange::LessThanOrEqual(_, nulls_match) => *nulls_match,
-                };
-                if nulls_match {
-                    for &doc in input_docs {
-                        output.push(crate::ComparableDoc {
-                            doc,
-                            sort_key: None,
-                        });
-                    }
-                }
-            }
-            (ColumnIndex::Full, value_range) => {
-                self.values
-                    .get_vals_in_value_range(input_docs, input_docs, output, value_range);
-            }
-            (ColumnIndex::Optional(optional_index), value_range) => {
-                let nulls_match = match &value_range {
-                    ValueRange::All => true,
-                    ValueRange::Inclusive(_) => false,
-                    ValueRange::GreaterThan(_, nulls_match) => *nulls_match,
-                    ValueRange::GreaterThanOrEqual(_, nulls_match) => *nulls_match,
-                    ValueRange::LessThan(_, nulls_match) => *nulls_match,
-                    ValueRange::LessThanOrEqual(_, nulls_match) => *nulls_match,
-                };
-
-                let fallback_needed = ROWS.with(|rows_cell| {
-                    DOCS.with(|docs_cell| {
-                        let mut rows = rows_cell.borrow_mut();
-                        let mut docs = docs_cell.borrow_mut();
-                        rows.clear();
-                        docs.clear();
-
-                        let mut has_nulls = false;
-
-                        for &doc_id in input_docs {
-                            if let Some(row_id) = optional_index.rank_if_exists(doc_id) {
-                                rows.push(row_id);
-                                docs.push(doc_id);
-                            } else {
-                                has_nulls = true;
-                                if nulls_match {
-                                    break;
-                                }
-                            }
-                        }
-
-                        if !has_nulls || !nulls_match {
-                            self.values.get_vals_in_value_range(
-                                &rows,
-                                &docs,
-                                output,
-                                value_range.clone(),
-                            );
-                            return false;
-                        }
-                        true
-                    })
-                });
-
-                if fallback_needed {
-                    for &doc_id in input_docs {
-                        if let Some(row_id) = optional_index.rank_if_exists(doc_id) {
-                            let val = self.values.get_val(row_id);
-                            let value_matches = match &value_range {
-                                ValueRange::All => true,
-                                ValueRange::Inclusive(r) => r.contains(&val),
-                                ValueRange::GreaterThan(t, _) => val > *t,
-                                ValueRange::GreaterThanOrEqual(t, _) => val >= *t,
-                                ValueRange::LessThan(t, _) => val < *t,
-                                ValueRange::LessThanOrEqual(t, _) => val <= *t,
-                            };
-
-                            if value_matches {
-                                output.push(crate::ComparableDoc {
-                                    doc: doc_id,
-                                    sort_key: Some(val),
-                                });
-                            }
-                        } else if nulls_match {
-                            output.push(crate::ComparableDoc {
-                                doc: doc_id,
-                                sort_key: None,
-                            });
-                        }
-                    }
-                }
-            }
-            (ColumnIndex::Multivalued(multivalued_index), value_range) => {
-                let nulls_match = match &value_range {
-                    ValueRange::All => true,
-                    ValueRange::Inclusive(_) => false,
-                    ValueRange::GreaterThan(_, nulls_match) => *nulls_match,
-                    ValueRange::GreaterThanOrEqual(_, nulls_match) => *nulls_match,
-                    ValueRange::LessThan(_, nulls_match) => *nulls_match,
-                    ValueRange::LessThanOrEqual(_, nulls_match) => *nulls_match,
-                };
-                for i in 0..input_docs.len() {
-                    let docid = input_docs[i];
-                    let row_range = multivalued_index.range(docid);
-                    let is_empty = row_range.start == row_range.end;
-                    if !is_empty {
-                        let val = self.values.get_val(row_range.start);
-                        let matches = match &value_range {
-                            ValueRange::All => true,
-                            ValueRange::Inclusive(r) => r.contains(&val),
-                            ValueRange::GreaterThan(t, _) => val > *t,
-                            ValueRange::GreaterThanOrEqual(t, _) => val >= *t,
-                            ValueRange::LessThan(t, _) => val < *t,
-                            ValueRange::LessThanOrEqual(t, _) => val <= *t,
-                        };
-                        if matches {
-                            output.push(crate::ComparableDoc {
-                                doc: docid,
-                                sort_key: Some(val),
-                            });
-                        }
-                    } else if nulls_match {
-                        output.push(crate::ComparableDoc {
-                            doc: docid,
-                            sort_key: None,
-                        });
-                    }
-                }
-            }
-        }
-    }
-}
-
-/// A range of values.
-///
-/// This type is intended to be used in batch APIs, where the cost of unpacking the enum
-/// is outweighed by the time spent processing a batch.
-///
-/// Implementers should pattern match on the variants to use optimized loops for each case.
-#[derive(Clone, Debug)]
-pub enum ValueRange<T> {
-    /// A range that includes both start and end.
-    Inclusive(RangeInclusive<T>),
-    /// A range that matches all values.
-    All,
-    /// A range that matches all values greater than the threshold.
-    /// The boolean flag indicates if null values should be included.
-    GreaterThan(T, bool),
-    /// A range that matches all values greater than or equal to the threshold.
-    /// The boolean flag indicates if null values should be included.
-    GreaterThanOrEqual(T, bool),
-    /// A range that matches all values less than the threshold.
-    /// The boolean flag indicates if null values should be included.
-    LessThan(T, bool),
-    /// A range that matches all values less than or equal to the threshold.
-    /// The boolean flag indicates if null values should be included.
-    LessThanOrEqual(T, bool),
-}
-
 impl BinarySerializable for Cardinality {
     fn serialize<W: Write + ?Sized>(&self, writer: &mut W) -> std::io::Result<()> {
         self.to_code().serialize(writer)

columnar/src/column/serialize.rs

@@ -2,7 +2,7 @@ use std::io;
 use std::io::Write;
 use std::sync::Arc;
 
-use common::file_slice::FileSlice;
+use common::OwnedBytes;
 use sstable::Dictionary;
 
 use crate::column::{BytesColumn, Column};
@@ -41,13 +41,12 @@ pub fn serialize_column_mappable_to_u64<T: MonotonicallyMappableToU64>(
 }
 
 pub fn open_column_u64<T: MonotonicallyMappableToU64>(
-    file_slice: FileSlice,
+    bytes: OwnedBytes,
     format_version: Version,
 ) -> io::Result<Column<T>> {
-    let (body, column_index_num_bytes_payload) = file_slice.split_from_end(4);
+    let (body, column_index_num_bytes_payload) = bytes.rsplit(4);
     let column_index_num_bytes = u32::from_le_bytes(
         column_index_num_bytes_payload
-            .read_bytes()?
             .as_slice()
             .try_into()
             .unwrap(),
@@ -62,13 +61,12 @@ pub fn open_column_u64<T: MonotonicallyMappableToU64>(
 }
 
 pub fn open_column_u128<T: MonotonicallyMappableToU128>(
-    file_slice: FileSlice,
+    bytes: OwnedBytes,
     format_version: Version,
 ) -> io::Result<Column<T>> {
-    let (body, column_index_num_bytes_payload) = file_slice.split_from_end(4);
+    let (body, column_index_num_bytes_payload) = bytes.rsplit(4);
     let column_index_num_bytes = u32::from_le_bytes(
         column_index_num_bytes_payload
-            .read_bytes()?
             .as_slice()
             .try_into()
             .unwrap(),
@@ -86,13 +84,12 @@ pub fn open_column_u128<T: MonotonicallyMappableToU128>(
 ///
 /// See [`open_u128_as_compact_u64`] for more details.
 pub fn open_column_u128_as_compact_u64(
-    file_slice: FileSlice,
+    bytes: OwnedBytes,
     format_version: Version,
 ) -> io::Result<Column<u64>> {
-    let (body, column_index_num_bytes_payload) = file_slice.split_from_end(4);
+    let (body, column_index_num_bytes_payload) = bytes.rsplit(4);
     let column_index_num_bytes = u32::from_le_bytes(
         column_index_num_bytes_payload
-            .read_bytes()?
             .as_slice()
             .try_into()
             .unwrap(),
@@ -106,21 +103,11 @@ pub fn open_column_u128_as_compact_u64(
     })
 }
 
-pub fn open_column_bytes(
-    file_slice: FileSlice,
-    format_version: Version,
-) -> io::Result<BytesColumn> {
-    let (body, dictionary_len_bytes) = file_slice.split_from_end(4);
-    let dictionary_len = u32::from_le_bytes(
-        dictionary_len_bytes
-            .read_bytes()?
-            .as_slice()
-            .try_into()
-            .unwrap(),
-    );
+pub fn open_column_bytes(data: OwnedBytes, format_version: Version) -> io::Result<BytesColumn> {
+    let (body, dictionary_len_bytes) = data.rsplit(4);
+    let dictionary_len = u32::from_le_bytes(dictionary_len_bytes.as_slice().try_into().unwrap());
     let (dictionary_bytes, column_bytes) = body.split(dictionary_len as usize);
-
-    let dictionary = Arc::new(Dictionary::open(dictionary_bytes)?);
+    let dictionary = Arc::new(Dictionary::from_bytes(dictionary_bytes)?);
     let term_ord_column = crate::column::open_column_u64::<u64>(column_bytes, format_version)?;
     Ok(BytesColumn {
         dictionary,
@@ -128,7 +115,7 @@ pub fn open_column_bytes(
     })
 }
 
-pub fn open_column_str(file_slice: FileSlice, format_version: Version) -> io::Result<StrColumn> {
-    let bytes_column = open_column_bytes(file_slice, format_version)?;
+pub fn open_column_str(data: OwnedBytes, format_version: Version) -> io::Result<StrColumn> {
+    let bytes_column = open_column_bytes(data, format_version)?;
     Ok(StrColumn::wrap(bytes_column))
 }

columnar/src/column_index/merge/mod.rs

@@ -95,7 +95,7 @@ pub fn merge_column_index<'a>(
 
 #[cfg(test)]
 mod tests {
-    use common::file_slice::FileSlice;
+    use common::OwnedBytes;
 
     use crate::column_index::merge::detect_cardinality;
     use crate::column_index::multivalued_index::{
@@ -178,7 +178,7 @@ mod tests {
         let mut output = Vec::new();
         serialize_multivalued_index(&start_index_iterable, &mut output).unwrap();
         let multivalue =
-            open_multivalued_index(FileSlice::from(output), crate::Version::V2).unwrap();
+            open_multivalued_index(OwnedBytes::new(output), crate::Version::V2).unwrap();
         let start_indexes: Vec<RowId> = multivalue.get_start_index_column().iter().collect();
         assert_eq!(&start_indexes, &[0, 3, 5]);
     }
@@ -216,7 +216,7 @@ mod tests {
         let mut output = Vec::new();
         serialize_multivalued_index(&start_index_iterable, &mut output).unwrap();
         let multivalue =
-            open_multivalued_index(FileSlice::from(output), crate::Version::V2).unwrap();
+            open_multivalued_index(OwnedBytes::new(output), crate::Version::V2).unwrap();
         let start_indexes: Vec<RowId> = multivalue.get_start_index_column().iter().collect();
         assert_eq!(&start_indexes, &[0, 3, 5, 6]);
     }

columnar/src/column_index/multivalued_index.rs

@@ -3,8 +3,7 @@ use std::io::Write;
 use std::ops::Range;
 use std::sync::Arc;
 
-use common::CountingWriter;
-use common::file_slice::FileSlice;
+use common::{CountingWriter, OwnedBytes};
 
 use super::optional_index::{open_optional_index, serialize_optional_index};
 use super::{OptionalIndex, SerializableOptionalIndex, Set};
@@ -45,26 +44,21 @@ pub fn serialize_multivalued_index(
 }
 
 pub fn open_multivalued_index(
-    file_slice: FileSlice,
+    bytes: OwnedBytes,
     format_version: Version,
 ) -> io::Result<MultiValueIndex> {
     match format_version {
         Version::V1 => {
             let start_index_column: Arc<dyn ColumnValues<RowId>> =
-                load_u64_based_column_values(file_slice)?;
+                load_u64_based_column_values(bytes)?;
             Ok(MultiValueIndex::MultiValueIndexV1(MultiValueIndexV1 {
                 start_index_column,
             }))
         }
         Version::V2 => {
-            let (body_bytes, optional_index_len) = file_slice.split_from_end(4);
-            let optional_index_len = u32::from_le_bytes(
-                optional_index_len
-                    .read_bytes()?
-                    .as_slice()
-                    .try_into()
-                    .unwrap(),
-            );
+            let (body_bytes, optional_index_len) = bytes.rsplit(4);
+            let optional_index_len =
+                u32::from_le_bytes(optional_index_len.as_slice().try_into().unwrap());
             let (optional_index_bytes, start_index_bytes) =
                 body_bytes.split(optional_index_len as usize);
             let optional_index = open_optional_index(optional_index_bytes)?;
@@ -191,8 +185,8 @@ impl MultiValueIndex {
         };
         let mut buffer = Vec::new();
         serialize_multivalued_index(&serializable_multivalued_index, &mut buffer).unwrap();
-        let file_slice = FileSlice::from(buffer);
-        open_multivalued_index(file_slice, Version::V2).unwrap()
+        let bytes = OwnedBytes::new(buffer);
+        open_multivalued_index(bytes, Version::V2).unwrap()
     }
 
     pub fn get_start_index_column(&self) -> &Arc<dyn crate::ColumnValues<RowId>> {
@@ -339,7 +333,7 @@ mod tests {
     use std::ops::Range;
 
     use super::MultiValueIndex;
-    use crate::{ColumnarReader, DynamicColumn, ValueRange};
+    use crate::{ColumnarReader, DynamicColumn};
 
     fn index_to_pos_helper(
         index: &MultiValueIndex,
@@ -419,7 +413,7 @@ mod tests {
         assert_eq!(row_id_range, 0..4);
 
         let check = |range, expected| {
-            let full_range = ValueRange::All;
+            let full_range = 0..=u64::MAX;
             let mut docids = Vec::new();
             column.get_docids_for_value_range(full_range, range, &mut docids);
             assert_eq!(docids, expected);

columnar/src/column_index/optional_index/mod.rs

@@ -4,7 +4,6 @@ use std::sync::Arc;
 mod set;
 mod set_block;
 
-use common::file_slice::FileSlice;
 use common::{BinarySerializable, OwnedBytes, VInt};
 pub use set::{SelectCursor, Set, SetCodec};
 use set_block::{
@@ -269,8 +268,8 @@ impl OptionalIndex {
         );
         let mut buffer = Vec::new();
         serialize_optional_index(&row_ids, num_rows, &mut buffer).unwrap();
-        let file_slice = FileSlice::from(buffer);
-        open_optional_index(file_slice).unwrap()
+        let bytes = OwnedBytes::new(buffer);
+        open_optional_index(bytes).unwrap()
     }
 
     pub fn num_docs(&self) -> RowId {
@@ -487,17 +486,10 @@ fn deserialize_optional_index_block_metadatas(
     (block_metas.into_boxed_slice(), non_null_rows_before_block)
 }
 
-pub fn open_optional_index(file_slice: FileSlice) -> io::Result<OptionalIndex> {
-    let (bytes, num_non_empty_blocks_bytes) = file_slice.split_from_end(2);
-    let num_non_empty_block_bytes = u16::from_le_bytes(
-        num_non_empty_blocks_bytes
-            .read_bytes()?
-            .as_slice()
-            .try_into()
-            .unwrap(),
-    );
-
-    let mut bytes = bytes.read_bytes()?;
+pub fn open_optional_index(bytes: OwnedBytes) -> io::Result<OptionalIndex> {
+    let (mut bytes, num_non_empty_blocks_bytes) = bytes.rsplit(2);
+    let num_non_empty_block_bytes =
+        u16::from_le_bytes(num_non_empty_blocks_bytes.as_slice().try_into().unwrap());
     let num_docs = VInt::deserialize_u64(&mut bytes)? as u32;
     let block_metas_num_bytes =
         num_non_empty_block_bytes as usize * SERIALIZED_BLOCK_META_NUM_BYTES;

columnar/src/column_index/optional_index/tests.rs

@@ -59,7 +59,7 @@ fn test_with_random_sets_simple() {
     let vals = 10..ELEMENTS_PER_BLOCK * 2;
     let mut out: Vec<u8> = Vec::new();
     serialize_optional_index(&vals, 100, &mut out).unwrap();
-    let null_index = open_optional_index(FileSlice::from(out)).unwrap();
+    let null_index = open_optional_index(OwnedBytes::new(out)).unwrap();
     let ranks: Vec<u32> = (65_472u32..65_473u32).collect();
     let els: Vec<u32> = ranks.iter().copied().map(|rank| rank + 10).collect();
     let mut select_cursor = null_index.select_cursor();
@@ -102,7 +102,7 @@ impl<'a> Iterable<RowId> for &'a [bool] {
 fn test_null_index(data: &[bool]) {
     let mut out: Vec<u8> = Vec::new();
     serialize_optional_index(&data, data.len() as RowId, &mut out).unwrap();
-    let null_index = open_optional_index(FileSlice::from(out)).unwrap();
+    let null_index = open_optional_index(OwnedBytes::new(out)).unwrap();
     let orig_idx_with_value: Vec<u32> = data
         .iter()
         .enumerate()
@@ -223,170 +223,3 @@ fn test_optional_index_for_tests() {
     assert!(!optional_index.contains(3));
     assert_eq!(optional_index.num_docs(), 4);
 }
-
-#[cfg(all(test, feature = "unstable"))]
-mod bench {
-
-    use rand::rngs::StdRng;
-    use rand::{Rng, SeedableRng};
-    use test::Bencher;
-
-    use super::*;
-
-    const TOTAL_NUM_VALUES: u32 = 1_000_000;
-    fn gen_bools(fill_ratio: f64) -> OptionalIndex {
-        let mut out = Vec::new();
-        let mut rng: StdRng = StdRng::from_seed([1u8; 32]);
-        let vals: Vec<RowId> = (0..TOTAL_NUM_VALUES)
-            .map(|_| rng.gen_bool(fill_ratio))
-            .enumerate()
-            .filter(|(_pos, val)| *val)
-            .map(|(pos, _)| pos as RowId)
-            .collect();
-        serialize_optional_index(&&vals[..], TOTAL_NUM_VALUES, &mut out).unwrap();
-
-        open_optional_index(FileSlice::from(out)).unwrap()
-    }
-
-    fn random_range_iterator(
-        start: u32,
-        end: u32,
-        avg_step_size: u32,
-        avg_deviation: u32,
-    ) -> impl Iterator<Item = u32> {
-        let mut rng: StdRng = StdRng::from_seed([1u8; 32]);
-        let mut current = start;
-        std::iter::from_fn(move || {
-            current += rng.gen_range(avg_step_size - avg_deviation..=avg_step_size + avg_deviation);
-            if current >= end { None } else { Some(current) }
-        })
-    }
-
-    fn n_percent_step_iterator(percent: f32, num_values: u32) -> impl Iterator<Item = u32> {
-        let ratio = percent / 100.0;
-        let step_size = (1f32 / ratio) as u32;
-        let deviation = step_size - 1;
-        random_range_iterator(0, num_values, step_size, deviation)
-    }
-
-    fn walk_over_data(codec: &OptionalIndex, avg_step_size: u32) -> Option<u32> {
-        walk_over_data_from_positions(
-            codec,
-            random_range_iterator(0, TOTAL_NUM_VALUES, avg_step_size, 0),
-        )
-    }
-
-    fn walk_over_data_from_positions(
-        codec: &OptionalIndex,
-        positions: impl Iterator<Item = u32>,
-    ) -> Option<u32> {
-        let mut dense_idx: Option<u32> = None;
-        for idx in positions {
-            dense_idx = dense_idx.or(codec.rank_if_exists(idx));
-        }
-        dense_idx
-    }
-
-    #[bench]
-    fn bench_translate_orig_to_codec_1percent_filled_10percent_hit(bench: &mut Bencher) {
-        let codec = gen_bools(0.01f64);
-        bench.iter(|| walk_over_data(&codec, 100));
-    }
-
-    #[bench]
-    fn bench_translate_orig_to_codec_5percent_filled_10percent_hit(bench: &mut Bencher) {
-        let codec = gen_bools(0.05f64);
-        bench.iter(|| walk_over_data(&codec, 100));
-    }
-
-    #[bench]
-    fn bench_translate_orig_to_codec_5percent_filled_1percent_hit(bench: &mut Bencher) {
-        let codec = gen_bools(0.05f64);
-        bench.iter(|| walk_over_data(&codec, 1000));
-    }
-
-    #[bench]
-    fn bench_translate_orig_to_codec_full_scan_1percent_filled(bench: &mut Bencher) {
-        let codec = gen_bools(0.01f64);
-        bench.iter(|| walk_over_data_from_positions(&codec, 0..TOTAL_NUM_VALUES));
-    }
-
-    #[bench]
-    fn bench_translate_orig_to_codec_full_scan_10percent_filled(bench: &mut Bencher) {
-        let codec = gen_bools(0.1f64);
-        bench.iter(|| walk_over_data_from_positions(&codec, 0..TOTAL_NUM_VALUES));
-    }
-
-    #[bench]
-    fn bench_translate_orig_to_codec_full_scan_90percent_filled(bench: &mut Bencher) {
-        let codec = gen_bools(0.9f64);
-        bench.iter(|| walk_over_data_from_positions(&codec, 0..TOTAL_NUM_VALUES));
-    }
-
-    #[bench]
-    fn bench_translate_orig_to_codec_10percent_filled_1percent_hit(bench: &mut Bencher) {
-        let codec = gen_bools(0.1f64);
-        bench.iter(|| walk_over_data(&codec, 100));
-    }
-
-    #[bench]
-    fn bench_translate_orig_to_codec_50percent_filled_1percent_hit(bench: &mut Bencher) {
-        let codec = gen_bools(0.5f64);
-        bench.iter(|| walk_over_data(&codec, 100));
-    }
-
-    #[bench]
-    fn bench_translate_orig_to_codec_90percent_filled_1percent_hit(bench: &mut Bencher) {
-        let codec = gen_bools(0.9f64);
-        bench.iter(|| walk_over_data(&codec, 100));
-    }
-
-    #[bench]
-    fn bench_translate_codec_to_orig_1percent_filled_0comma005percent_hit(bench: &mut Bencher) {
-        bench_translate_codec_to_orig_util(0.01f64, 0.005f32, bench);
-    }
-
-    #[bench]
-    fn bench_translate_codec_to_orig_10percent_filled_0comma005percent_hit(bench: &mut Bencher) {
-        bench_translate_codec_to_orig_util(0.1f64, 0.005f32, bench);
-    }
-
-    #[bench]
-    fn bench_translate_codec_to_orig_1percent_filled_10percent_hit(bench: &mut Bencher) {
-        bench_translate_codec_to_orig_util(0.01f64, 10f32, bench);
-    }
-
-    #[bench]
-    fn bench_translate_codec_to_orig_1percent_filled_full_scan(bench: &mut Bencher) {
-        bench_translate_codec_to_orig_util(0.01f64, 100f32, bench);
-    }
-
-    fn bench_translate_codec_to_orig_util(
-        percent_filled: f64,
-        percent_hit: f32,
-        bench: &mut Bencher,
-    ) {
-        let codec = gen_bools(percent_filled);
-        let num_non_nulls = codec.num_non_nulls();
-        let idxs: Vec<u32> = if percent_hit == 100.0f32 {
-            (0..num_non_nulls).collect()
-        } else {
-            n_percent_step_iterator(percent_hit, num_non_nulls).collect()
-        };
-        let mut output = vec![0u32; idxs.len()];
-        bench.iter(|| {
-            output.copy_from_slice(&idxs[..]);
-            codec.select_batch(&mut output);
-        });
-    }
-
-    #[bench]
-    fn bench_translate_codec_to_orig_90percent_filled_0comma005percent_hit(bench: &mut Bencher) {
-        bench_translate_codec_to_orig_util(0.9f64, 0.005, bench);
-    }
-
-    #[bench]
-    fn bench_translate_codec_to_orig_90percent_filled_full_scan(bench: &mut Bencher) {
-        bench_translate_codec_to_orig_util(0.9f64, 100.0f32, bench);
-    }
-}

columnar/src/column_index/serialize.rs

@@ -1,8 +1,7 @@
 use std::io;
 use std::io::Write;
 
-use common::file_slice::FileSlice;
-use common::{CountingWriter, HasLen};
+use common::{CountingWriter, OwnedBytes};
 
 use super::OptionalIndex;
 use super::multivalued_index::SerializableMultivalueIndex;
@@ -66,28 +65,27 @@ pub fn serialize_column_index(
 
 /// Open a serialized column index.
 pub fn open_column_index(
-    file_slice: FileSlice,
+    mut bytes: OwnedBytes,
     format_version: Version,
 ) -> io::Result<ColumnIndex> {
-    if file_slice.len() == 0 {
+    if bytes.is_empty() {
         return Err(io::Error::new(
             io::ErrorKind::UnexpectedEof,
             "Failed to deserialize column index. Empty buffer.",
         ));
     }
-    let (header, body) = file_slice.split(1);
-    let cardinality_code = header.read_bytes()?.as_slice()[0];
+    let cardinality_code = bytes[0];
     let cardinality = Cardinality::try_from_code(cardinality_code)?;
-
+    bytes.advance(1);
     match cardinality {
         Cardinality::Full => Ok(ColumnIndex::Full),
         Cardinality::Optional => {
-            let optional_index = super::optional_index::open_optional_index(body)?;
+            let optional_index = super::optional_index::open_optional_index(bytes)?;
             Ok(ColumnIndex::Optional(optional_index))
         }
         Cardinality::Multivalued => {
             let multivalue_index =
-                super::multivalued_index::open_multivalued_index(body, format_version)?;
+                super::multivalued_index::open_multivalued_index(bytes, format_version)?;
             Ok(ColumnIndex::Multivalued(multivalue_index))
         }
     }

columnar/src/column_values/mod.rs

@@ -7,15 +7,13 @@
 //! - Monotonically map values to u64/u128
 
 use std::fmt::Debug;
-use std::ops::Range;
+use std::ops::{Range, RangeInclusive};
 use std::sync::Arc;
 
 use downcast_rs::DowncastSync;
 pub use monotonic_mapping::{MonotonicallyMappableToU64, StrictlyMonotonicFn};
 pub use monotonic_mapping_u128::MonotonicallyMappableToU128;
 
-use crate::column::ValueRange;
-
 mod merge;
 pub(crate) mod monotonic_mapping;
 pub(crate) mod monotonic_mapping_u128;
@@ -29,7 +27,8 @@ mod monotonic_column;
 pub(crate) use merge::MergedColumnValues;
 pub use stats::ColumnStats;
 pub use u64_based::{
-    ALL_U64_CODEC_TYPES, CodecType, load_u64_based_column_values, serialize_u64_based_column_values,
+    ALL_U64_CODEC_TYPES, CodecType, load_u64_based_column_values,
+    serialize_and_load_u64_based_column_values, serialize_u64_based_column_values,
 };
 pub use u128_based::{
     CompactSpaceU64Accessor, open_u128_as_compact_u64, open_u128_mapped,
@@ -110,307 +109,6 @@ pub trait ColumnValues<T: PartialOrd = u64>: Send + Sync + DowncastSync {
         }
     }
 
-    /// Load the values for the provided docids.
-    ///
-    /// The values are filtered by the provided value range.
-    fn get_vals_in_value_range(
-        &self,
-        input_indexes: &[u32],
-        input_doc_ids: &[u32],
-        output: &mut Vec<crate::ComparableDoc<Option<T>, crate::DocId>>,
-        value_range: ValueRange<T>,
-    ) {
-        let len = input_indexes.len();
-        let mut read_head = 0;
-
-        match value_range {
-            ValueRange::All => {
-                while read_head + 3 < len {
-                    let idx0 = input_indexes[read_head];
-                    let idx1 = input_indexes[read_head + 1];
-                    let idx2 = input_indexes[read_head + 2];
-                    let idx3 = input_indexes[read_head + 3];
-
-                    let doc0 = input_doc_ids[read_head];
-                    let doc1 = input_doc_ids[read_head + 1];
-                    let doc2 = input_doc_ids[read_head + 2];
-                    let doc3 = input_doc_ids[read_head + 3];
-
-                    let val0 = self.get_val(idx0);
-                    let val1 = self.get_val(idx1);
-                    let val2 = self.get_val(idx2);
-                    let val3 = self.get_val(idx3);
-
-                    output.push(crate::ComparableDoc {
-                        doc: doc0,
-                        sort_key: Some(val0),
-                    });
-                    output.push(crate::ComparableDoc {
-                        doc: doc1,
-                        sort_key: Some(val1),
-                    });
-                    output.push(crate::ComparableDoc {
-                        doc: doc2,
-                        sort_key: Some(val2),
-                    });
-                    output.push(crate::ComparableDoc {
-                        doc: doc3,
-                        sort_key: Some(val3),
-                    });
-
-                    read_head += 4;
-                }
-            }
-            ValueRange::Inclusive(ref range) => {
-                while read_head + 3 < len {
-                    let idx0 = input_indexes[read_head];
-                    let idx1 = input_indexes[read_head + 1];
-                    let idx2 = input_indexes[read_head + 2];
-                    let idx3 = input_indexes[read_head + 3];
-
-                    let doc0 = input_doc_ids[read_head];
-                    let doc1 = input_doc_ids[read_head + 1];
-                    let doc2 = input_doc_ids[read_head + 2];
-                    let doc3 = input_doc_ids[read_head + 3];
-
-                    let val0 = self.get_val(idx0);
-                    let val1 = self.get_val(idx1);
-                    let val2 = self.get_val(idx2);
-                    let val3 = self.get_val(idx3);
-
-                    if range.contains(&val0) {
-                        output.push(crate::ComparableDoc {
-                            doc: doc0,
-                            sort_key: Some(val0),
-                        });
-                    }
-                    if range.contains(&val1) {
-                        output.push(crate::ComparableDoc {
-                            doc: doc1,
-                            sort_key: Some(val1),
-                        });
-                    }
-                    if range.contains(&val2) {
-                        output.push(crate::ComparableDoc {
-                            doc: doc2,
-                            sort_key: Some(val2),
-                        });
-                    }
-                    if range.contains(&val3) {
-                        output.push(crate::ComparableDoc {
-                            doc: doc3,
-                            sort_key: Some(val3),
-                        });
-                    }
-
-                    read_head += 4;
-                }
-            }
-            ValueRange::GreaterThan(ref threshold, _) => {
-                while read_head + 3 < len {
-                    let idx0 = input_indexes[read_head];
-                    let idx1 = input_indexes[read_head + 1];
-                    let idx2 = input_indexes[read_head + 2];
-                    let idx3 = input_indexes[read_head + 3];
-
-                    let doc0 = input_doc_ids[read_head];
-                    let doc1 = input_doc_ids[read_head + 1];
-                    let doc2 = input_doc_ids[read_head + 2];
-                    let doc3 = input_doc_ids[read_head + 3];
-
-                    let val0 = self.get_val(idx0);
-                    let val1 = self.get_val(idx1);
-                    let val2 = self.get_val(idx2);
-                    let val3 = self.get_val(idx3);
-
-                    if val0 > *threshold {
-                        output.push(crate::ComparableDoc {
-                            doc: doc0,
-                            sort_key: Some(val0),
-                        });
-                    }
-                    if val1 > *threshold {
-                        output.push(crate::ComparableDoc {
-                            doc: doc1,
-                            sort_key: Some(val1),
-                        });
-                    }
-                    if val2 > *threshold {
-                        output.push(crate::ComparableDoc {
-                            doc: doc2,
-                            sort_key: Some(val2),
-                        });
-                    }
-                    if val3 > *threshold {
-                        output.push(crate::ComparableDoc {
-                            doc: doc3,
-                            sort_key: Some(val3),
-                        });
-                    }
-
-                    read_head += 4;
-                }
-            }
-            ValueRange::GreaterThanOrEqual(ref threshold, _) => {
-                while read_head + 3 < len {
-                    let idx0 = input_indexes[read_head];
-                    let idx1 = input_indexes[read_head + 1];
-                    let idx2 = input_indexes[read_head + 2];
-                    let idx3 = input_indexes[read_head + 3];
-
-                    let doc0 = input_doc_ids[read_head];
-                    let doc1 = input_doc_ids[read_head + 1];
-                    let doc2 = input_doc_ids[read_head + 2];
-                    let doc3 = input_doc_ids[read_head + 3];
-
-                    let val0 = self.get_val(idx0);
-                    let val1 = self.get_val(idx1);
-                    let val2 = self.get_val(idx2);
-                    let val3 = self.get_val(idx3);
-
-                    if val0 >= *threshold {
-                        output.push(crate::ComparableDoc {
-                            doc: doc0,
-                            sort_key: Some(val0),
-                        });
-                    }
-                    if val1 >= *threshold {
-                        output.push(crate::ComparableDoc {
-                            doc: doc1,
-                            sort_key: Some(val1),
-                        });
-                    }
-                    if val2 >= *threshold {
-                        output.push(crate::ComparableDoc {
-                            doc: doc2,
-                            sort_key: Some(val2),
-                        });
-                    }
-                    if val3 >= *threshold {
-                        output.push(crate::ComparableDoc {
-                            doc: doc3,
-                            sort_key: Some(val3),
-                        });
-                    }
-
-                    read_head += 4;
-                }
-            }
-            ValueRange::LessThan(ref threshold, _) => {
-                while read_head + 3 < len {
-                    let idx0 = input_indexes[read_head];
-                    let idx1 = input_indexes[read_head + 1];
-                    let idx2 = input_indexes[read_head + 2];
-                    let idx3 = input_indexes[read_head + 3];
-
-                    let doc0 = input_doc_ids[read_head];
-                    let doc1 = input_doc_ids[read_head + 1];
-                    let doc2 = input_doc_ids[read_head + 2];
-                    let doc3 = input_doc_ids[read_head + 3];
-
-                    let val0 = self.get_val(idx0);
-                    let val1 = self.get_val(idx1);
-                    let val2 = self.get_val(idx2);
-                    let val3 = self.get_val(idx3);
-
-                    if val0 < *threshold {
-                        output.push(crate::ComparableDoc {
-                            doc: doc0,
-                            sort_key: Some(val0),
-                        });
-                    }
-                    if val1 < *threshold {
-                        output.push(crate::ComparableDoc {
-                            doc: doc1,
-                            sort_key: Some(val1),
-                        });
-                    }
-                    if val2 < *threshold {
-                        output.push(crate::ComparableDoc {
-                            doc: doc2,
-                            sort_key: Some(val2),
-                        });
-                    }
-                    if val3 < *threshold {
-                        output.push(crate::ComparableDoc {
-                            doc: doc3,
-                            sort_key: Some(val3),
-                        });
-                    }
-
-                    read_head += 4;
-                }
-            }
-            ValueRange::LessThanOrEqual(ref threshold, _) => {
-                while read_head + 3 < len {
-                    let idx0 = input_indexes[read_head];
-                    let idx1 = input_indexes[read_head + 1];
-                    let idx2 = input_indexes[read_head + 2];
-                    let idx3 = input_indexes[read_head + 3];
-
-                    let doc0 = input_doc_ids[read_head];
-                    let doc1 = input_doc_ids[read_head + 1];
-                    let doc2 = input_doc_ids[read_head + 2];
-                    let doc3 = input_doc_ids[read_head + 3];
-
-                    let val0 = self.get_val(idx0);
-                    let val1 = self.get_val(idx1);
-                    let val2 = self.get_val(idx2);
-                    let val3 = self.get_val(idx3);
-
-                    if val0 <= *threshold {
-                        output.push(crate::ComparableDoc {
-                            doc: doc0,
-                            sort_key: Some(val0),
-                        });
-                    }
-                    if val1 <= *threshold {
-                        output.push(crate::ComparableDoc {
-                            doc: doc1,
-                            sort_key: Some(val1),
-                        });
-                    }
-                    if val2 <= *threshold {
-                        output.push(crate::ComparableDoc {
-                            doc: doc2,
-                            sort_key: Some(val2),
-                        });
-                    }
-                    if val3 <= *threshold {
-                        output.push(crate::ComparableDoc {
-                            doc: doc3,
-                            sort_key: Some(val3),
-                        });
-                    }
-
-                    read_head += 4;
-                }
-            }
-        }
-        // Process remaining elements (0 to 3)
-        while read_head < len {
-            let idx = input_indexes[read_head];
-            let doc = input_doc_ids[read_head];
-            let val = self.get_val(idx);
-            let matches = match value_range {
-                // 'value_range' is still moved here. This is the outer `value_range`
-                ValueRange::All => true,
-                ValueRange::Inclusive(ref r) => r.contains(&val),
-                ValueRange::GreaterThan(ref t, _) => val > *t,
-                ValueRange::GreaterThanOrEqual(ref t, _) => val >= *t,
-                ValueRange::LessThan(ref t, _) => val < *t,
-                ValueRange::LessThanOrEqual(ref t, _) => val <= *t,
-            };
-            if matches {
-                output.push(crate::ComparableDoc {
-                    doc,
-                    sort_key: Some(val),
-                });
-            }
-            read_head += 1;
-        }
-    }
-
     /// Fills an output buffer with the fast field values
     /// associated with the `DocId` going from
     /// `start` to `start + output.len()`.
@@ -431,54 +129,15 @@ pub trait ColumnValues<T: PartialOrd = u64>: Send + Sync + DowncastSync {
     /// Note that position == docid for single value fast fields
     fn get_row_ids_for_value_range(
         &self,
-        value_range: ValueRange<T>,
+        value_range: RangeInclusive<T>,
         row_id_range: Range<RowId>,
         row_id_hits: &mut Vec<RowId>,
     ) {
         let row_id_range = row_id_range.start..row_id_range.end.min(self.num_vals());
-        match value_range {
-            ValueRange::Inclusive(range) => {
-                for idx in row_id_range {
-                    let val = self.get_val(idx);
-                    if range.contains(&val) {
-                        row_id_hits.push(idx);
-                    }
-                }
-            }
-            ValueRange::GreaterThan(threshold, _) => {
-                for idx in row_id_range {
-                    let val = self.get_val(idx);
-                    if val > threshold {
-                        row_id_hits.push(idx);
-                    }
-                }
-            }
-            ValueRange::GreaterThanOrEqual(threshold, _) => {
-                for idx in row_id_range {
-                    let val = self.get_val(idx);
-                    if val >= threshold {
-                        row_id_hits.push(idx);
-                    }
-                }
-            }
-            ValueRange::LessThan(threshold, _) => {
-                for idx in row_id_range {
-                    let val = self.get_val(idx);
-                    if val < threshold {
-                        row_id_hits.push(idx);
-                    }
-                }
-            }
-            ValueRange::LessThanOrEqual(threshold, _) => {
-                for idx in row_id_range {
-                    let val = self.get_val(idx);
-                    if val <= threshold {
-                        row_id_hits.push(idx);
-                    }
-                }
-            }
-            ValueRange::All => {
-                row_id_hits.extend(row_id_range);
+        for idx in row_id_range {
+            let val = self.get_val(idx);
+            if value_range.contains(&val) {
+                row_id_hits.push(idx);
             }
         }
     }
@@ -534,17 +193,6 @@ impl<T: PartialOrd + Default> ColumnValues<T> for EmptyColumnValues {
     fn num_vals(&self) -> u32 {
         0
     }
-
-    fn get_vals_in_value_range(
-        &self,
-        input_indexes: &[u32],
-        input_doc_ids: &[u32],
-        output: &mut Vec<crate::ComparableDoc<Option<T>, crate::DocId>>,
-        value_range: ValueRange<T>,
-    ) {
-        let _ = (input_indexes, input_doc_ids, output, value_range);
-        panic!("Internal Error: Called get_vals_in_value_range of empty column.")
-    }
 }
 
 impl<T: Copy + PartialOrd + Debug + 'static> ColumnValues<T> for Arc<dyn ColumnValues<T>> {
@@ -558,18 +206,6 @@ impl<T: Copy + PartialOrd + Debug + 'static> ColumnValues<T> for Arc<dyn ColumnV
         self.as_ref().get_vals_opt(indexes, output)
     }
 
-    #[inline(always)]
-    fn get_vals_in_value_range(
-        &self,
-        input_indexes: &[u32],
-        input_doc_ids: &[u32],
-        output: &mut Vec<crate::ComparableDoc<Option<T>, crate::DocId>>,
-        value_range: ValueRange<T>,
-    ) {
-        self.as_ref()
-            .get_vals_in_value_range(input_indexes, input_doc_ids, output, value_range)
-    }
-
     #[inline(always)]
     fn min_value(&self) -> T {
         self.as_ref().min_value()
@@ -598,7 +234,7 @@ impl<T: Copy + PartialOrd + Debug + 'static> ColumnValues<T> for Arc<dyn ColumnV
     #[inline(always)]
     fn get_row_ids_for_value_range(
         &self,
-        range: ValueRange<T>,
+        range: RangeInclusive<T>,
         doc_id_range: Range<u32>,
         positions: &mut Vec<u32>,
     ) {

columnar/src/column_values/monotonic_column.rs

@@ -1,9 +1,8 @@
 use std::fmt::Debug;
 use std::marker::PhantomData;
-use std::ops::Range;
+use std::ops::{Range, RangeInclusive};
 
 use crate::ColumnValues;
-use crate::column::ValueRange;
 use crate::column_values::monotonic_mapping::StrictlyMonotonicFn;
 
 struct MonotonicMappingColumn<C, T, Input> {
@@ -81,52 +80,16 @@ where
 
     fn get_row_ids_for_value_range(
         &self,
-        range: ValueRange<Output>,
+        range: RangeInclusive<Output>,
         doc_id_range: Range<u32>,
         positions: &mut Vec<u32>,
     ) {
-        match range {
-            ValueRange::Inclusive(range) => self.from_column.get_row_ids_for_value_range(
-                ValueRange::Inclusive(
-                    self.monotonic_mapping.inverse(range.start().clone())
-                        ..=self.monotonic_mapping.inverse(range.end().clone()),
-                ),
-                doc_id_range,
-                positions,
-            ),
-            ValueRange::All => self.from_column.get_row_ids_for_value_range(
-                ValueRange::All,
-                doc_id_range,
-                positions,
-            ),
-            ValueRange::GreaterThan(threshold, _) => self.from_column.get_row_ids_for_value_range(
-                ValueRange::GreaterThan(self.monotonic_mapping.inverse(threshold), false),
-                doc_id_range,
-                positions,
-            ),
-            ValueRange::GreaterThanOrEqual(threshold, _) => {
-                self.from_column.get_row_ids_for_value_range(
-                    ValueRange::GreaterThanOrEqual(
-                        self.monotonic_mapping.inverse(threshold),
-                        false,
-                    ),
-                    doc_id_range,
-                    positions,
-                )
-            }
-            ValueRange::LessThan(threshold, _) => self.from_column.get_row_ids_for_value_range(
-                ValueRange::LessThan(self.monotonic_mapping.inverse(threshold), false),
-                doc_id_range,
-                positions,
-            ),
-            ValueRange::LessThanOrEqual(threshold, _) => {
-                self.from_column.get_row_ids_for_value_range(
-                    ValueRange::LessThanOrEqual(self.monotonic_mapping.inverse(threshold), false),
-                    doc_id_range,
-                    positions,
-                )
-            }
-        }
+        self.from_column.get_row_ids_for_value_range(
+            self.monotonic_mapping.inverse(range.start().clone())
+                ..=self.monotonic_mapping.inverse(range.end().clone()),
+            doc_id_range,
+            positions,
+        )
     }
 
     // We voluntarily do not implement get_range as it yields a regression,

columnar/src/column_values/stats.rs

@@ -2,8 +2,7 @@ use std::io;
 use std::io::Write;
 use std::num::NonZeroU64;
 
-use common::file_slice::FileSlice;
-use common::{BinarySerializable, HasLen, VInt};
+use common::{BinarySerializable, VInt};
 
 use crate::RowId;
 
@@ -28,55 +27,6 @@ impl ColumnStats {
     }
 }
 
-impl ColumnStats {
-    /// Deserialize from the tail of the given FileSlice, and return the stats and remaining prefix
-    /// FileSlice.
-    pub fn deserialize_from_tail(file_slice: FileSlice) -> io::Result<(Self, FileSlice)> {
-        // [`deserialize_with_size`] deserializes 4 variable-width encoded u64s, which
-        // could end up being, in the worst case, 9 bytes each. this is where the 36 comes from
-        let (stats, _) = file_slice.clone().split(36.min(file_slice.len())); // hope that's enough bytes
-        let mut stats = stats.read_bytes()?;
-        let (stats, stats_nbytes) = ColumnStats::deserialize_with_size(&mut stats)?;
-        let (_, remainder) = file_slice.split(stats_nbytes);
-        Ok((stats, remainder))
-    }
-
-    /// Same as [`BinarySeerializable::deserialize`] but also returns the number of bytes
-    /// consumed from the reader `R`
-    fn deserialize_with_size<R: io::Read>(reader: &mut R) -> io::Result<(Self, usize)> {
-        let mut nbytes = 0;
-
-        let (min_value, len) = VInt::deserialize_with_size(reader)?;
-        let min_value = min_value.0;
-        nbytes += len;
-
-        let (gcd, len) = VInt::deserialize_with_size(reader)?;
-        let gcd = gcd.0;
-        let gcd = NonZeroU64::new(gcd)
-            .ok_or_else(|| io::Error::new(io::ErrorKind::InvalidData, "GCD of 0 is forbidden"))?;
-        nbytes += len;
-
-        let (amplitude, len) = VInt::deserialize_with_size(reader)?;
-        let amplitude = amplitude.0 * gcd.get();
-        let max_value = min_value + amplitude;
-        nbytes += len;
-
-        let (num_rows, len) = VInt::deserialize_with_size(reader)?;
-        let num_rows = num_rows.0 as RowId;
-        nbytes += len;
-
-        Ok((
-            ColumnStats {
-                min_value,
-                max_value,
-                num_rows,
-                gcd,
-            },
-            nbytes,
-        ))
-    }
-}
-
 impl BinarySerializable for ColumnStats {
     fn serialize<W: Write + ?Sized>(&self, writer: &mut W) -> io::Result<()> {
         VInt(self.min_value).serialize(writer)?;

columnar/src/column_values/u128_based/compact_space/mod.rs

@@ -25,7 +25,6 @@ use common::{BinarySerializable, CountingWriter, OwnedBytes, VInt, VIntU128};
 use tantivy_bitpacker::{BitPacker, BitUnpacker};
 
 use crate::RowId;
-use crate::column::ValueRange;
 use crate::column_values::ColumnValues;
 
 /// The cost per blank is quite hard actually, since blanks are delta encoded, the actual cost of
@@ -339,48 +338,14 @@ impl ColumnValues<u64> for CompactSpaceU64Accessor {
     #[inline]
     fn get_row_ids_for_value_range(
         &self,
-        value_range: ValueRange<u64>,
+        value_range: RangeInclusive<u64>,
         position_range: Range<u32>,
         positions: &mut Vec<u32>,
     ) {
-        match value_range {
-            ValueRange::Inclusive(value_range) => {
-                let value_range = ValueRange::Inclusive(
-                    self.0.compact_to_u128(*value_range.start() as u32)
-                        ..=self.0.compact_to_u128(*value_range.end() as u32),
-                );
-                self.0
-                    .get_row_ids_for_value_range(value_range, position_range, positions)
-            }
-            ValueRange::All => {
-                let position_range = position_range.start..position_range.end.min(self.num_vals());
-                positions.extend(position_range);
-            }
-            ValueRange::GreaterThan(threshold, _) => {
-                let value_range =
-                    ValueRange::GreaterThan(self.0.compact_to_u128(threshold as u32), false);
-                self.0
-                    .get_row_ids_for_value_range(value_range, position_range, positions)
-            }
-            ValueRange::GreaterThanOrEqual(threshold, _) => {
-                let value_range =
-                    ValueRange::GreaterThanOrEqual(self.0.compact_to_u128(threshold as u32), false);
-                self.0
-                    .get_row_ids_for_value_range(value_range, position_range, positions)
-            }
-            ValueRange::LessThan(threshold, _) => {
-                let value_range =
-                    ValueRange::LessThan(self.0.compact_to_u128(threshold as u32), false);
-                self.0
-                    .get_row_ids_for_value_range(value_range, position_range, positions)
-            }
-            ValueRange::LessThanOrEqual(threshold, _) => {
-                let value_range =
-                    ValueRange::LessThanOrEqual(self.0.compact_to_u128(threshold as u32), false);
-                self.0
-                    .get_row_ids_for_value_range(value_range, position_range, positions)
-            }
-        }
+        let value_range = self.0.compact_to_u128(*value_range.start() as u32)
+            ..=self.0.compact_to_u128(*value_range.end() as u32);
+        self.0
+            .get_row_ids_for_value_range(value_range, position_range, positions)
     }
 }
 
@@ -410,47 +375,10 @@ impl ColumnValues<u128> for CompactSpaceDecompressor {
     #[inline]
     fn get_row_ids_for_value_range(
         &self,
-        value_range: ValueRange<u128>,
+        value_range: RangeInclusive<u128>,
         position_range: Range<u32>,
         positions: &mut Vec<u32>,
     ) {
-        let value_range = match value_range {
-            ValueRange::Inclusive(value_range) => value_range,
-            ValueRange::All => {
-                let position_range = position_range.start..position_range.end.min(self.num_vals());
-                positions.extend(position_range);
-                return;
-            }
-            ValueRange::GreaterThan(threshold, _) => {
-                let max = self.max_value();
-                if threshold >= max {
-                    return;
-                }
-                (threshold + 1)..=max
-            }
-            ValueRange::GreaterThanOrEqual(threshold, _) => {
-                let max = self.max_value();
-                if threshold > max {
-                    return;
-                }
-                threshold..=max
-            }
-            ValueRange::LessThan(threshold, _) => {
-                let min = self.min_value();
-                if threshold <= min {
-                    return;
-                }
-                min..=(threshold - 1)
-            }
-            ValueRange::LessThanOrEqual(threshold, _) => {
-                let min = self.min_value();
-                if threshold < min {
-                    return;
-                }
-                min..=threshold
-            }
-        };
-
         if value_range.start() > value_range.end() {
             return;
         }
@@ -632,7 +560,7 @@ mod tests {
                     .collect::<Vec<_>>();
                 let mut positions = Vec::new();
                 decompressor.get_row_ids_for_value_range(
-                    ValueRange::Inclusive(range),
+                    range,
                     0..decompressor.num_vals(),
                     &mut positions,
                 );
@@ -676,11 +604,7 @@ mod tests {
             let val = *val;
             let pos = pos as u32;
             let mut positions = Vec::new();
-            decomp.get_row_ids_for_value_range(
-                ValueRange::Inclusive(val..=val),
-                pos..pos + 1,
-                &mut positions,
-            );
+            decomp.get_row_ids_for_value_range(val..=val, pos..pos + 1, &mut positions);
             assert_eq!(positions, vec![pos]);
         }
 
@@ -822,11 +746,7 @@ mod tests {
         doc_id_range: Range<u32>,
     ) -> Vec<u32> {
         let mut positions = Vec::new();
-        column.get_row_ids_for_value_range(
-            ValueRange::Inclusive(value_range),
-            doc_id_range,
-            &mut positions,
-        );
+        column.get_row_ids_for_value_range(value_range, doc_id_range, &mut positions);
         positions
     }
 
@@ -849,7 +769,7 @@ mod tests {
         ];
         let mut out = Vec::new();
         serialize_column_values_u128(&&vals[..], &mut out).unwrap();
-        let decomp = open_u128_mapped(FileSlice::from(out)).unwrap();
+        let decomp = open_u128_mapped(OwnedBytes::new(out)).unwrap();
         let complete_range = 0..vals.len() as u32;
 
         assert_eq!(
@@ -903,7 +823,6 @@ mod tests {
         let _data = test_aux_vals(vals);
     }
 
-    use common::file_slice::FileSlice;
     use proptest::prelude::*;
 
     fn num_strategy() -> impl Strategy<Value = u128> {

columnar/src/column_values/u128_based/mod.rs

@@ -5,8 +5,7 @@ use std::sync::Arc;
 
 mod compact_space;
 
-use common::file_slice::FileSlice;
-use common::{BinarySerializable, VInt};
+use common::{BinarySerializable, OwnedBytes, VInt};
 pub use compact_space::{
     CompactSpaceCompressor, CompactSpaceDecompressor, CompactSpaceU64Accessor,
 };
@@ -102,9 +101,8 @@ impl U128FastFieldCodecType {
 
 /// Returns the correct codec reader wrapped in the `Arc` for the data.
 pub fn open_u128_mapped<T: MonotonicallyMappableToU128 + Debug>(
-    file_slice: FileSlice,
+    mut bytes: OwnedBytes,
 ) -> io::Result<Arc<dyn ColumnValues<T>>> {
-    let mut bytes = file_slice.read_bytes()?;
     let header = U128Header::deserialize(&mut bytes)?;
     assert_eq!(header.codec_type, U128FastFieldCodecType::CompactSpace);
     let reader = CompactSpaceDecompressor::open(bytes)?;
@@ -122,8 +120,7 @@ pub fn open_u128_mapped<T: MonotonicallyMappableToU128 + Debug>(
 /// # Notice
 /// In case there are new codecs added, check for usages of `CompactSpaceDecompressorU64` and
 /// also handle the new codecs.
-pub fn open_u128_as_compact_u64(file_slice: FileSlice) -> io::Result<Arc<dyn ColumnValues<u64>>> {
-    let mut bytes = file_slice.read_bytes()?;
+pub fn open_u128_as_compact_u64(mut bytes: OwnedBytes) -> io::Result<Arc<dyn ColumnValues<u64>>> {
     let header = U128Header::deserialize(&mut bytes)?;
     assert_eq!(header.codec_type, U128FastFieldCodecType::CompactSpace);
     let reader = CompactSpaceU64Accessor::open(bytes)?;

columnar/src/column_values/u64_based/bitpacked.rs

@@ -1,14 +1,11 @@
 use std::io::{self, Write};
 use std::num::NonZeroU64;
 use std::ops::{Range, RangeInclusive};
-use std::sync::{Arc, OnceLock};
 
-use common::file_slice::FileSlice;
-use common::{BinarySerializable, HasLen, OwnedBytes};
+use common::{BinarySerializable, OwnedBytes};
 use fastdivide::DividerU64;
 use tantivy_bitpacker::{BitPacker, BitUnpacker, compute_num_bits};
 
-use crate::column::ValueRange;
 use crate::column_values::u64_based::{ColumnCodec, ColumnCodecEstimator, ColumnStats};
 use crate::{ColumnValues, RowId};
 
@@ -16,40 +13,9 @@ use crate::{ColumnValues, RowId};
 /// fast field is required.
 #[derive(Clone)]
 pub struct BitpackedReader {
-    data: FileSlice,
+    data: OwnedBytes,
     bit_unpacker: BitUnpacker,
     stats: ColumnStats,
-    blocks: Arc<[OnceLock<Block>]>,
-}
-
-impl BitpackedReader {
-    #[inline(always)]
-    fn unpack_val(&self, doc: u32) -> u64 {
-        let block_num = self.bit_unpacker.block_num(doc);
-
-        if block_num == 0 && self.blocks.len() == 0 {
-            return 0;
-        }
-
-        let block = self.blocks[block_num].get_or_init(|| {
-            let block_range = self.bit_unpacker.block(block_num, self.data.len());
-            let offset = block_range.start;
-            let data = self
-                .data
-                .slice(block_range)
-                .read_bytes()
-                .expect("Failed to read column values.");
-            Block { offset, data }
-        });
-
-        self.bit_unpacker
-            .get_from_subset(doc, block.offset, &block.data)
-    }
-}
-
-struct Block {
-    offset: usize,
-    data: OwnedBytes,
 }
 
 #[inline(always)]
@@ -91,9 +57,8 @@ fn transform_range_before_linear_transformation(
 impl ColumnValues for BitpackedReader {
     #[inline(always)]
     fn get_val(&self, doc: u32) -> u64 {
-        self.stats.min_value + self.stats.gcd.get() * self.unpack_val(doc)
+        self.stats.min_value + self.stats.gcd.get() * self.bit_unpacker.get(doc, &self.data)
     }
-
     #[inline]
     fn min_value(&self) -> u64 {
         self.stats.min_value
@@ -107,329 +72,24 @@ impl ColumnValues for BitpackedReader {
         self.stats.num_rows
     }
 
-    fn get_vals_in_value_range(
-        &self,
-        input_indexes: &[u32],
-        input_doc_ids: &[u32],
-        output: &mut Vec<crate::ComparableDoc<Option<u64>, crate::DocId>>,
-        value_range: ValueRange<u64>,
-    ) {
-        match value_range {
-            ValueRange::All => {
-                for (&idx, &doc) in input_indexes.iter().zip(input_doc_ids.iter()) {
-                    output.push(crate::ComparableDoc {
-                        doc,
-                        sort_key: Some(self.get_val(idx)),
-                    });
-                }
-            }
-            ValueRange::Inclusive(range) => {
-                if let Some(transformed_range) =
-                    transform_range_before_linear_transformation(&self.stats, range)
-                {
-                    for (&idx, &doc) in input_indexes.iter().zip(input_doc_ids.iter()) {
-                        let raw_val = self.unpack_val(idx);
-                        if transformed_range.contains(&raw_val) {
-                            output.push(crate::ComparableDoc {
-                                doc,
-                                sort_key: Some(
-                                    self.stats.min_value + self.stats.gcd.get() * raw_val,
-                                ),
-                            });
-                        }
-                    }
-                }
-            }
-            ValueRange::GreaterThan(threshold, _) => {
-                if threshold < self.stats.min_value {
-                    for (&idx, &doc) in input_indexes.iter().zip(input_doc_ids.iter()) {
-                        output.push(crate::ComparableDoc {
-                            doc,
-                            sort_key: Some(self.get_val(idx)),
-                        });
-                    }
-                } else if threshold >= self.stats.max_value {
-                    // All filtered out
-                } else {
-                    let raw_threshold = (threshold - self.stats.min_value) / self.stats.gcd.get();
-                    for (&idx, &doc) in input_indexes.iter().zip(input_doc_ids.iter()) {
-                        let raw_val = self.unpack_val(idx);
-                        if raw_val > raw_threshold {
-                            output.push(crate::ComparableDoc {
-                                doc,
-                                sort_key: Some(
-                                    self.stats.min_value + self.stats.gcd.get() * raw_val,
-                                ),
-                            });
-                        }
-                    }
-                }
-            }
-            ValueRange::GreaterThanOrEqual(threshold, _) => {
-                if threshold <= self.stats.min_value {
-                    for (&idx, &doc) in input_indexes.iter().zip(input_doc_ids.iter()) {
-                        output.push(crate::ComparableDoc {
-                            doc,
-                            sort_key: Some(self.get_val(idx)),
-                        });
-                    }
-                } else if threshold > self.stats.max_value {
-                    // All filtered out
-                } else {
-                    let diff = threshold - self.stats.min_value;
-                    let gcd = self.stats.gcd.get();
-                    let raw_threshold = (diff + gcd - 1) / gcd;
-                    for (&idx, &doc) in input_indexes.iter().zip(input_doc_ids.iter()) {
-                        let raw_val = self.unpack_val(idx);
-                        if raw_val >= raw_threshold {
-                            output.push(crate::ComparableDoc {
-                                doc,
-                                sort_key: Some(
-                                    self.stats.min_value + self.stats.gcd.get() * raw_val,
-                                ),
-                            });
-                        }
-                    }
-                }
-            }
-            ValueRange::LessThan(threshold, _) => {
-                if threshold > self.stats.max_value {
-                    for (&idx, &doc) in input_indexes.iter().zip(input_doc_ids.iter()) {
-                        output.push(crate::ComparableDoc {
-                            doc,
-                            sort_key: Some(self.get_val(idx)),
-                        });
-                    }
-                } else if threshold <= self.stats.min_value {
-                    // All filtered out
-                } else {
-                    let diff = threshold - self.stats.min_value;
-                    let gcd = self.stats.gcd.get();
-                    let raw_threshold = if diff % gcd == 0 {
-                        diff / gcd
-                    } else {
-                        diff / gcd + 1
-                    };
-
-                    for (&idx, &doc) in input_indexes.iter().zip(input_doc_ids.iter()) {
-                        let raw_val = self.unpack_val(idx);
-                        if raw_val < raw_threshold {
-                            output.push(crate::ComparableDoc {
-                                doc,
-                                sort_key: Some(
-                                    self.stats.min_value + self.stats.gcd.get() * raw_val,
-                                ),
-                            });
-                        }
-                    }
-                }
-            }
-            ValueRange::LessThanOrEqual(threshold, _) => {
-                if threshold >= self.stats.max_value {
-                    for (&idx, &doc) in input_indexes.iter().zip(input_doc_ids.iter()) {
-                        output.push(crate::ComparableDoc {
-                            doc,
-                            sort_key: Some(self.get_val(idx)),
-                        });
-                    }
-                } else if threshold < self.stats.min_value {
-                    // All filtered out
-                } else {
-                    let diff = threshold - self.stats.min_value;
-                    let gcd = self.stats.gcd.get();
-                    let raw_threshold = diff / gcd;
-
-                    for (&idx, &doc) in input_indexes.iter().zip(input_doc_ids.iter()) {
-                        let raw_val = self.unpack_val(idx);
-                        if raw_val <= raw_threshold {
-                            output.push(crate::ComparableDoc {
-                                doc,
-                                sort_key: Some(
-                                    self.stats.min_value + self.stats.gcd.get() * raw_val,
-                                ),
-                            });
-                        }
-                    }
-                }
-            }
-        }
-    }
     fn get_row_ids_for_value_range(
         &self,
-        range: ValueRange<u64>,
+        range: RangeInclusive<u64>,
         doc_id_range: Range<u32>,
         positions: &mut Vec<u32>,
     ) {
-        match range {
-            ValueRange::All => {
-                positions.extend(doc_id_range);
-                return;
-            }
-            ValueRange::Inclusive(range) => {
-                let Some(transformed_range) =
-                    transform_range_before_linear_transformation(&self.stats, range)
-                else {
-                    positions.clear();
-                    return;
-                };
-                // TODO: This does not use the `self.blocks` cache, because callers are usually
-                // already doing sequential, and fairly dense reads. Fix it to
-                // iterate over blocks if that assumption turns out to be incorrect!
-                let data_range = self
-                    .bit_unpacker
-                    .block_oblivious_range(doc_id_range.clone(), self.data.len());
-                let data_offset = data_range.start;
-                let data_subset = self
-                    .data
-                    .slice(data_range)
-                    .read_bytes()
-                    .expect("Failed to read column values.");
-                self.bit_unpacker.get_ids_for_value_range_from_subset(
-                    transformed_range,
-                    doc_id_range,
-                    data_offset,
-                    &data_subset,
-                    positions,
-                );
-            }
-            ValueRange::GreaterThan(threshold, _) => {
-                if threshold < self.stats.min_value {
-                    positions.extend(doc_id_range);
-                    return;
-                }
-                if threshold >= self.stats.max_value {
-                    return;
-                }
-                let raw_threshold = (threshold - self.stats.min_value) / self.stats.gcd.get();
-                // We want raw > raw_threshold.
-                // bit_unpacker.get_ids_for_value_range_from_subset takes a RangeInclusive.
-                // We can construct a RangeInclusive: (raw_threshold + 1) ..= u64::MAX
-                // But max raw value is known? (max_value - min_value) / gcd.
-                let max_raw = (self.stats.max_value - self.stats.min_value) / self.stats.gcd.get();
-                let transformed_range = (raw_threshold + 1)..=max_raw;
-
-                let data_range = self
-                    .bit_unpacker
-                    .block_oblivious_range(doc_id_range.clone(), self.data.len());
-                let data_offset = data_range.start;
-                let data_subset = self
-                    .data
-                    .slice(data_range)
-                    .read_bytes()
-                    .expect("Failed to read column values.");
-                self.bit_unpacker.get_ids_for_value_range_from_subset(
-                    transformed_range,
-                    doc_id_range,
-                    data_offset,
-                    &data_subset,
-                    positions,
-                );
-            }
-            ValueRange::GreaterThanOrEqual(threshold, _) => {
-                if threshold <= self.stats.min_value {
-                    positions.extend(doc_id_range);
-                    return;
-                }
-                if threshold > self.stats.max_value {
-                    return;
-                }
-                let diff = threshold - self.stats.min_value;
-                let gcd = self.stats.gcd.get();
-                let raw_threshold = (diff + gcd - 1) / gcd;
-                // We want raw >= raw_threshold.
-                let max_raw = (self.stats.max_value - self.stats.min_value) / self.stats.gcd.get();
-                let transformed_range = raw_threshold..=max_raw;
-
-                let data_range = self
-                    .bit_unpacker
-                    .block_oblivious_range(doc_id_range.clone(), self.data.len());
-                let data_offset = data_range.start;
-                let data_subset = self
-                    .data
-                    .slice(data_range)
-                    .read_bytes()
-                    .expect("Failed to read column values.");
-                self.bit_unpacker.get_ids_for_value_range_from_subset(
-                    transformed_range,
-                    doc_id_range,
-                    data_offset,
-                    &data_subset,
-                    positions,
-                );
-            }
-            ValueRange::LessThan(threshold, _) => {
-                if threshold > self.stats.max_value {
-                    positions.extend(doc_id_range);
-                    return;
-                }
-                if threshold <= self.stats.min_value {
-                    return;
-                }
-
-                let diff = threshold - self.stats.min_value;
-                let gcd = self.stats.gcd.get();
-                // We want raw < raw_threshold_limit
-                // raw <= raw_threshold_limit - 1
-                let raw_threshold_limit = if diff % gcd == 0 {
-                    diff / gcd
-                } else {
-                    diff / gcd + 1
-                };
-
-                if raw_threshold_limit == 0 {
-                    return;
-                }
-                let transformed_range = 0..=(raw_threshold_limit - 1);
-
-                let data_range = self
-                    .bit_unpacker
-                    .block_oblivious_range(doc_id_range.clone(), self.data.len());
-                let data_offset = data_range.start;
-                let data_subset = self
-                    .data
-                    .slice(data_range)
-                    .read_bytes()
-                    .expect("Failed to read column values.");
-                self.bit_unpacker.get_ids_for_value_range_from_subset(
-                    transformed_range,
-                    doc_id_range,
-                    data_offset,
-                    &data_subset,
-                    positions,
-                );
-            }
-            ValueRange::LessThanOrEqual(threshold, _) => {
-                if threshold >= self.stats.max_value {
-                    positions.extend(doc_id_range);
-                    return;
-                }
-                if threshold < self.stats.min_value {
-                    return;
-                }
-                let diff = threshold - self.stats.min_value;
-                let gcd = self.stats.gcd.get();
-                // We want raw <= raw_threshold.
-                let raw_threshold = diff / gcd;
-                let transformed_range = 0..=raw_threshold;
-
-                let data_range = self
-                    .bit_unpacker
-                    .block_oblivious_range(doc_id_range.clone(), self.data.len());
-                let data_offset = data_range.start;
-                let data_subset = self
-                    .data
-                    .slice(data_range)
-                    .read_bytes()
-                    .expect("Failed to read column values.");
-                self.bit_unpacker.get_ids_for_value_range_from_subset(
-                    transformed_range,
-                    doc_id_range,
-                    data_offset,
-                    &data_subset,
-                    positions,
-                );
-            }
-        }
+        let Some(transformed_range) =
+            transform_range_before_linear_transformation(&self.stats, range)
+        else {
+            positions.clear();
+            return;
+        };
+        self.bit_unpacker.get_ids_for_value_range(
+            transformed_range,
+            doc_id_range,
+            &self.data,
+            positions,
+        );
     }
 }
 
@@ -473,20 +133,14 @@ impl ColumnCodec for BitpackedCodec {
     type Estimator = BitpackedCodecEstimator;
 
     /// Opens a fast field given a file.
-    fn load(file_slice: FileSlice) -> io::Result<Self::ColumnValues> {
-        let (stats, data) = ColumnStats::deserialize_from_tail(file_slice)?;
-
+    fn load(mut data: OwnedBytes) -> io::Result<Self::ColumnValues> {
+        let stats = ColumnStats::deserialize(&mut data)?;
         let num_bits = num_bits(&stats);
         let bit_unpacker = BitUnpacker::new(num_bits);
-        let block_count = bit_unpacker.block_count(data.len());
         Ok(BitpackedReader {
             data,
             bit_unpacker,
             stats,
-            blocks: (0..block_count)
-                .into_iter()
-                .map(|_| OnceLock::new())
-                .collect(),
         })
     }
 }

columnar/src/column_values/u64_based/blockwise_linear.rs

@@ -1,10 +1,8 @@
-use std::io;
 use std::io::Write;
-use std::ops::{Deref, DerefMut};
-use std::sync::{Arc, OnceLock};
+use std::sync::Arc;
+use std::{io, iter};
 
-use common::file_slice::FileSlice;
-use common::{BinarySerializable, CountingWriter, DeserializeFrom, HasLen, OwnedBytes};
+use common::{BinarySerializable, CountingWriter, DeserializeFrom, OwnedBytes};
 use fastdivide::DividerU64;
 use tantivy_bitpacker::{BitPacker, BitUnpacker, compute_num_bits};
 
@@ -174,63 +172,32 @@ impl ColumnCodec<u64> for BlockwiseLinearCodec {
 
     type Estimator = BlockwiseLinearEstimator;
 
-    fn load(file_slice: FileSlice) -> io::Result<Self::ColumnValues> {
-        let (stats, body) = ColumnStats::deserialize_from_tail(file_slice)?;
-
-        let (_, footer) = body.clone().split_from_end(4);
-
-        let footer_len: u32 = footer.read_bytes()?.as_slice().deserialize()?;
-        let (data, footer) = body.split_from_end(footer_len as usize + 4);
-
-        let mut footer = footer.read_bytes()?;
+    fn load(mut bytes: OwnedBytes) -> io::Result<Self::ColumnValues> {
+        let stats = ColumnStats::deserialize(&mut bytes)?;
+        let footer_len: u32 = (&bytes[bytes.len() - 4..]).deserialize()?;
+        let footer_offset = bytes.len() - 4 - footer_len as usize;
+        let (data, mut footer) = bytes.split(footer_offset);
         let num_blocks = compute_num_blocks(stats.num_rows);
-
+        let mut blocks: Vec<Block> = iter::repeat_with(|| Block::deserialize(&mut footer))
+            .take(num_blocks as usize)
+            .collect::<io::Result<_>>()?;
         let mut start_offset = 0;
-        let mut blocks = Vec::with_capacity(num_blocks as usize);
-
-        for _ in 0..num_blocks {
-            let mut block = Block::deserialize(&mut footer)?;
-            let len = (block.bit_unpacker.bit_width() as usize) * BLOCK_SIZE as usize / 8;
-
+        for block in &mut blocks {
             block.data_start_offset = start_offset;
-            blocks.push(BlockWithData {
-                block,
-                file_slice: data.slice(start_offset..(start_offset + len).min(data.len())),
-                data: Default::default(),
-            });
-
-            start_offset += len;
+            start_offset += (block.bit_unpacker.bit_width() as usize) * BLOCK_SIZE as usize / 8;
         }
         Ok(BlockwiseLinearReader {
             blocks: blocks.into_boxed_slice().into(),
+            data,
             stats,
         })
     }
 }
 
-struct BlockWithData {
-    block: Block,
-    file_slice: FileSlice,
-    data: OnceLock<OwnedBytes>,
-}
-
-impl Deref for BlockWithData {
-    type Target = Block;
-
-    fn deref(&self) -> &Self::Target {
-        &self.block
-    }
-}
-
-impl DerefMut for BlockWithData {
-    fn deref_mut(&mut self) -> &mut Self::Target {
-        &mut self.block
-    }
-}
-
 #[derive(Clone)]
 pub struct BlockwiseLinearReader {
-    blocks: Arc<[BlockWithData]>,
+    blocks: Arc<[Block]>,
+    data: OwnedBytes,
     stats: ColumnStats,
 }
 
@@ -241,9 +208,7 @@ impl ColumnValues for BlockwiseLinearReader {
         let idx_within_block = idx % BLOCK_SIZE;
         let block = &self.blocks[block_id];
         let interpoled_val: u64 = block.line.eval(idx_within_block);
-        let block_bytes = block
-            .data
-            .get_or_init(|| block.file_slice.read_bytes().unwrap());
+        let block_bytes = &self.data[block.data_start_offset..];
         let bitpacked_diff = block.bit_unpacker.get(idx_within_block, block_bytes);
         // TODO optimize me! the line parameters could be tweaked to include the multiplication and
         // remove the dependency.

columnar/src/column_values/u64_based/linear.rs

@@ -1,6 +1,5 @@
 use std::io;
 
-use common::file_slice::FileSlice;
 use common::{BinarySerializable, OwnedBytes};
 use tantivy_bitpacker::{BitPacker, BitUnpacker, compute_num_bits};
 
@@ -191,8 +190,7 @@ impl ColumnCodec for LinearCodec {
 
     type Estimator = LinearCodecEstimator;
 
-    fn load(file_slice: FileSlice) -> io::Result<Self::ColumnValues> {
-        let mut data = file_slice.read_bytes()?;
+    fn load(mut data: OwnedBytes) -> io::Result<Self::ColumnValues> {
         let stats = ColumnStats::deserialize(&mut data)?;
         let linear_params = LinearParams::deserialize(&mut data)?;
         Ok(LinearReader {

columnar/src/column_values/u64_based/mod.rs

@@ -8,8 +8,7 @@ use std::io;
 use std::io::Write;
 use std::sync::Arc;
 
-use common::BinarySerializable;
-use common::file_slice::FileSlice;
+use common::{BinarySerializable, OwnedBytes};
 
 use crate::column_values::monotonic_mapping::{
     StrictlyMonotonicMappingInverter, StrictlyMonotonicMappingToInternal,
@@ -61,7 +60,7 @@ pub trait ColumnCodec<T: PartialOrd = u64> {
     type Estimator: ColumnCodecEstimator + Default;
 
     /// Loads a column that has been serialized using this codec.
-    fn load(file_slice: FileSlice) -> io::Result<Self::ColumnValues>;
+    fn load(bytes: OwnedBytes) -> io::Result<Self::ColumnValues>;
 
     /// Returns an estimator.
     fn estimator() -> Self::Estimator {
@@ -112,22 +111,20 @@ impl CodecType {
 
     fn load<T: MonotonicallyMappableToU64>(
         &self,
-        file_slice: FileSlice,
+        bytes: OwnedBytes,
     ) -> io::Result<Arc<dyn ColumnValues<T>>> {
         match self {
-            CodecType::Bitpacked => load_specific_codec::<BitpackedCodec, T>(file_slice),
-            CodecType::Linear => load_specific_codec::<LinearCodec, T>(file_slice),
-            CodecType::BlockwiseLinear => {
-                load_specific_codec::<BlockwiseLinearCodec, T>(file_slice)
-            }
+            CodecType::Bitpacked => load_specific_codec::<BitpackedCodec, T>(bytes),
+            CodecType::Linear => load_specific_codec::<LinearCodec, T>(bytes),
+            CodecType::BlockwiseLinear => load_specific_codec::<BlockwiseLinearCodec, T>(bytes),
         }
     }
 }
 
 fn load_specific_codec<C: ColumnCodec, T: MonotonicallyMappableToU64>(
-    file_slice: FileSlice,
+    bytes: OwnedBytes,
 ) -> io::Result<Arc<dyn ColumnValues<T>>> {
-    let reader = C::load(file_slice)?;
+    let reader = C::load(bytes)?;
     let reader_typed = monotonic_map_column(
         reader,
         StrictlyMonotonicMappingInverter::from(StrictlyMonotonicMappingToInternal::<T>::new()),
@@ -192,28 +189,25 @@ pub fn serialize_u64_based_column_values<T: MonotonicallyMappableToU64>(
 ///
 /// This method first identifies the codec off the first byte.
 pub fn load_u64_based_column_values<T: MonotonicallyMappableToU64>(
-    file_slice: FileSlice,
+    mut bytes: OwnedBytes,
 ) -> io::Result<Arc<dyn ColumnValues<T>>> {
-    let (header, body) = file_slice.split(1);
-    let codec_type: CodecType = header
-        .read_bytes()?
-        .as_slice()
-        .get(0)
-        .cloned()
+    let codec_type: CodecType = bytes
+        .first()
+        .copied()
         .and_then(CodecType::try_from_code)
         .ok_or_else(|| io::Error::new(io::ErrorKind::InvalidData, "Failed to read codec type"))?;
-    codec_type.load(body)
+    bytes.advance(1);
+    codec_type.load(bytes)
 }
 
 /// Helper function to serialize a column (autodetect from all codecs) and then open it
-#[cfg(test)]
 pub fn serialize_and_load_u64_based_column_values<T: MonotonicallyMappableToU64>(
     vals: &dyn Iterable,
     codec_types: &[CodecType],
 ) -> Arc<dyn ColumnValues<T>> {
     let mut buffer = Vec::new();
     serialize_u64_based_column_values(vals, codec_types, &mut buffer).unwrap();
-    load_u64_based_column_values::<T>(FileSlice::from(buffer)).unwrap()
+    load_u64_based_column_values::<T>(OwnedBytes::new(buffer)).unwrap()
 }
 
 #[cfg(test)]

columnar/src/column_values/u64_based/tests.rs

@@ -1,4 +1,3 @@
-use common::HasLen;
 use proptest::prelude::*;
 use proptest::{prop_oneof, proptest};
 use rand::Rng;
@@ -14,7 +13,7 @@ fn test_serialize_and_load_simple() {
     )
     .unwrap();
     assert_eq!(buffer.len(), 7);
-    let col = load_u64_based_column_values::<u64>(FileSlice::from(buffer)).unwrap();
+    let col = load_u64_based_column_values::<u64>(OwnedBytes::new(buffer)).unwrap();
     assert_eq!(col.num_vals(), 3);
     assert_eq!(col.get_val(0), 1);
     assert_eq!(col.get_val(1), 2);
@@ -31,7 +30,7 @@ fn test_empty_column_i64() {
             continue;
         }
         num_acceptable_codecs += 1;
-        let col = load_u64_based_column_values::<i64>(FileSlice::from(buffer)).unwrap();
+        let col = load_u64_based_column_values::<i64>(OwnedBytes::new(buffer)).unwrap();
         assert_eq!(col.num_vals(), 0);
         assert_eq!(col.min_value(), i64::MIN);
         assert_eq!(col.max_value(), i64::MIN);
@@ -49,7 +48,7 @@ fn test_empty_column_u64() {
             continue;
         }
         num_acceptable_codecs += 1;
-        let col = load_u64_based_column_values::<u64>(FileSlice::from(buffer)).unwrap();
+        let col = load_u64_based_column_values::<u64>(OwnedBytes::new(buffer)).unwrap();
         assert_eq!(col.num_vals(), 0);
         assert_eq!(col.min_value(), u64::MIN);
         assert_eq!(col.max_value(), u64::MIN);
@@ -67,7 +66,7 @@ fn test_empty_column_f64() {
             continue;
         }
         num_acceptable_codecs += 1;
-        let col = load_u64_based_column_values::<f64>(FileSlice::from(buffer)).unwrap();
+        let col = load_u64_based_column_values::<f64>(OwnedBytes::new(buffer)).unwrap();
         assert_eq!(col.num_vals(), 0);
         // FIXME. f64::MIN would be better!
         assert!(col.min_value().is_nan());
@@ -98,7 +97,7 @@ pub(crate) fn create_and_validate<TColumnCodec: ColumnCodec>(
 
     let actual_compression = buffer.len() as u64;
 
-    let reader = TColumnCodec::load(FileSlice::from(buffer)).unwrap();
+    let reader = TColumnCodec::load(OwnedBytes::new(buffer)).unwrap();
     assert_eq!(reader.num_vals(), vals.len() as u32);
     let mut buffer = Vec::new();
     for (doc, orig_val) in vals.iter().copied().enumerate() {
@@ -132,7 +131,7 @@ pub(crate) fn create_and_validate<TColumnCodec: ColumnCodec>(
             .collect();
         let mut positions = Vec::new();
         reader.get_row_ids_for_value_range(
-            crate::column::ValueRange::Inclusive(vals[test_rand_idx]..=vals[test_rand_idx]),
+            vals[test_rand_idx]..=vals[test_rand_idx],
             0..vals.len() as u32,
             &mut positions,
         );
@@ -327,7 +326,7 @@ fn test_fastfield_gcd_i64_with_codec(codec_type: CodecType, num_vals: usize) ->
         &[codec_type],
         &mut buffer,
     )?;
-    let buffer = FileSlice::from(buffer);
+    let buffer = OwnedBytes::new(buffer);
     let column = crate::column_values::load_u64_based_column_values::<i64>(buffer.clone())?;
     assert_eq!(column.get_val(0), -4000i64);
     assert_eq!(column.get_val(1), -3000i64);
@@ -344,7 +343,7 @@ fn test_fastfield_gcd_i64_with_codec(codec_type: CodecType, num_vals: usize) ->
         &[codec_type],
         &mut buffer_without_gcd,
     )?;
-    let buffer_without_gcd = FileSlice::from(buffer_without_gcd);
+    let buffer_without_gcd = OwnedBytes::new(buffer_without_gcd);
     assert!(buffer_without_gcd.len() > buffer.len());
 
     Ok(())
@@ -370,7 +369,7 @@ fn test_fastfield_gcd_u64_with_codec(codec_type: CodecType, num_vals: usize) ->
         &[codec_type],
         &mut buffer,
     )?;
-    let buffer = FileSlice::from(buffer);
+    let buffer = OwnedBytes::new(buffer);
     let column = crate::column_values::load_u64_based_column_values::<u64>(buffer.clone())?;
     assert_eq!(column.get_val(0), 1000u64);
     assert_eq!(column.get_val(1), 2000u64);
@@ -387,7 +386,7 @@ fn test_fastfield_gcd_u64_with_codec(codec_type: CodecType, num_vals: usize) ->
         &[codec_type],
         &mut buffer_without_gcd,
     )?;
-    let buffer_without_gcd = FileSlice::from(buffer_without_gcd);
+    let buffer_without_gcd = OwnedBytes::new(buffer_without_gcd);
     assert!(buffer_without_gcd.len() > buffer.len());
     Ok(())
 }
@@ -406,7 +405,7 @@ fn test_fastfield_gcd_u64() -> io::Result<()> {
 
 #[test]
 pub fn test_fastfield2() {
-    let test_fastfield = serialize_and_load_u64_based_column_values::<u64>(
+    let test_fastfield = crate::column_values::serialize_and_load_u64_based_column_values::<u64>(
         &&[100u64, 200u64, 300u64][..],
         &ALL_U64_CODEC_TYPES,
     );

columnar/src/columnar/merge/mod.rs

@@ -4,7 +4,6 @@ mod term_merger;
 
 use std::collections::{BTreeMap, HashSet};
 use std::io;
-use std::io::ErrorKind;
 use std::net::Ipv6Addr;
 use std::sync::Arc;
 
@@ -79,7 +78,6 @@ pub fn merge_columnar(
     required_columns: &[(String, ColumnType)],
     merge_row_order: MergeRowOrder,
     output: &mut impl io::Write,
-    cancel: impl Fn() -> bool,
 ) -> io::Result<()> {
     let mut serializer = ColumnarSerializer::new(output);
     let num_docs_per_columnar = columnar_readers
@@ -89,9 +87,6 @@ pub fn merge_columnar(
 
     let columns_to_merge = group_columns_for_merge(columnar_readers, required_columns)?;
     for res in columns_to_merge {
-        if cancel() {
-            return Err(io::Error::new(ErrorKind::Interrupted, "Merge cancelled"));
-        }
         let ((column_name, _column_type_category), grouped_columns) = res;
         let grouped_columns = grouped_columns.open(&merge_row_order)?;
         if grouped_columns.is_empty() {

columnar/src/columnar/merge/tests.rs

@@ -205,7 +205,6 @@ fn test_merge_columnar_numbers() {
         &[],
         MergeRowOrder::Stack(stack_merge_order),
         &mut buffer,
-        || false,
     )
     .unwrap();
     let columnar_reader = ColumnarReader::open(buffer).unwrap();
@@ -234,7 +233,6 @@ fn test_merge_columnar_texts() {
         &[],
         MergeRowOrder::Stack(stack_merge_order),
         &mut buffer,
-        || false,
     )
     .unwrap();
     let columnar_reader = ColumnarReader::open(buffer).unwrap();
@@ -284,7 +282,6 @@ fn test_merge_columnar_byte() {
         &[],
         MergeRowOrder::Stack(stack_merge_order),
         &mut buffer,
-        || false,
     )
     .unwrap();
     let columnar_reader = ColumnarReader::open(buffer).unwrap();
@@ -341,7 +338,6 @@ fn test_merge_columnar_byte_with_missing() {
         &[],
         MergeRowOrder::Stack(stack_merge_order),
         &mut buffer,
-        || false,
     )
     .unwrap();
     let columnar_reader = ColumnarReader::open(buffer).unwrap();
@@ -394,7 +390,6 @@ fn test_merge_columnar_different_types() {
         &[],
         MergeRowOrder::Stack(stack_merge_order),
         &mut buffer,
-        || false,
     )
     .unwrap();
     let columnar_reader = ColumnarReader::open(buffer).unwrap();
@@ -460,7 +455,6 @@ fn test_merge_columnar_different_empty_cardinality() {
         &[],
         MergeRowOrder::Stack(stack_merge_order),
         &mut buffer,
-        || false,
     )
     .unwrap();
     let columnar_reader = ColumnarReader::open(buffer).unwrap();
@@ -571,7 +565,6 @@ proptest! {
             &[],
             MergeRowOrder::Stack(stack_merge_order),
             &mut out,
-            || false,
         ).unwrap();
 
         let merged_reader = ColumnarReader::open(out).unwrap();
@@ -589,7 +582,6 @@ proptest! {
             &[],
             MergeRowOrder::Stack(stack_merge_order),
             &mut out,
-            || false,
         ).unwrap();
 
     }

columnar/src/comparable_doc.rs

@@ -1,22 +0,0 @@
-use serde::{Deserialize, Serialize};
-
-/// Contains a feature (field, score, etc.) of a document along with the document address.
-///
-/// Used only by TopNComputer, which implements the actual comparison via a `Comparator`.
-#[derive(Clone, Default, Eq, PartialEq, Serialize, Deserialize)]
-pub struct ComparableDoc<T, D> {
-    /// The feature of the document. In practice, this is
-    /// is a type which can be compared with a `Comparator<T>`.
-    pub sort_key: T,
-    /// The document address. In practice, this is either a `DocId` or `DocAddress`.
-    pub doc: D,
-}
-
-impl<T: std::fmt::Debug, D: std::fmt::Debug> std::fmt::Debug for ComparableDoc<T, D> {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
-        f.debug_struct("ComparableDoc")
-            .field("feature", &self.sort_key)
-            .field("doc", &self.doc)
-            .finish()
-    }
-}

columnar/src/compat_tests.rs

@@ -71,14 +71,7 @@ fn test_format(path: &str) {
     let columnar_readers = vec![&reader, &reader2];
     let merge_row_order = StackMergeOrder::stack(&columnar_readers[..]);
     let mut out = Vec::new();
-    merge_columnar(
-        &columnar_readers,
-        &[],
-        merge_row_order.into(),
-        &mut out,
-        || false,
-    )
-    .unwrap();
+    merge_columnar(&columnar_readers, &[], merge_row_order.into(), &mut out).unwrap();
     let reader = ColumnarReader::open(out).unwrap();
     check_columns(&reader);
 }

columnar/src/dynamic_column.rs

@@ -3,8 +3,7 @@ use std::sync::Arc;
 use std::{fmt, io};
 
 use common::file_slice::FileSlice;
-use common::{ByteCount, DateTime};
-use serde::{Deserialize, Serialize};
+use common::{ByteCount, DateTime, HasLen, OwnedBytes};
 
 use crate::column::{BytesColumn, Column, StrColumn};
 use crate::column_values::{StrictlyMonotonicFn, monotonic_map_column};
@@ -239,7 +238,8 @@ pub struct DynamicColumnHandle {
 impl DynamicColumnHandle {
     // TODO rename load
     pub fn open(&self) -> io::Result<DynamicColumn> {
-        self.open_internal(self.file_slice.clone())
+        let column_bytes: OwnedBytes = self.file_slice.read_bytes()?;
+        self.open_internal(column_bytes)
     }
 
     #[doc(hidden)]
@@ -258,15 +258,16 @@ impl DynamicColumnHandle {
     /// If not, the fastfield reader will returns the u64-value associated with the original
     /// FastValue.
     pub fn open_u64_lenient(&self) -> io::Result<Option<Column<u64>>> {
+        let column_bytes = self.file_slice.read_bytes()?;
         match self.column_type {
             ColumnType::Str | ColumnType::Bytes => {
                 let column: BytesColumn =
-                    crate::column::open_column_bytes(self.file_slice.clone(), self.format_version)?;
+                    crate::column::open_column_bytes(column_bytes, self.format_version)?;
                 Ok(Some(column.term_ord_column))
             }
             ColumnType::IpAddr => {
                 let column = crate::column::open_column_u128_as_compact_u64(
-                    self.file_slice.clone(),
+                    column_bytes,
                     self.format_version,
                 )?;
                 Ok(Some(column))
@@ -276,129 +277,50 @@ impl DynamicColumnHandle {
             | ColumnType::U64
             | ColumnType::F64
             | ColumnType::DateTime => {
-                let column = crate::column::open_column_u64::<u64>(
-                    self.file_slice.clone(),
-                    self.format_version,
-                )?;
+                let column =
+                    crate::column::open_column_u64::<u64>(column_bytes, self.format_version)?;
                 Ok(Some(column))
             }
         }
     }
 
-    fn open_internal(&self, file_slice: FileSlice) -> io::Result<DynamicColumn> {
+    fn open_internal(&self, column_bytes: OwnedBytes) -> io::Result<DynamicColumn> {
         let dynamic_column: DynamicColumn = match self.column_type {
             ColumnType::Bytes => {
-                crate::column::open_column_bytes(file_slice, self.format_version)?.into()
+                crate::column::open_column_bytes(column_bytes, self.format_version)?.into()
             }
             ColumnType::Str => {
-                crate::column::open_column_str(file_slice, self.format_version)?.into()
+                crate::column::open_column_str(column_bytes, self.format_version)?.into()
             }
             ColumnType::I64 => {
-                crate::column::open_column_u64::<i64>(file_slice, self.format_version)?.into()
+                crate::column::open_column_u64::<i64>(column_bytes, self.format_version)?.into()
             }
             ColumnType::U64 => {
-                crate::column::open_column_u64::<u64>(file_slice, self.format_version)?.into()
+                crate::column::open_column_u64::<u64>(column_bytes, self.format_version)?.into()
             }
             ColumnType::F64 => {
-                crate::column::open_column_u64::<f64>(file_slice, self.format_version)?.into()
+                crate::column::open_column_u64::<f64>(column_bytes, self.format_version)?.into()
             }
             ColumnType::Bool => {
-                crate::column::open_column_u64::<bool>(file_slice, self.format_version)?.into()
+                crate::column::open_column_u64::<bool>(column_bytes, self.format_version)?.into()
             }
             ColumnType::IpAddr => {
-                crate::column::open_column_u128::<Ipv6Addr>(file_slice, self.format_version)?.into()
+                crate::column::open_column_u128::<Ipv6Addr>(column_bytes, self.format_version)?
+                    .into()
             }
             ColumnType::DateTime => {
-                crate::column::open_column_u64::<DateTime>(file_slice, self.format_version)?.into()
+                crate::column::open_column_u64::<DateTime>(column_bytes, self.format_version)?
+                    .into()
             }
         };
         Ok(dynamic_column)
     }
 
     pub fn num_bytes(&self) -> ByteCount {
-        self.file_slice.num_bytes()
-    }
-
-    /// Legacy helper returning the column space usage.
-    pub fn column_and_dictionary_num_bytes(&self) -> io::Result<ColumnSpaceUsage> {
-        self.space_usage()
-    }
-
-    /// Return the space usage of the column, optionally broken down by dictionary and column
-    /// values.
-    ///
-    /// For dictionary encoded columns (strings and bytes), this splits the total footprint into
-    /// the dictionary and the remaining column data (including index and values).
-    /// For all other column types, the dictionary size is `None` and the column size
-    /// equals the total bytes.
-    pub fn space_usage(&self) -> io::Result<ColumnSpaceUsage> {
-        let total_num_bytes = self.num_bytes();
-        let dynamic_column = self.open()?;
-        let dictionary_num_bytes = match &dynamic_column {
-            DynamicColumn::Bytes(bytes_column) => bytes_column.dictionary().num_bytes(),
-            DynamicColumn::Str(str_column) => str_column.dictionary().num_bytes(),
-            _ => {
-                return Ok(ColumnSpaceUsage::new(self.num_bytes(), None));
-            }
-        };
-        assert!(dictionary_num_bytes <= total_num_bytes);
-        let column_num_bytes =
-            ByteCount::from(total_num_bytes.get_bytes() - dictionary_num_bytes.get_bytes());
-        Ok(ColumnSpaceUsage::new(
-            column_num_bytes,
-            Some(dictionary_num_bytes),
-        ))
+        self.file_slice.len().into()
     }
 
     pub fn column_type(&self) -> ColumnType {
         self.column_type
     }
 }
-
-/// Represents space usage of a column.
-///
-/// `column_num_bytes` tracks the column payload (index, values and footer).
-/// For dictionary encoded columns, `dictionary_num_bytes` captures the dictionary footprint.
-/// [`ColumnSpaceUsage::total_num_bytes`] returns the sum of both parts.
-#[derive(Clone, Debug, Serialize, Deserialize)]
-pub struct ColumnSpaceUsage {
-    column_num_bytes: ByteCount,
-    dictionary_num_bytes: Option<ByteCount>,
-}
-
-impl ColumnSpaceUsage {
-    pub(crate) fn new(
-        column_num_bytes: ByteCount,
-        dictionary_num_bytes: Option<ByteCount>,
-    ) -> Self {
-        ColumnSpaceUsage {
-            column_num_bytes,
-            dictionary_num_bytes,
-        }
-    }
-
-    pub fn column_num_bytes(&self) -> ByteCount {
-        self.column_num_bytes
-    }
-
-    pub fn dictionary_num_bytes(&self) -> Option<ByteCount> {
-        self.dictionary_num_bytes
-    }
-
-    pub fn total_num_bytes(&self) -> ByteCount {
-        self.column_num_bytes + self.dictionary_num_bytes.unwrap_or_default()
-    }
-
-    /// Merge two space usage values by summing their components.
-    pub fn merge(&self, other: &ColumnSpaceUsage) -> ColumnSpaceUsage {
-        let dictionary_num_bytes = match (self.dictionary_num_bytes, other.dictionary_num_bytes) {
-            (Some(lhs), Some(rhs)) => Some(lhs + rhs),
-            (Some(val), None) | (None, Some(val)) => Some(val),
-            (None, None) => None,
-        };
-        ColumnSpaceUsage {
-            column_num_bytes: self.column_num_bytes + other.column_num_bytes,
-            dictionary_num_bytes,
-        }
-    }
-}

columnar/src/lib.rs

@@ -29,7 +29,6 @@ mod column;
 pub mod column_index;
 pub mod column_values;
 mod columnar;
-mod comparable_doc;
 mod dictionary;
 mod dynamic_column;
 mod iterable;
@@ -37,7 +36,7 @@ pub(crate) mod utils;
 mod value;
 
 pub use block_accessor::ColumnBlockAccessor;
-pub use column::{BytesColumn, Column, StrColumn, ValueRange};
+pub use column::{BytesColumn, Column, StrColumn};
 pub use column_index::ColumnIndex;
 pub use column_values::{
     ColumnValues, EmptyColumnValues, MonotonicallyMappableToU64, MonotonicallyMappableToU128,
@@ -46,11 +45,10 @@ pub use columnar::{
     CURRENT_VERSION, ColumnType, ColumnarReader, ColumnarWriter, HasAssociatedColumnType,
     MergeRowOrder, ShuffleMergeOrder, StackMergeOrder, Version, merge_columnar,
 };
-pub use comparable_doc::ComparableDoc;
 use sstable::VoidSSTable;
 pub use value::{NumericalType, NumericalValue};
 
-pub use self::dynamic_column::{ColumnSpaceUsage, DynamicColumn, DynamicColumnHandle};
+pub use self::dynamic_column::{DynamicColumn, DynamicColumnHandle};
 
 pub type RowId = u32;
 pub type DocId = u32;

columnar/src/tests.rs

@@ -641,7 +641,7 @@ proptest! {
         let columnar_readers_arr: Vec<&ColumnarReader> = columnar_readers.iter().collect();
         let mut output: Vec<u8> = Vec::new();
         let stack_merge_order = StackMergeOrder::stack(&columnar_readers_arr[..]).into();
-        crate::merge_columnar(&columnar_readers_arr[..], &[], stack_merge_order, &mut output, || false,).unwrap();
+        crate::merge_columnar(&columnar_readers_arr[..], &[], stack_merge_order, &mut output).unwrap();
         let merged_columnar = ColumnarReader::open(output).unwrap();
         let concat_rows: Vec<Vec<(&'static str, ColumnValue)>> = columnar_docs.iter().flatten().cloned().collect();
         let expected_merged_columnar = build_columnar(&concat_rows[..]);
@@ -665,7 +665,6 @@ fn test_columnar_merging_empty_columnar() {
         &[],
         crate::MergeRowOrder::Stack(stack_merge_order),
         &mut output,
-        || false,
     )
     .unwrap();
     let merged_columnar = ColumnarReader::open(output).unwrap();
@@ -703,7 +702,6 @@ fn test_columnar_merging_number_columns() {
         &[],
         crate::MergeRowOrder::Stack(stack_merge_order),
         &mut output,
-        || false,
     )
     .unwrap();
     let merged_columnar = ColumnarReader::open(output).unwrap();
@@ -777,7 +775,6 @@ fn test_columnar_merge_and_remap(
         &[],
         shuffle_merge_order.into(),
         &mut output,
-        || false,
     )
     .unwrap();
     let merged_columnar = ColumnarReader::open(output).unwrap();
@@ -820,7 +817,6 @@ fn test_columnar_merge_empty() {
         &[],
         shuffle_merge_order.into(),
         &mut output,
-        || false,
     )
     .unwrap();
     let merged_columnar = ColumnarReader::open(output).unwrap();
@@ -847,7 +843,6 @@ fn test_columnar_merge_single_str_column() {
         &[],
         shuffle_merge_order.into(),
         &mut output,
-        || false,
     )
     .unwrap();
     let merged_columnar = ColumnarReader::open(output).unwrap();
@@ -880,7 +875,6 @@ fn test_delete_decrease_cardinality() {
         &[],
         shuffle_merge_order.into(),
         &mut output,
-        || false,
     )
     .unwrap();
     let merged_columnar = ColumnarReader::open(output).unwrap();

common/src/bitset.rs

@@ -181,6 +181,14 @@ pub struct BitSet {
     len: u64,
     max_value: u32,
 }
+impl std::fmt::Debug for BitSet {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("BitSet")
+            .field("len", &self.len)
+            .field("max_value", &self.max_value)
+            .finish()
+    }
+}
 
 fn num_buckets(max_val: u32) -> u32 {
     max_val.div_ceil(64u32)

common/src/buffered_file_slice.rs

@@ -1,106 +0,0 @@
-use std::cell::RefCell;
-use std::cmp::min;
-use std::io;
-use std::ops::Range;
-
-use super::file_slice::FileSlice;
-use super::{HasLen, OwnedBytes};
-
-const DEFAULT_BUFFER_MAX_SIZE: usize = 512 * 1024; // 512K
-
-/// A buffered reader for a FileSlice.
-///
-/// Reads the underlying `FileSlice` in large, sequential chunks to amortize
-/// the cost of `read_bytes` calls, while keeping peak memory usage under control.
-///
-/// TODO: Rather than wrapping a `FileSlice` in buffering, it will usually be better to adjust a
-/// `FileHandle` to directly handle buffering itself.
-/// TODO: See: https://github.com/paradedb/paradedb/issues/3374
-pub struct BufferedFileSlice {
-    file_slice: FileSlice,
-    buffer: RefCell<OwnedBytes>,
-    buffer_range: RefCell<Range<u64>>,
-    buffer_max_size: usize,
-}
-
-impl BufferedFileSlice {
-    /// Creates a new `BufferedFileSlice`.
-    ///
-    /// The `buffer_max_size` is the amount of data that will be read from the
-    /// `FileSlice` on a buffer miss.
-    pub fn new(file_slice: FileSlice, buffer_max_size: usize) -> Self {
-        Self {
-            file_slice,
-            buffer: RefCell::new(OwnedBytes::empty()),
-            buffer_range: RefCell::new(0..0),
-            buffer_max_size,
-        }
-    }
-
-    /// Creates a new `BufferedFileSlice` with a default buffer max size.
-    pub fn new_with_default_buffer_size(file_slice: FileSlice) -> Self {
-        Self::new(file_slice, DEFAULT_BUFFER_MAX_SIZE)
-    }
-
-    /// Creates an empty `BufferedFileSlice`.
-    pub fn empty() -> Self {
-        Self::new(FileSlice::empty(), 0)
-    }
-
-    /// Returns an `OwnedBytes` corresponding to the given `required_range`.
-    ///
-    /// If the requested range is not in the buffer, this will trigger a read
-    /// from the underlying `FileSlice`.
-    ///
-    /// If the requested range is larger than the buffer_max_size, it will be read directly from the
-    /// source without buffering.
-    ///
-    /// # Errors
-    ///
-    /// Returns an `io::Error` if the underlying read fails or the range is
-    /// out of bounds.
-    pub fn get_bytes(&self, required_range: Range<u64>) -> io::Result<OwnedBytes> {
-        let buffer_range = self.buffer_range.borrow();
-
-        // Cache miss condition: the required range is not fully contained in the current buffer.
-        if required_range.start < buffer_range.start || required_range.end > buffer_range.end {
-            drop(buffer_range); // release borrow before mutating
-
-            if required_range.end > self.file_slice.len() as u64 {
-                return Err(io::Error::new(
-                    io::ErrorKind::UnexpectedEof,
-                    "Requested range extends beyond the end of the file slice.",
-                ));
-            }
-
-            if (required_range.end - required_range.start) as usize > self.buffer_max_size {
-                // This read is larger than our buffer max size.
-                // Read it directly and bypass the buffer to avoid churning.
-                return self
-                    .file_slice
-                    .read_bytes_slice(required_range.start as usize..required_range.end as usize);
-            }
-
-            let new_buffer_start = required_range.start;
-            let new_buffer_end = min(
-                new_buffer_start + self.buffer_max_size as u64,
-                self.file_slice.len() as u64,
-            );
-            let read_range = new_buffer_start..new_buffer_end;
-
-            let new_buffer = self
-                .file_slice
-                .read_bytes_slice(read_range.start as usize..read_range.end as usize)?;
-
-            self.buffer.replace(new_buffer);
-            self.buffer_range.replace(read_range);
-        }
-
-        // Now the data is guaranteed to be in the buffer.
-        let buffer = self.buffer.borrow();
-        let buffer_range = self.buffer_range.borrow();
-        let local_start = (required_range.start - buffer_range.start) as usize;
-        let local_end = (required_range.end - buffer_range.start) as usize;
-        Ok(buffer.slice(local_start..local_end))
-    }
-}

common/src/file_slice.rs

@@ -1,7 +1,7 @@
 use std::fs::File;
 use std::ops::{Deref, Range, RangeBounds};
 use std::path::Path;
-use std::sync::{Arc, OnceLock};
+use std::sync::Arc;
 use std::{fmt, io};
 
 use async_trait::async_trait;
@@ -339,27 +339,6 @@ impl FileHandle for OwnedBytes {
     }
 }
 
-pub struct DeferredFileSlice {
-    opener: Arc<dyn Fn() -> io::Result<FileSlice> + Send + Sync + 'static>,
-    file_slice: OnceLock<std::io::Result<FileSlice>>,
-}
-
-impl DeferredFileSlice {
-    pub fn new(opener: impl Fn() -> io::Result<FileSlice> + Send + Sync + 'static) -> Self {
-        DeferredFileSlice {
-            opener: Arc::new(opener),
-            file_slice: OnceLock::default(),
-        }
-    }
-
-    pub fn open(&self) -> io::Result<&FileSlice> {
-        match self.file_slice.get_or_init(|| (self.opener)()) {
-            Ok(file_slice) => Ok(file_slice),
-            Err(e) => Err(io::Error::new(io::ErrorKind::Other, e.to_string())),
-        }
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use std::io;

common/src/lib.rs

@@ -6,7 +6,6 @@ pub use byteorder::LittleEndian as Endianness;
 
 mod bitset;
 pub mod bounds;
-pub mod buffered_file_slice;
 mod byte_count;
 mod datetime;
 pub mod file_slice;

common/src/vint.rs

@@ -58,33 +58,6 @@ impl BinarySerializable for VIntU128 {
 #[derive(Clone, Copy, Debug, Eq, PartialEq)]
 pub struct VInt(pub u64);
 
-impl VInt {
-    pub fn deserialize_with_size<R: Read>(reader: &mut R) -> io::Result<(Self, usize)> {
-        let mut nbytes = 0;
-        let mut bytes = reader.bytes();
-        let mut result = 0u64;
-        let mut shift = 0u64;
-        loop {
-            match bytes.next() {
-                Some(Ok(b)) => {
-                    nbytes += 1;
-                    result |= u64::from(b % 128u8) << shift;
-                    if b >= STOP_BIT {
-                        return Ok((VInt(result), nbytes));
-                    }
-                    shift += 7;
-                }
-                _ => {
-                    return Err(io::Error::new(
-                        io::ErrorKind::InvalidData,
-                        "Reach end of buffer while reading VInt",
-                    ));
-                }
-            }
-        }
-    }
-}
-
 const STOP_BIT: u8 = 128;
 
 #[inline]
@@ -252,6 +225,7 @@ impl BinarySerializable for VInt {
 
 #[cfg(test)]
 mod tests {
+
     use super::{BinarySerializable, VInt, serialize_vint_u32};
 
     fn aux_test_vint(val: u64) {

examples/multiple_snippets.rs

@@ -1,86 +0,0 @@
-// # Multiple Snippets Example
-//
-// This example demonstrates how to return multiple text fragments
-// from a document, useful for long documents with matches in different locations.
-
-use tantivy::collector::TopDocs;
-use tantivy::query::QueryParser;
-use tantivy::schema::*;
-use tantivy::snippet::SnippetGenerator;
-use tantivy::{doc, Index, IndexWriter};
-use tempfile::TempDir;
-
-fn main() -> tantivy::Result<()> {
-    let index_path = TempDir::new()?;
-
-    // Define the schema
-    let mut schema_builder = Schema::builder();
-    let title = schema_builder.add_text_field("title", TEXT | STORED);
-    let body = schema_builder.add_text_field("body", TEXT | STORED);
-    let schema = schema_builder.build();
-
-    // Create the index
-    let index = Index::create_in_dir(&index_path, schema)?;
-    let mut index_writer: IndexWriter = index.writer(50_000_000)?;
-
-    // Index a long document with multiple occurrences of "rust"
-    index_writer.add_document(doc!(
-        title => "The Rust Programming Language",
-        body => "Rust is a systems programming language that runs blazingly fast, prevents \
-                 segfaults, and guarantees thread safety. Lorem ipsum dolor sit amet, \
-                 consectetur adipiscing elit. Sed do eiusmod tempor incididunt ut labore. \
-                 Rust empowers everyone to build reliable and efficient software. More filler \
-                 text to create distance between matches. Ut enim ad minim veniam, quis nostrud \
-                 exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. \
-                 The Rust compiler is known for its helpful error messages. Duis aute irure \
-                 dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla \
-                 pariatur. Rust has a strong type system and ownership model."
-    ))?;
-
-    index_writer.commit()?;
-
-    let reader = index.reader()?;
-    let searcher = reader.searcher();
-    let query_parser = QueryParser::for_index(&index, vec![title, body]);
-    let query = query_parser.parse_query("rust")?;
-
-    let top_docs = searcher.search(&query, &TopDocs::with_limit(10).order_by_score())?;
-
-    // Create snippet generator
-    let mut snippet_generator = SnippetGenerator::create(&searcher, &*query, body)?;
-
-    println!("=== Single Snippet (Default Behavior) ===\n");
-    for (score, doc_address) in &top_docs {
-        let doc = searcher.doc::<TantivyDocument>(*doc_address)?;
-        let snippet = snippet_generator.snippet_from_doc(&doc);
-        println!("Document score: {}", score);
-        println!("Title: {}", doc.get_first(title).unwrap().as_str().unwrap());
-        println!("Single snippet: {}\n", snippet.to_html());
-    }
-
-    println!("\n=== Multiple Snippets (New Feature) ===\n");
-
-    // Configure to return multiple snippets
-    // Get up to 3 snippets
-    snippet_generator.set_snippets_limit(3);
-    // Smaller fragments
-    snippet_generator.set_max_num_chars(80);
-    // By default, multiple snippets are sorted by score. You can change this to sort by position.
-    // snippet_generator.set_sort_order(SnippetSortOrder::Position);
-
-    for (score, doc_address) in top_docs {
-        let doc = searcher.doc::<TantivyDocument>(doc_address)?;
-        let snippets = snippet_generator.snippets_from_doc(&doc);
-
-        println!("Document score: {}", score);
-        println!("Title: {}", doc.get_first(title).unwrap().as_str().unwrap());
-        println!("Found {} snippets:", snippets.len());
-
-        for (i, snippet) in snippets.iter().enumerate() {
-            println!("  Snippet {}: {}", i + 1, snippet.to_html());
-        }
-        println!();
-    }
-
-    Ok(())
-}

runtests.sh

@@ -1,3 +0,0 @@
-#! /bin/bash
-
-cargo +stable nextest run --features quickwit,mmap,stopwords,lz4-compression,zstd-compression,failpoints --verbose --workspace

src/aggregation/agg_data.rs

@@ -1,4 +1,4 @@
-use columnar::{Column, ColumnType, StrColumn};
+use columnar::{Column, ColumnBlockAccessor, ColumnType, StrColumn};
 use common::BitSet;
 use rustc_hash::FxHashSet;
 use serde::Serialize;
@@ -10,16 +10,16 @@ use crate::aggregation::accessor_helpers::{
 };
 use crate::aggregation::agg_req::{Aggregation, AggregationVariants, Aggregations};
 use crate::aggregation::bucket::{
-    FilterAggReqData, HistogramAggReqData, HistogramBounds, IncludeExcludeParam,
-    MissingTermAggReqData, RangeAggReqData, SegmentFilterCollector, SegmentHistogramCollector,
-    SegmentRangeCollector, TermMissingAgg, TermsAggReqData, TermsAggregation,
+    build_segment_filter_collector, build_segment_range_collector, FilterAggReqData,
+    HistogramAggReqData, HistogramBounds, IncludeExcludeParam, MissingTermAggReqData,
+    RangeAggReqData, SegmentHistogramCollector, TermMissingAgg, TermsAggReqData, TermsAggregation,
     TermsAggregationInternal,
 };
 use crate::aggregation::metric::{
-    AverageAggregation, CardinalityAggReqData, CardinalityAggregationReq, CountAggregation,
-    ExtendedStatsAggregation, MaxAggregation, MetricAggReqData, MinAggregation,
-    SegmentCardinalityCollector, SegmentExtendedStatsCollector, SegmentPercentilesCollector,
-    SegmentStatsCollector, StatsAggregation, StatsType, SumAggregation, TopHitsAggReqData,
+    build_segment_stats_collector, AverageAggregation, CardinalityAggReqData,
+    CardinalityAggregationReq, CountAggregation, ExtendedStatsAggregation, MaxAggregation,
+    MetricAggReqData, MinAggregation, SegmentCardinalityCollector, SegmentExtendedStatsCollector,
+    SegmentPercentilesCollector, StatsAggregation, StatsType, SumAggregation, TopHitsAggReqData,
     TopHitsSegmentCollector,
 };
 use crate::aggregation::segment_agg_result::{
@@ -35,6 +35,7 @@ pub struct AggregationsSegmentCtx {
     /// Request data for each aggregation type.
     pub per_request: PerRequestAggSegCtx,
     pub context: AggContextParams,
+    pub column_block_accessor: ColumnBlockAccessor<u64>,
 }
 
 impl AggregationsSegmentCtx {
@@ -107,21 +108,14 @@ impl AggregationsSegmentCtx {
             .as_deref()
             .expect("range_req_data slot is empty (taken)")
     }
-    #[inline]
-    pub(crate) fn get_filter_req_data(&self, idx: usize) -> &FilterAggReqData {
-        self.per_request.filter_req_data[idx]
-            .as_deref()
-            .expect("filter_req_data slot is empty (taken)")
-    }
 
     // ---------- mutable getters ----------
 
     #[inline]
-    pub(crate) fn get_term_req_data_mut(&mut self, idx: usize) -> &mut TermsAggReqData {
-        self.per_request.term_req_data[idx]
-            .as_deref_mut()
-            .expect("term_req_data slot is empty (taken)")
+    pub(crate) fn get_metric_req_data_mut(&mut self, idx: usize) -> &mut MetricAggReqData {
+        &mut self.per_request.stats_metric_req_data[idx]
     }
+
     #[inline]
     pub(crate) fn get_cardinality_req_data_mut(
         &mut self,
@@ -129,10 +123,7 @@ impl AggregationsSegmentCtx {
     ) -> &mut CardinalityAggReqData {
         &mut self.per_request.cardinality_req_data[idx]
     }
-    #[inline]
-    pub(crate) fn get_metric_req_data_mut(&mut self, idx: usize) -> &mut MetricAggReqData {
-        &mut self.per_request.stats_metric_req_data[idx]
-    }
+
     #[inline]
     pub(crate) fn get_histogram_req_data_mut(&mut self, idx: usize) -> &mut HistogramAggReqData {
         self.per_request.histogram_req_data[idx]
@@ -142,21 +133,6 @@ impl AggregationsSegmentCtx {
 
     // ---------- take / put (terms, histogram, range) ----------
 
-    /// Move out the boxed Terms request at `idx`, leaving `None`.
-    #[inline]
-    pub(crate) fn take_term_req_data(&mut self, idx: usize) -> Box<TermsAggReqData> {
-        self.per_request.term_req_data[idx]
-            .take()
-            .expect("term_req_data slot is empty (taken)")
-    }
-
-    /// Put back a Terms request into an empty slot at `idx`.
-    #[inline]
-    pub(crate) fn put_back_term_req_data(&mut self, idx: usize, value: Box<TermsAggReqData>) {
-        debug_assert!(self.per_request.term_req_data[idx].is_none());
-        self.per_request.term_req_data[idx] = Some(value);
-    }
-
     /// Move out the boxed Histogram request at `idx`, leaving `None`.
     #[inline]
     pub(crate) fn take_histogram_req_data(&mut self, idx: usize) -> Box<HistogramAggReqData> {
@@ -320,6 +296,7 @@ impl PerRequestAggSegCtx {
 
     /// Convert the aggregation tree into a serializable struct representation.
     /// Each node contains: { name, kind, children }.
+    #[allow(dead_code)]
     pub fn get_view_tree(&self) -> Vec<AggTreeViewNode> {
         fn node_to_view(node: &AggRefNode, pr: &PerRequestAggSegCtx) -> AggTreeViewNode {
             let mut children: Vec<AggTreeViewNode> =
@@ -345,12 +322,19 @@ impl PerRequestAggSegCtx {
 pub(crate) fn build_segment_agg_collectors_root(
     req: &mut AggregationsSegmentCtx,
 ) -> crate::Result<Box<dyn SegmentAggregationCollector>> {
-    build_segment_agg_collectors(req, &req.per_request.agg_tree.clone())
+    build_segment_agg_collectors_generic(req, &req.per_request.agg_tree.clone())
 }
 
 pub(crate) fn build_segment_agg_collectors(
     req: &mut AggregationsSegmentCtx,
     nodes: &[AggRefNode],
+) -> crate::Result<Box<dyn SegmentAggregationCollector>> {
+    build_segment_agg_collectors_generic(req, nodes)
+}
+
+fn build_segment_agg_collectors_generic(
+    req: &mut AggregationsSegmentCtx,
+    nodes: &[AggRefNode],
 ) -> crate::Result<Box<dyn SegmentAggregationCollector>> {
     let mut collectors = Vec::new();
     for node in nodes.iter() {
@@ -388,6 +372,8 @@ pub(crate) fn build_segment_agg_collector(
             Ok(Box::new(SegmentCardinalityCollector::from_req(
                 req_data.column_type,
                 node.idx_in_req_data,
+                req_data.accessor.clone(),
+                req_data.missing_value_for_accessor,
             )))
         }
         AggKind::StatsKind(stats_type) => {
@@ -398,20 +384,21 @@ pub(crate) fn build_segment_agg_collector(
                 | StatsType::Count
                 | StatsType::Max
                 | StatsType::Min
-                | StatsType::Stats => Ok(Box::new(SegmentStatsCollector::from_req(
-                    node.idx_in_req_data,
-                ))),
-                StatsType::ExtendedStats(sigma) => {
-                    Ok(Box::new(SegmentExtendedStatsCollector::from_req(
-                        req_data.field_type,
-                        sigma,
-                        node.idx_in_req_data,
-                        req_data.missing,
-                    )))
-                }
-                StatsType::Percentiles => Ok(Box::new(
-                    SegmentPercentilesCollector::from_req_and_validate(node.idx_in_req_data)?,
+                | StatsType::Stats => build_segment_stats_collector(req_data),
+                StatsType::ExtendedStats(sigma) => Ok(Box::new(
+                    SegmentExtendedStatsCollector::from_req(req_data, sigma),
                 )),
+                StatsType::Percentiles => {
+                    let req_data = req.get_metric_req_data_mut(node.idx_in_req_data);
+                    Ok(Box::new(
+                        SegmentPercentilesCollector::from_req_and_validate(
+                            req_data.field_type,
+                            req_data.missing_u64,
+                            req_data.accessor.clone(),
+                            node.idx_in_req_data,
+                        ),
+                    ))
+                }
             }
         }
         AggKind::TopHits => {
@@ -428,12 +415,8 @@ pub(crate) fn build_segment_agg_collector(
         AggKind::DateHistogram => Ok(Box::new(SegmentHistogramCollector::from_req_and_validate(
             req, node,
         )?)),
-        AggKind::Range => Ok(Box::new(SegmentRangeCollector::from_req_and_validate(
-            req, node,
-        )?)),
-        AggKind::Filter => Ok(Box::new(SegmentFilterCollector::from_req_and_validate(
-            req, node,
-        )?)),
+        AggKind::Range => Ok(build_segment_range_collector(req, node)?),
+        AggKind::Filter => build_segment_filter_collector(req, node),
     }
 }
 
@@ -493,6 +476,7 @@ pub(crate) fn build_aggregations_data_from_req(
     let mut data = AggregationsSegmentCtx {
         per_request: Default::default(),
         context,
+        column_block_accessor: ColumnBlockAccessor::default(),
     };
 
     for (name, agg) in aggs.iter() {
@@ -521,9 +505,9 @@ fn build_nodes(
             let idx_in_req_data = data.push_range_req_data(RangeAggReqData {
                 accessor,
                 field_type,
-                column_block_accessor: Default::default(),
                 name: agg_name.to_string(),
                 req: range_req.clone(),
+                is_top_level,
             });
             let children = build_children(&req.sub_aggregation, reader, segment_ordinal, data)?;
             Ok(vec![AggRefNode {
@@ -541,9 +525,7 @@ fn build_nodes(
             let idx_in_req_data = data.push_histogram_req_data(HistogramAggReqData {
                 accessor,
                 field_type,
-                column_block_accessor: Default::default(),
                 name: agg_name.to_string(),
-                sub_aggregation_blueprint: None,
                 req: histo_req.clone(),
                 is_date_histogram: false,
                 bounds: HistogramBounds {
@@ -568,9 +550,7 @@ fn build_nodes(
             let idx_in_req_data = data.push_histogram_req_data(HistogramAggReqData {
                 accessor,
                 field_type,
-                column_block_accessor: Default::default(),
                 name: agg_name.to_string(),
-                sub_aggregation_blueprint: None,
                 req: histo_req,
                 is_date_histogram: true,
                 bounds: HistogramBounds {
@@ -650,7 +630,6 @@ fn build_nodes(
             let idx_in_req_data = data.push_metric_req_data(MetricAggReqData {
                 accessor,
                 field_type,
-                column_block_accessor: Default::default(),
                 name: agg_name.to_string(),
                 collecting_for,
                 missing: *missing,
@@ -678,7 +657,6 @@ fn build_nodes(
             let idx_in_req_data = data.push_metric_req_data(MetricAggReqData {
                 accessor,
                 field_type,
-                column_block_accessor: Default::default(),
                 name: agg_name.to_string(),
                 collecting_for: StatsType::Percentiles,
                 missing: percentiles_req.missing,
@@ -753,6 +731,7 @@ fn build_nodes(
                 segment_reader: reader.clone(),
                 evaluator,
                 matching_docs_buffer,
+                is_top_level,
             });
             let children = build_children(&req.sub_aggregation, reader, segment_ordinal, data)?;
             Ok(vec![AggRefNode {
@@ -895,7 +874,7 @@ fn build_terms_or_cardinality_nodes(
         });
     }
 
-    // Add one node per accessor to mirror previous behavior and allow per-type missing handling.
+    // Add one node per accessor
     for (accessor, column_type) in column_and_types {
         let missing_value_for_accessor = if use_special_missing_agg {
             None
@@ -926,11 +905,8 @@ fn build_terms_or_cardinality_nodes(
                     column_type,
                     str_dict_column: str_dict_column.clone(),
                     missing_value_for_accessor,
-                    column_block_accessor: Default::default(),
                     name: agg_name.to_string(),
                     req: TermsAggregationInternal::from_req(req),
-                    // Will be filled later when building collectors
-                    sub_aggregation_blueprint: None,
                     sug_aggregations: sub_aggs.clone(),
                     allowed_term_ids,
                     is_top_level,
@@ -943,7 +919,6 @@ fn build_terms_or_cardinality_nodes(
                     column_type,
                     str_dict_column: str_dict_column.clone(),
                     missing_value_for_accessor,
-                    column_block_accessor: Default::default(),
                     name: agg_name.to_string(),
                     req: req.clone(),
                 });

src/aggregation/agg_tests.rs

@@ -2,15 +2,441 @@ use serde_json::Value;
 
 use crate::aggregation::agg_req::{Aggregation, Aggregations};
 use crate::aggregation::agg_result::AggregationResults;
-use crate::aggregation::buf_collector::DOC_BLOCK_SIZE;
 use crate::aggregation::collector::AggregationCollector;
 use crate::aggregation::intermediate_agg_result::IntermediateAggregationResults;
 use crate::aggregation::tests::{get_test_index_2_segments, get_test_index_from_values_and_terms};
 use crate::aggregation::DistributedAggregationCollector;
+use crate::docset::COLLECT_BLOCK_BUFFER_LEN;
 use crate::query::{AllQuery, TermQuery};
 use crate::schema::{IndexRecordOption, Schema, FAST};
 use crate::{Index, IndexWriter, Term};
 
+// The following tests ensure that each bucket aggregation type correctly functions as a
+// sub-aggregation of another bucket aggregation in two scenarios:
+// 1) The parent has more buckets than the child sub-aggregation
+// 2) The child sub-aggregation has more buckets than the parent
+//
+// These scenarios exercise the bucket id mapping and sub-aggregation routing logic.
+
+#[test]
+fn test_terms_as_subagg_parent_more_vs_child_more() -> crate::Result<()> {
+    let index = get_test_index_2_segments(false)?;
+
+    // Case A: parent has more buckets than child
+    // Parent: range with 4 buckets
+    // Child: terms on text -> 2 buckets
+    let agg_parent_more: Aggregations = serde_json::from_value(json!({
+        "parent_range": {
+            "range": {
+                "field": "score",
+                "ranges": [
+                    {"to": 3.0},
+                    {"from": 3.0, "to": 7.0},
+                    {"from": 7.0, "to": 20.0},
+                    {"from": 20.0}
+                ]
+            },
+            "aggs": {
+                "child_terms": {"terms": {"field": "text", "order": {"_key": "asc"}}}
+            }
+        }
+    }))
+    .unwrap();
+
+    let res = crate::aggregation::tests::exec_request(agg_parent_more, &index)?;
+    // Exact expected structure and counts
+    assert_eq!(
+        res["parent_range"]["buckets"],
+        json!([
+            {
+                "key": "*-3",
+                "doc_count": 1,
+                "to": 3.0,
+                "child_terms": {
+                    "buckets": [
+                        {"doc_count": 1, "key": "cool"}
+                    ],
+                    "sum_other_doc_count": 0
+                }
+            },
+            {
+                "key": "3-7",
+                "doc_count": 3,
+                "from": 3.0,
+                "to": 7.0,
+                "child_terms": {
+                    "buckets": [
+                        {"doc_count": 2, "key": "cool"},
+                        {"doc_count": 1, "key": "nohit"}
+                    ],
+                    "sum_other_doc_count": 0
+                }
+            },
+            {
+                "key": "7-20",
+                "doc_count": 3,
+                "from": 7.0,
+                "to": 20.0,
+                "child_terms": {
+                    "buckets": [
+                        {"doc_count": 3, "key": "cool"}
+                    ],
+                    "sum_other_doc_count": 0
+                }
+            },
+            {
+                "key": "20-*",
+                "doc_count": 2,
+                "from": 20.0,
+                "child_terms": {
+                    "buckets": [
+                        {"doc_count": 1, "key": "cool"},
+                        {"doc_count": 1, "key": "nohit"}
+                    ],
+                    "sum_other_doc_count": 0
+                }
+            }
+        ])
+    );
+
+    // Case B: child has more buckets than parent
+    // Parent: histogram on score with large interval -> 1 bucket
+    // Child: terms on text -> 2 buckets (cool/nohit)
+    let agg_child_more: Aggregations = serde_json::from_value(json!({
+        "parent_hist": {
+            "histogram": {"field": "score", "interval": 100.0},
+            "aggs": {
+                "child_terms": {"terms": {"field": "text", "order": {"_key": "asc"}}}
+            }
+        }
+    }))
+    .unwrap();
+
+    let res = crate::aggregation::tests::exec_request(agg_child_more, &index)?;
+    assert_eq!(
+        res["parent_hist"],
+        json!({
+            "buckets": [
+                {
+                    "key": 0.0,
+                    "doc_count": 9,
+                    "child_terms": {
+                        "buckets": [
+                            {"doc_count": 7, "key": "cool"},
+                            {"doc_count": 2, "key": "nohit"}
+                        ],
+                        "sum_other_doc_count": 0
+                    }
+                }
+            ]
+        })
+    );
+
+    Ok(())
+}
+
+#[test]
+fn test_range_as_subagg_parent_more_vs_child_more() -> crate::Result<()> {
+    let index = get_test_index_2_segments(false)?;
+
+    // Case A: parent has more buckets than child
+    // Parent: range with 5 buckets
+    // Child: coarse range with 3 buckets
+    let agg_parent_more: Aggregations = serde_json::from_value(json!({
+        "parent_range": {
+            "range": {
+                "field": "score",
+                "ranges": [
+                    {"to": 3.0},
+                    {"from": 3.0, "to": 7.0},
+                    {"from": 7.0, "to": 11.0},
+                    {"from": 11.0, "to": 20.0},
+                    {"from": 20.0}
+                ]
+            },
+            "aggs": {
+                "child_range": {
+                    "range": {
+                        "field": "score",
+                        "ranges": [
+                            {"to": 3.0},
+                            {"from": 3.0, "to": 20.0}
+                        ]
+                    }
+                }
+            }
+        }
+    }))
+    .unwrap();
+    let res = crate::aggregation::tests::exec_request(agg_parent_more, &index)?;
+    assert_eq!(
+        res["parent_range"]["buckets"],
+        json!([
+            {"key": "*-3", "doc_count": 1, "to": 3.0,
+                "child_range": {"buckets": [
+                    {"key": "*-3", "doc_count": 1, "to": 3.0},
+                    {"key": "3-20", "doc_count": 0, "from": 3.0, "to": 20.0},
+                    {"key": "20-*", "doc_count": 0, "from": 20.0}
+                ]}
+            },
+            {"key": "3-7", "doc_count": 3, "from": 3.0, "to": 7.0,
+                "child_range": {"buckets": [
+                    {"key": "*-3", "doc_count": 0, "to": 3.0},
+                    {"key": "3-20", "doc_count": 3, "from": 3.0, "to": 20.0},
+                    {"key": "20-*", "doc_count": 0, "from": 20.0}
+                ]}
+            },
+            {"key": "7-11", "doc_count": 1, "from": 7.0, "to": 11.0,
+                "child_range": {"buckets": [
+                    {"key": "*-3", "doc_count": 0, "to": 3.0},
+                    {"key": "3-20", "doc_count": 1, "from": 3.0, "to": 20.0},
+                    {"key": "20-*", "doc_count": 0, "from": 20.0}
+                ]}
+            },
+            {"key": "11-20", "doc_count": 2, "from": 11.0, "to": 20.0,
+                "child_range": {"buckets": [
+                    {"key": "*-3", "doc_count": 0, "to": 3.0},
+                    {"key": "3-20", "doc_count": 2, "from": 3.0, "to": 20.0},
+                    {"key": "20-*", "doc_count": 0, "from": 20.0}
+                ]}
+            },
+            {"key": "20-*", "doc_count": 2, "from": 20.0,
+                "child_range": {"buckets": [
+                    {"key": "*-3", "doc_count": 0, "to": 3.0},
+                    {"key": "3-20", "doc_count": 0, "from": 3.0, "to": 20.0},
+                    {"key": "20-*", "doc_count": 2, "from": 20.0}
+                ]}
+            }
+        ])
+    );
+
+    // Case B: child has more buckets than parent
+    // Parent: terms on text (2 buckets)
+    // Child: range with 4 buckets
+    let agg_child_more: Aggregations = serde_json::from_value(json!({
+        "parent_terms": {
+            "terms": {"field": "text"},
+            "aggs": {
+                "child_range": {
+                    "range": {
+                        "field": "score",
+                        "ranges": [
+                            {"to": 3.0},
+                            {"from": 3.0, "to": 7.0},
+                            {"from": 7.0, "to": 20.0}
+                        ]
+                    }
+                }
+            }
+        }
+    }))
+    .unwrap();
+    let res = crate::aggregation::tests::exec_request(agg_child_more, &index)?;
+
+    assert_eq!(
+        res["parent_terms"],
+        json!({
+            "buckets": [
+                {
+                    "key": "cool",
+                    "doc_count": 7,
+                    "child_range": {
+                        "buckets": [
+                            {"key": "*-3", "doc_count": 1, "to": 3.0},
+                            {"key": "3-7", "doc_count": 2, "from": 3.0, "to": 7.0},
+                            {"key": "7-20", "doc_count": 3, "from": 7.0, "to": 20.0},
+                            {"key": "20-*", "doc_count": 1, "from": 20.0}
+                        ]
+                    }
+                },
+                {
+                    "key": "nohit",
+                    "doc_count": 2,
+                    "child_range": {
+                        "buckets": [
+                            {"key": "*-3", "doc_count": 0, "to": 3.0},
+                            {"key": "3-7", "doc_count": 1, "from": 3.0, "to": 7.0},
+                            {"key": "7-20", "doc_count": 0, "from": 7.0, "to": 20.0},
+                            {"key": "20-*", "doc_count": 1, "from": 20.0}
+                        ]
+                    }
+                }
+            ],
+            "doc_count_error_upper_bound": 0,
+            "sum_other_doc_count": 0
+        })
+    );
+
+    Ok(())
+}
+
+#[test]
+fn test_histogram_as_subagg_parent_more_vs_child_more() -> crate::Result<()> {
+    let index = get_test_index_2_segments(false)?;
+
+    // Case A: parent has more buckets than child
+    // Parent: range with several ranges
+    // Child: histogram with large interval (single bucket per parent)
+    let agg_parent_more: Aggregations = serde_json::from_value(json!({
+        "parent_range": {
+            "range": {
+                "field": "score",
+                "ranges": [
+                    {"to": 3.0},
+                    {"from": 3.0, "to": 7.0},
+                    {"from": 7.0, "to": 11.0},
+                    {"from": 11.0, "to": 20.0},
+                    {"from": 20.0}
+                ]
+            },
+            "aggs": {
+                "child_hist": {"histogram": {"field": "score", "interval": 100.0}}
+            }
+        }
+    }))
+    .unwrap();
+    let res = crate::aggregation::tests::exec_request(agg_parent_more, &index)?;
+    assert_eq!(
+        res["parent_range"]["buckets"],
+        json!([
+            {"key": "*-3", "doc_count": 1, "to": 3.0,
+                "child_hist": {"buckets": [ {"key": 0.0, "doc_count": 1} ]}
+            },
+            {"key": "3-7", "doc_count": 3, "from": 3.0, "to": 7.0,
+                "child_hist": {"buckets": [ {"key": 0.0, "doc_count": 3} ]}
+            },
+            {"key": "7-11", "doc_count": 1, "from": 7.0, "to": 11.0,
+                "child_hist": {"buckets": [ {"key": 0.0, "doc_count": 1} ]}
+            },
+            {"key": "11-20", "doc_count": 2, "from": 11.0, "to": 20.0,
+                "child_hist": {"buckets": [ {"key": 0.0, "doc_count": 2} ]}
+            },
+            {"key": "20-*", "doc_count": 2, "from": 20.0,
+                "child_hist": {"buckets": [ {"key": 0.0, "doc_count": 2} ]}
+            }
+        ])
+    );
+
+    // Case B: child has more buckets than parent
+    // Parent: terms on text -> 2 buckets
+    // Child: histogram with small interval -> multiple buckets including empties
+    let agg_child_more: Aggregations = serde_json::from_value(json!({
+        "parent_terms": {
+            "terms": {"field": "text"},
+            "aggs": {
+                "child_hist": {"histogram": {"field": "score", "interval": 10.0}}
+            }
+        }
+    }))
+    .unwrap();
+    let res = crate::aggregation::tests::exec_request(agg_child_more, &index)?;
+    assert_eq!(
+        res["parent_terms"],
+        json!({
+            "buckets": [
+                {
+                    "key": "cool",
+                    "doc_count": 7,
+                    "child_hist": {
+                        "buckets": [
+                            {"key": 0.0, "doc_count": 4},
+                            {"key": 10.0, "doc_count": 2},
+                            {"key": 20.0, "doc_count": 0},
+                            {"key": 30.0, "doc_count": 0},
+                            {"key": 40.0, "doc_count": 1}
+                        ]
+                    }
+                },
+                {
+                    "key": "nohit",
+                    "doc_count": 2,
+                    "child_hist": {
+                        "buckets": [
+                            {"key": 0.0, "doc_count": 1},
+                            {"key": 10.0, "doc_count": 0},
+                            {"key": 20.0, "doc_count": 0},
+                            {"key": 30.0, "doc_count": 0},
+                            {"key": 40.0, "doc_count": 1}
+                        ]
+                    }
+                }
+            ],
+            "doc_count_error_upper_bound": 0,
+            "sum_other_doc_count": 0
+        })
+    );
+
+    Ok(())
+}
+
+#[test]
+fn test_date_histogram_as_subagg_parent_more_vs_child_more() -> crate::Result<()> {
+    let index = get_test_index_2_segments(false)?;
+
+    // Case A: parent has more buckets than child
+    // Parent: range with several buckets
+    // Child: date_histogram with 30d -> single bucket per parent
+    let agg_parent_more: Aggregations = serde_json::from_value(json!({
+        "parent_range": {
+            "range": {
+                "field": "score",
+                "ranges": [
+                    {"to": 3.0},
+                    {"from": 3.0, "to": 7.0},
+                    {"from": 7.0, "to": 11.0},
+                    {"from": 11.0, "to": 20.0},
+                    {"from": 20.0}
+                ]
+            },
+            "aggs": {
+                "child_date_hist": {"date_histogram": {"field": "date", "fixed_interval": "30d"}}
+            }
+        }
+    }))
+    .unwrap();
+    let res = crate::aggregation::tests::exec_request(agg_parent_more, &index)?;
+    let buckets = res["parent_range"]["buckets"].as_array().unwrap();
+    // Verify each parent bucket has exactly one child date bucket with matching doc_count
+    for bucket in buckets {
+        let parent_count = bucket["doc_count"].as_u64().unwrap();
+        let child_buckets = bucket["child_date_hist"]["buckets"].as_array().unwrap();
+        assert_eq!(child_buckets.len(), 1);
+        assert_eq!(child_buckets[0]["doc_count"], parent_count);
+    }
+
+    // Case B: child has more buckets than parent
+    // Parent: terms on text (2 buckets)
+    // Child: date_histogram with 1d -> multiple buckets
+    let agg_child_more: Aggregations = serde_json::from_value(json!({
+        "parent_terms": {
+            "terms": {"field": "text"},
+            "aggs": {
+                "child_date_hist": {"date_histogram": {"field": "date", "fixed_interval": "1d"}}
+            }
+        }
+    }))
+    .unwrap();
+    let res = crate::aggregation::tests::exec_request(agg_child_more, &index)?;
+    let buckets = res["parent_terms"]["buckets"].as_array().unwrap();
+
+    // cool bucket
+    assert_eq!(buckets[0]["key"], "cool");
+    let cool_buckets = buckets[0]["child_date_hist"]["buckets"].as_array().unwrap();
+    assert_eq!(cool_buckets.len(), 3);
+    assert_eq!(cool_buckets[0]["doc_count"], 1); // day 0
+    assert_eq!(cool_buckets[1]["doc_count"], 4); // day 1
+    assert_eq!(cool_buckets[2]["doc_count"], 2); // day 2
+
+    // nohit bucket
+    assert_eq!(buckets[1]["key"], "nohit");
+    let nohit_buckets = buckets[1]["child_date_hist"]["buckets"].as_array().unwrap();
+    assert_eq!(nohit_buckets.len(), 2);
+    assert_eq!(nohit_buckets[0]["doc_count"], 1); // day 1
+    assert_eq!(nohit_buckets[1]["doc_count"], 1); // day 2
+
+    Ok(())
+}
+
 fn get_avg_req(field_name: &str) -> Aggregation {
     serde_json::from_value(json!({
         "avg": {
@@ -25,6 +451,10 @@ fn get_collector(agg_req: Aggregations) -> AggregationCollector {
 }
 
 // *** EVERY BUCKET-TYPE SHOULD BE TESTED HERE ***
+// Note: The flushng part of these  tests are outdated, since the buffering change after converting
+// the collection into one collector per request instead of per bucket.
+//
+// However they are useful as they test a complex aggregation requests.
 fn test_aggregation_flushing(
     merge_segments: bool,
     use_distributed_collector: bool,
@@ -37,8 +467,9 @@ fn test_aggregation_flushing(
 
     let reader = index.reader()?;
 
-    assert_eq!(DOC_BLOCK_SIZE, 64);
-    // In the tree we cache Documents of DOC_BLOCK_SIZE, before passing them down as one block.
+    assert_eq!(COLLECT_BLOCK_BUFFER_LEN, 64);
+    // In the tree we cache documents of COLLECT_BLOCK_BUFFER_LEN before passing them down as one
+    // block.
     //
     // Build a request so that on the first level we have one full cache, which is then flushed.
     // The same cache should have some residue docs at the end, which are flushed (Range 0-70)

src/aggregation/bucket/filter.rs

@@ -6,10 +6,14 @@ use serde::{Deserialize, Deserializer, Serialize, Serializer};
 use crate::aggregation::agg_data::{
     build_segment_agg_collectors, AggRefNode, AggregationsSegmentCtx,
 };
+use crate::aggregation::cached_sub_aggs::{
+    CachedSubAggs, HighCardSubAggCache, LowCardSubAggCache, SubAggCache,
+};
 use crate::aggregation::intermediate_agg_result::{
     IntermediateAggregationResult, IntermediateAggregationResults, IntermediateBucketResult,
 };
-use crate::aggregation::segment_agg_result::{CollectorClone, SegmentAggregationCollector};
+use crate::aggregation::segment_agg_result::{BucketIdProvider, SegmentAggregationCollector};
+use crate::aggregation::BucketId;
 use crate::docset::DocSet;
 use crate::query::{AllQuery, EnableScoring, Query, QueryParser};
 use crate::schema::Schema;
@@ -404,15 +408,18 @@ pub struct FilterAggReqData {
     pub evaluator: DocumentQueryEvaluator,
     /// Reusable buffer for matching documents to minimize allocations during collection
     pub matching_docs_buffer: Vec<DocId>,
+    /// True if this filter aggregation is at the top level of the aggregation tree (not nested).
+    pub is_top_level: bool,
 }
 
 impl FilterAggReqData {
     pub(crate) fn get_memory_consumption(&self) -> usize {
         // Estimate: name + segment reader reference + bitset + buffer capacity
         self.name.len()
-            + std::mem::size_of::<SegmentReader>()
-            + self.evaluator.bitset.len() / 8 // BitSet memory (bits to bytes)
-            + self.matching_docs_buffer.capacity() * std::mem::size_of::<DocId>()
+        + std::mem::size_of::<SegmentReader>()
+        + self.evaluator.bitset.len() / 8 // BitSet memory (bits to bytes)
+        + self.matching_docs_buffer.capacity() * std::mem::size_of::<DocId>()
+        + std::mem::size_of::<bool>()
     }
 }
 
@@ -489,17 +496,24 @@ impl Debug for DocumentQueryEvaluator {
     }
 }
 
-/// Segment collector for filter aggregation
-pub struct SegmentFilterCollector {
-    /// Document count in this bucket
+#[derive(Debug, Clone, PartialEq, Copy)]
+struct DocCount {
     doc_count: u64,
+    bucket_id: BucketId,
+}
+
+/// Segment collector for filter aggregation
+pub struct SegmentFilterCollector<C: SubAggCache> {
+    /// Document counts per parent bucket
+    parent_buckets: Vec<DocCount>,
     /// Sub-aggregation collectors
-    sub_aggregations: Option<Box<dyn SegmentAggregationCollector>>,
+    sub_aggregations: Option<CachedSubAggs<C>>,
+    bucket_id_provider: BucketIdProvider,
     /// Accessor index for this filter aggregation (to access FilterAggReqData)
     accessor_idx: usize,
 }
 
-impl SegmentFilterCollector {
+impl<C: SubAggCache> SegmentFilterCollector<C> {
     /// Create a new filter segment collector following the new agg_data pattern
     pub(crate) fn from_req_and_validate(
         req: &mut AggregationsSegmentCtx,
@@ -511,47 +525,75 @@ impl SegmentFilterCollector {
         } else {
             None
         };
+        let sub_agg_collector = sub_agg_collector.map(CachedSubAggs::new);
 
         Ok(SegmentFilterCollector {
-            doc_count: 0,
+            parent_buckets: Vec::new(),
             sub_aggregations: sub_agg_collector,
             accessor_idx: node.idx_in_req_data,
+            bucket_id_provider: BucketIdProvider::default(),
         })
     }
 }
 
-impl Debug for SegmentFilterCollector {
+pub(crate) fn build_segment_filter_collector(
+    req: &mut AggregationsSegmentCtx,
+    node: &AggRefNode,
+) -> crate::Result<Box<dyn SegmentAggregationCollector>> {
+    let is_top_level = req.per_request.filter_req_data[node.idx_in_req_data]
+        .as_ref()
+        .expect("filter_req_data slot is empty")
+        .is_top_level;
+
+    if is_top_level {
+        Ok(Box::new(
+            SegmentFilterCollector::<LowCardSubAggCache>::from_req_and_validate(req, node)?,
+        ))
+    } else {
+        Ok(Box::new(
+            SegmentFilterCollector::<HighCardSubAggCache>::from_req_and_validate(req, node)?,
+        ))
+    }
+}
+
+impl<C: SubAggCache> Debug for SegmentFilterCollector<C> {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         f.debug_struct("SegmentFilterCollector")
-            .field("doc_count", &self.doc_count)
+            .field("buckets", &self.parent_buckets)
             .field("has_sub_aggs", &self.sub_aggregations.is_some())
             .field("accessor_idx", &self.accessor_idx)
             .finish()
     }
 }
 
-impl CollectorClone for SegmentFilterCollector {
-    fn clone_box(&self) -> Box<dyn SegmentAggregationCollector> {
-        // For now, panic - this needs proper implementation with weight recreation
-        panic!("SegmentFilterCollector cloning not yet implemented - requires weight recreation")
-    }
-}
-
-impl SegmentAggregationCollector for SegmentFilterCollector {
+impl<C: SubAggCache> SegmentAggregationCollector for SegmentFilterCollector<C> {
     fn add_intermediate_aggregation_result(
-        self: Box<Self>,
+        &mut self,
         agg_data: &AggregationsSegmentCtx,
         results: &mut IntermediateAggregationResults,
+        parent_bucket_id: BucketId,
     ) -> crate::Result<()> {
         let mut sub_results = IntermediateAggregationResults::default();
+        let bucket_opt = self.parent_buckets.get(parent_bucket_id as usize);
 
-        if let Some(sub_aggs) = self.sub_aggregations {
-            sub_aggs.add_intermediate_aggregation_result(agg_data, &mut sub_results)?;
+        if let Some(sub_aggs) = &mut self.sub_aggregations {
+            sub_aggs
+                .get_sub_agg_collector()
+                .add_intermediate_aggregation_result(
+                    agg_data,
+                    &mut sub_results,
+                    // Here we create a new bucket ID for sub-aggregations if the bucket doesn't
+                    // exist, so that sub-aggregations can still produce results (e.g., zero doc
+                    // count)
+                    bucket_opt
+                        .map(|bucket| bucket.bucket_id)
+                        .unwrap_or(self.bucket_id_provider.next_bucket_id()),
+                )?;
         }
 
         // Create the filter bucket result
         let filter_bucket_result = IntermediateBucketResult::Filter {
-            doc_count: self.doc_count,
+            doc_count: bucket_opt.map(|b| b.doc_count).unwrap_or(0),
             sub_aggregations: sub_results,
         };
 
@@ -570,32 +612,17 @@ impl SegmentAggregationCollector for SegmentFilterCollector {
         Ok(())
     }
 
-    fn collect(&mut self, doc: DocId, agg_data: &mut AggregationsSegmentCtx) -> crate::Result<()> {
-        // Access the evaluator from FilterAggReqData
-        let req_data = agg_data.get_filter_req_data(self.accessor_idx);
-
-        // O(1) BitSet lookup to check if document matches filter
-        if req_data.evaluator.matches_document(doc) {
-            self.doc_count += 1;
-
-            // If we have sub-aggregations, collect on them for this filtered document
-            if let Some(sub_aggs) = &mut self.sub_aggregations {
-                sub_aggs.collect(doc, agg_data)?;
-            }
-        }
-        Ok(())
-    }
-
-    #[inline]
-    fn collect_block(
+    fn collect(
         &mut self,
-        docs: &[DocId],
+        parent_bucket_id: BucketId,
+        docs: &[crate::DocId],
         agg_data: &mut AggregationsSegmentCtx,
     ) -> crate::Result<()> {
         if docs.is_empty() {
             return Ok(());
         }
 
+        let mut bucket = self.parent_buckets[parent_bucket_id as usize];
         // Take the request data to avoid borrow checker issues with sub-aggregations
         let mut req = agg_data.take_filter_req_data(self.accessor_idx);
 
@@ -604,18 +631,24 @@ impl SegmentAggregationCollector for SegmentFilterCollector {
         req.evaluator
             .filter_batch(docs, &mut req.matching_docs_buffer);
 
-        self.doc_count += req.matching_docs_buffer.len() as u64;
+        bucket.doc_count += req.matching_docs_buffer.len() as u64;
 
         // Batch process sub-aggregations if we have matches
         if !req.matching_docs_buffer.is_empty() {
             if let Some(sub_aggs) = &mut self.sub_aggregations {
-                // Use collect_block for better sub-aggregation performance
-                sub_aggs.collect_block(&req.matching_docs_buffer, agg_data)?;
+                for &doc_id in &req.matching_docs_buffer {
+                    sub_aggs.push(bucket.bucket_id, doc_id);
+                }
             }
         }
 
         // Put the request data back
         agg_data.put_back_filter_req_data(self.accessor_idx, req);
+        if let Some(sub_aggs) = &mut self.sub_aggregations {
+            sub_aggs.check_flush_local(agg_data)?;
+        }
+        // put back bucket
+        self.parent_buckets[parent_bucket_id as usize] = bucket;
 
         Ok(())
     }
@@ -626,6 +659,21 @@ impl SegmentAggregationCollector for SegmentFilterCollector {
         }
         Ok(())
     }
+
+    fn prepare_max_bucket(
+        &mut self,
+        max_bucket: BucketId,
+        _agg_data: &AggregationsSegmentCtx,
+    ) -> crate::Result<()> {
+        while self.parent_buckets.len() <= max_bucket as usize {
+            let bucket_id = self.bucket_id_provider.next_bucket_id();
+            self.parent_buckets.push(DocCount {
+                doc_count: 0,
+                bucket_id,
+            });
+        }
+        Ok(())
+    }
 }
 
 /// Intermediate result for filter aggregation
@@ -1519,9 +1567,9 @@ mod tests {
         let searcher = reader.searcher();
 
         let agg = json!({
-            "test": {
-                "filter": deserialized,
-                "aggs": { "count": { "value_count": { "field": "brand" } } }
+                "test": {
+                    "filter": deserialized,
+                    "aggs": { "count": { "value_count": { "field": "brand" } } }
             }
         });
 

src/aggregation/bucket/histogram/histogram.rs

@@ -1,6 +1,6 @@
 use std::cmp::Ordering;
 
-use columnar::{Column, ColumnBlockAccessor, ColumnType};
+use columnar::{Column, ColumnType};
 use rustc_hash::FxHashMap;
 use serde::{Deserialize, Serialize};
 use tantivy_bitpacker::minmax;
@@ -8,14 +8,14 @@ use tantivy_bitpacker::minmax;
 use crate::aggregation::agg_data::{
     build_segment_agg_collectors, AggRefNode, AggregationsSegmentCtx,
 };
-use crate::aggregation::agg_limits::MemoryConsumption;
 use crate::aggregation::agg_req::Aggregations;
 use crate::aggregation::agg_result::BucketEntry;
+use crate::aggregation::cached_sub_aggs::{CachedSubAggs, HighCardCachedSubAggs};
 use crate::aggregation::intermediate_agg_result::{
     IntermediateAggregationResult, IntermediateAggregationResults, IntermediateBucketResult,
     IntermediateHistogramBucketEntry,
 };
-use crate::aggregation::segment_agg_result::SegmentAggregationCollector;
+use crate::aggregation::segment_agg_result::{BucketIdProvider, SegmentAggregationCollector};
 use crate::aggregation::*;
 use crate::TantivyError;
 
@@ -26,13 +26,8 @@ pub struct HistogramAggReqData {
     pub accessor: Column<u64>,
     /// The field type of the fast field.
     pub field_type: ColumnType,
-    /// The column block accessor to access the fast field values.
-    pub column_block_accessor: ColumnBlockAccessor<u64>,
     /// The name of the aggregation.
     pub name: String,
-    /// The sub aggregation blueprint, used to create sub aggregations for each bucket.
-    /// Will be filled during initialization of the collector.
-    pub sub_aggregation_blueprint: Option<Box<dyn SegmentAggregationCollector>>,
     /// The histogram aggregation request.
     pub req: HistogramAggregation,
     /// True if this is a date_histogram aggregation.
@@ -257,18 +252,24 @@ impl HistogramBounds {
 pub(crate) struct SegmentHistogramBucketEntry {
     pub key: f64,
     pub doc_count: u64,
+    pub bucket_id: BucketId,
 }
 
 impl SegmentHistogramBucketEntry {
     pub(crate) fn into_intermediate_bucket_entry(
         self,
-        sub_aggregation: Option<Box<dyn SegmentAggregationCollector>>,
+        sub_aggregation: &mut Option<HighCardCachedSubAggs>,
         agg_data: &AggregationsSegmentCtx,
     ) -> crate::Result<IntermediateHistogramBucketEntry> {
         let mut sub_aggregation_res = IntermediateAggregationResults::default();
         if let Some(sub_aggregation) = sub_aggregation {
             sub_aggregation
-                .add_intermediate_aggregation_result(agg_data, &mut sub_aggregation_res)?;
+                .get_sub_agg_collector()
+                .add_intermediate_aggregation_result(
+                    agg_data,
+                    &mut sub_aggregation_res,
+                    self.bucket_id,
+                )?;
         }
         Ok(IntermediateHistogramBucketEntry {
             key: self.key,
@@ -278,27 +279,38 @@ impl SegmentHistogramBucketEntry {
     }
 }
 
+#[derive(Clone, Debug, Default)]
+struct HistogramBuckets {
+    pub buckets: FxHashMap<i64, SegmentHistogramBucketEntry>,
+}
+
 /// The collector puts values from the fast field into the correct buckets and does a conversion to
 /// the correct datatype.
-#[derive(Clone, Debug)]
+#[derive(Debug)]
 pub struct SegmentHistogramCollector {
     /// The buckets containing the aggregation data.
-    buckets: FxHashMap<i64, SegmentHistogramBucketEntry>,
-    sub_aggregations: FxHashMap<i64, Box<dyn SegmentAggregationCollector>>,
+    /// One Histogram bucket per parent bucket id.
+    parent_buckets: Vec<HistogramBuckets>,
+    sub_agg: Option<HighCardCachedSubAggs>,
     accessor_idx: usize,
+    bucket_id_provider: BucketIdProvider,
 }
 
 impl SegmentAggregationCollector for SegmentHistogramCollector {
     fn add_intermediate_aggregation_result(
-        self: Box<Self>,
+        &mut self,
         agg_data: &AggregationsSegmentCtx,
         results: &mut IntermediateAggregationResults,
+        parent_bucket_id: BucketId,
     ) -> crate::Result<()> {
         let name = agg_data
             .get_histogram_req_data(self.accessor_idx)
             .name
             .clone();
-        let bucket = self.into_intermediate_bucket_result(agg_data)?;
+        // TODO: avoid prepare_max_bucket here and handle empty buckets.
+        self.prepare_max_bucket(parent_bucket_id, agg_data)?;
+        let histogram = std::mem::take(&mut self.parent_buckets[parent_bucket_id as usize]);
+        let bucket = self.add_intermediate_bucket_result(agg_data, histogram)?;
         results.push(name, IntermediateAggregationResult::Bucket(bucket))?;
 
         Ok(())
@@ -307,44 +319,40 @@ impl SegmentAggregationCollector for SegmentHistogramCollector {
     #[inline]
     fn collect(
         &mut self,
-        doc: crate::DocId,
-        agg_data: &mut AggregationsSegmentCtx,
-    ) -> crate::Result<()> {
-        self.collect_block(&[doc], agg_data)
-    }
-
-    #[inline]
-    fn collect_block(
-        &mut self,
+        parent_bucket_id: BucketId,
         docs: &[crate::DocId],
         agg_data: &mut AggregationsSegmentCtx,
     ) -> crate::Result<()> {
-        let mut req = agg_data.take_histogram_req_data(self.accessor_idx);
+        let req = agg_data.take_histogram_req_data(self.accessor_idx);
         let mem_pre = self.get_memory_consumption();
+        let buckets = &mut self.parent_buckets[parent_bucket_id as usize].buckets;
 
         let bounds = req.bounds;
         let interval = req.req.interval;
         let offset = req.offset;
         let get_bucket_pos = |val| get_bucket_pos_f64(val, interval, offset) as i64;
 
-        req.column_block_accessor.fetch_block(docs, &req.accessor);
-        for (doc, val) in req
+        agg_data
+            .column_block_accessor
+            .fetch_block(docs, &req.accessor);
+        for (doc, val) in agg_data
             .column_block_accessor
             .iter_docid_vals(docs, &req.accessor)
         {
-            let val = f64_from_fastfield_u64(val, &req.field_type);
+            let val = f64_from_fastfield_u64(val, req.field_type);
             let bucket_pos = get_bucket_pos(val);
             if bounds.contains(val) {
-                let bucket = self.buckets.entry(bucket_pos).or_insert_with(|| {
+                let bucket = buckets.entry(bucket_pos).or_insert_with(|| {
                     let key = get_bucket_key_from_pos(bucket_pos as f64, interval, offset);
-                    SegmentHistogramBucketEntry { key, doc_count: 0 }
+                    SegmentHistogramBucketEntry {
+                        key,
+                        doc_count: 0,
+                        bucket_id: self.bucket_id_provider.next_bucket_id(),
+                    }
                 });
                 bucket.doc_count += 1;
-                if let Some(sub_aggregation_blueprint) = req.sub_aggregation_blueprint.as_ref() {
-                    self.sub_aggregations
-                        .entry(bucket_pos)
-                        .or_insert_with(|| sub_aggregation_blueprint.clone())
-                        .collect(doc, agg_data)?;
+                if let Some(sub_agg) = &mut self.sub_agg {
+                    sub_agg.push(bucket.bucket_id, doc);
                 }
             }
         }
@@ -358,14 +366,30 @@ impl SegmentAggregationCollector for SegmentHistogramCollector {
                 .add_memory_consumed(mem_delta as u64)?;
         }
 
+        if let Some(sub_agg) = &mut self.sub_agg {
+            sub_agg.check_flush_local(agg_data)?;
+        }
+
         Ok(())
     }
 
     fn flush(&mut self, agg_data: &mut AggregationsSegmentCtx) -> crate::Result<()> {
-        for sub_aggregation in self.sub_aggregations.values_mut() {
+        if let Some(sub_aggregation) = &mut self.sub_agg {
             sub_aggregation.flush(agg_data)?;
         }
+        Ok(())
+    }
 
+    fn prepare_max_bucket(
+        &mut self,
+        max_bucket: BucketId,
+        _agg_data: &AggregationsSegmentCtx,
+    ) -> crate::Result<()> {
+        while self.parent_buckets.len() <= max_bucket as usize {
+            self.parent_buckets.push(HistogramBuckets {
+                buckets: FxHashMap::default(),
+            });
+        }
         Ok(())
     }
 }
@@ -373,22 +397,19 @@ impl SegmentAggregationCollector for SegmentHistogramCollector {
 impl SegmentHistogramCollector {
     fn get_memory_consumption(&self) -> usize {
         let self_mem = std::mem::size_of::<Self>();
-        let sub_aggs_mem = self.sub_aggregations.memory_consumption();
-        let buckets_mem = self.buckets.memory_consumption();
-        self_mem + sub_aggs_mem + buckets_mem
+        let buckets_mem = self.parent_buckets.len() * std::mem::size_of::<HistogramBuckets>();
+        self_mem + buckets_mem
     }
     /// Converts the collector result into a intermediate bucket result.
-    pub fn into_intermediate_bucket_result(
-        self,
+    fn add_intermediate_bucket_result(
+        &mut self,
         agg_data: &AggregationsSegmentCtx,
+        histogram: HistogramBuckets,
     ) -> crate::Result<IntermediateBucketResult> {
-        let mut buckets = Vec::with_capacity(self.buckets.len());
+        let mut buckets = Vec::with_capacity(histogram.buckets.len());
 
-        for (bucket_pos, bucket) in self.buckets {
-            let bucket_res = bucket.into_intermediate_bucket_entry(
-                self.sub_aggregations.get(&bucket_pos).cloned(),
-                agg_data,
-            );
+        for bucket in histogram.buckets.into_values() {
+            let bucket_res = bucket.into_intermediate_bucket_entry(&mut self.sub_agg, agg_data);
 
             buckets.push(bucket_res?);
         }
@@ -408,7 +429,7 @@ impl SegmentHistogramCollector {
         agg_data: &mut AggregationsSegmentCtx,
         node: &AggRefNode,
     ) -> crate::Result<Self> {
-        let blueprint = if !node.children.is_empty() {
+        let sub_agg = if !node.children.is_empty() {
             Some(build_segment_agg_collectors(agg_data, &node.children)?)
         } else {
             None
@@ -423,13 +444,13 @@ impl SegmentHistogramCollector {
             max: f64::MAX,
         });
         req_data.offset = req_data.req.offset.unwrap_or(0.0);
-
-        req_data.sub_aggregation_blueprint = blueprint;
+        let sub_agg = sub_agg.map(CachedSubAggs::new);
 
         Ok(Self {
-            buckets: Default::default(),
-            sub_aggregations: Default::default(),
+            parent_buckets: Default::default(),
+            sub_agg,
             accessor_idx: node.idx_in_req_data,
+            bucket_id_provider: BucketIdProvider::default(),
         })
     }
 }

src/aggregation/bucket/range.rs

@@ -1,18 +1,22 @@
 use std::fmt::Debug;
 use std::ops::Range;
 
-use columnar::{Column, ColumnBlockAccessor, ColumnType};
+use columnar::{Column, ColumnType};
 use rustc_hash::FxHashMap;
 use serde::{Deserialize, Serialize};
 
 use crate::aggregation::agg_data::{
     build_segment_agg_collectors, AggRefNode, AggregationsSegmentCtx,
 };
+use crate::aggregation::agg_limits::AggregationLimitsGuard;
+use crate::aggregation::cached_sub_aggs::{
+    CachedSubAggs, HighCardSubAggCache, LowCardCachedSubAggs, LowCardSubAggCache, SubAggCache,
+};
 use crate::aggregation::intermediate_agg_result::{
     IntermediateAggregationResult, IntermediateAggregationResults, IntermediateBucketResult,
     IntermediateRangeBucketEntry, IntermediateRangeBucketResult,
 };
-use crate::aggregation::segment_agg_result::SegmentAggregationCollector;
+use crate::aggregation::segment_agg_result::{BucketIdProvider, SegmentAggregationCollector};
 use crate::aggregation::*;
 use crate::TantivyError;
 
@@ -23,12 +27,12 @@ pub struct RangeAggReqData {
     pub accessor: Column<u64>,
     /// The type of the fast field.
     pub field_type: ColumnType,
-    /// The column block accessor to access the fast field values.
-    pub column_block_accessor: ColumnBlockAccessor<u64>,
     /// The range aggregation request.
     pub req: RangeAggregation,
     /// The name of the aggregation.
     pub name: String,
+    /// Whether this is a top-level aggregation.
+    pub is_top_level: bool,
 }
 
 impl RangeAggReqData {
@@ -151,19 +155,47 @@ pub(crate) struct SegmentRangeAndBucketEntry {
 
 /// The collector puts values from the fast field into the correct buckets and does a conversion to
 /// the correct datatype.
-#[derive(Clone, Debug)]
-pub struct SegmentRangeCollector {
+pub struct SegmentRangeCollector<C: SubAggCache> {
     /// The buckets containing the aggregation data.
-    buckets: Vec<SegmentRangeAndBucketEntry>,
+    /// One for each ParentBucketId
+    parent_buckets: Vec<Vec<SegmentRangeAndBucketEntry>>,
     column_type: ColumnType,
     pub(crate) accessor_idx: usize,
+    sub_agg: Option<CachedSubAggs<C>>,
+    /// Here things get a bit weird. We need to assign unique bucket ids across all
+    /// parent buckets. So we keep track of the next available bucket id here.
+    /// This allows a kind of flattening of the bucket ids across all parent buckets.
+    /// E.g. in nested aggregations:
+    /// Term Agg -> Range aggregation -> Stats aggregation
+    /// E.g. the Term Agg creates 3 buckets ["INFO", "ERROR", "WARN"], each of these has a Range
+    /// aggregation with 4 buckets. The Range aggregation will create buckets with ids:
+    /// - INFO: 0,1,2,3
+    /// - ERROR: 4,5,6,7
+    /// - WARN: 8,9,10,11
+    ///
+    /// This allows the Stats aggregation to have unique bucket ids to refer to.
+    bucket_id_provider: BucketIdProvider,
+    limits: AggregationLimitsGuard,
 }
 
+impl<C: SubAggCache> Debug for SegmentRangeCollector<C> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("SegmentRangeCollector")
+            .field("parent_buckets_len", &self.parent_buckets.len())
+            .field("column_type", &self.column_type)
+            .field("accessor_idx", &self.accessor_idx)
+            .field("has_sub_agg", &self.sub_agg.is_some())
+            .finish()
+    }
+}
+
+/// TODO: Bad naming, there's also SegmentRangeAndBucketEntry
 #[derive(Clone)]
 pub(crate) struct SegmentRangeBucketEntry {
     pub key: Key,
     pub doc_count: u64,
-    pub sub_aggregation: Option<Box<dyn SegmentAggregationCollector>>,
+    // pub sub_aggregation: Option<Box<dyn SegmentAggregationCollector>>,
+    pub bucket_id: BucketId,
     /// The from range of the bucket. Equals `f64::MIN` when `None`.
     pub from: Option<f64>,
     /// The to range of the bucket. Equals `f64::MAX` when `None`. Open interval, `to` is not
@@ -184,48 +216,50 @@ impl Debug for SegmentRangeBucketEntry {
 impl SegmentRangeBucketEntry {
     pub(crate) fn into_intermediate_bucket_entry(
         self,
-        agg_data: &AggregationsSegmentCtx,
     ) -> crate::Result<IntermediateRangeBucketEntry> {
-        let mut sub_aggregation_res = IntermediateAggregationResults::default();
-        if let Some(sub_aggregation) = self.sub_aggregation {
-            sub_aggregation
-                .add_intermediate_aggregation_result(agg_data, &mut sub_aggregation_res)?
-        } else {
-            Default::default()
-        };
+        let sub_aggregation = IntermediateAggregationResults::default();
 
         Ok(IntermediateRangeBucketEntry {
             key: self.key.into(),
             doc_count: self.doc_count,
-            sub_aggregation: sub_aggregation_res,
+            sub_aggregation_res: sub_aggregation,
             from: self.from,
             to: self.to,
         })
     }
 }
 
-impl SegmentAggregationCollector for SegmentRangeCollector {
+impl<C: SubAggCache> SegmentAggregationCollector for SegmentRangeCollector<C> {
     fn add_intermediate_aggregation_result(
-        self: Box<Self>,
+        &mut self,
         agg_data: &AggregationsSegmentCtx,
         results: &mut IntermediateAggregationResults,
+        parent_bucket_id: BucketId,
     ) -> crate::Result<()> {
+        self.prepare_max_bucket(parent_bucket_id, agg_data)?;
         let field_type = self.column_type;
         let name = agg_data
             .get_range_req_data(self.accessor_idx)
             .name
             .to_string();
 
-        let buckets: FxHashMap<SerializedKey, IntermediateRangeBucketEntry> = self
-            .buckets
+        let buckets = std::mem::take(&mut self.parent_buckets[parent_bucket_id as usize]);
+
+        let buckets: FxHashMap<SerializedKey, IntermediateRangeBucketEntry> = buckets
             .into_iter()
-            .map(move |range_bucket| {
-                Ok((
-                    range_to_string(&range_bucket.range, &field_type)?,
-                    range_bucket
-                        .bucket
-                        .into_intermediate_bucket_entry(agg_data)?,
-                ))
+            .map(|range_bucket| {
+                let bucket_id = range_bucket.bucket.bucket_id;
+                let mut agg = range_bucket.bucket.into_intermediate_bucket_entry()?;
+                if let Some(sub_aggregation) = &mut self.sub_agg {
+                    sub_aggregation
+                        .get_sub_agg_collector()
+                        .add_intermediate_aggregation_result(
+                            agg_data,
+                            &mut agg.sub_aggregation_res,
+                            bucket_id,
+                        )?;
+                }
+                Ok((range_to_string(&range_bucket.range, &field_type)?, agg))
             })
             .collect::<crate::Result<_>>()?;
 
@@ -242,73 +276,114 @@ impl SegmentAggregationCollector for SegmentRangeCollector {
     #[inline]
     fn collect(
         &mut self,
-        doc: crate::DocId,
-        agg_data: &mut AggregationsSegmentCtx,
-    ) -> crate::Result<()> {
-        self.collect_block(&[doc], agg_data)
-    }
-
-    #[inline]
-    fn collect_block(
-        &mut self,
+        parent_bucket_id: BucketId,
         docs: &[crate::DocId],
         agg_data: &mut AggregationsSegmentCtx,
     ) -> crate::Result<()> {
-        // Take request data to avoid borrow conflicts during sub-aggregation
-        let mut req = agg_data.take_range_req_data(self.accessor_idx);
+        let req = agg_data.take_range_req_data(self.accessor_idx);
 
-        req.column_block_accessor.fetch_block(docs, &req.accessor);
+        agg_data
+            .column_block_accessor
+            .fetch_block(docs, &req.accessor);
 
-        for (doc, val) in req
+        let buckets = &mut self.parent_buckets[parent_bucket_id as usize];
+
+        for (doc, val) in agg_data
             .column_block_accessor
             .iter_docid_vals(docs, &req.accessor)
         {
-            let bucket_pos = self.get_bucket_pos(val);
-            let bucket = &mut self.buckets[bucket_pos];
+            let bucket_pos = get_bucket_pos(val, buckets);
+            let bucket = &mut buckets[bucket_pos];
             bucket.bucket.doc_count += 1;
-            if let Some(sub_agg) = bucket.bucket.sub_aggregation.as_mut() {
-                sub_agg.collect(doc, agg_data)?;
+            if let Some(sub_agg) = self.sub_agg.as_mut() {
+                sub_agg.push(bucket.bucket.bucket_id, doc);
             }
         }
 
         agg_data.put_back_range_req_data(self.accessor_idx, req);
+        if let Some(sub_agg) = self.sub_agg.as_mut() {
+            sub_agg.check_flush_local(agg_data)?;
+        }
 
         Ok(())
     }
 
     fn flush(&mut self, agg_data: &mut AggregationsSegmentCtx) -> crate::Result<()> {
-        for bucket in self.buckets.iter_mut() {
-            if let Some(sub_agg) = bucket.bucket.sub_aggregation.as_mut() {
-                sub_agg.flush(agg_data)?;
-            }
+        if let Some(sub_agg) = self.sub_agg.as_mut() {
+            sub_agg.flush(agg_data)?;
         }
         Ok(())
     }
+
+    fn prepare_max_bucket(
+        &mut self,
+        max_bucket: BucketId,
+        agg_data: &AggregationsSegmentCtx,
+    ) -> crate::Result<()> {
+        while self.parent_buckets.len() <= max_bucket as usize {
+            let new_buckets = self.create_new_buckets(agg_data)?;
+            self.parent_buckets.push(new_buckets);
+        }
+
+        Ok(())
+    }
+}
+/// Build a concrete `SegmentRangeCollector` with either a Vec- or HashMap-backed
+/// bucket storage, depending on the column type and aggregation level.
+pub(crate) fn build_segment_range_collector(
+    agg_data: &mut AggregationsSegmentCtx,
+    node: &AggRefNode,
+) -> crate::Result<Box<dyn SegmentAggregationCollector>> {
+    let accessor_idx = node.idx_in_req_data;
+    let req_data = agg_data.get_range_req_data(node.idx_in_req_data);
+    let field_type = req_data.field_type;
+
+    // TODO: A better metric instead of is_top_level would be the number of buckets expected.
+    // E.g. If range agg is not top level, but the parent is a bucket agg with less than 10 buckets,
+    // we can are still in low cardinality territory.
+    let is_low_card = req_data.is_top_level && req_data.req.ranges.len() <= 64;
+
+    let sub_agg = if !node.children.is_empty() {
+        Some(build_segment_agg_collectors(agg_data, &node.children)?)
+    } else {
+        None
+    };
+
+    if is_low_card {
+        Ok(Box::new(SegmentRangeCollector::<LowCardSubAggCache> {
+            sub_agg: sub_agg.map(LowCardCachedSubAggs::new),
+            column_type: field_type,
+            accessor_idx,
+            parent_buckets: Vec::new(),
+            bucket_id_provider: BucketIdProvider::default(),
+            limits: agg_data.context.limits.clone(),
+        }))
+    } else {
+        Ok(Box::new(SegmentRangeCollector::<HighCardSubAggCache> {
+            sub_agg: sub_agg.map(CachedSubAggs::new),
+            column_type: field_type,
+            accessor_idx,
+            parent_buckets: Vec::new(),
+            bucket_id_provider: BucketIdProvider::default(),
+            limits: agg_data.context.limits.clone(),
+        }))
+    }
 }
 
-impl SegmentRangeCollector {
-    pub(crate) fn from_req_and_validate(
-        req_data: &mut AggregationsSegmentCtx,
-        node: &AggRefNode,
-    ) -> crate::Result<Self> {
-        let accessor_idx = node.idx_in_req_data;
-        let (field_type, ranges) = {
-            let req_view = req_data.get_range_req_data(node.idx_in_req_data);
-            (req_view.field_type, req_view.req.ranges.clone())
-        };
-
+impl<C: SubAggCache> SegmentRangeCollector<C> {
+    pub(crate) fn create_new_buckets(
+        &mut self,
+        agg_data: &AggregationsSegmentCtx,
+    ) -> crate::Result<Vec<SegmentRangeAndBucketEntry>> {
+        let field_type = self.column_type;
+        let req_data = agg_data.get_range_req_data(self.accessor_idx);
         // The range input on the request is f64.
         // We need to convert to u64 ranges, because we read the values as u64.
         // The mapping from the conversion is monotonic so ordering is preserved.
-        let sub_agg_prototype = if !node.children.is_empty() {
-            Some(build_segment_agg_collectors(req_data, &node.children)?)
-        } else {
-            None
-        };
-
-        let buckets: Vec<_> = extend_validate_ranges(&ranges, &field_type)?
+        let buckets: Vec<_> = extend_validate_ranges(&req_data.req.ranges, &field_type)?
             .iter()
             .map(|range| {
+                let bucket_id = self.bucket_id_provider.next_bucket_id();
                 let key = range
                     .key
                     .clone()
@@ -317,20 +392,20 @@ impl SegmentRangeCollector {
                 let to = if range.range.end == u64::MAX {
                     None
                 } else {
-                    Some(f64_from_fastfield_u64(range.range.end, &field_type))
+                    Some(f64_from_fastfield_u64(range.range.end, field_type))
                 };
                 let from = if range.range.start == u64::MIN {
                     None
                 } else {
-                    Some(f64_from_fastfield_u64(range.range.start, &field_type))
+                    Some(f64_from_fastfield_u64(range.range.start, field_type))
                 };
-                let sub_aggregation = sub_agg_prototype.clone();
+                // let sub_aggregation = sub_agg_prototype.clone();
 
                 Ok(SegmentRangeAndBucketEntry {
                     range: range.range.clone(),
                     bucket: SegmentRangeBucketEntry {
                         doc_count: 0,
-                        sub_aggregation,
+                        bucket_id,
                         key,
                         from,
                         to,
@@ -339,27 +414,20 @@ impl SegmentRangeCollector {
             })
             .collect::<crate::Result<_>>()?;
 
-        req_data.context.limits.add_memory_consumed(
+        self.limits.add_memory_consumed(
             buckets.len() as u64 * std::mem::size_of::<SegmentRangeAndBucketEntry>() as u64,
         )?;
-
-        Ok(SegmentRangeCollector {
-            buckets,
-            column_type: field_type,
-            accessor_idx,
-        })
-    }
-
-    #[inline]
-    fn get_bucket_pos(&self, val: u64) -> usize {
-        let pos = self
-            .buckets
-            .binary_search_by_key(&val, |probe| probe.range.start)
-            .unwrap_or_else(|pos| pos - 1);
-        debug_assert!(self.buckets[pos].range.contains(&val));
-        pos
+        Ok(buckets)
     }
 }
+#[inline]
+fn get_bucket_pos(val: u64, buckets: &[SegmentRangeAndBucketEntry]) -> usize {
+    let pos = buckets
+        .binary_search_by_key(&val, |probe| probe.range.start)
+        .unwrap_or_else(|pos| pos - 1);
+    debug_assert!(buckets[pos].range.contains(&val));
+    pos
+}
 
 /// Converts the user provided f64 range value to fast field value space.
 ///
@@ -456,7 +524,7 @@ pub(crate) fn range_to_string(
             let val = i64::from_u64(val);
             format_date(val)
         } else {
-            Ok(f64_from_fastfield_u64(val, field_type).to_string())
+            Ok(f64_from_fastfield_u64(val, *field_type).to_string())
         }
     };
 
@@ -486,7 +554,7 @@ mod tests {
     pub fn get_collector_from_ranges(
         ranges: Vec<RangeAggregationRange>,
         field_type: ColumnType,
-    ) -> SegmentRangeCollector {
+    ) -> SegmentRangeCollector<HighCardSubAggCache> {
         let req = RangeAggregation {
             field: "dummy".to_string(),
             ranges,
@@ -506,30 +574,33 @@ mod tests {
                 let to = if range.range.end == u64::MAX {
                     None
                 } else {
-                    Some(f64_from_fastfield_u64(range.range.end, &field_type))
+                    Some(f64_from_fastfield_u64(range.range.end, field_type))
                 };
                 let from = if range.range.start == u64::MIN {
                     None
                 } else {
-                    Some(f64_from_fastfield_u64(range.range.start, &field_type))
+                    Some(f64_from_fastfield_u64(range.range.start, field_type))
                 };
                 SegmentRangeAndBucketEntry {
                     range: range.range.clone(),
                     bucket: SegmentRangeBucketEntry {
                         doc_count: 0,
-                        sub_aggregation: None,
                         key,
                         from,
                         to,
+                        bucket_id: 0,
                     },
                 }
             })
             .collect();
 
         SegmentRangeCollector {
-            buckets,
+            parent_buckets: vec![buckets],
             column_type: field_type,
             accessor_idx: 0,
+            sub_agg: None,
+            bucket_id_provider: Default::default(),
+            limits: AggregationLimitsGuard::default(),
         }
     }
 
@@ -776,7 +847,7 @@ mod tests {
         let buckets = vec![(10f64..20f64).into(), (30f64..40f64).into()];
         let collector = get_collector_from_ranges(buckets, ColumnType::F64);
 
-        let buckets = collector.buckets;
+        let buckets = collector.parent_buckets[0].clone();
         assert_eq!(buckets[0].range.start, u64::MIN);
         assert_eq!(buckets[0].range.end, 10f64.to_u64());
         assert_eq!(buckets[1].range.start, 10f64.to_u64());
@@ -799,7 +870,7 @@ mod tests {
         ];
         let collector = get_collector_from_ranges(buckets, ColumnType::F64);
 
-        let buckets = collector.buckets;
+        let buckets = collector.parent_buckets[0].clone();
         assert_eq!(buckets[0].range.start, u64::MIN);
         assert_eq!(buckets[0].range.end, 10f64.to_u64());
         assert_eq!(buckets[1].range.start, 10f64.to_u64());
@@ -814,7 +885,7 @@ mod tests {
         let buckets = vec![(-10f64..-1f64).into()];
         let collector = get_collector_from_ranges(buckets, ColumnType::F64);
 
-        let buckets = collector.buckets;
+        let buckets = collector.parent_buckets[0].clone();
         assert_eq!(&buckets[0].bucket.key.to_string(), "*--10");
         assert_eq!(&buckets[buckets.len() - 1].bucket.key.to_string(), "-1-*");
     }
@@ -823,7 +894,7 @@ mod tests {
         let buckets = vec![(0f64..10f64).into()];
         let collector = get_collector_from_ranges(buckets, ColumnType::F64);
 
-        let buckets = collector.buckets;
+        let buckets = collector.parent_buckets[0].clone();
         assert_eq!(&buckets[0].bucket.key.to_string(), "*-0");
         assert_eq!(&buckets[buckets.len() - 1].bucket.key.to_string(), "10-*");
     }
@@ -832,7 +903,7 @@ mod tests {
     fn range_binary_search_test_u64() {
         let check_ranges = |ranges: Vec<RangeAggregationRange>| {
             let collector = get_collector_from_ranges(ranges, ColumnType::U64);
-            let search = |val: u64| collector.get_bucket_pos(val);
+            let search = |val: u64| get_bucket_pos(val, &collector.parent_buckets[0]);
 
             assert_eq!(search(u64::MIN), 0);
             assert_eq!(search(9), 0);
@@ -878,7 +949,7 @@ mod tests {
         let ranges = vec![(10.0..100.0).into()];
 
         let collector = get_collector_from_ranges(ranges, ColumnType::F64);
-        let search = |val: u64| collector.get_bucket_pos(val);
+        let search = |val: u64| get_bucket_pos(val, &collector.parent_buckets[0]);
 
         assert_eq!(search(u64::MIN), 0);
         assert_eq!(search(9f64.to_u64()), 0);
@@ -890,63 +961,3 @@ mod tests {
                                              // the max value
     }
 }
-
-#[cfg(all(test, feature = "unstable"))]
-mod bench {
-
-    use itertools::Itertools;
-    use rand::seq::SliceRandom;
-    use rand::thread_rng;
-
-    use super::*;
-    use crate::aggregation::bucket::range::tests::get_collector_from_ranges;
-
-    const TOTAL_DOCS: u64 = 1_000_000u64;
-    const NUM_DOCS: u64 = 50_000u64;
-
-    fn get_collector_with_buckets(num_buckets: u64, num_docs: u64) -> SegmentRangeCollector {
-        let bucket_size = num_docs / num_buckets;
-        let mut buckets: Vec<RangeAggregationRange> = vec![];
-        for i in 0..num_buckets {
-            let bucket_start = (i * bucket_size) as f64;
-            buckets.push((bucket_start..bucket_start + bucket_size as f64).into())
-        }
-
-        get_collector_from_ranges(buckets, ColumnType::U64)
-    }
-
-    fn get_rand_docs(total_docs: u64, num_docs_returned: u64) -> Vec<u64> {
-        let mut rng = thread_rng();
-
-        let all_docs = (0..total_docs - 1).collect_vec();
-        let mut vals = all_docs
-            .as_slice()
-            .choose_multiple(&mut rng, num_docs_returned as usize)
-            .cloned()
-            .collect_vec();
-        vals.sort();
-        vals
-    }
-
-    fn bench_range_binary_search(b: &mut test::Bencher, num_buckets: u64) {
-        let collector = get_collector_with_buckets(num_buckets, TOTAL_DOCS);
-        let vals = get_rand_docs(TOTAL_DOCS, NUM_DOCS);
-        b.iter(|| {
-            let mut bucket_pos = 0;
-            for val in &vals {
-                bucket_pos = collector.get_bucket_pos(*val);
-            }
-            bucket_pos
-        })
-    }
-
-    #[bench]
-    fn bench_range_100_buckets(b: &mut test::Bencher) {
-        bench_range_binary_search(b, 100)
-    }
-
-    #[bench]
-    fn bench_range_10_buckets(b: &mut test::Bencher) {
-        bench_range_binary_search(b, 10)
-    }
-}

src/aggregation/bucket/term_missing_agg.rs

@@ -5,11 +5,13 @@ use crate::aggregation::agg_data::{
     build_segment_agg_collectors, AggRefNode, AggregationsSegmentCtx,
 };
 use crate::aggregation::bucket::term_agg::TermsAggregation;
+use crate::aggregation::cached_sub_aggs::{CachedSubAggs, HighCardCachedSubAggs};
 use crate::aggregation::intermediate_agg_result::{
     IntermediateAggregationResult, IntermediateAggregationResults, IntermediateBucketResult,
     IntermediateKey, IntermediateTermBucketEntry, IntermediateTermBucketResult,
 };
-use crate::aggregation::segment_agg_result::SegmentAggregationCollector;
+use crate::aggregation::segment_agg_result::{BucketIdProvider, SegmentAggregationCollector};
+use crate::aggregation::BucketId;
 
 /// Special aggregation to handle missing values for term aggregations.
 /// This missing aggregation will check multiple columns for existence.
@@ -35,41 +37,55 @@ impl MissingTermAggReqData {
     }
 }
 
-/// The specialized missing term aggregation.
 #[derive(Default, Debug, Clone)]
-pub struct TermMissingAgg {
+struct MissingCount {
     missing_count: u32,
+    bucket_id: BucketId,
+}
+
+/// The specialized missing term aggregation.
+#[derive(Default, Debug)]
+pub struct TermMissingAgg {
     accessor_idx: usize,
-    sub_agg: Option<Box<dyn SegmentAggregationCollector>>,
+    sub_agg: Option<HighCardCachedSubAggs>,
+    /// Idx = parent bucket id, Value = missing count for that bucket
+    missing_count_per_bucket: Vec<MissingCount>,
+    bucket_id_provider: BucketIdProvider,
 }
 impl TermMissingAgg {
     pub(crate) fn new(
-        req_data: &mut AggregationsSegmentCtx,
+        agg_data: &mut AggregationsSegmentCtx,
         node: &AggRefNode,
     ) -> crate::Result<Self> {
         let has_sub_aggregations = !node.children.is_empty();
         let accessor_idx = node.idx_in_req_data;
         let sub_agg = if has_sub_aggregations {
-            let sub_aggregation = build_segment_agg_collectors(req_data, &node.children)?;
+            let sub_aggregation = build_segment_agg_collectors(agg_data, &node.children)?;
             Some(sub_aggregation)
         } else {
             None
         };
 
+        let sub_agg = sub_agg.map(CachedSubAggs::new);
+        let bucket_id_provider = BucketIdProvider::default();
+
         Ok(Self {
             accessor_idx,
             sub_agg,
-            ..Default::default()
+            missing_count_per_bucket: Vec::new(),
+            bucket_id_provider,
         })
     }
 }
 
 impl SegmentAggregationCollector for TermMissingAgg {
     fn add_intermediate_aggregation_result(
-        self: Box<Self>,
+        &mut self,
         agg_data: &AggregationsSegmentCtx,
         results: &mut IntermediateAggregationResults,
+        parent_bucket_id: BucketId,
     ) -> crate::Result<()> {
+        self.prepare_max_bucket(parent_bucket_id, agg_data)?;
         let req_data = agg_data.get_missing_term_req_data(self.accessor_idx);
         let term_agg = &req_data.req;
         let missing = term_agg
@@ -80,13 +96,16 @@ impl SegmentAggregationCollector for TermMissingAgg {
         let mut entries: FxHashMap<IntermediateKey, IntermediateTermBucketEntry> =
             Default::default();
 
+        let missing_count = &self.missing_count_per_bucket[parent_bucket_id as usize];
         let mut missing_entry = IntermediateTermBucketEntry {
-            doc_count: self.missing_count,
+            doc_count: missing_count.missing_count,
             sub_aggregation: Default::default(),
         };
-        if let Some(sub_agg) = self.sub_agg {
+        if let Some(sub_agg) = &mut self.sub_agg {
             let mut res = IntermediateAggregationResults::default();
-            sub_agg.add_intermediate_aggregation_result(agg_data, &mut res)?;
+            sub_agg
+                .get_sub_agg_collector()
+                .add_intermediate_aggregation_result(agg_data, &mut res, missing_count.bucket_id)?;
             missing_entry.sub_aggregation = res;
         }
         entries.insert(missing.into(), missing_entry);
@@ -109,30 +128,52 @@ impl SegmentAggregationCollector for TermMissingAgg {
 
     fn collect(
         &mut self,
-        doc: crate::DocId,
+        parent_bucket_id: BucketId,
+        docs: &[crate::DocId],
         agg_data: &mut AggregationsSegmentCtx,
     ) -> crate::Result<()> {
+        let bucket = &mut self.missing_count_per_bucket[parent_bucket_id as usize];
         let req_data = agg_data.get_missing_term_req_data(self.accessor_idx);
-        let has_value = req_data
-            .accessors
-            .iter()
-            .any(|(acc, _)| acc.index.has_value(doc));
-        if !has_value {
-            self.missing_count += 1;
-            if let Some(sub_agg) = self.sub_agg.as_mut() {
-                sub_agg.collect(doc, agg_data)?;
+
+        for doc in docs {
+            let doc = *doc;
+            let has_value = req_data
+                .accessors
+                .iter()
+                .any(|(acc, _)| acc.index.has_value(doc));
+            if !has_value {
+                bucket.missing_count += 1;
+
+                if let Some(sub_agg) = self.sub_agg.as_mut() {
+                    sub_agg.push(bucket.bucket_id, doc);
+                }
             }
         }
+
+        if let Some(sub_agg) = self.sub_agg.as_mut() {
+            sub_agg.check_flush_local(agg_data)?;
+        }
         Ok(())
     }
 
-    fn collect_block(
+    fn prepare_max_bucket(
         &mut self,
-        docs: &[crate::DocId],
-        agg_data: &mut AggregationsSegmentCtx,
+        max_bucket: BucketId,
+        _agg_data: &AggregationsSegmentCtx,
     ) -> crate::Result<()> {
-        for doc in docs {
-            self.collect(*doc, agg_data)?;
+        while self.missing_count_per_bucket.len() <= max_bucket as usize {
+            let bucket_id = self.bucket_id_provider.next_bucket_id();
+            self.missing_count_per_bucket.push(MissingCount {
+                missing_count: 0,
+                bucket_id,
+            });
+        }
+        Ok(())
+    }
+
+    fn flush(&mut self, agg_data: &mut AggregationsSegmentCtx) -> crate::Result<()> {
+        if let Some(sub_agg) = self.sub_agg.as_mut() {
+            sub_agg.flush(agg_data)?;
         }
         Ok(())
     }

src/aggregation/buf_collector.rs

@@ -1,87 +0,0 @@
-use super::intermediate_agg_result::IntermediateAggregationResults;
-use super::segment_agg_result::SegmentAggregationCollector;
-use crate::aggregation::agg_data::AggregationsSegmentCtx;
-use crate::DocId;
-
-#[cfg(test)]
-pub(crate) const DOC_BLOCK_SIZE: usize = 64;
-
-#[cfg(not(test))]
-pub(crate) const DOC_BLOCK_SIZE: usize = 256;
-
-pub(crate) type DocBlock = [DocId; DOC_BLOCK_SIZE];
-
-/// BufAggregationCollector buffers documents before calling collect_block().
-#[derive(Clone)]
-pub(crate) struct BufAggregationCollector {
-    pub(crate) collector: Box<dyn SegmentAggregationCollector>,
-    staged_docs: DocBlock,
-    num_staged_docs: usize,
-}
-
-impl std::fmt::Debug for BufAggregationCollector {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
-        f.debug_struct("SegmentAggregationResultsCollector")
-            .field("staged_docs", &&self.staged_docs[..self.num_staged_docs])
-            .field("num_staged_docs", &self.num_staged_docs)
-            .finish()
-    }
-}
-
-impl BufAggregationCollector {
-    pub fn new(collector: Box<dyn SegmentAggregationCollector>) -> Self {
-        Self {
-            collector,
-            num_staged_docs: 0,
-            staged_docs: [0; DOC_BLOCK_SIZE],
-        }
-    }
-}
-
-impl SegmentAggregationCollector for BufAggregationCollector {
-    #[inline]
-    fn add_intermediate_aggregation_result(
-        self: Box<Self>,
-        agg_data: &AggregationsSegmentCtx,
-        results: &mut IntermediateAggregationResults,
-    ) -> crate::Result<()> {
-        Box::new(self.collector).add_intermediate_aggregation_result(agg_data, results)
-    }
-
-    #[inline]
-    fn collect(
-        &mut self,
-        doc: crate::DocId,
-        agg_data: &mut AggregationsSegmentCtx,
-    ) -> crate::Result<()> {
-        self.staged_docs[self.num_staged_docs] = doc;
-        self.num_staged_docs += 1;
-        if self.num_staged_docs == self.staged_docs.len() {
-            self.collector
-                .collect_block(&self.staged_docs[..self.num_staged_docs], agg_data)?;
-            self.num_staged_docs = 0;
-        }
-        Ok(())
-    }
-
-    #[inline]
-    fn collect_block(
-        &mut self,
-        docs: &[crate::DocId],
-        agg_data: &mut AggregationsSegmentCtx,
-    ) -> crate::Result<()> {
-        self.collector.collect_block(docs, agg_data)?;
-        Ok(())
-    }
-
-    #[inline]
-    fn flush(&mut self, agg_data: &mut AggregationsSegmentCtx) -> crate::Result<()> {
-        self.collector
-            .collect_block(&self.staged_docs[..self.num_staged_docs], agg_data)?;
-        self.num_staged_docs = 0;
-
-        self.collector.flush(agg_data)?;
-
-        Ok(())
-    }
-}

src/aggregation/cached_sub_aggs.rs

@@ -0,0 +1,245 @@
+use std::fmt::Debug;
+
+use super::segment_agg_result::SegmentAggregationCollector;
+use crate::aggregation::agg_data::AggregationsSegmentCtx;
+use crate::aggregation::bucket::MAX_NUM_TERMS_FOR_VEC;
+use crate::aggregation::BucketId;
+use crate::DocId;
+
+/// A cache for sub-aggregations, storing doc ids per bucket id.
+/// Depending on the cardinality of the parent aggregation, we use different
+/// storage strategies.
+///
+/// ## Low Cardinality
+/// Cardinality here refers to the number of unique flattened buckets that can be created
+/// by the parent aggregation.
+/// Flattened buckets are the result of combining all buckets per collector
+/// into a single list of buckets, where each bucket is identified by its BucketId.
+///
+/// ## Usage
+/// Since this is caching for sub-aggregations, it is only used by bucket
+/// aggregations.
+///
+/// TODO: consider using a more advanced data structure for high cardinality
+/// aggregations.
+/// What this datastructure does in general is to group docs by bucket id.
+#[derive(Debug)]
+pub(crate) struct CachedSubAggs<C: SubAggCache> {
+    cache: C,
+    sub_agg_collector: Box<dyn SegmentAggregationCollector>,
+    num_docs: usize,
+}
+
+pub type LowCardCachedSubAggs = CachedSubAggs<LowCardSubAggCache>;
+pub type HighCardCachedSubAggs = CachedSubAggs<HighCardSubAggCache>;
+
+const FLUSH_THRESHOLD: usize = 2048;
+
+/// A trait for caching sub-aggregation doc ids per bucket id.
+/// Different implementations can be used depending on the cardinality
+/// of the parent aggregation.
+pub trait SubAggCache: Debug {
+    fn new() -> Self;
+    fn push(&mut self, bucket_id: BucketId, doc_id: DocId);
+    fn flush_local(
+        &mut self,
+        sub_agg: &mut Box<dyn SegmentAggregationCollector>,
+        agg_data: &mut AggregationsSegmentCtx,
+        force: bool,
+    ) -> crate::Result<()>;
+}
+
+impl<Backend: SubAggCache + Debug> CachedSubAggs<Backend> {
+    pub fn new(sub_agg: Box<dyn SegmentAggregationCollector>) -> Self {
+        Self {
+            cache: Backend::new(),
+            sub_agg_collector: sub_agg,
+            num_docs: 0,
+        }
+    }
+
+    pub fn get_sub_agg_collector(&mut self) -> &mut Box<dyn SegmentAggregationCollector> {
+        &mut self.sub_agg_collector
+    }
+
+    #[inline]
+    pub fn push(&mut self, bucket_id: BucketId, doc_id: DocId) {
+        self.cache.push(bucket_id, doc_id);
+        self.num_docs += 1;
+    }
+
+    /// Check if we need to flush based on the number of documents cached.
+    /// If so, flushes the cache to the provided aggregation collector.
+    pub fn check_flush_local(
+        &mut self,
+        agg_data: &mut AggregationsSegmentCtx,
+    ) -> crate::Result<()> {
+        if self.num_docs >= FLUSH_THRESHOLD {
+            self.cache
+                .flush_local(&mut self.sub_agg_collector, agg_data, false)?;
+            self.num_docs = 0;
+        }
+        Ok(())
+    }
+
+    /// Note: this _does_ flush the sub aggregations.
+    pub fn flush(&mut self, agg_data: &mut AggregationsSegmentCtx) -> crate::Result<()> {
+        if self.num_docs != 0 {
+            self.cache
+                .flush_local(&mut self.sub_agg_collector, agg_data, true)?;
+            self.num_docs = 0;
+        }
+        self.sub_agg_collector.flush(agg_data)?;
+        Ok(())
+    }
+}
+
+/// Number of partitions for high cardinality sub-aggregation cache.
+const NUM_PARTITIONS: usize = 16;
+
+#[derive(Debug)]
+pub(crate) struct HighCardSubAggCache {
+    /// This weird partitioning is used to do some cheap grouping on the bucket ids.
+    /// bucket ids are dense, e.g. when we don't detect the cardinality as low cardinality,
+    /// but there are just 16 bucket ids, each bucket id will go to its own partition.
+    ///
+    /// We want to keep this cheap, because high cardinality aggregations can have a lot of
+    /// buckets, and there may be nothing to group.
+    partitions: Box<[PartitionEntry; NUM_PARTITIONS]>,
+}
+
+impl HighCardSubAggCache {
+    #[inline]
+    fn clear(&mut self) {
+        for partition in self.partitions.iter_mut() {
+            partition.clear();
+        }
+    }
+}
+
+#[derive(Debug, Clone, Default)]
+struct PartitionEntry {
+    bucket_ids: Vec<BucketId>,
+    docs: Vec<DocId>,
+}
+
+impl PartitionEntry {
+    #[inline]
+    fn clear(&mut self) {
+        self.bucket_ids.clear();
+        self.docs.clear();
+    }
+}
+
+impl SubAggCache for HighCardSubAggCache {
+    fn new() -> Self {
+        Self {
+            partitions: Box::new(core::array::from_fn(|_| PartitionEntry::default())),
+        }
+    }
+
+    fn push(&mut self, bucket_id: BucketId, doc_id: DocId) {
+        let idx = bucket_id % NUM_PARTITIONS as u32;
+        let slot = &mut self.partitions[idx as usize];
+        slot.bucket_ids.push(bucket_id);
+        slot.docs.push(doc_id);
+    }
+
+    fn flush_local(
+        &mut self,
+        sub_agg: &mut Box<dyn SegmentAggregationCollector>,
+        agg_data: &mut AggregationsSegmentCtx,
+        _force: bool,
+    ) -> crate::Result<()> {
+        let mut max_bucket = 0u32;
+        for partition in self.partitions.iter() {
+            if let Some(&local_max) = partition.bucket_ids.iter().max() {
+                max_bucket = max_bucket.max(local_max);
+            }
+        }
+
+        sub_agg.prepare_max_bucket(max_bucket, agg_data)?;
+
+        for slot in self.partitions.iter() {
+            if !slot.bucket_ids.is_empty() {
+                // Reduce dynamic dispatch overhead by collecting a full partition in one call.
+                sub_agg.collect_multiple(&slot.bucket_ids, &slot.docs, agg_data)?;
+            }
+        }
+
+        self.clear();
+        Ok(())
+    }
+}
+
+#[derive(Debug)]
+pub(crate) struct LowCardSubAggCache {
+    /// Cache doc ids per bucket for sub-aggregations.
+    ///
+    /// The outer Vec is indexed by BucketId.
+    per_bucket_docs: Vec<Vec<DocId>>,
+}
+
+impl LowCardSubAggCache {
+    #[inline]
+    fn clear(&mut self) {
+        for v in &mut self.per_bucket_docs {
+            v.clear();
+        }
+    }
+}
+
+impl SubAggCache for LowCardSubAggCache {
+    fn new() -> Self {
+        Self {
+            per_bucket_docs: Vec::new(),
+        }
+    }
+
+    fn push(&mut self, bucket_id: BucketId, doc_id: DocId) {
+        let idx = bucket_id as usize;
+        if self.per_bucket_docs.len() <= idx {
+            self.per_bucket_docs.resize_with(idx + 1, Vec::new);
+        }
+        self.per_bucket_docs[idx].push(doc_id);
+    }
+
+    fn flush_local(
+        &mut self,
+        sub_agg: &mut Box<dyn SegmentAggregationCollector>,
+        agg_data: &mut AggregationsSegmentCtx,
+        force: bool,
+    ) -> crate::Result<()> {
+        // Pre-aggregated: call collect per bucket.
+        let max_bucket = (self.per_bucket_docs.len() as BucketId).saturating_sub(1);
+        sub_agg.prepare_max_bucket(max_bucket, agg_data)?;
+        // The threshold above which we flush buckets individually.
+        // Note: We need to make sure that we don't lock ourselves into a situation where we hit
+        // the FLUSH_THRESHOLD, but never flush any buckets. (except the final flush)
+        let mut bucket_treshold = FLUSH_THRESHOLD / (self.per_bucket_docs.len().max(1) * 2);
+        const _: () = {
+            // MAX_NUM_TERMS_FOR_VEC threshold is used for term aggregations
+            // Note: There may be other flexible values, for other aggregations, but we can use the
+            // const value here as a upper bound. (better than nothing)
+            let bucket_treshold_limit = FLUSH_THRESHOLD / (MAX_NUM_TERMS_FOR_VEC as usize * 2);
+            assert!(
+                bucket_treshold_limit > 0,
+                "Bucket threshold must be greater than 0"
+            );
+        };
+        if force {
+            bucket_treshold = 0;
+        }
+        for (bucket_id, docs) in self
+            .per_bucket_docs
+            .iter()
+            .enumerate()
+            .filter(|(_, docs)| docs.len() > bucket_treshold)
+        {
+            sub_agg.collect(bucket_id as BucketId, docs, agg_data)?;
+        }
+
+        self.clear();
+        Ok(())
+    }
+}

src/aggregation/collector.rs

@@ -1,9 +1,9 @@
 use super::agg_req::Aggregations;
 use super::agg_result::AggregationResults;
-use super::buf_collector::BufAggregationCollector;
+use super::cached_sub_aggs::LowCardCachedSubAggs;
 use super::intermediate_agg_result::IntermediateAggregationResults;
-use super::segment_agg_result::SegmentAggregationCollector;
 use super::AggContextParams;
+// group buffering strategy is chosen explicitly by callers; no need to hash-group on the fly.
 use crate::aggregation::agg_data::{
     build_aggregations_data_from_req, build_segment_agg_collectors_root, AggregationsSegmentCtx,
 };
@@ -136,7 +136,7 @@ fn merge_fruits(
 /// `AggregationSegmentCollector` does the aggregation collection on a segment.
 pub struct AggregationSegmentCollector {
     aggs_with_accessor: AggregationsSegmentCtx,
-    agg_collector: BufAggregationCollector,
+    agg_collector: LowCardCachedSubAggs,
     error: Option<TantivyError>,
 }
 
@@ -151,8 +151,11 @@ impl AggregationSegmentCollector {
     ) -> crate::Result<Self> {
         let mut agg_data =
             build_aggregations_data_from_req(agg, reader, segment_ordinal, context.clone())?;
-        let result =
-            BufAggregationCollector::new(build_segment_agg_collectors_root(&mut agg_data)?);
+        let mut result =
+            LowCardCachedSubAggs::new(build_segment_agg_collectors_root(&mut agg_data)?);
+        result
+            .get_sub_agg_collector()
+            .prepare_max_bucket(0, &agg_data)?; // prepare for bucket zero
 
         Ok(AggregationSegmentCollector {
             aggs_with_accessor: agg_data,
@@ -170,26 +173,31 @@ impl SegmentCollector for AggregationSegmentCollector {
         if self.error.is_some() {
             return;
         }
-        if let Err(err) = self
+        self.agg_collector.push(0, doc);
+        match self
             .agg_collector
-            .collect(doc, &mut self.aggs_with_accessor)
+            .check_flush_local(&mut self.aggs_with_accessor)
         {
-            self.error = Some(err);
+            Ok(_) => {}
+            Err(e) => {
+                self.error = Some(e);
+            }
         }
     }
-
-    /// The query pushes the documents to the collector via this method.
-    ///
-    /// Only valid for Collectors that ignore docs
     fn collect_block(&mut self, docs: &[DocId]) {
         if self.error.is_some() {
             return;
         }
-        if let Err(err) = self
-            .agg_collector
-            .collect_block(docs, &mut self.aggs_with_accessor)
-        {
-            self.error = Some(err);
+
+        match self.agg_collector.get_sub_agg_collector().collect(
+            0,
+            docs,
+            &mut self.aggs_with_accessor,
+        ) {
+            Ok(_) => {}
+            Err(e) => {
+                self.error = Some(e);
+            }
         }
     }
 
@@ -200,10 +208,13 @@ impl SegmentCollector for AggregationSegmentCollector {
         self.agg_collector.flush(&mut self.aggs_with_accessor)?;
 
         let mut sub_aggregation_res = IntermediateAggregationResults::default();
-        Box::new(self.agg_collector).add_intermediate_aggregation_result(
-            &self.aggs_with_accessor,
-            &mut sub_aggregation_res,
-        )?;
+        self.agg_collector
+            .get_sub_agg_collector()
+            .add_intermediate_aggregation_result(
+                &self.aggs_with_accessor,
+                &mut sub_aggregation_res,
+                0,
+            )?;
 
         Ok(sub_aggregation_res)
     }

src/aggregation/intermediate_agg_result.rs

@@ -792,7 +792,7 @@ pub struct IntermediateRangeBucketEntry {
     /// The number of documents in the bucket.
     pub doc_count: u64,
     /// The sub_aggregation in this bucket.
-    pub sub_aggregation: IntermediateAggregationResults,
+    pub sub_aggregation_res: IntermediateAggregationResults,
     /// The from range of the bucket. Equals `f64::MIN` when `None`.
     pub from: Option<f64>,
     /// The to range of the bucket. Equals `f64::MAX` when `None`.
@@ -811,7 +811,7 @@ impl IntermediateRangeBucketEntry {
             key: self.key.into(),
             doc_count: self.doc_count,
             sub_aggregation: self
-                .sub_aggregation
+                .sub_aggregation_res
                 .into_final_result_internal(req, limits)?,
             to: self.to,
             from: self.from,
@@ -857,7 +857,8 @@ impl MergeFruits for IntermediateTermBucketEntry {
 impl MergeFruits for IntermediateRangeBucketEntry {
     fn merge_fruits(&mut self, other: IntermediateRangeBucketEntry) -> crate::Result<()> {
         self.doc_count += other.doc_count;
-        self.sub_aggregation.merge_fruits(other.sub_aggregation)?;
+        self.sub_aggregation_res
+            .merge_fruits(other.sub_aggregation_res)?;
         Ok(())
     }
 }
@@ -887,7 +888,7 @@ mod tests {
                 IntermediateRangeBucketEntry {
                     key: IntermediateKey::Str(key.to_string()),
                     doc_count: *doc_count,
-                    sub_aggregation: Default::default(),
+                    sub_aggregation_res: Default::default(),
                     from: None,
                     to: None,
                 },
@@ -920,7 +921,7 @@ mod tests {
                     doc_count: *doc_count,
                     from: None,
                     to: None,
-                    sub_aggregation: get_sub_test_tree(&[(
+                    sub_aggregation_res: get_sub_test_tree(&[(
                         sub_aggregation_key.to_string(),
                         *sub_aggregation_count,
                     )]),

src/aggregation/metric/average.rs

@@ -52,10 +52,8 @@ pub struct IntermediateAverage {
 
 impl IntermediateAverage {
     /// Creates a new [`IntermediateAverage`] instance from a [`SegmentStatsCollector`].
-    pub(crate) fn from_collector(collector: SegmentStatsCollector) -> Self {
-        Self {
-            stats: collector.stats,
-        }
+    pub(crate) fn from_stats(stats: IntermediateStats) -> Self {
+        Self { stats }
     }
     /// Merges the other intermediate result into self.
     pub fn merge_fruits(&mut self, other: IntermediateAverage) {

src/aggregation/metric/cardinality.rs

@@ -2,7 +2,7 @@ use std::collections::hash_map::DefaultHasher;
 use std::hash::{BuildHasher, Hasher};
 
 use columnar::column_values::CompactSpaceU64Accessor;
-use columnar::{Column, ColumnBlockAccessor, ColumnType, Dictionary, StrColumn};
+use columnar::{Column, ColumnType, Dictionary, StrColumn};
 use common::f64_to_u64;
 use hyperloglogplus::{HyperLogLog, HyperLogLogPlus};
 use rustc_hash::FxHashSet;
@@ -106,8 +106,6 @@ pub struct CardinalityAggReqData {
     pub str_dict_column: Option<StrColumn>,
     /// The missing value normalized to the internal u64 representation of the field type.
     pub missing_value_for_accessor: Option<u64>,
-    /// The column block accessor to access the fast field values.
-    pub(crate) column_block_accessor: ColumnBlockAccessor<u64>,
     /// The name of the aggregation.
     pub name: String,
     /// The aggregation request.
@@ -135,45 +133,34 @@ impl CardinalityAggregationReq {
     }
 }
 
-#[derive(Clone, Debug, PartialEq)]
+#[derive(Clone, Debug)]
 pub(crate) struct SegmentCardinalityCollector {
-    cardinality: CardinalityCollector,
-    entries: FxHashSet<u64>,
+    buckets: Vec<SegmentCardinalityCollectorBucket>,
     accessor_idx: usize,
+    /// The column accessor to access the fast field values.
+    accessor: Column<u64>,
+    /// The column_type of the field.
+    column_type: ColumnType,
+    /// The missing value normalized to the internal u64 representation of the field type.
+    missing_value_for_accessor: Option<u64>,
 }
 
-impl SegmentCardinalityCollector {
-    pub fn from_req(column_type: ColumnType, accessor_idx: usize) -> Self {
+#[derive(Clone, Debug, PartialEq, Default)]
+pub(crate) struct SegmentCardinalityCollectorBucket {
+    cardinality: CardinalityCollector,
+    entries: FxHashSet<u64>,
+}
+impl SegmentCardinalityCollectorBucket {
+    pub fn new(column_type: ColumnType) -> Self {
         Self {
             cardinality: CardinalityCollector::new(column_type as u8),
-            entries: Default::default(),
-            accessor_idx,
+            entries: FxHashSet::default(),
         }
     }
-
-    fn fetch_block_with_field(
-        &mut self,
-        docs: &[crate::DocId],
-        agg_data: &mut CardinalityAggReqData,
-    ) {
-        if let Some(missing) = agg_data.missing_value_for_accessor {
-            agg_data.column_block_accessor.fetch_block_with_missing(
-                docs,
-                &agg_data.accessor,
-                missing,
-            );
-        } else {
-            agg_data
-                .column_block_accessor
-                .fetch_block(docs, &agg_data.accessor);
-        }
-    }
-
     fn into_intermediate_metric_result(
         mut self,
-        agg_data: &AggregationsSegmentCtx,
+        req_data: &CardinalityAggReqData,
     ) -> crate::Result<IntermediateMetricResult> {
-        let req_data = &agg_data.get_cardinality_req_data(self.accessor_idx);
         if req_data.column_type == ColumnType::Str {
             let fallback_dict = Dictionary::empty();
             let dict = req_data
@@ -194,6 +181,7 @@ impl SegmentCardinalityCollector {
                     term_ids.push(term_ord as u32);
                 }
             }
+
             term_ids.sort_unstable();
             dict.sorted_ords_to_term_cb(term_ids.iter().map(|term| *term as u64), |term| {
                 self.cardinality.sketch.insert_any(&term);
@@ -227,16 +215,49 @@ impl SegmentCardinalityCollector {
     }
 }
 
+impl SegmentCardinalityCollector {
+    pub fn from_req(
+        column_type: ColumnType,
+        accessor_idx: usize,
+        accessor: Column<u64>,
+        missing_value_for_accessor: Option<u64>,
+    ) -> Self {
+        Self {
+            buckets: vec![SegmentCardinalityCollectorBucket::new(column_type); 1],
+            column_type,
+            accessor_idx,
+            accessor,
+            missing_value_for_accessor,
+        }
+    }
+
+    fn fetch_block_with_field(
+        &mut self,
+        docs: &[crate::DocId],
+        agg_data: &mut AggregationsSegmentCtx,
+    ) {
+        agg_data.column_block_accessor.fetch_block_with_missing(
+            docs,
+            &self.accessor,
+            self.missing_value_for_accessor,
+        );
+    }
+}
+
 impl SegmentAggregationCollector for SegmentCardinalityCollector {
     fn add_intermediate_aggregation_result(
-        self: Box<Self>,
+        &mut self,
         agg_data: &AggregationsSegmentCtx,
         results: &mut IntermediateAggregationResults,
+        parent_bucket_id: BucketId,
     ) -> crate::Result<()> {
+        self.prepare_max_bucket(parent_bucket_id, agg_data)?;
         let req_data = &agg_data.get_cardinality_req_data(self.accessor_idx);
         let name = req_data.name.to_string();
+        // take the bucket in buckets and replace it with a new empty one
+        let bucket = std::mem::take(&mut self.buckets[parent_bucket_id as usize]);
 
-        let intermediate_result = self.into_intermediate_metric_result(agg_data)?;
+        let intermediate_result = bucket.into_intermediate_metric_result(req_data)?;
         results.push(
             name,
             IntermediateAggregationResult::Metric(intermediate_result),
@@ -247,27 +268,20 @@ impl SegmentAggregationCollector for SegmentCardinalityCollector {
 
     fn collect(
         &mut self,
-        doc: crate::DocId,
-        agg_data: &mut AggregationsSegmentCtx,
-    ) -> crate::Result<()> {
-        self.collect_block(&[doc], agg_data)
-    }
-
-    fn collect_block(
-        &mut self,
+        parent_bucket_id: BucketId,
         docs: &[crate::DocId],
         agg_data: &mut AggregationsSegmentCtx,
     ) -> crate::Result<()> {
-        let req_data = agg_data.get_cardinality_req_data_mut(self.accessor_idx);
-        self.fetch_block_with_field(docs, req_data);
+        self.fetch_block_with_field(docs, agg_data);
+        let bucket = &mut self.buckets[parent_bucket_id as usize];
 
-        let col_block_accessor = &req_data.column_block_accessor;
-        if req_data.column_type == ColumnType::Str {
+        let col_block_accessor = &agg_data.column_block_accessor;
+        if self.column_type == ColumnType::Str {
             for term_ord in col_block_accessor.iter_vals() {
-                self.entries.insert(term_ord);
+                bucket.entries.insert(term_ord);
             }
-        } else if req_data.column_type == ColumnType::IpAddr {
-            let compact_space_accessor = req_data
+        } else if self.column_type == ColumnType::IpAddr {
+            let compact_space_accessor = self
                 .accessor
                 .values
                 .clone()
@@ -282,16 +296,29 @@ impl SegmentAggregationCollector for SegmentCardinalityCollector {
                 })?;
             for val in col_block_accessor.iter_vals() {
                 let val: u128 = compact_space_accessor.compact_to_u128(val as u32);
-                self.cardinality.sketch.insert_any(&val);
+                bucket.cardinality.sketch.insert_any(&val);
             }
         } else {
             for val in col_block_accessor.iter_vals() {
-                self.cardinality.sketch.insert_any(&val);
+                bucket.cardinality.sketch.insert_any(&val);
             }
         }
 
         Ok(())
     }
+
+    fn prepare_max_bucket(
+        &mut self,
+        max_bucket: BucketId,
+        _agg_data: &AggregationsSegmentCtx,
+    ) -> crate::Result<()> {
+        if max_bucket as usize >= self.buckets.len() {
+            self.buckets.resize_with(max_bucket as usize + 1, || {
+                SegmentCardinalityCollectorBucket::new(self.column_type)
+            });
+        }
+        Ok(())
+    }
 }
 
 #[derive(Clone, Debug, Serialize, Deserialize)]

src/aggregation/metric/count.rs

@@ -52,10 +52,8 @@ pub struct IntermediateCount {
 
 impl IntermediateCount {
     /// Creates a new [`IntermediateCount`] instance from a [`SegmentStatsCollector`].
-    pub(crate) fn from_collector(collector: SegmentStatsCollector) -> Self {
-        Self {
-            stats: collector.stats,
-        }
+    pub(crate) fn from_stats(stats: IntermediateStats) -> Self {
+        Self { stats }
     }
     /// Merges the other intermediate result into self.
     pub fn merge_fruits(&mut self, other: IntermediateCount) {

src/aggregation/metric/extended_stats.rs

@@ -8,10 +8,9 @@ use crate::aggregation::agg_data::AggregationsSegmentCtx;
 use crate::aggregation::intermediate_agg_result::{
     IntermediateAggregationResult, IntermediateAggregationResults, IntermediateMetricResult,
 };
-use crate::aggregation::metric::MetricAggReqData;
 use crate::aggregation::segment_agg_result::SegmentAggregationCollector;
 use crate::aggregation::*;
-use crate::{DocId, TantivyError};
+use crate::TantivyError;
 
 /// A multi-value metric aggregation that computes a collection of extended statistics
 /// on numeric values that are extracted
@@ -318,51 +317,28 @@ impl IntermediateExtendedStats {
     }
 }
 
-#[derive(Clone, Debug, PartialEq)]
+#[derive(Clone, Debug)]
 pub(crate) struct SegmentExtendedStatsCollector {
+    name: String,
     missing: Option<u64>,
     field_type: ColumnType,
-    pub(crate) extended_stats: IntermediateExtendedStats,
-    pub(crate) accessor_idx: usize,
-    val_cache: Vec<u64>,
+    accessor: columnar::Column<u64>,
+    buckets: Vec<IntermediateExtendedStats>,
+    sigma: Option<f64>,
 }
 
 impl SegmentExtendedStatsCollector {
-    pub fn from_req(
-        field_type: ColumnType,
-        sigma: Option<f64>,
-        accessor_idx: usize,
-        missing: Option<f64>,
-    ) -> Self {
-        let missing = missing.and_then(|val| f64_to_fastfield_u64(val, &field_type));
+    pub fn from_req(req: &MetricAggReqData, sigma: Option<f64>) -> Self {
+        let missing = req
+            .missing
+            .and_then(|val| f64_to_fastfield_u64(val, &req.field_type));
         Self {
-            field_type,
-            extended_stats: IntermediateExtendedStats::with_sigma(sigma),
-            accessor_idx,
+            name: req.name.clone(),
+            field_type: req.field_type,
+            accessor: req.accessor.clone(),
             missing,
-            val_cache: Default::default(),
-        }
-    }
-    #[inline]
-    pub(crate) fn collect_block_with_field(
-        &mut self,
-        docs: &[DocId],
-        req_data: &mut MetricAggReqData,
-    ) {
-        if let Some(missing) = self.missing.as_ref() {
-            req_data.column_block_accessor.fetch_block_with_missing(
-                docs,
-                &req_data.accessor,
-                *missing,
-            );
-        } else {
-            req_data
-                .column_block_accessor
-                .fetch_block(docs, &req_data.accessor);
-        }
-        for val in req_data.column_block_accessor.iter_vals() {
-            let val1 = f64_from_fastfield_u64(val, &self.field_type);
-            self.extended_stats.collect(val1);
+            buckets: vec![IntermediateExtendedStats::with_sigma(sigma); 16],
+            sigma,
         }
     }
 }
@@ -370,15 +346,18 @@ impl SegmentExtendedStatsCollector {
 impl SegmentAggregationCollector for SegmentExtendedStatsCollector {
     #[inline]
     fn add_intermediate_aggregation_result(
-        self: Box<Self>,
+        &mut self,
         agg_data: &AggregationsSegmentCtx,
         results: &mut IntermediateAggregationResults,
+        parent_bucket_id: BucketId,
     ) -> crate::Result<()> {
-        let name = agg_data.get_metric_req_data(self.accessor_idx).name.clone();
+        let name = self.name.clone();
+        self.prepare_max_bucket(parent_bucket_id, agg_data)?;
+        let extended_stats = std::mem::take(&mut self.buckets[parent_bucket_id as usize]);
         results.push(
             name,
             IntermediateAggregationResult::Metric(IntermediateMetricResult::ExtendedStats(
-                self.extended_stats,
+                extended_stats,
             )),
         )?;
 
@@ -388,39 +367,36 @@ impl SegmentAggregationCollector for SegmentExtendedStatsCollector {
     #[inline]
     fn collect(
         &mut self,
-        doc: crate::DocId,
+        parent_bucket_id: BucketId,
+        docs: &[crate::DocId],
         agg_data: &mut AggregationsSegmentCtx,
     ) -> crate::Result<()> {
-        let req_data = agg_data.get_metric_req_data(self.accessor_idx);
-        if let Some(missing) = self.missing {
-            let mut has_val = false;
-            for val in req_data.accessor.values_for_doc(doc) {
-                let val1 = f64_from_fastfield_u64(val, &self.field_type);
-                self.extended_stats.collect(val1);
-                has_val = true;
-            }
-            if !has_val {
-                self.extended_stats
-                    .collect(f64_from_fastfield_u64(missing, &self.field_type));
-            }
-        } else {
-            for val in req_data.accessor.values_for_doc(doc) {
-                let val1 = f64_from_fastfield_u64(val, &self.field_type);
-                self.extended_stats.collect(val1);
-            }
+        let mut extended_stats = self.buckets[parent_bucket_id as usize].clone();
+
+        agg_data
+            .column_block_accessor
+            .fetch_block_with_missing(docs, &self.accessor, self.missing);
+        for val in agg_data.column_block_accessor.iter_vals() {
+            let val1 = f64_from_fastfield_u64(val, self.field_type);
+            extended_stats.collect(val1);
         }
 
+        // store back
+        self.buckets[parent_bucket_id as usize] = extended_stats;
+
         Ok(())
     }
 
-    #[inline]
-    fn collect_block(
+    fn prepare_max_bucket(
         &mut self,
-        docs: &[crate::DocId],
-        agg_data: &mut AggregationsSegmentCtx,
+        max_bucket: BucketId,
+        _agg_data: &AggregationsSegmentCtx,
     ) -> crate::Result<()> {
-        let req_data = agg_data.get_metric_req_data_mut(self.accessor_idx);
-        self.collect_block_with_field(docs, req_data);
+        if self.buckets.len() <= max_bucket as usize {
+            self.buckets.resize_with(max_bucket as usize + 1, || {
+                IntermediateExtendedStats::with_sigma(self.sigma)
+            });
+        }
         Ok(())
     }
 }

src/aggregation/metric/max.rs

@@ -52,10 +52,8 @@ pub struct IntermediateMax {
 
 impl IntermediateMax {
     /// Creates a new [`IntermediateMax`] instance from a [`SegmentStatsCollector`].
-    pub(crate) fn from_collector(collector: SegmentStatsCollector) -> Self {
-        Self {
-            stats: collector.stats,
-        }
+    pub(crate) fn from_stats(stats: IntermediateStats) -> Self {
+        Self { stats }
     }
     /// Merges the other intermediate result into self.
     pub fn merge_fruits(&mut self, other: IntermediateMax) {

src/aggregation/metric/min.rs

@@ -52,10 +52,8 @@ pub struct IntermediateMin {
 
 impl IntermediateMin {
     /// Creates a new [`IntermediateMin`] instance from a [`SegmentStatsCollector`].
-    pub(crate) fn from_collector(collector: SegmentStatsCollector) -> Self {
-        Self {
-            stats: collector.stats,
-        }
+    pub(crate) fn from_stats(stats: IntermediateStats) -> Self {
+        Self { stats }
     }
     /// Merges the other intermediate result into self.
     pub fn merge_fruits(&mut self, other: IntermediateMin) {

src/aggregation/metric/mod.rs

@@ -31,7 +31,7 @@ use std::collections::HashMap;
 
 pub use average::*;
 pub use cardinality::*;
-use columnar::{Column, ColumnBlockAccessor, ColumnType};
+use columnar::{Column, ColumnType};
 pub use count::*;
 pub use extended_stats::*;
 pub use max::*;
@@ -55,8 +55,6 @@ pub struct MetricAggReqData {
     pub field_type: ColumnType,
     /// The missing value normalized to the internal u64 representation of the field type.
     pub missing_u64: Option<u64>,
-    /// The column block accessor to access the fast field values.
-    pub column_block_accessor: ColumnBlockAccessor<u64>,
     /// The column accessor to access the fast field values.
     pub accessor: Column<u64>,
     /// Used when converting to intermediate result

src/aggregation/metric/percentiles.rs

@@ -7,10 +7,9 @@ use crate::aggregation::agg_data::AggregationsSegmentCtx;
 use crate::aggregation::intermediate_agg_result::{
     IntermediateAggregationResult, IntermediateAggregationResults, IntermediateMetricResult,
 };
-use crate::aggregation::metric::MetricAggReqData;
 use crate::aggregation::segment_agg_result::SegmentAggregationCollector;
 use crate::aggregation::*;
-use crate::{DocId, TantivyError};
+use crate::TantivyError;
 
 /// # Percentiles
 ///
@@ -131,10 +130,16 @@ impl PercentilesAggregationReq {
     }
 }
 
-#[derive(Clone, Debug, PartialEq)]
+#[derive(Clone, Debug)]
 pub(crate) struct SegmentPercentilesCollector {
-    pub(crate) percentiles: PercentilesCollector,
+    pub(crate) buckets: Vec<PercentilesCollector>,
     pub(crate) accessor_idx: usize,
+    /// The type of the field.
+    pub field_type: ColumnType,
+    /// The missing value normalized to the internal u64 representation of the field type.
+    pub missing_u64: Option<u64>,
+    /// The column accessor to access the fast field values.
+    pub accessor: Column<u64>,
 }
 
 #[derive(Clone, Serialize, Deserialize)]
@@ -229,33 +234,18 @@ impl PercentilesCollector {
 }
 
 impl SegmentPercentilesCollector {
-    pub fn from_req_and_validate(accessor_idx: usize) -> crate::Result<Self> {
-        Ok(Self {
-            percentiles: PercentilesCollector::new(),
+    pub fn from_req_and_validate(
+        field_type: ColumnType,
+        missing_u64: Option<u64>,
+        accessor: Column<u64>,
+        accessor_idx: usize,
+    ) -> Self {
+        Self {
+            buckets: Vec::with_capacity(64),
+            field_type,
+            missing_u64,
+            accessor,
             accessor_idx,
-        })
-    }
-    #[inline]
-    pub(crate) fn collect_block_with_field(
-        &mut self,
-        docs: &[DocId],
-        req_data: &mut MetricAggReqData,
-    ) {
-        if let Some(missing) = req_data.missing_u64.as_ref() {
-            req_data.column_block_accessor.fetch_block_with_missing(
-                docs,
-                &req_data.accessor,
-                *missing,
-            );
-        } else {
-            req_data
-                .column_block_accessor
-                .fetch_block(docs, &req_data.accessor);
-        }
-
-        for val in req_data.column_block_accessor.iter_vals() {
-            let val1 = f64_from_fastfield_u64(val, &req_data.field_type);
-            self.percentiles.collect(val1);
         }
     }
 }
@@ -263,12 +253,18 @@ impl SegmentPercentilesCollector {
 impl SegmentAggregationCollector for SegmentPercentilesCollector {
     #[inline]
     fn add_intermediate_aggregation_result(
-        self: Box<Self>,
+        &mut self,
         agg_data: &AggregationsSegmentCtx,
         results: &mut IntermediateAggregationResults,
+        parent_bucket_id: BucketId,
     ) -> crate::Result<()> {
         let name = agg_data.get_metric_req_data(self.accessor_idx).name.clone();
-        let intermediate_metric_result = IntermediateMetricResult::Percentiles(self.percentiles);
+        self.prepare_max_bucket(parent_bucket_id, agg_data)?;
+        // Swap collector with an empty one to avoid cloning
+        let percentiles_collector = std::mem::take(&mut self.buckets[parent_bucket_id as usize]);
+
+        let intermediate_metric_result =
+            IntermediateMetricResult::Percentiles(percentiles_collector);
 
         results.push(
             name,
@@ -281,40 +277,33 @@ impl SegmentAggregationCollector for SegmentPercentilesCollector {
     #[inline]
     fn collect(
         &mut self,
-        doc: crate::DocId,
+        parent_bucket_id: BucketId,
+        docs: &[crate::DocId],
         agg_data: &mut AggregationsSegmentCtx,
     ) -> crate::Result<()> {
-        let req_data = agg_data.get_metric_req_data(self.accessor_idx);
+        let percentiles = &mut self.buckets[parent_bucket_id as usize];
+        agg_data.column_block_accessor.fetch_block_with_missing(
+            docs,
+            &self.accessor,
+            self.missing_u64,
+        );
 
-        if let Some(missing) = req_data.missing_u64 {
-            let mut has_val = false;
-            for val in req_data.accessor.values_for_doc(doc) {
-                let val1 = f64_from_fastfield_u64(val, &req_data.field_type);
-                self.percentiles.collect(val1);
-                has_val = true;
-            }
-            if !has_val {
-                self.percentiles
-                    .collect(f64_from_fastfield_u64(missing, &req_data.field_type));
-            }
-        } else {
-            for val in req_data.accessor.values_for_doc(doc) {
-                let val1 = f64_from_fastfield_u64(val, &req_data.field_type);
-                self.percentiles.collect(val1);
-            }
+        for val in agg_data.column_block_accessor.iter_vals() {
+            let val1 = f64_from_fastfield_u64(val, self.field_type);
+            percentiles.collect(val1);
         }
 
         Ok(())
     }
 
-    #[inline]
-    fn collect_block(
+    fn prepare_max_bucket(
         &mut self,
-        docs: &[crate::DocId],
-        agg_data: &mut AggregationsSegmentCtx,
+        max_bucket: BucketId,
+        _agg_data: &AggregationsSegmentCtx,
     ) -> crate::Result<()> {
-        let req_data = agg_data.get_metric_req_data_mut(self.accessor_idx);
-        self.collect_block_with_field(docs, req_data);
+        while self.buckets.len() <= max_bucket as usize {
+            self.buckets.push(PercentilesCollector::new());
+        }
         Ok(())
     }
 }

src/aggregation/metric/stats.rs

@@ -1,5 +1,6 @@
 use std::fmt::Debug;
 
+use columnar::{Column, ColumnType};
 use serde::{Deserialize, Serialize};
 
 use super::*;
@@ -7,10 +8,9 @@ use crate::aggregation::agg_data::AggregationsSegmentCtx;
 use crate::aggregation::intermediate_agg_result::{
     IntermediateAggregationResult, IntermediateAggregationResults, IntermediateMetricResult,
 };
-use crate::aggregation::metric::MetricAggReqData;
 use crate::aggregation::segment_agg_result::SegmentAggregationCollector;
 use crate::aggregation::*;
-use crate::{DocId, TantivyError};
+use crate::TantivyError;
 
 /// A multi-value metric aggregation that computes a collection of statistics on numeric values that
 /// are extracted from the aggregated documents.
@@ -83,7 +83,7 @@ impl Stats {
 
 /// Intermediate result of the stats aggregation that can be combined with other intermediate
 /// results.
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+#[derive(Clone, Copy, Debug, PartialEq, Serialize, Deserialize)]
 pub struct IntermediateStats {
     /// The number of extracted values.
     pub(crate) count: u64,
@@ -187,75 +187,75 @@ pub enum StatsType {
     Percentiles,
 }
 
+fn create_collector<const TYPE_ID: u8>(
+    req: &MetricAggReqData,
+) -> Box<dyn SegmentAggregationCollector> {
+    Box::new(SegmentStatsCollector::<TYPE_ID> {
+        name: req.name.clone(),
+        collecting_for: req.collecting_for,
+        is_number_or_date_type: req.is_number_or_date_type,
+        missing_u64: req.missing_u64,
+        accessor: req.accessor.clone(),
+        buckets: vec![IntermediateStats::default()],
+    })
+}
+
+/// Build a concrete `SegmentStatsCollector` depending on the column type.
+pub(crate) fn build_segment_stats_collector(
+    req: &MetricAggReqData,
+) -> crate::Result<Box<dyn SegmentAggregationCollector>> {
+    match req.field_type {
+        ColumnType::I64 => Ok(create_collector::<{ ColumnType::I64 as u8 }>(req)),
+        ColumnType::U64 => Ok(create_collector::<{ ColumnType::U64 as u8 }>(req)),
+        ColumnType::F64 => Ok(create_collector::<{ ColumnType::F64 as u8 }>(req)),
+        ColumnType::Bool => Ok(create_collector::<{ ColumnType::Bool as u8 }>(req)),
+        ColumnType::DateTime => Ok(create_collector::<{ ColumnType::DateTime as u8 }>(req)),
+        ColumnType::Bytes => Ok(create_collector::<{ ColumnType::Bytes as u8 }>(req)),
+        ColumnType::Str => Ok(create_collector::<{ ColumnType::Str as u8 }>(req)),
+        ColumnType::IpAddr => Ok(create_collector::<{ ColumnType::IpAddr as u8 }>(req)),
+    }
+}
+
+#[repr(C)]
 #[derive(Clone, Debug)]
-pub(crate) struct SegmentStatsCollector {
-    pub(crate) stats: IntermediateStats,
-    pub(crate) accessor_idx: usize,
+pub(crate) struct SegmentStatsCollector<const COLUMN_TYPE_ID: u8> {
+    pub(crate) missing_u64: Option<u64>,
+    pub(crate) accessor: Column<u64>,
+    pub(crate) is_number_or_date_type: bool,
+    pub(crate) buckets: Vec<IntermediateStats>,
+    pub(crate) name: String,
+    pub(crate) collecting_for: StatsType,
 }
 
-impl SegmentStatsCollector {
-    pub fn from_req(accessor_idx: usize) -> Self {
-        Self {
-            stats: IntermediateStats::default(),
-            accessor_idx,
-        }
-    }
-    #[inline]
-    pub(crate) fn collect_block_with_field(
-        &mut self,
-        docs: &[DocId],
-        req_data: &mut MetricAggReqData,
-    ) {
-        if let Some(missing) = req_data.missing_u64.as_ref() {
-            req_data.column_block_accessor.fetch_block_with_missing(
-                docs,
-                &req_data.accessor,
-                *missing,
-            );
-        } else {
-            req_data
-                .column_block_accessor
-                .fetch_block(docs, &req_data.accessor);
-        }
-        if req_data.is_number_or_date_type {
-            for val in req_data.column_block_accessor.iter_vals() {
-                let val1 = f64_from_fastfield_u64(val, &req_data.field_type);
-                self.stats.collect(val1);
-            }
-        } else {
-            for _val in req_data.column_block_accessor.iter_vals() {
-                // we ignore the value and simply record that we got something
-                self.stats.collect(0.0);
-            }
-        }
-    }
-}
-
-impl SegmentAggregationCollector for SegmentStatsCollector {
+impl<const COLUMN_TYPE_ID: u8> SegmentAggregationCollector
+    for SegmentStatsCollector<COLUMN_TYPE_ID>
+{
     #[inline]
     fn add_intermediate_aggregation_result(
-        self: Box<Self>,
+        &mut self,
         agg_data: &AggregationsSegmentCtx,
         results: &mut IntermediateAggregationResults,
+        parent_bucket_id: BucketId,
     ) -> crate::Result<()> {
-        let req = agg_data.get_metric_req_data(self.accessor_idx);
-        let name = req.name.clone();
+        let name = self.name.clone();
 
-        let intermediate_metric_result = match req.collecting_for {
+        self.prepare_max_bucket(parent_bucket_id, agg_data)?;
+        let stats = self.buckets[parent_bucket_id as usize];
+        let intermediate_metric_result = match self.collecting_for {
             StatsType::Average => {
-                IntermediateMetricResult::Average(IntermediateAverage::from_collector(*self))
+                IntermediateMetricResult::Average(IntermediateAverage::from_stats(stats))
             }
             StatsType::Count => {
-                IntermediateMetricResult::Count(IntermediateCount::from_collector(*self))
+                IntermediateMetricResult::Count(IntermediateCount::from_stats(stats))
             }
-            StatsType::Max => IntermediateMetricResult::Max(IntermediateMax::from_collector(*self)),
-            StatsType::Min => IntermediateMetricResult::Min(IntermediateMin::from_collector(*self)),
-            StatsType::Stats => IntermediateMetricResult::Stats(self.stats),
-            StatsType::Sum => IntermediateMetricResult::Sum(IntermediateSum::from_collector(*self)),
+            StatsType::Max => IntermediateMetricResult::Max(IntermediateMax::from_stats(stats)),
+            StatsType::Min => IntermediateMetricResult::Min(IntermediateMin::from_stats(stats)),
+            StatsType::Stats => IntermediateMetricResult::Stats(stats),
+            StatsType::Sum => IntermediateMetricResult::Sum(IntermediateSum::from_stats(stats)),
             _ => {
                 return Err(TantivyError::InvalidArgument(format!(
                     "Unsupported stats type for stats aggregation: {:?}",
-                    req.collecting_for
+                    self.collecting_for
                 )))
             }
         };
@@ -271,41 +271,67 @@ impl SegmentAggregationCollector for SegmentStatsCollector {
     #[inline]
     fn collect(
         &mut self,
-        doc: crate::DocId,
-        agg_data: &mut AggregationsSegmentCtx,
-    ) -> crate::Result<()> {
-        let req_data = agg_data.get_metric_req_data(self.accessor_idx);
-        if let Some(missing) = req_data.missing_u64 {
-            let mut has_val = false;
-            for val in req_data.accessor.values_for_doc(doc) {
-                let val1 = f64_from_fastfield_u64(val, &req_data.field_type);
-                self.stats.collect(val1);
-                has_val = true;
-            }
-            if !has_val {
-                self.stats
-                    .collect(f64_from_fastfield_u64(missing, &req_data.field_type));
-            }
-        } else {
-            for val in req_data.accessor.values_for_doc(doc) {
-                let val1 = f64_from_fastfield_u64(val, &req_data.field_type);
-                self.stats.collect(val1);
-            }
-        }
-
-        Ok(())
-    }
-
-    #[inline]
-    fn collect_block(
-        &mut self,
+        parent_bucket_id: BucketId,
         docs: &[crate::DocId],
         agg_data: &mut AggregationsSegmentCtx,
     ) -> crate::Result<()> {
-        let req_data = agg_data.get_metric_req_data_mut(self.accessor_idx);
-        self.collect_block_with_field(docs, req_data);
+        // TODO: remove once we fetch all values for all bucket ids in one go
+        if docs.len() == 1 && self.missing_u64.is_none() {
+            collect_stats::<COLUMN_TYPE_ID>(
+                &mut self.buckets[parent_bucket_id as usize],
+                self.accessor.values_for_doc(docs[0]),
+                self.is_number_or_date_type,
+            )?;
+
+            return Ok(());
+        }
+        agg_data.column_block_accessor.fetch_block_with_missing(
+            docs,
+            &self.accessor,
+            self.missing_u64,
+        );
+        collect_stats::<COLUMN_TYPE_ID>(
+            &mut self.buckets[parent_bucket_id as usize],
+            agg_data.column_block_accessor.iter_vals(),
+            self.is_number_or_date_type,
+        )?;
+
         Ok(())
     }
+
+    fn prepare_max_bucket(
+        &mut self,
+        max_bucket: BucketId,
+        _agg_data: &AggregationsSegmentCtx,
+    ) -> crate::Result<()> {
+        let required_buckets = (max_bucket as usize) + 1;
+        if self.buckets.len() < required_buckets {
+            self.buckets
+                .resize_with(required_buckets, IntermediateStats::default);
+        }
+        Ok(())
+    }
+}
+
+#[inline]
+fn collect_stats<const COLUMN_TYPE_ID: u8>(
+    stats: &mut IntermediateStats,
+    vals: impl Iterator<Item = u64>,
+    is_number_or_date_type: bool,
+) -> crate::Result<()> {
+    if is_number_or_date_type {
+        for val in vals {
+            let val1 = convert_to_f64::<COLUMN_TYPE_ID>(val);
+            stats.collect(val1);
+        }
+    } else {
+        for _val in vals {
+            // we ignore the value and simply record that we got something
+            stats.collect(0.0);
+        }
+    }
+
+    Ok(())
 }
 
 #[cfg(test)]

src/aggregation/metric/sum.rs

@@ -52,10 +52,8 @@ pub struct IntermediateSum {
 
 impl IntermediateSum {
     /// Creates a new [`IntermediateSum`] instance from a [`SegmentStatsCollector`].
-    pub(crate) fn from_collector(collector: SegmentStatsCollector) -> Self {
-        Self {
-            stats: collector.stats,
-        }
+    pub(crate) fn from_stats(stats: IntermediateStats) -> Self {
+        Self { stats }
     }
     /// Merges the other intermediate result into self.
     pub fn merge_fruits(&mut self, other: IntermediateSum) {

src/aggregation/metric/top_hits.rs

@@ -1,8 +1,7 @@
-use std::cmp::Ordering;
 use std::collections::HashMap;
 use std::net::Ipv6Addr;
 
-use columnar::{Column, ColumnType, ColumnarReader, DynamicColumn, ValueRange};
+use columnar::{Column, ColumnType, ColumnarReader, DynamicColumn};
 use common::json_path_writer::JSON_PATH_SEGMENT_SEP_STR;
 use common::DateTime;
 use regex::Regex;
@@ -16,12 +15,11 @@ use crate::aggregation::intermediate_agg_result::{
     IntermediateAggregationResult, IntermediateMetricResult,
 };
 use crate::aggregation::segment_agg_result::SegmentAggregationCollector;
-use crate::aggregation::AggregationError;
-use crate::collector::sort_key::{Comparator, ReverseComparator};
+use crate::aggregation::{AggregationError, BucketId};
+use crate::collector::sort_key::ReverseComparator;
 use crate::collector::TopNComputer;
 use crate::schema::OwnedValue;
 use crate::{DocAddress, DocId, SegmentOrdinal};
-// duplicate import removed; already imported above
 
 /// Contains all information required by the TopHitsSegmentCollector to perform the
 /// top_hits aggregation on a segment.
@@ -384,7 +382,7 @@ impl From<FastFieldValue> for OwnedValue {
 
 /// Holds a fast field value in its u64 representation, and the order in which it should be sorted.
 #[derive(Clone, Serialize, Deserialize, Debug)]
-pub(crate) struct DocValueAndOrder {
+struct DocValueAndOrder {
     /// A fast field value in its u64 representation.
     value: Option<u64>,
     /// Sort order for the value
@@ -456,37 +454,6 @@ impl PartialEq for DocSortValuesAndFields {
 
 impl Eq for DocSortValuesAndFields {}
 
-impl Comparator<DocSortValuesAndFields> for ReverseComparator {
-    #[inline(always)]
-    fn compare(&self, lhs: &DocSortValuesAndFields, rhs: &DocSortValuesAndFields) -> Ordering {
-        rhs.cmp(lhs)
-    }
-
-    fn threshold_to_valuerange(
-        &self,
-        threshold: DocSortValuesAndFields,
-    ) -> ValueRange<DocSortValuesAndFields> {
-        ValueRange::LessThan(threshold, true)
-    }
-}
-
-#[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
-pub(crate) struct TopHitsSegmentSortKey(pub Vec<DocValueAndOrder>);
-
-impl Comparator<TopHitsSegmentSortKey> for ReverseComparator {
-    #[inline(always)]
-    fn compare(&self, lhs: &TopHitsSegmentSortKey, rhs: &TopHitsSegmentSortKey) -> Ordering {
-        rhs.cmp(lhs)
-    }
-
-    fn threshold_to_valuerange(
-        &self,
-        threshold: TopHitsSegmentSortKey,
-    ) -> ValueRange<TopHitsSegmentSortKey> {
-        ValueRange::LessThan(threshold, true)
-    }
-}
-
 /// The TopHitsCollector used for collecting over segments and merging results.
 #[derive(Clone, Serialize, Deserialize, Debug)]
 pub struct TopHitsTopNComputer {
@@ -504,7 +471,10 @@ impl TopHitsTopNComputer {
     /// Create a new TopHitsCollector
     pub fn new(req: &TopHitsAggregationReq) -> Self {
         Self {
-            top_n: TopNComputer::new(req.size + req.from.unwrap_or(0)),
+            top_n: TopNComputer::new_with_comparator(
+                req.size + req.from.unwrap_or(0),
+                ReverseComparator,
+            ),
             req: req.clone(),
         }
     }
@@ -550,7 +520,8 @@ impl TopHitsTopNComputer {
 pub(crate) struct TopHitsSegmentCollector {
     segment_ordinal: SegmentOrdinal,
     accessor_idx: usize,
-    top_n: TopNComputer<TopHitsSegmentSortKey, DocAddress, ReverseComparator>,
+    buckets: Vec<TopNComputer<Vec<DocValueAndOrder>, DocAddress, ReverseComparator>>,
+    num_hits: usize,
 }
 
 impl TopHitsSegmentCollector {
@@ -559,27 +530,35 @@ impl TopHitsSegmentCollector {
         accessor_idx: usize,
         segment_ordinal: SegmentOrdinal,
     ) -> Self {
+        let num_hits = req.size + req.from.unwrap_or(0);
         Self {
-            top_n: TopNComputer::new(req.size + req.from.unwrap_or(0)),
+            num_hits,
             segment_ordinal,
             accessor_idx,
+            buckets: vec![TopNComputer::new_with_comparator(num_hits, ReverseComparator); 1],
         }
     }
-    fn into_top_hits_collector(
-        self,
+    fn get_top_hits_computer(
+        &mut self,
+        parent_bucket_id: BucketId,
         value_accessors: &HashMap<String, Vec<DynamicColumn>>,
         req: &TopHitsAggregationReq,
     ) -> TopHitsTopNComputer {
+        if parent_bucket_id as usize >= self.buckets.len() {
+            return TopHitsTopNComputer::new(req);
+        }
+        let top_n = std::mem::replace(
+            &mut self.buckets[parent_bucket_id as usize],
+            TopNComputer::new(0),
+        );
         let mut top_hits_computer = TopHitsTopNComputer::new(req);
-        // Map TopHitsSegmentSortKey back to Vec<DocValueAndOrder> if needed or use directly
-        // The TopNComputer here stores TopHitsSegmentSortKey.
-        let top_results = self.top_n.into_vec();
+        let top_results = top_n.into_vec();
 
         for res in top_results {
             let doc_value_fields = req.get_document_field_data(value_accessors, res.doc.doc_id);
             top_hits_computer.collect(
                 DocSortValuesAndFields {
-                    sorts: res.sort_key.0,
+                    sorts: res.sort_key,
                     doc_value_fields,
                 },
                 res.doc,
@@ -588,54 +567,24 @@ impl TopHitsSegmentCollector {
 
         top_hits_computer
     }
-
-    /// TODO add a specialized variant for a single sort field
-    fn collect_with(
-        &mut self,
-        doc_id: crate::DocId,
-        req: &TopHitsAggregationReq,
-        accessors: &[(Column<u64>, ColumnType)],
-    ) -> crate::Result<()> {
-        let sorts: Vec<DocValueAndOrder> = req
-            .sort
-            .iter()
-            .enumerate()
-            .map(|(idx, KeyOrder { order, .. })| {
-                let order = *order;
-                let value = accessors
-                    .get(idx)
-                    .expect("could not find field in accessors")
-                    .0
-                    .values_for_doc(doc_id)
-                    .next();
-                DocValueAndOrder { value, order }
-            })
-            .collect();
-
-        self.top_n.push(
-            TopHitsSegmentSortKey(sorts),
-            DocAddress {
-                segment_ord: self.segment_ordinal,
-                doc_id,
-            },
-        );
-        Ok(())
-    }
 }
 
 impl SegmentAggregationCollector for TopHitsSegmentCollector {
     fn add_intermediate_aggregation_result(
-        self: Box<Self>,
+        &mut self,
         agg_data: &AggregationsSegmentCtx,
         results: &mut crate::aggregation::intermediate_agg_result::IntermediateAggregationResults,
+        parent_bucket_id: BucketId,
     ) -> crate::Result<()> {
         let req_data = agg_data.get_top_hits_req_data(self.accessor_idx);
 
         let value_accessors = &req_data.value_accessors;
 
-        let intermediate_result = IntermediateMetricResult::TopHits(
-            self.into_top_hits_collector(value_accessors, &req_data.req),
-        );
+        let intermediate_result = IntermediateMetricResult::TopHits(self.get_top_hits_computer(
+            parent_bucket_id,
+            value_accessors,
+            &req_data.req,
+        ));
         results.push(
             req_data.name.to_string(),
             IntermediateAggregationResult::Metric(intermediate_result),
@@ -645,26 +594,56 @@ impl SegmentAggregationCollector for TopHitsSegmentCollector {
     /// TODO: Consider a caching layer to reduce the call overhead
     fn collect(
         &mut self,
-        doc_id: crate::DocId,
-        agg_data: &mut AggregationsSegmentCtx,
-    ) -> crate::Result<()> {
-        let req_data = agg_data.get_top_hits_req_data(self.accessor_idx);
-        self.collect_with(doc_id, &req_data.req, &req_data.accessors)?;
-        Ok(())
-    }
-
-    fn collect_block(
-        &mut self,
+        parent_bucket_id: BucketId,
         docs: &[crate::DocId],
         agg_data: &mut AggregationsSegmentCtx,
     ) -> crate::Result<()> {
+        let top_n = &mut self.buckets[parent_bucket_id as usize];
         let req_data = agg_data.get_top_hits_req_data(self.accessor_idx);
-        // TODO: Consider getting fields with the column block accessor.
-        for doc in docs {
-            self.collect_with(*doc, &req_data.req, &req_data.accessors)?;
+        let req = &req_data.req;
+        let accessors = &req_data.accessors;
+        for &doc_id in docs {
+            // TODO: this is terrible, a new vec is allocated for every doc
+            // We can fetch blocks instead
+            // We don't need to store the order for every value
+            let sorts: Vec<DocValueAndOrder> = req
+                .sort
+                .iter()
+                .enumerate()
+                .map(|(idx, KeyOrder { order, .. })| {
+                    let order = *order;
+                    let value = accessors
+                        .get(idx)
+                        .expect("could not find field in accessors")
+                        .0
+                        .values_for_doc(doc_id)
+                        .next();
+                    DocValueAndOrder { value, order }
+                })
+                .collect();
+
+            top_n.push(
+                sorts,
+                DocAddress {
+                    segment_ord: self.segment_ordinal,
+                    doc_id,
+                },
+            );
         }
         Ok(())
     }
+
+    fn prepare_max_bucket(
+        &mut self,
+        max_bucket: BucketId,
+        _agg_data: &AggregationsSegmentCtx,
+    ) -> crate::Result<()> {
+        self.buckets.resize(
+            (max_bucket as usize) + 1,
+            TopNComputer::new_with_comparator(self.num_hits, ReverseComparator),
+        );
+        Ok(())
+    }
 }
 
 #[cfg(test)]
@@ -780,7 +759,7 @@ mod tests {
                     ],
                     "from": 0,
                 }
-        }
+            }
         }))
         .unwrap();
 
@@ -909,7 +888,7 @@ mod tests {
                         "mixed.*",
                     ],
                 }
-        }
+            }
         }))?;
 
         let collector = AggregationCollector::from_aggs(d, Default::default());

src/aggregation/mod.rs

@@ -133,7 +133,7 @@ mod agg_limits;
 pub mod agg_req;
 pub mod agg_result;
 pub mod bucket;
-mod buf_collector;
+pub(crate) mod cached_sub_aggs;
 mod collector;
 mod date;
 mod error;
@@ -162,6 +162,19 @@ use serde::{Deserialize, Deserializer, Serialize};
 
 use crate::tokenizer::TokenizerManager;
 
+/// A bucket id is a dense identifier for a bucket within an aggregation.
+/// It is used to index into a Vec that hold per-bucket data.
+///
+/// For example, in a terms aggregation, each unique term will be assigned a incremental BucketId.
+/// This BucketId will be forwarded to sub-aggregations to identify the parent bucket.
+///
+/// This allows to have a single AggregationCollector instance per aggregation,
+/// that can handle multiple buckets efficiently.
+///
+/// The API to call sub-aggregations is therefore a &[(BucketId, &[DocId])].
+/// For that we'll need a buffer. One Vec per bucket aggregation is needed.
+pub type BucketId = u32;
+
 /// Context parameters for aggregation execution
 ///
 /// This struct holds shared resources needed during aggregation execution:
@@ -335,19 +348,37 @@ impl Display for Key {
     }
 }
 
+pub(crate) fn convert_to_f64<const COLUMN_TYPE_ID: u8>(val: u64) -> f64 {
+    if COLUMN_TYPE_ID == ColumnType::U64 as u8 {
+        val as f64
+    } else if COLUMN_TYPE_ID == ColumnType::I64 as u8
+        || COLUMN_TYPE_ID == ColumnType::DateTime as u8
+    {
+        i64::from_u64(val) as f64
+    } else if COLUMN_TYPE_ID == ColumnType::F64 as u8 {
+        f64::from_u64(val)
+    } else if COLUMN_TYPE_ID == ColumnType::Bool as u8 {
+        val as f64
+    } else {
+        panic!(
+            "ColumnType ID {} cannot be converted to f64 metric",
+            COLUMN_TYPE_ID
+        )
+    }
+}
+
 /// Inverse of `to_fastfield_u64`. Used to convert to `f64` for metrics.
 ///
 /// # Panics
 /// Only `u64`, `f64`, `date`, and `i64` are supported.
-pub(crate) fn f64_from_fastfield_u64(val: u64, field_type: &ColumnType) -> f64 {
+pub(crate) fn f64_from_fastfield_u64(val: u64, field_type: ColumnType) -> f64 {
     match field_type {
-        ColumnType::U64 => val as f64,
-        ColumnType::I64 | ColumnType::DateTime => i64::from_u64(val) as f64,
-        ColumnType::F64 => f64::from_u64(val),
-        ColumnType::Bool => val as f64,
-        _ => {
-            panic!("unexpected type {field_type:?}. This should not happen")
-        }
+        ColumnType::U64 => convert_to_f64::<{ ColumnType::U64 as u8 }>(val),
+        ColumnType::I64 => convert_to_f64::<{ ColumnType::I64 as u8 }>(val),
+        ColumnType::F64 => convert_to_f64::<{ ColumnType::F64 as u8 }>(val),
+        ColumnType::Bool => convert_to_f64::<{ ColumnType::Bool as u8 }>(val),
+        ColumnType::DateTime => convert_to_f64::<{ ColumnType::DateTime as u8 }>(val),
+        _ => panic!("unexpected type {field_type:?}. This should not happen"),
     }
 }
 

src/aggregation/segment_agg_result.rs

@@ -8,25 +8,67 @@ use std::fmt::Debug;
 pub(crate) use super::agg_limits::AggregationLimitsGuard;
 use super::intermediate_agg_result::IntermediateAggregationResults;
 use crate::aggregation::agg_data::AggregationsSegmentCtx;
+use crate::aggregation::BucketId;
+
+/// Monotonically increasing provider of BucketIds.
+#[derive(Debug, Clone, Default)]
+pub struct BucketIdProvider(u32);
+impl BucketIdProvider {
+    /// Get the next BucketId.
+    pub fn next_bucket_id(&mut self) -> BucketId {
+        let bucket_id = self.0;
+        self.0 += 1;
+        bucket_id
+    }
+}
 
 /// A SegmentAggregationCollector is used to collect aggregation results.
-pub trait SegmentAggregationCollector: CollectorClone + Debug {
+pub trait SegmentAggregationCollector: Debug {
     fn add_intermediate_aggregation_result(
-        self: Box<Self>,
+        &mut self,
         agg_data: &AggregationsSegmentCtx,
         results: &mut IntermediateAggregationResults,
+        parent_bucket_id: BucketId,
     ) -> crate::Result<()>;
 
+    /// Note: The caller needs to call `prepare_max_bucket` before calling `collect`.
     fn collect(
         &mut self,
-        doc: crate::DocId,
+        parent_bucket_id: BucketId,
+        docs: &[crate::DocId],
         agg_data: &mut AggregationsSegmentCtx,
     ) -> crate::Result<()>;
 
-    fn collect_block(
+    /// Collect docs for multiple buckets in one call.
+    /// Minimizes dynamic dispatch overhead when collecting many buckets.
+    ///
+    /// Note: The caller needs to call `prepare_max_bucket` before calling `collect`.
+    fn collect_multiple(
         &mut self,
+        bucket_ids: &[BucketId],
         docs: &[crate::DocId],
         agg_data: &mut AggregationsSegmentCtx,
+    ) -> crate::Result<()> {
+        debug_assert_eq!(bucket_ids.len(), docs.len());
+        let mut start = 0;
+        while start < bucket_ids.len() {
+            let bucket_id = bucket_ids[start];
+            let mut end = start + 1;
+            while end < bucket_ids.len() && bucket_ids[end] == bucket_id {
+                end += 1;
+            }
+            self.collect(bucket_id, &docs[start..end], agg_data)?;
+            start = end;
+        }
+        Ok(())
+    }
+
+    /// Prepare the collector for collecting up to BucketId `max_bucket`.
+    /// This is useful so we can split allocation ahead of time of collecting.
+    fn prepare_max_bucket(
+        &mut self,
+        max_bucket: BucketId,
+        agg_data: &AggregationsSegmentCtx,
     ) -> crate::Result<()>;
 
     /// Finalize method. Some Aggregator collect blocks of docs before calling `collect_block`.
@@ -36,26 +78,7 @@ pub trait SegmentAggregationCollector: CollectorClone + Debug {
     }
 }
 
-/// A helper trait to enable cloning of Box<dyn SegmentAggregationCollector>
-pub trait CollectorClone {
-    fn clone_box(&self) -> Box<dyn SegmentAggregationCollector>;
-}
-
-impl<T> CollectorClone for T
-where T: 'static + SegmentAggregationCollector + Clone
-{
-    fn clone_box(&self) -> Box<dyn SegmentAggregationCollector> {
-        Box::new(self.clone())
-    }
-}
-
-impl Clone for Box<dyn SegmentAggregationCollector> {
-    fn clone(&self) -> Box<dyn SegmentAggregationCollector> {
-        self.clone_box()
-    }
-}
-
-#[derive(Clone, Default)]
+#[derive(Default)]
 /// The GenericSegmentAggregationResultsCollector is the generic version of the collector, which
 /// can handle arbitrary complexity of  sub-aggregations. Ideally we never have to pick this one
 /// and can provide specialized versions instead, that remove some of its overhead.
@@ -73,12 +96,13 @@ impl Debug for GenericSegmentAggregationResultsCollector {
 
 impl SegmentAggregationCollector for GenericSegmentAggregationResultsCollector {
     fn add_intermediate_aggregation_result(
-        self: Box<Self>,
+        &mut self,
         agg_data: &AggregationsSegmentCtx,
         results: &mut IntermediateAggregationResults,
+        parent_bucket_id: BucketId,
     ) -> crate::Result<()> {
-        for agg in self.aggs {
-            agg.add_intermediate_aggregation_result(agg_data, results)?;
+        for agg in &mut self.aggs {
+            agg.add_intermediate_aggregation_result(agg_data, results, parent_bucket_id)?;
         }
 
         Ok(())
@@ -86,23 +110,13 @@ impl SegmentAggregationCollector for GenericSegmentAggregationResultsCollector {
 
     fn collect(
         &mut self,
-        doc: crate::DocId,
-        agg_data: &mut AggregationsSegmentCtx,
-    ) -> crate::Result<()> {
-        self.collect_block(&[doc], agg_data)?;
-
-        Ok(())
-    }
-
-    fn collect_block(
-        &mut self,
+        parent_bucket_id: BucketId,
         docs: &[crate::DocId],
         agg_data: &mut AggregationsSegmentCtx,
     ) -> crate::Result<()> {
         for collector in &mut self.aggs {
-            collector.collect_block(docs, agg_data)?;
+            collector.collect(parent_bucket_id, docs, agg_data)?;
         }
-
         Ok(())
     }
 
@@ -112,4 +126,15 @@ impl SegmentAggregationCollector for GenericSegmentAggregationResultsCollector {
         }
         Ok(())
     }
+
+    fn prepare_max_bucket(
+        &mut self,
+        max_bucket: BucketId,
+        agg_data: &AggregationsSegmentCtx,
+    ) -> crate::Result<()> {
+        for collector in &mut self.aggs {
+            collector.prepare_max_bucket(max_bucket, agg_data)?;
+        }
+        Ok(())
+    }
 }

src/collector/facet_collector.rs

@@ -821,6 +821,7 @@ mod tests {
 
 #[cfg(all(test, feature = "unstable"))]
 mod bench {
+
     use rand::seq::SliceRandom;
     use rand::thread_rng;
     use test::Bencher;

src/collector/mod.rs

@@ -96,10 +96,11 @@ mod histogram_collector;
 pub use histogram_collector::HistogramCollector;
 
 mod multi_collector;
-pub use columnar::ComparableDoc;
-
 pub use self::multi_collector::{FruitHandle, MultiCollector, MultiFruit};
 
+mod top_collector;
+pub use self::top_collector::ComparableDoc;
+
 mod top_score_collector;
 pub use self::top_score_collector::{TopDocs, TopNComputer};
 

src/collector/multi_collector.rs

@@ -281,6 +281,7 @@ impl SegmentCollector for MultiCollectorChild {
 
 #[cfg(test)]
 mod tests {
+
     use super::*;
     use crate::collector::{Count, TopDocs};
     use crate::query::TermQuery;

src/collector/sort_key/mod.rs

@@ -1,12 +1,10 @@
 mod order;
-mod sort_by_erased_type;
 mod sort_by_score;
 mod sort_by_static_fast_value;
 mod sort_by_string;
 mod sort_key_computer;
 
 pub use order::*;
-pub use sort_by_erased_type::SortByErasedType;
 pub use sort_by_score::SortBySimilarityScore;
 pub use sort_by_static_fast_value::SortByStaticFastValue;
 pub use sort_by_string::SortByString;
@@ -17,14 +15,11 @@ mod tests {
     use std::collections::HashMap;
     use std::ops::Range;
 
-    use crate::collector::sort_key::{
-        Comparator, NaturalComparator, ReverseComparator, SortByErasedType, SortBySimilarityScore,
-        SortByStaticFastValue, SortByString,
-    };
+    use crate::collector::sort_key::{SortBySimilarityScore, SortByStaticFastValue, SortByString};
     use crate::collector::{ComparableDoc, DocSetCollector, TopDocs};
     use crate::indexer::NoMergePolicy;
     use crate::query::{AllQuery, QueryParser};
-    use crate::schema::{OwnedValue, Schema, FAST, TEXT};
+    use crate::schema::{Schema, FAST, TEXT};
     use crate::{DocAddress, Document, Index, Order, Score, Searcher};
 
     fn make_index() -> crate::Result<Index> {
@@ -299,121 +294,32 @@ mod tests {
                 (SortBySimilarityScore, score_order),
                 (SortByString::for_field("city"), city_order),
             ));
-            let results: Vec<((Score, Option<String>), DocAddress)> =
-                searcher.search(&AllQuery, &top_collector)?;
-            Ok(results.into_iter().map(|(f, doc)| (f, ids[&doc])).collect())
-        }
-
-        assert_eq!(
-            &query(&index, Order::Asc, Order::Asc)?,
-            &[
-                ((1.0, Some("austin".to_owned())), 0),
-                ((1.0, Some("greenville".to_owned())), 1),
-                ((1.0, Some("tokyo".to_owned())), 2),
-                ((1.0, None), 3),
-            ]
-        );
-
-        assert_eq!(
-            &query(&index, Order::Asc, Order::Desc)?,
-            &[
-                ((1.0, Some("tokyo".to_owned())), 2),
-                ((1.0, Some("greenville".to_owned())), 1),
-                ((1.0, Some("austin".to_owned())), 0),
-                ((1.0, None), 3),
-            ]
-        );
-        Ok(())
-    }
-
-    #[test]
-    fn test_order_by_score_then_owned_value() -> crate::Result<()> {
-        let index = make_index()?;
-
-        type SortKey = (Score, OwnedValue);
-
-        fn query(
-            index: &Index,
-            score_order: Order,
-            city_order: Order,
-        ) -> crate::Result<Vec<(SortKey, u64)>> {
-            let searcher = index.reader()?.searcher();
-            let ids = id_mapping(&searcher);
-
-            let top_collector = TopDocs::with_limit(4).order_by::<(Score, OwnedValue)>((
-                (SortBySimilarityScore, score_order),
-                (SortByErasedType::for_field("city"), city_order),
-            ));
-            let results: Vec<((Score, OwnedValue), DocAddress)> =
-                searcher.search(&AllQuery, &top_collector)?;
-            Ok(results.into_iter().map(|(f, doc)| (f, ids[&doc])).collect())
-        }
-
-        assert_eq!(
-            &query(&index, Order::Asc, Order::Asc)?,
-            &[
-                ((1.0, OwnedValue::Str("austin".to_owned())), 0),
-                ((1.0, OwnedValue::Str("greenville".to_owned())), 1),
-                ((1.0, OwnedValue::Str("tokyo".to_owned())), 2),
-                ((1.0, OwnedValue::Null), 3),
-            ]
-        );
-
-        assert_eq!(
-            &query(&index, Order::Asc, Order::Desc)?,
-            &[
-                ((1.0, OwnedValue::Str("tokyo".to_owned())), 2),
-                ((1.0, OwnedValue::Str("greenville".to_owned())), 1),
-                ((1.0, OwnedValue::Str("austin".to_owned())), 0),
-                ((1.0, OwnedValue::Null), 3),
-            ]
-        );
-        Ok(())
-    }
-
-    #[test]
-    fn test_order_by_compound_fast_fields() -> crate::Result<()> {
-        let index = make_index()?;
-
-        type CompoundSortKey = (Option<String>, Option<f64>);
-
-        fn assert_query(
-            index: &Index,
-            city_order: Order,
-            altitude_order: Order,
-            expected: Vec<(CompoundSortKey, u64)>,
-        ) -> crate::Result<()> {
-            let searcher = index.reader()?.searcher();
-            let ids = id_mapping(&searcher);
-
-            let top_collector = TopDocs::with_limit(4).order_by((
-                (SortByString::for_field("city"), city_order),
-                (
-                    SortByStaticFastValue::<f64>::for_field("altitude"),
-                    altitude_order,
-                ),
-            ));
-            let actual = searcher
+            Ok(searcher
                 .search(&AllQuery, &top_collector)?
                 .into_iter()
-                .map(|(key, doc)| (key, ids[&doc]))
-                .collect::<Vec<_>>();
-            assert_eq!(actual, expected);
-            Ok(())
+                .map(|(f, doc)| (f, ids[&doc]))
+                .collect())
         }
 
-        assert_query(
-            &index,
-            Order::Asc,
-            Order::Desc,
-            vec![
-                ((Some("austin".to_owned()), Some(149.0)), 0),
-                ((Some("greenville".to_owned()), Some(27.0)), 1),
-                ((Some("tokyo".to_owned()), Some(40.0)), 2),
-                ((None, Some(0.0)), 3),
-            ],
-        )?;
+        assert_eq!(
+            &query(&index, Order::Asc, Order::Asc)?,
+            &[
+                ((1.0, Some("austin".to_owned())), 0),
+                ((1.0, Some("greenville".to_owned())), 1),
+                ((1.0, Some("tokyo".to_owned())), 2),
+                ((1.0, None), 3),
+            ]
+        );
 
+        assert_eq!(
+            &query(&index, Order::Asc, Order::Desc)?,
+            &[
+                ((1.0, Some("tokyo".to_owned())), 2),
+                ((1.0, Some("greenville".to_owned())), 1),
+                ((1.0, Some("austin".to_owned())), 0),
+                ((1.0, None), 3),
+            ]
+        );
         Ok(())
     }
 
@@ -466,14 +372,15 @@ mod tests {
 
             // Using the TopDocs collector should always be equivalent to sorting, skipping the
             // offset, and then taking the limit.
-            let sorted_docs: Vec<_> = {
-                let mut comparable_docs: Vec<ComparableDoc<_, _>> =
+            let sorted_docs: Vec<_> = if order.is_desc() {
+                let mut comparable_docs: Vec<ComparableDoc<_, _, true>> =
                     all_results.into_iter().map(|(sort_key, doc)| ComparableDoc { sort_key, doc}).collect();
-                if order.is_desc() {
-                    comparable_docs.sort_by(|l, r| NaturalComparator.compare_doc(l, r));
-                } else {
-                    comparable_docs.sort_by(|l, r| ReverseComparator.compare_doc(l, r));
-                }
+                comparable_docs.sort();
+                comparable_docs.into_iter().map(|cd| (cd.sort_key, cd.doc)).collect()
+            } else {
+                let mut comparable_docs: Vec<ComparableDoc<_, _, false>> =
+                    all_results.into_iter().map(|(sort_key, doc)| ComparableDoc { sort_key, doc}).collect();
+                comparable_docs.sort();
                 comparable_docs.into_iter().map(|cd| (cd.sort_key, cd.doc)).collect()
             };
             let expected_docs = sorted_docs.into_iter().skip(offset).take(limit).collect::<Vec<_>>();
@@ -483,197 +390,4 @@ mod tests {
             );
         }
     }
-
-    proptest! {
-    #[test]
-    fn test_order_by_compound_prop(
-        city_order in prop_oneof!(Just(Order::Desc), Just(Order::Asc)),
-        altitude_order in prop_oneof!(Just(Order::Desc), Just(Order::Asc)),
-        limit in 1..20_usize,
-        offset in 0..20_usize,
-        segments_data in proptest::collection::vec(
-            proptest::collection::vec(
-                (proptest::option::of("[a-c]"), proptest::option::of(0..50u64)),
-                1..10_usize // segment size
-            ),
-            1..4_usize // num segments
-        )
-    ) {
-        use crate::collector::sort_key::ComparatorEnum;
-        use crate::TantivyDocument;
-
-        let mut schema_builder = Schema::builder();
-        let city = schema_builder.add_text_field("city", TEXT | FAST);
-        let altitude = schema_builder.add_u64_field("altitude", FAST);
-        let schema = schema_builder.build();
-        let index = Index::create_in_ram(schema);
-        let mut index_writer = index.writer_for_tests().unwrap();
-
-        for segment_data in segments_data.into_iter() {
-            for (city_val, altitude_val) in segment_data.into_iter() {
-                let mut doc = TantivyDocument::default();
-                if let Some(c) = city_val {
-                    doc.add_text(city, c);
-                }
-                if let Some(a) = altitude_val {
-                    doc.add_u64(altitude, a);
-                }
-                index_writer.add_document(doc).unwrap();
-            }
-            index_writer.commit().unwrap();
-        }
-
-        let searcher = index.reader().unwrap().searcher();
-
-        let top_collector = TopDocs::with_limit(limit)
-            .and_offset(offset)
-            .order_by((
-                (SortByString::for_field("city"), city_order),
-                (
-                    SortByStaticFastValue::<u64>::for_field("altitude"),
-                    altitude_order,
-                ),
-            ));
-
-        let actual_results = searcher.search(&AllQuery, &top_collector).unwrap();
-        let actual_doc_ids: Vec<DocAddress> =
-            actual_results.into_iter().map(|(_, doc)| doc).collect();
-
-        // Verification logic
-        let all_docs_collector = DocSetCollector;
-        let all_docs = searcher.search(&AllQuery, &all_docs_collector).unwrap();
-
-        let docs_with_keys: Vec<((Option<String>, Option<u64>), DocAddress)> = all_docs
-            .into_iter()
-            .map(|doc_addr| {
-                let reader = searcher.segment_reader(doc_addr.segment_ord);
-
-                let city_val = if let Some(col) = reader.fast_fields().str("city").unwrap() {
-                     let ord = col.ords().first(doc_addr.doc_id);
-                     if let Some(ord) = ord {
-                         let mut out = Vec::new();
-                         col.dictionary().ord_to_term(ord, &mut out).unwrap();
-                         String::from_utf8(out).ok()
-                     } else {
-                         None
-                     }
-                } else {
-                    None
-                };
-
-                let alt_val = if let Some((col, _)) = reader.fast_fields().u64_lenient("altitude").unwrap() {
-                    col.first(doc_addr.doc_id)
-                } else {
-                    None
-                };
-
-                ((city_val, alt_val), doc_addr)
-            })
-            .collect();
-
-        let city_comparator = ComparatorEnum::from(city_order);
-        let alt_comparator = ComparatorEnum::from(altitude_order);
-        let comparator = (city_comparator, alt_comparator);
-
-        let mut comparable_docs: Vec<ComparableDoc<_, _>> = docs_with_keys
-            .into_iter()
-            .map(|(sort_key, doc)| ComparableDoc { sort_key, doc })
-            .collect();
-
-        comparable_docs.sort_by(|l, r| comparator.compare_doc(l, r));
-
-        let expected_results = comparable_docs
-            .into_iter()
-            .skip(offset)
-            .take(limit)
-            .collect::<Vec<_>>();
-
-        let expected_doc_ids: Vec<DocAddress> =
-            expected_results.into_iter().map(|cd| cd.doc).collect();
-
-        prop_assert_eq!(actual_doc_ids, expected_doc_ids);
-    }
-    }
-
-    proptest! {
-    #[test]
-    fn test_order_by_u64_prop(
-        order in prop_oneof!(Just(Order::Desc), Just(Order::Asc)),
-        limit in 1..20_usize,
-        offset in 0..20_usize,
-        segments_data in proptest::collection::vec(
-            proptest::collection::vec(
-                proptest::option::of(0..100u64),
-                1..1000_usize // segment size
-            ),
-            1..4_usize // num segments
-        )
-    ) {
-        use crate::collector::sort_key::ComparatorEnum;
-        use crate::TantivyDocument;
-
-        let mut schema_builder = Schema::builder();
-        let field = schema_builder.add_u64_field("field", FAST);
-        let schema = schema_builder.build();
-        let index = Index::create_in_ram(schema);
-        let mut index_writer = index.writer_for_tests().unwrap();
-
-        for segment_data in segments_data.into_iter() {
-            for val in segment_data.into_iter() {
-                let mut doc = TantivyDocument::default();
-                if let Some(v) = val {
-                    doc.add_u64(field, v);
-                }
-                index_writer.add_document(doc).unwrap();
-            }
-            index_writer.commit().unwrap();
-        }
-
-        let searcher = index.reader().unwrap().searcher();
-
-        let top_collector = TopDocs::with_limit(limit)
-            .and_offset(offset)
-            .order_by((SortByStaticFastValue::<u64>::for_field("field"), order));
-
-        let actual_results = searcher.search(&AllQuery, &top_collector).unwrap();
-        let actual_doc_ids: Vec<DocAddress> =
-            actual_results.into_iter().map(|(_, doc)| doc).collect();
-
-        // Verification logic
-        let all_docs_collector = DocSetCollector;
-        let all_docs = searcher.search(&AllQuery, &all_docs_collector).unwrap();
-
-        let docs_with_keys: Vec<(Option<u64>, DocAddress)> = all_docs
-            .into_iter()
-            .map(|doc_addr| {
-                let reader = searcher.segment_reader(doc_addr.segment_ord);
-                let val = if let Some((col, _)) = reader.fast_fields().u64_lenient("field").unwrap() {
-                    col.first(doc_addr.doc_id)
-                } else {
-                    None
-                };
-                (val, doc_addr)
-            })
-            .collect();
-
-        let comparator = ComparatorEnum::from(order);
-        let mut comparable_docs: Vec<ComparableDoc<_, _>> = docs_with_keys
-            .into_iter()
-            .map(|(sort_key, doc)| ComparableDoc { sort_key, doc })
-            .collect();
-
-        comparable_docs.sort_by(|l, r| comparator.compare_doc(l, r));
-
-        let expected_results = comparable_docs
-            .into_iter()
-            .skip(offset)
-            .take(limit)
-            .collect::<Vec<_>>();
-
-        let expected_doc_ids: Vec<DocAddress> =
-            expected_results.into_iter().map(|cd| cd.doc).collect();
-
-        prop_assert_eq!(actual_doc_ids, expected_doc_ids);
-    }
-    }
 }

src/collector/sort_key/order.rs

@@ -1,103 +1,19 @@
 use std::cmp::Ordering;
 
-use columnar::{MonotonicallyMappableToU64, ValueRange};
 use serde::{Deserialize, Serialize};
 
-use crate::collector::{ComparableDoc, SegmentSortKeyComputer, SortKeyComputer};
-use crate::schema::{OwnedValue, Schema};
+use crate::collector::{SegmentSortKeyComputer, SortKeyComputer};
+use crate::schema::Schema;
 use crate::{DocId, Order, Score};
 
-fn compare_owned_value<const NULLS_FIRST: bool>(lhs: &OwnedValue, rhs: &OwnedValue) -> Ordering {
-    match (lhs, rhs) {
-        (OwnedValue::Null, OwnedValue::Null) => Ordering::Equal,
-        (OwnedValue::Null, _) => {
-            if NULLS_FIRST {
-                Ordering::Less
-            } else {
-                Ordering::Greater
-            }
-        }
-        (_, OwnedValue::Null) => {
-            if NULLS_FIRST {
-                Ordering::Greater
-            } else {
-                Ordering::Less
-            }
-        }
-        (OwnedValue::Str(a), OwnedValue::Str(b)) => a.cmp(b),
-        (OwnedValue::PreTokStr(a), OwnedValue::PreTokStr(b)) => a.cmp(b),
-        (OwnedValue::U64(a), OwnedValue::U64(b)) => a.cmp(b),
-        (OwnedValue::I64(a), OwnedValue::I64(b)) => a.cmp(b),
-        (OwnedValue::F64(a), OwnedValue::F64(b)) => a.to_u64().cmp(&b.to_u64()),
-        (OwnedValue::Bool(a), OwnedValue::Bool(b)) => a.cmp(b),
-        (OwnedValue::Date(a), OwnedValue::Date(b)) => a.cmp(b),
-        (OwnedValue::Facet(a), OwnedValue::Facet(b)) => a.cmp(b),
-        (OwnedValue::Bytes(a), OwnedValue::Bytes(b)) => a.cmp(b),
-        (OwnedValue::IpAddr(a), OwnedValue::IpAddr(b)) => a.cmp(b),
-        (OwnedValue::U64(a), OwnedValue::I64(b)) => {
-            if *b < 0 {
-                Ordering::Greater
-            } else {
-                a.cmp(&(*b as u64))
-            }
-        }
-        (OwnedValue::I64(a), OwnedValue::U64(b)) => {
-            if *a < 0 {
-                Ordering::Less
-            } else {
-                (*a as u64).cmp(b)
-            }
-        }
-        (OwnedValue::U64(a), OwnedValue::F64(b)) => (*a as f64).to_u64().cmp(&b.to_u64()),
-        (OwnedValue::F64(a), OwnedValue::U64(b)) => a.to_u64().cmp(&(*b as f64).to_u64()),
-        (OwnedValue::I64(a), OwnedValue::F64(b)) => (*a as f64).to_u64().cmp(&b.to_u64()),
-        (OwnedValue::F64(a), OwnedValue::I64(b)) => a.to_u64().cmp(&(*b as f64).to_u64()),
-        (a, b) => {
-            let ord = a.discriminant_value().cmp(&b.discriminant_value());
-            // If the discriminant is equal, it's because a new type was added, but hasn't been
-            // included in this `match` statement.
-            assert!(
-                ord != Ordering::Equal,
-                "Unimplemented comparison for type of {a:?}, {b:?}"
-            );
-            ord
-        }
-    }
-}
-
 /// Comparator trait defining the order in which documents should be ordered.
 pub trait Comparator<T>: Send + Sync + std::fmt::Debug + Default {
     /// Return the order between two values.
     fn compare(&self, lhs: &T, rhs: &T) -> Ordering;
-    /// Return the order between two ComparableDoc values, using the semantics which are
-    /// implemented by TopNComputer.
-    #[inline(always)]
-    fn compare_doc<D: Ord>(
-        &self,
-        lhs: &ComparableDoc<T, D>,
-        rhs: &ComparableDoc<T, D>,
-    ) -> Ordering {
-        // TopNComputer sorts in descending order of the SortKey by default: we apply that ordering
-        // here to ease comparison in testing.
-        self.compare(&rhs.sort_key, &lhs.sort_key).then_with(|| {
-            // In case of a tie on the sort key, we always sort by ascending `DocAddress` in order
-            // to ensure a stable sorting of the documents, regardless of the sort key's order.
-            // See the TopNComputer docs for more information.
-            lhs.doc.cmp(&rhs.doc)
-        })
-    }
-
-    /// Return a `ValueRange` that matches all values that are greater than the provided threshold.
-    fn threshold_to_valuerange(&self, threshold: T) -> ValueRange<T>;
 }
 
-/// Compare values naturally (e.g. 1 < 2).
-///
-/// When used with `TopDocs`, which reverses the order, this results in a
-/// "Descending" sort (Greatest values first).
-///
-/// `None` (or Null for `OwnedValue`) values are considered to be smaller than any other value,
-/// and will therefore appear last in a descending sort (e.g. `[Some(20), Some(10), None]`).
+/// With the natural comparator, the top k collector will return
+/// the top documents in decreasing order.
 #[derive(Debug, Copy, Clone, Default, Serialize, Deserialize)]
 pub struct NaturalComparator;
 
@@ -106,116 +22,32 @@ impl<T: PartialOrd> Comparator<T> for NaturalComparator {
     fn compare(&self, lhs: &T, rhs: &T) -> Ordering {
         lhs.partial_cmp(rhs).unwrap()
     }
-
-    fn threshold_to_valuerange(&self, threshold: T) -> ValueRange<T> {
-        ValueRange::GreaterThan(threshold, false)
-    }
 }
 
-/// A (partial) implementation of comparison for OwnedValue.
+/// Sorts document in reverse order.
 ///
-/// Intended for use within columns of homogenous types, and so will panic for OwnedValues with
-/// mismatched types. The one exception is Null, for which we do define all comparisons.
-impl Comparator<OwnedValue> for NaturalComparator {
-    #[inline(always)]
-    fn compare(&self, lhs: &OwnedValue, rhs: &OwnedValue) -> Ordering {
-        compare_owned_value::</* NULLS_FIRST= */ true>(lhs, rhs)
-    }
-
-    fn threshold_to_valuerange(&self, threshold: OwnedValue) -> ValueRange<OwnedValue> {
-        ValueRange::GreaterThan(threshold, false)
-    }
-}
-
-/// Compare values in reverse (e.g. 2 < 1).
-///
-/// When used with `TopDocs`, which reverses the order, this results in an
-/// "Ascending" sort (Smallest values first).
-///
-/// `None` is considered smaller than `Some` in the underlying comparator, but because the
-/// comparison is reversed, `None` is effectively treated as the lowest value in the resulting
-/// Ascending sort (e.g. `[None, Some(10), Some(20)]`).
+/// If the sort key is None, it will considered as the lowest value, and will therefore appear
+/// first.
 ///
 /// The ReverseComparator does not necessarily imply that the sort order is reversed compared
-/// to the NaturalComparator. In presence of a tie on the sort key, documents will always be
-/// sorted by ascending `DocId`/`DocAddress` in TopN results, regardless of the sort key's order.
+/// to the NaturalComparator. In presence of a tie, both version will retain the higher doc ids.
 #[derive(Debug, Copy, Clone, Default, Serialize, Deserialize)]
 pub struct ReverseComparator;
 
-macro_rules! impl_reverse_comparator_primitive {
-    ($($t:ty),*) => {
-        $(
-            impl Comparator<$t> for ReverseComparator {
-                #[inline(always)]
-                fn compare(&self, lhs: &$t, rhs: &$t) -> Ordering {
-                    NaturalComparator.compare(rhs, lhs)
-                }
-
-                fn threshold_to_valuerange(&self, threshold: $t) -> ValueRange<$t> {
-                    ValueRange::LessThan(threshold, true)
-                }
-            }
-        )*
-    }
-}
-
-impl_reverse_comparator_primitive!(
-    bool,
-    u8,
-    u16,
-    u32,
-    u64,
-    u128,
-    usize,
-    i8,
-    i16,
-    i32,
-    i64,
-    i128,
-    isize,
-    f32,
-    f64,
-    String,
-    crate::DateTime,
-    Vec<u8>,
-    crate::schema::Facet
-);
-
-impl<T: PartialOrd + Send + Sync + std::fmt::Debug + Clone + 'static> Comparator<Option<T>>
-    for ReverseComparator
+impl<T> Comparator<T> for ReverseComparator
+where NaturalComparator: Comparator<T>
 {
     #[inline(always)]
-    fn compare(&self, lhs: &Option<T>, rhs: &Option<T>) -> Ordering {
+    fn compare(&self, lhs: &T, rhs: &T) -> Ordering {
         NaturalComparator.compare(rhs, lhs)
     }
-
-    fn threshold_to_valuerange(&self, threshold: Option<T>) -> ValueRange<Option<T>> {
-        let is_some = threshold.is_some();
-        ValueRange::LessThan(threshold, is_some)
-    }
 }
 
-impl Comparator<OwnedValue> for ReverseComparator {
-    #[inline(always)]
-    fn compare(&self, lhs: &OwnedValue, rhs: &OwnedValue) -> Ordering {
-        NaturalComparator.compare(rhs, lhs)
-    }
-
-    fn threshold_to_valuerange(&self, threshold: OwnedValue) -> ValueRange<OwnedValue> {
-        let is_not_null = !matches!(threshold, OwnedValue::Null);
-        ValueRange::LessThan(threshold, is_not_null)
-    }
-}
-
-/// Compare values in reverse, but treating `None` as lower than `Some`.
-///
-/// When used with `TopDocs`, which reverses the order, this results in an
-/// "Ascending" sort (Smallest values first), but with `None` values appearing last
-/// (e.g. `[Some(10), Some(20), None]`).
+/// Sorts document in reverse order, but considers None as having the lowest value.
 ///
 /// This is usually what is wanted when sorting by a field in an ascending order.
-/// For instance, in an e-commerce website, if sorting by price ascending,
-/// the cheapest items would appear first, and items without a price would appear last.
+/// For instance, in a e-commerce website, if I sort by price ascending, I most likely want the
+/// cheapest items first, and the items without a price at last.
 #[derive(Debug, Copy, Clone, Default)]
 pub struct ReverseNoneIsLowerComparator;
 
@@ -231,14 +63,6 @@ where ReverseComparator: Comparator<T>
             (Some(lhs), Some(rhs)) => ReverseComparator.compare(lhs, rhs),
         }
     }
-
-    fn threshold_to_valuerange(&self, threshold: Option<T>) -> ValueRange<Option<T>> {
-        if threshold.is_some() {
-            ValueRange::LessThan(threshold, false)
-        } else {
-            ValueRange::GreaterThan(threshold, false)
-        }
-    }
 }
 
 impl Comparator<u32> for ReverseNoneIsLowerComparator {
@@ -246,10 +70,6 @@ impl Comparator<u32> for ReverseNoneIsLowerComparator {
     fn compare(&self, lhs: &u32, rhs: &u32) -> Ordering {
         ReverseComparator.compare(lhs, rhs)
     }
-
-    fn threshold_to_valuerange(&self, threshold: u32) -> ValueRange<u32> {
-        ValueRange::LessThan(threshold, false)
-    }
 }
 
 impl Comparator<u64> for ReverseNoneIsLowerComparator {
@@ -257,10 +77,6 @@ impl Comparator<u64> for ReverseNoneIsLowerComparator {
     fn compare(&self, lhs: &u64, rhs: &u64) -> Ordering {
         ReverseComparator.compare(lhs, rhs)
     }
-
-    fn threshold_to_valuerange(&self, threshold: u64) -> ValueRange<u64> {
-        ValueRange::LessThan(threshold, false)
-    }
 }
 
 impl Comparator<f64> for ReverseNoneIsLowerComparator {
@@ -268,10 +84,6 @@ impl Comparator<f64> for ReverseNoneIsLowerComparator {
     fn compare(&self, lhs: &f64, rhs: &f64) -> Ordering {
         ReverseComparator.compare(lhs, rhs)
     }
-
-    fn threshold_to_valuerange(&self, threshold: f64) -> ValueRange<f64> {
-        ValueRange::LessThan(threshold, false)
-    }
 }
 
 impl Comparator<f32> for ReverseNoneIsLowerComparator {
@@ -279,10 +91,6 @@ impl Comparator<f32> for ReverseNoneIsLowerComparator {
     fn compare(&self, lhs: &f32, rhs: &f32) -> Ordering {
         ReverseComparator.compare(lhs, rhs)
     }
-
-    fn threshold_to_valuerange(&self, threshold: f32) -> ValueRange<f32> {
-        ValueRange::LessThan(threshold, false)
-    }
 }
 
 impl Comparator<i64> for ReverseNoneIsLowerComparator {
@@ -290,10 +98,6 @@ impl Comparator<i64> for ReverseNoneIsLowerComparator {
     fn compare(&self, lhs: &i64, rhs: &i64) -> Ordering {
         ReverseComparator.compare(lhs, rhs)
     }
-
-    fn threshold_to_valuerange(&self, threshold: i64) -> ValueRange<i64> {
-        ValueRange::LessThan(threshold, false)
-    }
 }
 
 impl Comparator<String> for ReverseNoneIsLowerComparator {
@@ -301,129 +105,6 @@ impl Comparator<String> for ReverseNoneIsLowerComparator {
     fn compare(&self, lhs: &String, rhs: &String) -> Ordering {
         ReverseComparator.compare(lhs, rhs)
     }
-
-    fn threshold_to_valuerange(&self, threshold: String) -> ValueRange<String> {
-        ValueRange::LessThan(threshold, false)
-    }
-}
-
-impl Comparator<OwnedValue> for ReverseNoneIsLowerComparator {
-    #[inline(always)]
-    fn compare(&self, lhs: &OwnedValue, rhs: &OwnedValue) -> Ordering {
-        compare_owned_value::</* NULLS_FIRST= */ false>(rhs, lhs)
-    }
-
-    fn threshold_to_valuerange(&self, threshold: OwnedValue) -> ValueRange<OwnedValue> {
-        ValueRange::LessThan(threshold, false)
-    }
-}
-
-/// Compare values naturally, but treating `None` as higher than `Some`.
-///
-/// When used with `TopDocs`, which reverses the order, this results in a
-/// "Descending" sort (Greatest values first), but with `None` values appearing first
-/// (e.g. `[None, Some(20), Some(10)]`).
-#[derive(Debug, Copy, Clone, Default, Serialize, Deserialize)]
-pub struct NaturalNoneIsHigherComparator;
-
-impl<T> Comparator<Option<T>> for NaturalNoneIsHigherComparator
-where NaturalComparator: Comparator<T>
-{
-    #[inline(always)]
-    fn compare(&self, lhs_opt: &Option<T>, rhs_opt: &Option<T>) -> Ordering {
-        match (lhs_opt, rhs_opt) {
-            (None, None) => Ordering::Equal,
-            (None, Some(_)) => Ordering::Greater,
-            (Some(_), None) => Ordering::Less,
-            (Some(lhs), Some(rhs)) => NaturalComparator.compare(lhs, rhs),
-        }
-    }
-
-    fn threshold_to_valuerange(&self, threshold: Option<T>) -> ValueRange<Option<T>> {
-        if threshold.is_some() {
-            let is_some = threshold.is_some();
-            ValueRange::GreaterThan(threshold, is_some)
-        } else {
-            ValueRange::LessThan(threshold, false)
-        }
-    }
-}
-
-impl Comparator<u32> for NaturalNoneIsHigherComparator {
-    #[inline(always)]
-    fn compare(&self, lhs: &u32, rhs: &u32) -> Ordering {
-        NaturalComparator.compare(lhs, rhs)
-    }
-
-    fn threshold_to_valuerange(&self, threshold: u32) -> ValueRange<u32> {
-        ValueRange::GreaterThan(threshold, true)
-    }
-}
-
-impl Comparator<u64> for NaturalNoneIsHigherComparator {
-    #[inline(always)]
-    fn compare(&self, lhs: &u64, rhs: &u64) -> Ordering {
-        NaturalComparator.compare(lhs, rhs)
-    }
-
-    fn threshold_to_valuerange(&self, threshold: u64) -> ValueRange<u64> {
-        ValueRange::GreaterThan(threshold, true)
-    }
-}
-
-impl Comparator<f64> for NaturalNoneIsHigherComparator {
-    #[inline(always)]
-    fn compare(&self, lhs: &f64, rhs: &f64) -> Ordering {
-        NaturalComparator.compare(lhs, rhs)
-    }
-
-    fn threshold_to_valuerange(&self, threshold: f64) -> ValueRange<f64> {
-        ValueRange::GreaterThan(threshold, true)
-    }
-}
-
-impl Comparator<f32> for NaturalNoneIsHigherComparator {
-    #[inline(always)]
-    fn compare(&self, lhs: &f32, rhs: &f32) -> Ordering {
-        NaturalComparator.compare(lhs, rhs)
-    }
-
-    fn threshold_to_valuerange(&self, threshold: f32) -> ValueRange<f32> {
-        ValueRange::GreaterThan(threshold, true)
-    }
-}
-
-impl Comparator<i64> for NaturalNoneIsHigherComparator {
-    #[inline(always)]
-    fn compare(&self, lhs: &i64, rhs: &i64) -> Ordering {
-        NaturalComparator.compare(lhs, rhs)
-    }
-
-    fn threshold_to_valuerange(&self, threshold: i64) -> ValueRange<i64> {
-        ValueRange::GreaterThan(threshold, true)
-    }
-}
-
-impl Comparator<String> for NaturalNoneIsHigherComparator {
-    #[inline(always)]
-    fn compare(&self, lhs: &String, rhs: &String) -> Ordering {
-        NaturalComparator.compare(lhs, rhs)
-    }
-
-    fn threshold_to_valuerange(&self, threshold: String) -> ValueRange<String> {
-        ValueRange::GreaterThan(threshold, true)
-    }
-}
-
-impl Comparator<OwnedValue> for NaturalNoneIsHigherComparator {
-    #[inline(always)]
-    fn compare(&self, lhs: &OwnedValue, rhs: &OwnedValue) -> Ordering {
-        compare_owned_value::</* NULLS_FIRST= */ false>(lhs, rhs)
-    }
-
-    fn threshold_to_valuerange(&self, threshold: OwnedValue) -> ValueRange<OwnedValue> {
-        ValueRange::GreaterThan(threshold, true)
-    }
 }
 
 /// An enum representing the different sort orders.
@@ -434,10 +115,8 @@ pub enum ComparatorEnum {
     Natural,
     /// Reverse order (See [ReverseComparator])
     Reverse,
-    /// Reverse order by treating None as the lowest value. (See [ReverseNoneLowerComparator])
+    /// Reverse order by treating None as the lowest value.(See [ReverseNoneLowerComparator])
     ReverseNoneLower,
-    /// Natural order but treating None as the highest value. (See [NaturalNoneIsHigherComparator])
-    NaturalNoneHigher,
 }
 
 impl From<Order> for ComparatorEnum {
@@ -454,7 +133,6 @@ where
     ReverseNoneIsLowerComparator: Comparator<T>,
     NaturalComparator: Comparator<T>,
     ReverseComparator: Comparator<T>,
-    NaturalNoneIsHigherComparator: Comparator<T>,
 {
     #[inline(always)]
     fn compare(&self, lhs: &T, rhs: &T) -> Ordering {
@@ -462,20 +140,6 @@ where
             ComparatorEnum::Natural => NaturalComparator.compare(lhs, rhs),
             ComparatorEnum::Reverse => ReverseComparator.compare(lhs, rhs),
             ComparatorEnum::ReverseNoneLower => ReverseNoneIsLowerComparator.compare(lhs, rhs),
-            ComparatorEnum::NaturalNoneHigher => NaturalNoneIsHigherComparator.compare(lhs, rhs),
-        }
-    }
-
-    fn threshold_to_valuerange(&self, threshold: T) -> ValueRange<T> {
-        match self {
-            ComparatorEnum::Natural => NaturalComparator.threshold_to_valuerange(threshold),
-            ComparatorEnum::Reverse => ReverseComparator.threshold_to_valuerange(threshold),
-            ComparatorEnum::ReverseNoneLower => {
-                ReverseNoneIsLowerComparator.threshold_to_valuerange(threshold)
-            }
-            ComparatorEnum::NaturalNoneHigher => {
-                NaturalNoneIsHigherComparator.threshold_to_valuerange(threshold)
-            }
         }
     }
 }
@@ -492,10 +156,6 @@ where
             .compare(&lhs.0, &rhs.0)
             .then_with(|| self.1.compare(&lhs.1, &rhs.1))
     }
-
-    fn threshold_to_valuerange(&self, threshold: (Head, Tail)) -> ValueRange<(Head, Tail)> {
-        ValueRange::GreaterThan(threshold, false)
-    }
 }
 
 impl<Type1, Type2, Type3, Comparator1, Comparator2, Comparator3> Comparator<(Type1, (Type2, Type3))>
@@ -512,13 +172,6 @@ where
             .then_with(|| self.1.compare(&lhs.1 .0, &rhs.1 .0))
             .then_with(|| self.2.compare(&lhs.1 .1, &rhs.1 .1))
     }
-
-    fn threshold_to_valuerange(
-        &self,
-        threshold: (Type1, (Type2, Type3)),
-    ) -> ValueRange<(Type1, (Type2, Type3))> {
-        ValueRange::GreaterThan(threshold, false)
-    }
 }
 
 impl<Type1, Type2, Type3, Comparator1, Comparator2, Comparator3> Comparator<(Type1, Type2, Type3)>
@@ -535,13 +188,6 @@ where
             .then_with(|| self.1.compare(&lhs.1, &rhs.1))
             .then_with(|| self.2.compare(&lhs.2, &rhs.2))
     }
-
-    fn threshold_to_valuerange(
-        &self,
-        threshold: (Type1, Type2, Type3),
-    ) -> ValueRange<(Type1, Type2, Type3)> {
-        ValueRange::GreaterThan(threshold, false)
-    }
 }
 
 impl<Type1, Type2, Type3, Type4, Comparator1, Comparator2, Comparator3, Comparator4>
@@ -565,13 +211,6 @@ where
             .then_with(|| self.2.compare(&lhs.1 .1 .0, &rhs.1 .1 .0))
             .then_with(|| self.3.compare(&lhs.1 .1 .1, &rhs.1 .1 .1))
     }
-
-    fn threshold_to_valuerange(
-        &self,
-        threshold: (Type1, (Type2, (Type3, Type4))),
-    ) -> ValueRange<(Type1, (Type2, (Type3, Type4)))> {
-        ValueRange::GreaterThan(threshold, false)
-    }
 }
 
 impl<Type1, Type2, Type3, Type4, Comparator1, Comparator2, Comparator3, Comparator4>
@@ -595,13 +234,6 @@ where
             .then_with(|| self.2.compare(&lhs.2, &rhs.2))
             .then_with(|| self.3.compare(&lhs.3, &rhs.3))
     }
-
-    fn threshold_to_valuerange(
-        &self,
-        threshold: (Type1, Type2, Type3, Type4),
-    ) -> ValueRange<(Type1, Type2, Type3, Type4)> {
-        ValueRange::GreaterThan(threshold, false)
-    }
 }
 
 impl<TSortKeyComputer> SortKeyComputer for (TSortKeyComputer, ComparatorEnum)
@@ -690,33 +322,16 @@ impl<TSegmentSortKeyComputer, TSegmentSortKey, TComparator> SegmentSortKeyComput
     for SegmentSortKeyComputerWithComparator<TSegmentSortKeyComputer, TComparator>
 where
     TSegmentSortKeyComputer: SegmentSortKeyComputer<SegmentSortKey = TSegmentSortKey>,
-    TSegmentSortKey: Clone + 'static + Sync + Send,
-    TComparator: Comparator<TSegmentSortKey> + Clone + 'static + Sync + Send,
+    TSegmentSortKey: PartialOrd + Clone + 'static + Sync + Send,
+    TComparator: Comparator<TSegmentSortKey> + 'static + Sync + Send,
 {
     type SortKey = TSegmentSortKeyComputer::SortKey;
     type SegmentSortKey = TSegmentSortKey;
-    type SegmentComparator = TComparator;
-    type Buffer = TSegmentSortKeyComputer::Buffer;
-
-    fn segment_comparator(&self) -> Self::SegmentComparator {
-        self.comparator.clone()
-    }
 
     fn segment_sort_key(&mut self, doc: DocId, score: Score) -> Self::SegmentSortKey {
         self.segment_sort_key_computer.segment_sort_key(doc, score)
     }
 
-    fn segment_sort_keys(
-        &mut self,
-        input_docs: &[DocId],
-        output: &mut Vec<ComparableDoc<Self::SegmentSortKey, DocId>>,
-        buffer: &mut Self::Buffer,
-        filter: ValueRange<Self::SegmentSortKey>,
-    ) {
-        self.segment_sort_key_computer
-            .segment_sort_keys(input_docs, output, buffer, filter)
-    }
-
     #[inline(always)]
     fn compare_segment_sort_key(
         &self,
@@ -731,55 +346,3 @@ where
             .convert_segment_sort_key(sort_key)
     }
 }
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use crate::schema::OwnedValue;
-
-    #[test]
-    fn test_mixed_ownedvalue_compare() {
-        let u = OwnedValue::U64(10);
-        let i = OwnedValue::I64(10);
-        let f = OwnedValue::F64(10.0);
-
-        let nc = NaturalComparator::default();
-        assert_eq!(nc.compare(&u, &i), Ordering::Equal);
-        assert_eq!(nc.compare(&u, &f), Ordering::Equal);
-        assert_eq!(nc.compare(&i, &f), Ordering::Equal);
-
-        let u2 = OwnedValue::U64(11);
-        assert_eq!(nc.compare(&u2, &f), Ordering::Greater);
-
-        let s = OwnedValue::Str("a".to_string());
-        // Str < U64
-        assert_eq!(nc.compare(&s, &u), Ordering::Less);
-        // Str < I64
-        assert_eq!(nc.compare(&s, &i), Ordering::Less);
-        // Str < F64
-        assert_eq!(nc.compare(&s, &f), Ordering::Less);
-    }
-
-    #[test]
-    fn test_natural_none_is_higher() {
-        let comp = NaturalNoneIsHigherComparator;
-        let null = OwnedValue::Null;
-        let v1 = OwnedValue::U64(1);
-        let v2 = OwnedValue::U64(2);
-
-        // NaturalNoneIsGreaterComparator logic:
-        // 1. Delegates to NaturalComparator for non-nulls.
-        // NaturalComparator compare(2, 1) -> 2.cmp(1) -> Greater.
-        assert_eq!(comp.compare(&v2, &v1), Ordering::Greater);
-
-        // 2. Treats None (Null) as Greater than any value.
-        // compare(Null, 2) should be Greater.
-        assert_eq!(comp.compare(&null, &v2), Ordering::Greater);
-
-        // compare(1, Null) should be Less.
-        assert_eq!(comp.compare(&v1, &null), Ordering::Less);
-
-        // compare(Null, Null) should be Equal.
-        assert_eq!(comp.compare(&null, &null), Ordering::Equal);
-    }
-}

src/collector/sort_key/sort_by_erased_type.rs

@@ -1,410 +0,0 @@
-use columnar::{ColumnType, MonotonicallyMappableToU64, ValueRange};
-
-use crate::collector::sort_key::sort_by_score::SortBySimilarityScoreSegmentComputer;
-use crate::collector::sort_key::{
-    NaturalComparator, SortBySimilarityScore, SortByStaticFastValue, SortByString,
-};
-use crate::collector::{ComparableDoc, SegmentSortKeyComputer, SortKeyComputer};
-use crate::fastfield::FastFieldNotAvailableError;
-use crate::schema::OwnedValue;
-use crate::{DateTime, DocId, Score};
-
-/// Sort by the boxed / OwnedValue representation of either a fast field, or of the score.
-///
-/// Using the OwnedValue representation allows for type erasure, and can be useful when sort orders
-/// are not known until runtime. But it comes with a performance cost: wherever possible, prefer to
-/// use a SortKeyComputer implementation with a known-type at compile time.
-#[derive(Debug, Clone)]
-pub enum SortByErasedType {
-    /// Sort by a fast field
-    Field(String),
-    /// Sort by score
-    Score,
-}
-
-impl SortByErasedType {
-    /// Creates a new sort key computer which will sort by the given fast field column, with type
-    /// erasure.
-    pub fn for_field(column_name: impl ToString) -> Self {
-        Self::Field(column_name.to_string())
-    }
-
-    /// Creates a new sort key computer which will sort by score, with type erasure.
-    pub fn for_score() -> Self {
-        Self::Score
-    }
-}
-
-trait ErasedSegmentSortKeyComputer: Send + Sync {
-    fn segment_sort_key(&mut self, doc: DocId, score: Score) -> Option<u64>;
-    fn segment_sort_keys(
-        &mut self,
-        input_docs: &[DocId],
-        output: &mut Vec<ComparableDoc<Option<u64>, DocId>>,
-        filter: ValueRange<Option<u64>>,
-    );
-    fn convert_segment_sort_key(&self, sort_key: Option<u64>) -> OwnedValue;
-}
-
-struct ErasedSegmentSortKeyComputerWrapper<C, F>
-where
-    C: SegmentSortKeyComputer<SegmentSortKey = Option<u64>> + Send + Sync,
-    F: Fn(C::SortKey) -> OwnedValue + Send + Sync + 'static,
-{
-    inner: C,
-    converter: F,
-    buffer: C::Buffer,
-}
-
-impl<C, F> ErasedSegmentSortKeyComputer for ErasedSegmentSortKeyComputerWrapper<C, F>
-where
-    C: SegmentSortKeyComputer<SegmentSortKey = Option<u64>> + Send + Sync,
-    F: Fn(C::SortKey) -> OwnedValue + Send + Sync + 'static,
-{
-    fn segment_sort_key(&mut self, doc: DocId, score: Score) -> Option<u64> {
-        self.inner.segment_sort_key(doc, score)
-    }
-
-    fn segment_sort_keys(
-        &mut self,
-        input_docs: &[DocId],
-        output: &mut Vec<ComparableDoc<Option<u64>, DocId>>,
-        filter: ValueRange<Option<u64>>,
-    ) {
-        self.inner
-            .segment_sort_keys(input_docs, output, &mut self.buffer, filter)
-    }
-
-    fn convert_segment_sort_key(&self, sort_key: Option<u64>) -> OwnedValue {
-        let val = self.inner.convert_segment_sort_key(sort_key);
-        (self.converter)(val)
-    }
-}
-
-struct ScoreSegmentSortKeyComputer {
-    segment_computer: SortBySimilarityScoreSegmentComputer,
-}
-
-impl ErasedSegmentSortKeyComputer for ScoreSegmentSortKeyComputer {
-    fn segment_sort_key(&mut self, doc: DocId, score: Score) -> Option<u64> {
-        let score_value: f64 = self.segment_computer.segment_sort_key(doc, score).into();
-        Some(score_value.to_u64())
-    }
-
-    fn segment_sort_keys(
-        &mut self,
-        _input_docs: &[DocId],
-        _output: &mut Vec<ComparableDoc<Option<u64>, DocId>>,
-        _filter: ValueRange<Option<u64>>,
-    ) {
-        unimplemented!("Batch computation not supported for score sorting")
-    }
-
-    fn convert_segment_sort_key(&self, sort_key: Option<u64>) -> OwnedValue {
-        let score_value: u64 = sort_key.expect("This implementation always produces a score.");
-        OwnedValue::F64(f64::from_u64(score_value))
-    }
-}
-
-impl SortKeyComputer for SortByErasedType {
-    type SortKey = OwnedValue;
-    type Child = ErasedColumnSegmentSortKeyComputer;
-    type Comparator = NaturalComparator;
-
-    fn requires_scoring(&self) -> bool {
-        matches!(self, Self::Score)
-    }
-
-    fn segment_sort_key_computer(
-        &self,
-        segment_reader: &crate::SegmentReader,
-    ) -> crate::Result<Self::Child> {
-        let inner: Box<dyn ErasedSegmentSortKeyComputer> = match self {
-            Self::Field(column_name) => {
-                let fast_fields = segment_reader.fast_fields();
-                // TODO: We currently double-open the column to avoid relying on the implementation
-                // details of `SortByString` or `SortByStaticFastValue`. Once
-                // https://github.com/quickwit-oss/tantivy/issues/2776 is resolved, we should
-                // consider directly constructing the appropriate `SegmentSortKeyComputer` type for
-                // the column that we open here.
-                let (_column, column_type) =
-                    fast_fields.u64_lenient(column_name)?.ok_or_else(|| {
-                        FastFieldNotAvailableError {
-                            field_name: column_name.to_owned(),
-                        }
-                    })?;
-
-                match column_type {
-                    ColumnType::Str => {
-                        let computer = SortByString::for_field(column_name);
-                        let inner = computer.segment_sort_key_computer(segment_reader)?;
-                        Box::new(ErasedSegmentSortKeyComputerWrapper {
-                            inner,
-                            converter: |val: Option<String>| {
-                                val.map(OwnedValue::Str).unwrap_or(OwnedValue::Null)
-                            },
-                            buffer: Default::default(),
-                        })
-                    }
-                    ColumnType::U64 => {
-                        let computer = SortByStaticFastValue::<u64>::for_field(column_name);
-                        let inner = computer.segment_sort_key_computer(segment_reader)?;
-                        Box::new(ErasedSegmentSortKeyComputerWrapper {
-                            inner,
-                            converter: |val: Option<u64>| {
-                                val.map(OwnedValue::U64).unwrap_or(OwnedValue::Null)
-                            },
-                            buffer: Default::default(),
-                        })
-                    }
-                    ColumnType::I64 => {
-                        let computer = SortByStaticFastValue::<i64>::for_field(column_name);
-                        let inner = computer.segment_sort_key_computer(segment_reader)?;
-                        Box::new(ErasedSegmentSortKeyComputerWrapper {
-                            inner,
-                            converter: |val: Option<i64>| {
-                                val.map(OwnedValue::I64).unwrap_or(OwnedValue::Null)
-                            },
-                            buffer: Default::default(),
-                        })
-                    }
-                    ColumnType::F64 => {
-                        let computer = SortByStaticFastValue::<f64>::for_field(column_name);
-                        let inner = computer.segment_sort_key_computer(segment_reader)?;
-                        Box::new(ErasedSegmentSortKeyComputerWrapper {
-                            inner,
-                            converter: |val: Option<f64>| {
-                                val.map(OwnedValue::F64).unwrap_or(OwnedValue::Null)
-                            },
-                            buffer: Default::default(),
-                        })
-                    }
-                    ColumnType::Bool => {
-                        let computer = SortByStaticFastValue::<bool>::for_field(column_name);
-                        let inner = computer.segment_sort_key_computer(segment_reader)?;
-                        Box::new(ErasedSegmentSortKeyComputerWrapper {
-                            inner,
-                            converter: |val: Option<bool>| {
-                                val.map(OwnedValue::Bool).unwrap_or(OwnedValue::Null)
-                            },
-                            buffer: Default::default(),
-                        })
-                    }
-                    ColumnType::DateTime => {
-                        let computer = SortByStaticFastValue::<DateTime>::for_field(column_name);
-                        let inner = computer.segment_sort_key_computer(segment_reader)?;
-                        Box::new(ErasedSegmentSortKeyComputerWrapper {
-                            inner,
-                            converter: |val: Option<DateTime>| {
-                                val.map(OwnedValue::Date).unwrap_or(OwnedValue::Null)
-                            },
-                            buffer: Default::default(),
-                        })
-                    }
-                    column_type => {
-                        return Err(crate::TantivyError::SchemaError(format!(
-                            "Field `{}` is of type {column_type:?}, which is not supported for \
-                             sorting by owned value yet.",
-                            column_name
-                        )))
-                    }
-                }
-            }
-            Self::Score => Box::new(ScoreSegmentSortKeyComputer {
-                segment_computer: SortBySimilarityScore
-                    .segment_sort_key_computer(segment_reader)?,
-            }),
-        };
-        Ok(ErasedColumnSegmentSortKeyComputer { inner })
-    }
-}
-
-pub struct ErasedColumnSegmentSortKeyComputer {
-    inner: Box<dyn ErasedSegmentSortKeyComputer>,
-}
-
-impl SegmentSortKeyComputer for ErasedColumnSegmentSortKeyComputer {
-    type SortKey = OwnedValue;
-    type SegmentSortKey = Option<u64>;
-    type SegmentComparator = NaturalComparator;
-    type Buffer = ();
-
-    #[inline(always)]
-    fn segment_sort_key(&mut self, doc: DocId, score: Score) -> Option<u64> {
-        self.inner.segment_sort_key(doc, score)
-    }
-
-    fn segment_sort_keys(
-        &mut self,
-        input_docs: &[DocId],
-        output: &mut Vec<ComparableDoc<Self::SegmentSortKey, DocId>>,
-        _buffer: &mut Self::Buffer,
-        filter: ValueRange<Self::SegmentSortKey>,
-    ) {
-        self.inner.segment_sort_keys(input_docs, output, filter)
-    }
-
-    fn convert_segment_sort_key(&self, segment_sort_key: Self::SegmentSortKey) -> OwnedValue {
-        self.inner.convert_segment_sort_key(segment_sort_key)
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use crate::collector::sort_key::{ComparatorEnum, SortByErasedType};
-    use crate::collector::TopDocs;
-    use crate::query::AllQuery;
-    use crate::schema::{OwnedValue, Schema, FAST, TEXT};
-    use crate::Index;
-
-    #[test]
-    fn test_sort_by_owned_u64() {
-        let mut schema_builder = Schema::builder();
-        let id_field = schema_builder.add_u64_field("id", FAST);
-        let schema = schema_builder.build();
-        let index = Index::create_in_ram(schema);
-        let mut writer = index.writer_for_tests().unwrap();
-        writer.add_document(doc!(id_field => 10u64)).unwrap();
-        writer.add_document(doc!(id_field => 2u64)).unwrap();
-        writer.add_document(doc!()).unwrap();
-        writer.commit().unwrap();
-
-        let reader = index.reader().unwrap();
-        let searcher = reader.searcher();
-
-        let collector = TopDocs::with_limit(10)
-            .order_by((SortByErasedType::for_field("id"), ComparatorEnum::Natural));
-        let top_docs = searcher.search(&AllQuery, &collector).unwrap();
-
-        let values: Vec<OwnedValue> = top_docs.into_iter().map(|(key, _)| key).collect();
-
-        assert_eq!(
-            values,
-            vec![OwnedValue::U64(10), OwnedValue::U64(2), OwnedValue::Null]
-        );
-
-        let collector = TopDocs::with_limit(10).order_by((
-            SortByErasedType::for_field("id"),
-            ComparatorEnum::ReverseNoneLower,
-        ));
-        let top_docs = searcher.search(&AllQuery, &collector).unwrap();
-
-        let values: Vec<OwnedValue> = top_docs.into_iter().map(|(key, _)| key).collect();
-
-        assert_eq!(
-            values,
-            vec![OwnedValue::U64(2), OwnedValue::U64(10), OwnedValue::Null]
-        );
-    }
-
-    #[test]
-    fn test_sort_by_owned_string() {
-        let mut schema_builder = Schema::builder();
-        let city_field = schema_builder.add_text_field("city", FAST | TEXT);
-        let schema = schema_builder.build();
-        let index = Index::create_in_ram(schema);
-        let mut writer = index.writer_for_tests().unwrap();
-        writer.add_document(doc!(city_field => "tokyo")).unwrap();
-        writer.add_document(doc!(city_field => "austin")).unwrap();
-        writer.add_document(doc!()).unwrap();
-        writer.commit().unwrap();
-
-        let reader = index.reader().unwrap();
-        let searcher = reader.searcher();
-
-        let collector = TopDocs::with_limit(10).order_by((
-            SortByErasedType::for_field("city"),
-            ComparatorEnum::ReverseNoneLower,
-        ));
-        let top_docs = searcher.search(&AllQuery, &collector).unwrap();
-
-        let values: Vec<OwnedValue> = top_docs.into_iter().map(|(key, _)| key).collect();
-
-        assert_eq!(
-            values,
-            vec![
-                OwnedValue::Str("austin".to_string()),
-                OwnedValue::Str("tokyo".to_string()),
-                OwnedValue::Null
-            ]
-        );
-    }
-
-    #[test]
-    fn test_sort_by_owned_reverse() {
-        let mut schema_builder = Schema::builder();
-        let id_field = schema_builder.add_u64_field("id", FAST);
-        let schema = schema_builder.build();
-        let index = Index::create_in_ram(schema);
-        let mut writer = index.writer_for_tests().unwrap();
-        writer.add_document(doc!(id_field => 10u64)).unwrap();
-        writer.add_document(doc!(id_field => 2u64)).unwrap();
-        writer.add_document(doc!()).unwrap();
-        writer.commit().unwrap();
-
-        let reader = index.reader().unwrap();
-        let searcher = reader.searcher();
-
-        let collector = TopDocs::with_limit(10)
-            .order_by((SortByErasedType::for_field("id"), ComparatorEnum::Reverse));
-        let top_docs = searcher.search(&AllQuery, &collector).unwrap();
-
-        let values: Vec<OwnedValue> = top_docs.into_iter().map(|(key, _)| key).collect();
-
-        assert_eq!(
-            values,
-            vec![OwnedValue::Null, OwnedValue::U64(2), OwnedValue::U64(10)]
-        );
-    }
-
-    #[test]
-    fn test_sort_by_owned_score() {
-        let mut schema_builder = Schema::builder();
-        let body_field = schema_builder.add_text_field("body", TEXT);
-        let schema = schema_builder.build();
-        let index = Index::create_in_ram(schema);
-        let mut writer = index.writer_for_tests().unwrap();
-        writer.add_document(doc!(body_field => "a a")).unwrap();
-        writer.add_document(doc!(body_field => "a")).unwrap();
-        writer.commit().unwrap();
-
-        let reader = index.reader().unwrap();
-        let searcher = reader.searcher();
-        let query_parser = crate::query::QueryParser::for_index(&index, vec![body_field]);
-        let query = query_parser.parse_query("a").unwrap();
-
-        // Sort by score descending (Natural)
-        let collector = TopDocs::with_limit(10)
-            .order_by((SortByErasedType::for_score(), ComparatorEnum::Natural));
-        let top_docs = searcher.search(&query, &collector).unwrap();
-
-        let values: Vec<f64> = top_docs
-            .into_iter()
-            .map(|(key, _)| match key {
-                OwnedValue::F64(val) => val,
-                _ => panic!("Wrong type {:?}", key),
-            })
-            .collect();
-
-        assert_eq!(values.len(), 2);
-        assert!(values[0] > values[1]);
-
-        // Sort by score ascending (ReverseNoneLower)
-        let collector = TopDocs::with_limit(10).order_by((
-            SortByErasedType::for_score(),
-            ComparatorEnum::ReverseNoneLower,
-        ));
-        let top_docs = searcher.search(&query, &collector).unwrap();
-
-        let values: Vec<f64> = top_docs
-            .into_iter()
-            .map(|(key, _)| match key {
-                OwnedValue::F64(val) => val,
-                _ => panic!("Wrong type {:?}", key),
-            })
-            .collect();
-
-        assert_eq!(values.len(), 2);
-        assert!(values[0] < values[1]);
-    }
-}

src/collector/sort_key/sort_by_score.rs

@@ -1,7 +1,5 @@
-use columnar::ValueRange;
-
 use crate::collector::sort_key::NaturalComparator;
-use crate::collector::{ComparableDoc, SegmentSortKeyComputer, SortKeyComputer, TopNComputer};
+use crate::collector::{SegmentSortKeyComputer, SortKeyComputer, TopNComputer};
 use crate::{DocAddress, DocId, Score};
 
 /// Sort by similarity score.
@@ -11,7 +9,7 @@ pub struct SortBySimilarityScore;
 impl SortKeyComputer for SortBySimilarityScore {
     type SortKey = Score;
 
-    type Child = SortBySimilarityScoreSegmentComputer;
+    type Child = SortBySimilarityScore;
 
     type Comparator = NaturalComparator;
 
@@ -23,7 +21,7 @@ impl SortKeyComputer for SortBySimilarityScore {
         &self,
         _segment_reader: &crate::SegmentReader,
     ) -> crate::Result<Self::Child> {
-        Ok(SortBySimilarityScoreSegmentComputer)
+        Ok(SortBySimilarityScore)
     }
 
     // Sorting by score is special in that it allows for the Block-Wand optimization.
@@ -63,29 +61,16 @@ impl SortKeyComputer for SortBySimilarityScore {
     }
 }
 
-pub struct SortBySimilarityScoreSegmentComputer;
-
-impl SegmentSortKeyComputer for SortBySimilarityScoreSegmentComputer {
+impl SegmentSortKeyComputer for SortBySimilarityScore {
     type SortKey = Score;
+
     type SegmentSortKey = Score;
-    type SegmentComparator = NaturalComparator;
-    type Buffer = ();
 
     #[inline(always)]
     fn segment_sort_key(&mut self, _doc: DocId, score: Score) -> Score {
         score
     }
 
-    fn segment_sort_keys(
-        &mut self,
-        _input_docs: &[DocId],
-        _output: &mut Vec<ComparableDoc<Self::SegmentSortKey, DocId>>,
-        _buffer: &mut Self::Buffer,
-        _filter: ValueRange<Self::SegmentSortKey>,
-    ) {
-        unimplemented!("Batch computation not supported for score sorting")
-    }
-
     fn convert_segment_sort_key(&self, score: Score) -> Score {
         score
     }

src/collector/sort_key/sort_by_static_fast_value.rs

@@ -1,10 +1,9 @@
 use std::marker::PhantomData;
 
-use columnar::{Column, ValueRange};
+use columnar::Column;
 
-use crate::collector::sort_key::sort_key_computer::convert_optional_u64_range_to_u64_range;
 use crate::collector::sort_key::NaturalComparator;
-use crate::collector::{ComparableDoc, SegmentSortKeyComputer, SortKeyComputer};
+use crate::collector::{SegmentSortKeyComputer, SortKeyComputer};
 use crate::fastfield::{FastFieldNotAvailableError, FastValue};
 use crate::{DocId, Score, SegmentReader};
 
@@ -35,7 +34,9 @@ impl<T: FastValue> SortByStaticFastValue<T> {
 
 impl<T: FastValue> SortKeyComputer for SortByStaticFastValue<T> {
     type Child = SortByFastValueSegmentSortKeyComputer<T>;
+
     type SortKey = Option<T>;
+
     type Comparator = NaturalComparator;
 
     fn check_schema(&self, schema: &crate::schema::Schema) -> crate::Result<()> {
@@ -83,112 +84,15 @@ pub struct SortByFastValueSegmentSortKeyComputer<T> {
 
 impl<T: FastValue> SegmentSortKeyComputer for SortByFastValueSegmentSortKeyComputer<T> {
     type SortKey = Option<T>;
+
     type SegmentSortKey = Option<u64>;
-    type SegmentComparator = NaturalComparator;
-    type Buffer = ();
 
     #[inline(always)]
     fn segment_sort_key(&mut self, doc: DocId, _score: Score) -> Self::SegmentSortKey {
         self.sort_column.first(doc)
     }
 
-    fn segment_sort_keys(
-        &mut self,
-        input_docs: &[DocId],
-        output: &mut Vec<ComparableDoc<Self::SegmentSortKey, DocId>>,
-        _buffer: &mut Self::Buffer,
-        filter: ValueRange<Self::SegmentSortKey>,
-    ) {
-        let u64_filter = convert_optional_u64_range_to_u64_range(filter);
-        self.sort_column
-            .first_vals_in_value_range(input_docs, output, u64_filter);
-    }
-
     fn convert_segment_sort_key(&self, sort_key: Self::SegmentSortKey) -> Self::SortKey {
         sort_key.map(T::from_u64)
     }
 }
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use crate::schema::{Schema, FAST};
-    use crate::Index;
-
-    #[test]
-    fn test_sort_by_fast_value_batch() {
-        let mut schema_builder = Schema::builder();
-        let field_col = schema_builder.add_u64_field("field", FAST);
-        let schema = schema_builder.build();
-        let index = Index::create_in_ram(schema);
-        let mut index_writer = index.writer_for_tests().unwrap();
-
-        index_writer
-            .add_document(crate::doc!(field_col => 10u64))
-            .unwrap();
-        index_writer
-            .add_document(crate::doc!(field_col => 20u64))
-            .unwrap();
-        index_writer.add_document(crate::doc!()).unwrap();
-        index_writer.commit().unwrap();
-
-        let reader = index.reader().unwrap();
-        let searcher = reader.searcher();
-        let segment_reader = searcher.segment_reader(0);
-
-        let sorter = SortByStaticFastValue::<u64>::for_field("field");
-        let mut computer = sorter.segment_sort_key_computer(segment_reader).unwrap();
-
-        let mut docs = vec![0, 1, 2];
-        let mut output = Vec::new();
-        let mut buffer = ();
-        computer.segment_sort_keys(&mut docs, &mut output, &mut buffer, ValueRange::All);
-
-        assert_eq!(
-            output.iter().map(|c| c.sort_key).collect::<Vec<_>>(),
-            &[Some(10), Some(20), None]
-        );
-        assert_eq!(output.iter().map(|c| c.doc).collect::<Vec<_>>(), &[0, 1, 2]);
-    }
-
-    #[test]
-    fn test_sort_by_fast_value_batch_with_filter() {
-        let mut schema_builder = Schema::builder();
-        let field_col = schema_builder.add_u64_field("field", FAST);
-        let schema = schema_builder.build();
-        let index = Index::create_in_ram(schema);
-        let mut index_writer = index.writer_for_tests().unwrap();
-
-        index_writer
-            .add_document(crate::doc!(field_col => 10u64))
-            .unwrap();
-        index_writer
-            .add_document(crate::doc!(field_col => 20u64))
-            .unwrap();
-        index_writer.add_document(crate::doc!()).unwrap();
-        index_writer.commit().unwrap();
-
-        let reader = index.reader().unwrap();
-        let searcher = reader.searcher();
-        let segment_reader = searcher.segment_reader(0);
-
-        let sorter = SortByStaticFastValue::<u64>::for_field("field");
-        let mut computer = sorter.segment_sort_key_computer(segment_reader).unwrap();
-
-        let mut docs = vec![0, 1, 2];
-        let mut output = Vec::new();
-        let mut buffer = ();
-        computer.segment_sort_keys(
-            &mut docs,
-            &mut output,
-            &mut buffer,
-            ValueRange::GreaterThan(Some(15u64), false /* inclusive */),
-        );
-
-        assert_eq!(
-            output.iter().map(|c| c.sort_key).collect::<Vec<_>>(),
-            &[Some(20)]
-        );
-        assert_eq!(output.iter().map(|c| c.doc).collect::<Vec<_>>(), &[1]);
-    }
-}

src/collector/sort_key/sort_by_string.rs

@@ -1,10 +1,7 @@
-use columnar::{StrColumn, ValueRange};
+use columnar::StrColumn;
 
-use crate::collector::sort_key::sort_key_computer::{
-    convert_optional_u64_range_to_u64_range, range_contains_none,
-};
 use crate::collector::sort_key::NaturalComparator;
-use crate::collector::{ComparableDoc, SegmentSortKeyComputer, SortKeyComputer};
+use crate::collector::{SegmentSortKeyComputer, SortKeyComputer};
 use crate::termdict::TermOrdinal;
 use crate::{DocId, Score};
 
@@ -33,7 +30,9 @@ impl SortByString {
 
 impl SortKeyComputer for SortByString {
     type SortKey = Option<String>;
+
     type Child = ByStringColumnSegmentSortKeyComputer;
+
     type Comparator = NaturalComparator;
 
     fn segment_sort_key_computer(
@@ -51,9 +50,8 @@ pub struct ByStringColumnSegmentSortKeyComputer {
 
 impl SegmentSortKeyComputer for ByStringColumnSegmentSortKeyComputer {
     type SortKey = Option<String>;
+
     type SegmentSortKey = Option<TermOrdinal>;
-    type SegmentComparator = NaturalComparator;
-    type Buffer = ();
 
     #[inline(always)]
     fn segment_sort_key(&mut self, doc: DocId, _score: Score) -> Option<TermOrdinal> {
@@ -61,31 +59,7 @@ impl SegmentSortKeyComputer for ByStringColumnSegmentSortKeyComputer {
         str_column.ords().first(doc)
     }
 
-    fn segment_sort_keys(
-        &mut self,
-        input_docs: &[DocId],
-        output: &mut Vec<ComparableDoc<Self::SegmentSortKey, DocId>>,
-        _buffer: &mut Self::Buffer,
-        filter: ValueRange<Self::SegmentSortKey>,
-    ) {
-        if let Some(str_column) = &self.str_column_opt {
-            let u64_filter = convert_optional_u64_range_to_u64_range(filter);
-            str_column
-                .ords()
-                .first_vals_in_value_range(input_docs, output, u64_filter);
-        } else if range_contains_none(&filter) {
-            for &doc in input_docs {
-                output.push(ComparableDoc {
-                    doc,
-                    sort_key: None,
-                });
-            }
-        }
-    }
-
     fn convert_segment_sort_key(&self, term_ord_opt: Option<TermOrdinal>) -> Option<String> {
-        // TODO: Individual lookups to the dictionary like this are very likely to repeatedly
-        // decompress the same blocks. See https://github.com/quickwit-oss/tantivy/issues/2776
         let term_ord = term_ord_opt?;
         let str_column = self.str_column_opt.as_ref()?;
         let mut bytes = Vec::new();
@@ -96,90 +70,3 @@ impl SegmentSortKeyComputer for ByStringColumnSegmentSortKeyComputer {
         String::try_from(bytes).ok()
     }
 }
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use crate::schema::{Schema, FAST, TEXT};
-    use crate::Index;
-
-    #[test]
-    fn test_sort_by_string_batch() {
-        let mut schema_builder = Schema::builder();
-        let field_col = schema_builder.add_text_field("field", FAST | TEXT);
-        let schema = schema_builder.build();
-        let index = Index::create_in_ram(schema);
-        let mut index_writer = index.writer_for_tests().unwrap();
-
-        index_writer
-            .add_document(crate::doc!(field_col => "a"))
-            .unwrap();
-        index_writer
-            .add_document(crate::doc!(field_col => "c"))
-            .unwrap();
-        index_writer.add_document(crate::doc!()).unwrap();
-        index_writer.commit().unwrap();
-
-        let reader = index.reader().unwrap();
-        let searcher = reader.searcher();
-        let segment_reader = searcher.segment_reader(0);
-
-        let sorter = SortByString::for_field("field");
-        let mut computer = sorter.segment_sort_key_computer(segment_reader).unwrap();
-
-        let mut docs = vec![0, 1, 2];
-        let mut output = Vec::new();
-        let mut buffer = ();
-        computer.segment_sort_keys(&mut docs, &mut output, &mut buffer, ValueRange::All);
-
-        assert_eq!(
-            output.iter().map(|c| c.sort_key).collect::<Vec<_>>(),
-            &[Some(0), Some(1), None]
-        );
-        assert_eq!(output.iter().map(|c| c.doc).collect::<Vec<_>>(), &[0, 1, 2]);
-    }
-
-    #[test]
-    fn test_sort_by_string_batch_with_filter() {
-        let mut schema_builder = Schema::builder();
-        let field_col = schema_builder.add_text_field("field", FAST | TEXT);
-        let schema = schema_builder.build();
-        let index = Index::create_in_ram(schema);
-        let mut index_writer = index.writer_for_tests().unwrap();
-
-        index_writer
-            .add_document(crate::doc!(field_col => "a"))
-            .unwrap();
-        index_writer
-            .add_document(crate::doc!(field_col => "c"))
-            .unwrap();
-        index_writer.add_document(crate::doc!()).unwrap();
-        index_writer.commit().unwrap();
-
-        let reader = index.reader().unwrap();
-        let searcher = reader.searcher();
-        let segment_reader = searcher.segment_reader(0);
-
-        let sorter = SortByString::for_field("field");
-        let mut computer = sorter.segment_sort_key_computer(segment_reader).unwrap();
-
-        let mut docs = vec![0, 1, 2];
-        let mut output = Vec::new();
-        // Filter: > "b". "a" is 0, "c" is 1.
-        // We want > "a" (ord 0). So we filter > ord 0.
-        // 0 is "a", 1 is "c".
-        let mut buffer = ();
-        computer.segment_sort_keys(
-            &mut docs,
-            &mut output,
-            &mut buffer,
-            ValueRange::GreaterThan(Some(0), false /* inclusive */),
-        );
-
-        assert_eq!(
-            output.iter().map(|c| c.sort_key).collect::<Vec<_>>(),
-            &[Some(1)]
-        );
-        assert_eq!(output.iter().map(|c| c.doc).collect::<Vec<_>>(), &[1]);
-    }
-}

src/collector/sort_key/sort_key_computer.rs

@@ -1,12 +1,8 @@
 use std::cmp::Ordering;
 
-use columnar::ValueRange;
-
 use crate::collector::sort_key::{Comparator, NaturalComparator};
 use crate::collector::sort_key_top_collector::TopBySortKeySegmentCollector;
-use crate::collector::{
-    default_collect_segment_impl, ComparableDoc, SegmentCollector as _, TopNComputer,
-};
+use crate::collector::{default_collect_segment_impl, SegmentCollector as _, TopNComputer};
 use crate::schema::Schema;
 use crate::{DocAddress, DocId, Result, Score, SegmentReader};
 
@@ -16,40 +12,17 @@ use crate::{DocAddress, DocId, Result, Score, SegmentReader};
 /// It is the segment local version of the [`SortKeyComputer`].
 pub trait SegmentSortKeyComputer: 'static {
     /// The final score being emitted.
-    type SortKey: 'static + Send + Sync + Clone;
+    type SortKey: 'static + PartialOrd + Send + Sync + Clone;
 
     /// Sort key used by at the segment level by the `SegmentSortKeyComputer`.
     ///
     /// It is typically small like a `u64`, and is meant to be converted
     /// to the final score at the end of the collection of the segment.
-    type SegmentSortKey: 'static + Clone + Send + Sync + Clone;
-
-    /// Comparator type.
-    type SegmentComparator: Comparator<Self::SegmentSortKey> + Clone + 'static;
-
-    /// Buffer type used for scratch space.
-    type Buffer: Default + Send + Sync + 'static;
-
-    /// Returns the segment sort key comparator.
-    fn segment_comparator(&self) -> Self::SegmentComparator {
-        Self::SegmentComparator::default()
-    }
+    type SegmentSortKey: 'static + PartialOrd + Clone + Send + Sync + Clone;
 
     /// Computes the sort key for the given document and score.
     fn segment_sort_key(&mut self, doc: DocId, score: Score) -> Self::SegmentSortKey;
 
-    /// Computes the sort keys for a batch of documents.
-    ///
-    /// The computed sort keys and document IDs are pushed into the `output` vector.
-    /// The `buffer` is used for scratch space.
-    fn segment_sort_keys(
-        &mut self,
-        input_docs: &[DocId],
-        output: &mut Vec<ComparableDoc<Self::SegmentSortKey, DocId>>,
-        buffer: &mut Self::Buffer,
-        filter: ValueRange<Self::SegmentSortKey>,
-    );
-
     /// Computes the sort key and pushes the document in a TopN Computer.
     ///
     /// When using a tuple as the sorting key, the sort key is evaluated in a lazy manner.
@@ -58,32 +31,12 @@ pub trait SegmentSortKeyComputer: 'static {
         &mut self,
         doc: DocId,
         score: Score,
-        top_n_computer: &mut TopNComputer<Self::SegmentSortKey, DocId, C, Self::Buffer>,
+        top_n_computer: &mut TopNComputer<Self::SegmentSortKey, DocId, C>,
     ) {
         let sort_key = self.segment_sort_key(doc, score);
         top_n_computer.push(sort_key, doc);
     }
 
-    fn compute_sort_keys_and_collect<C: Comparator<Self::SegmentSortKey>>(
-        &mut self,
-        docs: &[DocId],
-        top_n_computer: &mut TopNComputer<Self::SegmentSortKey, DocId, C, Self::Buffer>,
-    ) {
-        // The capacity of a TopNComputer is larger than 2*n + COLLECT_BLOCK_BUFFER_LEN, so we
-        // should always be able to `reserve` space for the entire block.
-        top_n_computer.reserve(docs.len());
-
-        let comparator = self.segment_comparator();
-        let value_range = if let Some(threshold) = &top_n_computer.threshold {
-            comparator.threshold_to_valuerange(threshold.clone())
-        } else {
-            ValueRange::All
-        };
-
-        let (buffer, scratch) = top_n_computer.buffer_and_scratch();
-        self.segment_sort_keys(docs, buffer, scratch, value_range);
-    }
-
     /// A SegmentSortKeyComputer maps to a SegmentSortKey, but it can also decide on
     /// its ordering.
     ///
@@ -94,7 +47,27 @@ pub trait SegmentSortKeyComputer: 'static {
         left: &Self::SegmentSortKey,
         right: &Self::SegmentSortKey,
     ) -> Ordering {
-        self.segment_comparator().compare(left, right)
+        NaturalComparator.compare(left, right)
+    }
+
+    /// Implementing this method makes it possible to avoid computing
+    /// a sort_key entirely if we can assess that it won't pass a threshold
+    /// with a partial computation.
+    ///
+    /// This is currently used for lexicographic sorting.
+    fn accept_sort_key_lazy(
+        &mut self,
+        doc_id: DocId,
+        score: Score,
+        threshold: &Self::SegmentSortKey,
+    ) -> Option<(Ordering, Self::SegmentSortKey)> {
+        let sort_key = self.segment_sort_key(doc_id, score);
+        let cmp = self.compare_segment_sort_key(&sort_key, threshold);
+        if cmp == Ordering::Less {
+            None
+        } else {
+            Some((cmp, sort_key))
+        }
     }
 
     /// Convert a segment level sort key into the global sort key.
@@ -108,7 +81,7 @@ pub trait SegmentSortKeyComputer: 'static {
 /// the sort key at a segment scale.
 pub trait SortKeyComputer: Sync {
     /// The sort key type.
-    type SortKey: 'static + Send + Sync + Clone + std::fmt::Debug;
+    type SortKey: 'static + Send + Sync + PartialOrd + Clone + std::fmt::Debug;
     /// Type of the associated [`SegmentSortKeyComputer`].
     type Child: SegmentSortKeyComputer<SortKey = Self::SortKey>;
     /// Comparator type.
@@ -163,9 +136,11 @@ where
     HeadSortKeyComputer: SortKeyComputer,
     TailSortKeyComputer: SortKeyComputer,
 {
-    type SortKey = (HeadSortKeyComputer::SortKey, TailSortKeyComputer::SortKey);
-    type Child =
-        ChainSegmentSortKeyComputer<HeadSortKeyComputer::Child, TailSortKeyComputer::Child>;
+    type SortKey = (
+        <HeadSortKeyComputer::Child as SegmentSortKeyComputer>::SortKey,
+        <TailSortKeyComputer::Child as SegmentSortKeyComputer>::SortKey,
+    );
+    type Child = (HeadSortKeyComputer::Child, TailSortKeyComputer::Child);
 
     type Comparator = (
         HeadSortKeyComputer::Comparator,
@@ -177,10 +152,10 @@ where
     }
 
     fn segment_sort_key_computer(&self, segment_reader: &SegmentReader) -> Result<Self::Child> {
-        Ok(ChainSegmentSortKeyComputer {
-            head: self.0.segment_sort_key_computer(segment_reader)?,
-            tail: self.1.segment_sort_key_computer(segment_reader)?,
-        })
+        Ok((
+            self.0.segment_sort_key_computer(segment_reader)?,
+            self.1.segment_sort_key_computer(segment_reader)?,
+        ))
     }
 
     /// Checks whether the schema is compatible with the sort key computer.
@@ -198,91 +173,20 @@ where
     }
 }
 
-pub struct ChainSegmentSortKeyComputer<Head, Tail>
+impl<HeadSegmentSortKeyComputer, TailSegmentSortKeyComputer> SegmentSortKeyComputer
+    for (HeadSegmentSortKeyComputer, TailSegmentSortKeyComputer)
 where
-    Head: SegmentSortKeyComputer,
-    Tail: SegmentSortKeyComputer,
+    HeadSegmentSortKeyComputer: SegmentSortKeyComputer,
+    TailSegmentSortKeyComputer: SegmentSortKeyComputer,
 {
-    head: Head,
-    tail: Tail,
-}
-
-pub struct ChainBuffer<HeadBuffer, TailBuffer, HeadKey, TailKey> {
-    pub head: HeadBuffer,
-    pub tail: TailBuffer,
-    pub head_output: Vec<ComparableDoc<HeadKey, DocId>>,
-    pub tail_output: Vec<ComparableDoc<TailKey, DocId>>,
-    pub tail_input_docs: Vec<DocId>,
-}
-
-impl<HeadBuffer: Default, TailBuffer: Default, HeadKey, TailKey> Default
-    for ChainBuffer<HeadBuffer, TailBuffer, HeadKey, TailKey>
-{
-    fn default() -> Self {
-        ChainBuffer {
-            head: HeadBuffer::default(),
-            tail: TailBuffer::default(),
-            head_output: Vec::new(),
-            tail_output: Vec::new(),
-            tail_input_docs: Vec::new(),
-        }
-    }
-}
-
-impl<Head, Tail> ChainSegmentSortKeyComputer<Head, Tail>
-where
-    Head: SegmentSortKeyComputer,
-    Tail: SegmentSortKeyComputer,
-{
-    fn accept_sort_key_lazy(
-        &mut self,
-        doc_id: DocId,
-        score: Score,
-        threshold: &<Self as SegmentSortKeyComputer>::SegmentSortKey,
-    ) -> Option<(Ordering, <Self as SegmentSortKeyComputer>::SegmentSortKey)> {
-        let (head_threshold, tail_threshold) = threshold;
-        let head_sort_key = self.head.segment_sort_key(doc_id, score);
-        let head_cmp = self
-            .head
-            .compare_segment_sort_key(&head_sort_key, head_threshold);
-        if head_cmp == Ordering::Less {
-            None
-        } else if head_cmp == Ordering::Equal {
-            let tail_sort_key = self.tail.segment_sort_key(doc_id, score);
-            let tail_cmp = self
-                .tail
-                .compare_segment_sort_key(&tail_sort_key, tail_threshold);
-            if tail_cmp == Ordering::Less {
-                None
-            } else {
-                Some((tail_cmp, (head_sort_key, tail_sort_key)))
-            }
-        } else {
-            let tail_sort_key = self.tail.segment_sort_key(doc_id, score);
-            Some((head_cmp, (head_sort_key, tail_sort_key)))
-        }
-    }
-}
-
-impl<Head, Tail> SegmentSortKeyComputer for ChainSegmentSortKeyComputer<Head, Tail>
-where
-    Head: SegmentSortKeyComputer,
-    Tail: SegmentSortKeyComputer,
-{
-    type SortKey = (Head::SortKey, Tail::SortKey);
-    type SegmentSortKey = (Head::SegmentSortKey, Tail::SegmentSortKey);
-
-    type SegmentComparator = (Head::SegmentComparator, Tail::SegmentComparator);
-
-    type Buffer =
-        ChainBuffer<Head::Buffer, Tail::Buffer, Head::SegmentSortKey, Tail::SegmentSortKey>;
-
-    fn segment_comparator(&self) -> Self::SegmentComparator {
-        (
-            self.head.segment_comparator(),
-            self.tail.segment_comparator(),
-        )
-    }
+    type SortKey = (
+        HeadSegmentSortKeyComputer::SortKey,
+        TailSegmentSortKeyComputer::SortKey,
+    );
+    type SegmentSortKey = (
+        HeadSegmentSortKeyComputer::SegmentSortKey,
+        TailSegmentSortKeyComputer::SegmentSortKey,
+    );
 
     /// A SegmentSortKeyComputer maps to a SegmentSortKey, but it can also decide on
     /// its ordering.
@@ -294,90 +198,9 @@ where
         left: &Self::SegmentSortKey,
         right: &Self::SegmentSortKey,
     ) -> Ordering {
-        self.head
+        self.0
             .compare_segment_sort_key(&left.0, &right.0)
-            .then_with(|| self.tail.compare_segment_sort_key(&left.1, &right.1))
-    }
-
-    fn segment_sort_keys(
-        &mut self,
-        input_docs: &[DocId],
-        output: &mut Vec<ComparableDoc<Self::SegmentSortKey, DocId>>,
-        buffer: &mut Self::Buffer,
-        filter: ValueRange<Self::SegmentSortKey>,
-    ) {
-        let (head_filter, threshold) = match filter {
-            ValueRange::GreaterThan((head_threshold, tail_threshold), _)
-            | ValueRange::LessThan((head_threshold, tail_threshold), _) => {
-                let head_cmp = self.head.segment_comparator();
-                let strict_head_filter = head_cmp.threshold_to_valuerange(head_threshold.clone());
-                let head_filter = match strict_head_filter {
-                    ValueRange::GreaterThan(t, m) => ValueRange::GreaterThanOrEqual(t, m),
-                    ValueRange::LessThan(t, m) => ValueRange::LessThanOrEqual(t, m),
-                    other => other,
-                };
-                (head_filter, Some((head_threshold, tail_threshold)))
-            }
-            _ => (ValueRange::All, None),
-        };
-
-        buffer.head_output.clear();
-        self.head.segment_sort_keys(
-            input_docs,
-            &mut buffer.head_output,
-            &mut buffer.head,
-            head_filter,
-        );
-
-        if buffer.head_output.is_empty() {
-            return;
-        }
-
-        buffer.tail_output.clear();
-        buffer.tail_input_docs.clear();
-        for cd in &buffer.head_output {
-            buffer.tail_input_docs.push(cd.doc);
-        }
-
-        self.tail.segment_sort_keys(
-            &buffer.tail_input_docs,
-            &mut buffer.tail_output,
-            &mut buffer.tail,
-            ValueRange::All,
-        );
-
-        let head_cmp = self.head.segment_comparator();
-        let tail_cmp = self.tail.segment_comparator();
-
-        for (head_doc, tail_doc) in buffer
-            .head_output
-            .drain(..)
-            .zip(buffer.tail_output.drain(..))
-        {
-            debug_assert_eq!(head_doc.doc, tail_doc.doc);
-            let doc = head_doc.doc;
-            let head_key = head_doc.sort_key;
-            let tail_key = tail_doc.sort_key;
-
-            let accept = if let Some((head_threshold, tail_threshold)) = &threshold {
-                let head_ord = head_cmp.compare(&head_key, head_threshold);
-                let ord = if head_ord == Ordering::Equal {
-                    tail_cmp.compare(&tail_key, tail_threshold)
-                } else {
-                    head_ord
-                };
-                ord == Ordering::Greater
-            } else {
-                true
-            };
-
-            if accept {
-                output.push(ComparableDoc {
-                    sort_key: (head_key, tail_key),
-                    doc,
-                });
-            }
-        }
+            .then_with(|| self.1.compare_segment_sort_key(&left.1, &right.1))
     }
 
     #[inline(always)]
@@ -385,7 +208,7 @@ where
         &mut self,
         doc: DocId,
         score: Score,
-        top_n_computer: &mut TopNComputer<Self::SegmentSortKey, DocId, C, Self::Buffer>,
+        top_n_computer: &mut TopNComputer<Self::SegmentSortKey, DocId, C>,
     ) {
         let sort_key: Self::SegmentSortKey;
         if let Some(threshold) = &top_n_computer.threshold {
@@ -402,56 +225,68 @@ where
 
     #[inline(always)]
     fn segment_sort_key(&mut self, doc: DocId, score: Score) -> Self::SegmentSortKey {
-        let head_sort_key = self.head.segment_sort_key(doc, score);
-        let tail_sort_key = self.tail.segment_sort_key(doc, score);
+        let head_sort_key = self.0.segment_sort_key(doc, score);
+        let tail_sort_key = self.1.segment_sort_key(doc, score);
         (head_sort_key, tail_sort_key)
     }
 
+    fn accept_sort_key_lazy(
+        &mut self,
+        doc_id: DocId,
+        score: Score,
+        threshold: &Self::SegmentSortKey,
+    ) -> Option<(Ordering, Self::SegmentSortKey)> {
+        let (head_threshold, tail_threshold) = threshold;
+        let (head_cmp, head_sort_key) =
+            self.0.accept_sort_key_lazy(doc_id, score, head_threshold)?;
+        if head_cmp == Ordering::Equal {
+            let (tail_cmp, tail_sort_key) =
+                self.1.accept_sort_key_lazy(doc_id, score, tail_threshold)?;
+            Some((tail_cmp, (head_sort_key, tail_sort_key)))
+        } else {
+            let tail_sort_key = self.1.segment_sort_key(doc_id, score);
+            Some((head_cmp, (head_sort_key, tail_sort_key)))
+        }
+    }
+
     fn convert_segment_sort_key(&self, sort_key: Self::SegmentSortKey) -> Self::SortKey {
         let (head_sort_key, tail_sort_key) = sort_key;
         (
-            self.head.convert_segment_sort_key(head_sort_key),
-            self.tail.convert_segment_sort_key(tail_sort_key),
+            self.0.convert_segment_sort_key(head_sort_key),
+            self.1.convert_segment_sort_key(tail_sort_key),
         )
     }
 }
 
 /// This struct is used as an adapter to take a sort key computer and map its score to another
 /// new sort key.
-pub struct MappedSegmentSortKeyComputer<T: SegmentSortKeyComputer, NewSortKey> {
+pub struct MappedSegmentSortKeyComputer<T, PreviousSortKey, NewSortKey> {
     sort_key_computer: T,
-    map: fn(T::SortKey) -> NewSortKey,
+    map: fn(PreviousSortKey) -> NewSortKey,
 }
 
 impl<T, PreviousScore, NewScore> SegmentSortKeyComputer
-    for MappedSegmentSortKeyComputer<T, NewScore>
+    for MappedSegmentSortKeyComputer<T, PreviousScore, NewScore>
 where
     T: SegmentSortKeyComputer<SortKey = PreviousScore>,
-    PreviousScore: 'static + Clone + Send + Sync,
-    NewScore: 'static + Clone + Send + Sync,
+    PreviousScore: 'static + Clone + Send + Sync + PartialOrd,
+    NewScore: 'static + Clone + Send + Sync + PartialOrd,
 {
     type SortKey = NewScore;
     type SegmentSortKey = T::SegmentSortKey;
-    type SegmentComparator = T::SegmentComparator;
-    type Buffer = T::Buffer;
-
-    fn segment_comparator(&self) -> Self::SegmentComparator {
-        self.sort_key_computer.segment_comparator()
-    }
 
     fn segment_sort_key(&mut self, doc: DocId, score: Score) -> Self::SegmentSortKey {
         self.sort_key_computer.segment_sort_key(doc, score)
     }
 
-    fn segment_sort_keys(
+    fn accept_sort_key_lazy(
         &mut self,
-        input_docs: &[DocId],
-        output: &mut Vec<ComparableDoc<Self::SegmentSortKey, DocId>>,
-        buffer: &mut Self::Buffer,
-        filter: ValueRange<Self::SegmentSortKey>,
-    ) {
+        doc_id: DocId,
+        score: Score,
+        threshold: &Self::SegmentSortKey,
+    ) -> Option<(Ordering, Self::SegmentSortKey)> {
         self.sort_key_computer
-            .segment_sort_keys(input_docs, output, buffer, filter)
+            .accept_sort_key_lazy(doc_id, score, threshold)
     }
 
     #[inline(always)]
@@ -459,21 +294,12 @@ where
         &mut self,
         doc: DocId,
         score: Score,
-        top_n_computer: &mut TopNComputer<Self::SegmentSortKey, DocId, C, Self::Buffer>,
+        top_n_computer: &mut TopNComputer<Self::SegmentSortKey, DocId, C>,
     ) {
         self.sort_key_computer
             .compute_sort_key_and_collect(doc, score, top_n_computer);
     }
 
-    fn compute_sort_keys_and_collect<C: Comparator<Self::SegmentSortKey>>(
-        &mut self,
-        docs: &[DocId],
-        top_n_computer: &mut TopNComputer<Self::SegmentSortKey, DocId, C, Self::Buffer>,
-    ) {
-        self.sort_key_computer
-            .compute_sort_keys_and_collect(docs, top_n_computer);
-    }
-
     fn convert_segment_sort_key(&self, segment_sort_key: Self::SegmentSortKey) -> Self::SortKey {
         (self.map)(
             self.sort_key_computer
@@ -499,6 +325,10 @@ where
     );
     type Child = MappedSegmentSortKeyComputer<
         <(SortKeyComputer1, (SortKeyComputer2, SortKeyComputer3)) as SortKeyComputer>::Child,
+        (
+            SortKeyComputer1::SortKey,
+            (SortKeyComputer2::SortKey, SortKeyComputer3::SortKey),
+        ),
         Self::SortKey,
     >;
 
@@ -522,13 +352,7 @@ where
         let sort_key_computer3 = self.2.segment_sort_key_computer(segment_reader)?;
         let map = |(sort_key1, (sort_key2, sort_key3))| (sort_key1, sort_key2, sort_key3);
         Ok(MappedSegmentSortKeyComputer {
-            sort_key_computer: ChainSegmentSortKeyComputer {
-                head: sort_key_computer1,
-                tail: ChainSegmentSortKeyComputer {
-                    head: sort_key_computer2,
-                    tail: sort_key_computer3,
-                },
-            },
+            sort_key_computer: (sort_key_computer1, (sort_key_computer2, sort_key_computer3)),
             map,
         })
     }
@@ -563,6 +387,13 @@ where
             SortKeyComputer1,
             (SortKeyComputer2, (SortKeyComputer3, SortKeyComputer4)),
         ) as SortKeyComputer>::Child,
+        (
+            SortKeyComputer1::SortKey,
+            (
+                SortKeyComputer2::SortKey,
+                (SortKeyComputer3::SortKey, SortKeyComputer4::SortKey),
+            ),
+        ),
         Self::SortKey,
     >;
     type SortKey = (
@@ -584,16 +415,10 @@ where
         let sort_key_computer3 = self.2.segment_sort_key_computer(segment_reader)?;
         let sort_key_computer4 = self.3.segment_sort_key_computer(segment_reader)?;
         Ok(MappedSegmentSortKeyComputer {
-            sort_key_computer: ChainSegmentSortKeyComputer {
-                head: sort_key_computer1,
-                tail: ChainSegmentSortKeyComputer {
-                    head: sort_key_computer2,
-                    tail: ChainSegmentSortKeyComputer {
-                        head: sort_key_computer3,
-                        tail: sort_key_computer4,
-                    },
-                },
-            },
+            sort_key_computer: (
+                sort_key_computer1,
+                (sort_key_computer2, (sort_key_computer3, sort_key_computer4)),
+            ),
             map: |(sort_key1, (sort_key2, (sort_key3, sort_key4)))| {
                 (sort_key1, sort_key2, sort_key3, sort_key4)
             },
@@ -616,13 +441,6 @@ where
     }
 }
 
-use std::marker::PhantomData;
-
-pub struct FuncSegmentSortKeyComputer<F, TSortKey> {
-    func: F,
-    _phantom: PhantomData<TSortKey>,
-}
-
 impl<F, SegmentF, TSortKey> SortKeyComputer for F
 where
     F: 'static + Send + Sync + Fn(&SegmentReader) -> SegmentF,
@@ -630,44 +448,24 @@ where
     TSortKey: 'static + PartialOrd + Clone + Send + Sync + std::fmt::Debug,
 {
     type SortKey = TSortKey;
-    type Child = FuncSegmentSortKeyComputer<SegmentF, TSortKey>;
+    type Child = SegmentF;
     type Comparator = NaturalComparator;
 
     fn segment_sort_key_computer(&self, segment_reader: &SegmentReader) -> Result<Self::Child> {
-        Ok(FuncSegmentSortKeyComputer {
-            func: (self)(segment_reader),
-            _phantom: PhantomData,
-        })
+        Ok((self)(segment_reader))
     }
 }
 
-impl<F, TSortKey> SegmentSortKeyComputer for FuncSegmentSortKeyComputer<F, TSortKey>
+impl<F, TSortKey> SegmentSortKeyComputer for F
 where
     F: 'static + FnMut(DocId) -> TSortKey,
     TSortKey: 'static + PartialOrd + Clone + Send + Sync,
 {
     type SortKey = TSortKey;
     type SegmentSortKey = TSortKey;
-    type SegmentComparator = NaturalComparator;
-    type Buffer = ();
 
     fn segment_sort_key(&mut self, doc: DocId, _score: Score) -> TSortKey {
-        (self.func)(doc)
-    }
-
-    fn segment_sort_keys(
-        &mut self,
-        input_docs: &[DocId],
-        output: &mut Vec<ComparableDoc<Self::SegmentSortKey, DocId>>,
-        _buffer: &mut Self::Buffer,
-        _filter: ValueRange<Self::SegmentSortKey>,
-    ) {
-        for &doc in input_docs {
-            output.push(ComparableDoc {
-                sort_key: (self.func)(doc),
-                doc,
-            });
-        }
+        (self)(doc)
     }
 
     /// Convert a segment level score into the global level score.
@@ -676,75 +474,13 @@ where
     }
 }
 
-pub(crate) fn range_contains_none(range: &ValueRange<Option<u64>>) -> bool {
-    match range {
-        ValueRange::All => true,
-        ValueRange::Inclusive(r) => r.contains(&None),
-        ValueRange::GreaterThan(_threshold, match_nulls) => *match_nulls,
-        ValueRange::GreaterThanOrEqual(_threshold, match_nulls) => *match_nulls,
-        ValueRange::LessThan(_threshold, match_nulls) => *match_nulls,
-        ValueRange::LessThanOrEqual(_threshold, match_nulls) => *match_nulls,
-    }
-}
-
-pub(crate) fn convert_optional_u64_range_to_u64_range(
-    range: ValueRange<Option<u64>>,
-) -> ValueRange<u64> {
-    match range {
-        ValueRange::Inclusive(r) => {
-            let start = r.start().unwrap_or(0);
-            let end = r.end().unwrap_or(u64::MAX);
-            ValueRange::Inclusive(start..=end)
-        }
-        ValueRange::GreaterThan(Some(val), match_nulls) => {
-            ValueRange::GreaterThan(val, match_nulls)
-        }
-        ValueRange::GreaterThan(None, match_nulls) => {
-            if match_nulls {
-                ValueRange::All
-            } else {
-                ValueRange::Inclusive(u64::MIN..=u64::MAX)
-            }
-        }
-        ValueRange::GreaterThanOrEqual(Some(val), match_nulls) => {
-            ValueRange::GreaterThanOrEqual(val, match_nulls)
-        }
-        ValueRange::GreaterThanOrEqual(None, match_nulls) => {
-            if match_nulls {
-                ValueRange::All
-            } else {
-                ValueRange::Inclusive(u64::MIN..=u64::MAX)
-            }
-        }
-        ValueRange::LessThan(None, match_nulls) => {
-            if match_nulls {
-                ValueRange::LessThan(u64::MIN, true)
-            } else {
-                ValueRange::Inclusive(1..=0)
-            }
-        }
-        ValueRange::LessThan(Some(val), match_nulls) => ValueRange::LessThan(val, match_nulls),
-        ValueRange::LessThanOrEqual(None, match_nulls) => {
-            if match_nulls {
-                ValueRange::LessThan(u64::MIN, true)
-            } else {
-                ValueRange::Inclusive(1..=0)
-            }
-        }
-        ValueRange::LessThanOrEqual(Some(val), match_nulls) => {
-            ValueRange::LessThanOrEqual(val, match_nulls)
-        }
-        ValueRange::All => ValueRange::All,
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use std::cmp::Ordering;
     use std::sync::atomic::{AtomicUsize, Ordering as AtomicOrdering};
     use std::sync::Arc;
 
-    use crate::collector::{SegmentSortKeyComputer, SortKeyComputer, TopNComputer};
+    use crate::collector::{SegmentSortKeyComputer, SortKeyComputer};
     use crate::schema::Schema;
     use crate::{DocId, Index, Order, SegmentReader};
 
@@ -892,178 +628,4 @@ mod tests {
             (200u32, 2u32)
         );
     }
-    #[test]
-    fn test_batch_score_computer_edge_case() {
-        let score_computer_primary = |_segment_reader: &SegmentReader| |_doc: DocId| 200u32;
-        let score_computer_secondary = |_segment_reader: &SegmentReader| |_doc: DocId| "b";
-        let lazy_score_computer = (score_computer_primary, score_computer_secondary);
-        let index = build_test_index();
-        let searcher = index.reader().unwrap().searcher();
-        let mut segment_sort_key_computer = lazy_score_computer
-            .segment_sort_key_computer(searcher.segment_reader(0))
-            .unwrap();
-
-        let mut top_n_computer =
-            TopNComputer::new_with_comparator(10, lazy_score_computer.comparator());
-        // Threshold (200, "a"). Doc is (200, "b"). 200 == 200, "b" > "a". Should be accepted.
-        top_n_computer.threshold = Some((200, "a"));
-
-        let docs = vec![0];
-        segment_sort_key_computer.compute_sort_keys_and_collect(&docs, &mut top_n_computer);
-
-        let results = top_n_computer.into_sorted_vec();
-        assert_eq!(results.len(), 1);
-        let result = &results[0];
-        assert_eq!(result.doc, 0);
-        assert_eq!(result.sort_key, (200, "b"));
-    }
-}
-
-#[cfg(test)]
-mod proptest_tests {
-    use proptest::prelude::*;
-
-    use super::*;
-    use crate::collector::sort_key::order::*;
-
-    // Re-implement logic to interpret ValueRange<Option<u64>> manually to verify expectations
-    fn range_contains_opt(range: &ValueRange<Option<u64>>, val: &Option<u64>) -> bool {
-        match range {
-            ValueRange::All => true,
-            ValueRange::Inclusive(r) => r.contains(val),
-            ValueRange::GreaterThan(t, match_nulls) => {
-                if val.is_none() {
-                    *match_nulls
-                } else {
-                    val > t
-                }
-            }
-            ValueRange::GreaterThanOrEqual(t, match_nulls) => {
-                if val.is_none() {
-                    *match_nulls
-                } else {
-                    val >= t
-                }
-            }
-            ValueRange::LessThan(t, match_nulls) => {
-                if val.is_none() {
-                    *match_nulls
-                } else {
-                    val < t
-                }
-            }
-            ValueRange::LessThanOrEqual(t, match_nulls) => {
-                if val.is_none() {
-                    *match_nulls
-                } else {
-                    val <= t
-                }
-            }
-        }
-    }
-
-    fn range_contains_u64(range: &ValueRange<u64>, val: &u64) -> bool {
-        match range {
-            ValueRange::All => true,
-            ValueRange::Inclusive(r) => r.contains(val),
-            ValueRange::GreaterThan(t, _) => val > t,
-            ValueRange::GreaterThanOrEqual(t, _) => val >= t,
-            ValueRange::LessThan(t, _) => val < t,
-            ValueRange::LessThanOrEqual(t, _) => val <= t,
-        }
-    }
-
-    proptest! {
-        #[test]
-        fn test_comparator_consistency_natural_none_is_lower(
-            threshold in any::<Option<u64>>(),
-            val in any::<Option<u64>>()
-        ) {
-             check_comparator::<NaturalComparator>(threshold, val)?;
-        }
-
-        #[test]
-        fn test_comparator_consistency_reverse(
-            threshold in any::<Option<u64>>(),
-            val in any::<Option<u64>>()
-        ) {
-             check_comparator::<ReverseComparator>(threshold, val)?;
-        }
-
-        #[test]
-        fn test_comparator_consistency_reverse_none_is_lower(
-            threshold in any::<Option<u64>>(),
-            val in any::<Option<u64>>()
-        ) {
-             check_comparator::<ReverseNoneIsLowerComparator>(threshold, val)?;
-        }
-
-        #[test]
-        fn test_comparator_consistency_natural_none_is_higher(
-            threshold in any::<Option<u64>>(),
-            val in any::<Option<u64>>()
-        ) {
-             check_comparator::<NaturalNoneIsHigherComparator>(threshold, val)?;
-        }
-    }
-
-    fn check_comparator<C: Comparator<Option<u64>>>(
-        threshold: Option<u64>,
-        val: Option<u64>,
-    ) -> std::result::Result<(), proptest::test_runner::TestCaseError> {
-        let comparator = C::default();
-        let range = comparator.threshold_to_valuerange(threshold);
-        let ordering = comparator.compare(&val, &threshold);
-        let should_be_in_range = ordering == Ordering::Greater;
-
-        let in_range_opt = range_contains_opt(&range, &val);
-
-        prop_assert_eq!(
-            in_range_opt,
-            should_be_in_range,
-            "Comparator consistency failed for {:?}. Threshold: {:?}, Val: {:?}, Range: {:?}, \
-             Ordering: {:?}. range_contains_opt says {}, but compare says {}",
-            std::any::type_name::<C>(),
-            threshold,
-            val,
-            range,
-            ordering,
-            in_range_opt,
-            should_be_in_range
-        );
-
-        // Check range_contains_none
-        let expected_none_in_range = range_contains_opt(&range, &None);
-        let actual_none_in_range = range_contains_none(&range);
-        prop_assert_eq!(
-            actual_none_in_range,
-            expected_none_in_range,
-            "range_contains_none failed for {:?}. Range: {:?}. Expected (from \
-             range_contains_opt): {}, Actual: {}",
-            std::any::type_name::<C>(),
-            range,
-            expected_none_in_range,
-            actual_none_in_range
-        );
-
-        // Check convert_optional_u64_range_to_u64_range
-        let u64_range = convert_optional_u64_range_to_u64_range(range.clone());
-        if let Some(v) = val {
-            let in_u64_range = range_contains_u64(&u64_range, &v);
-            let in_opt_range = range_contains_opt(&range, &Some(v));
-            prop_assert_eq!(
-                in_u64_range,
-                in_opt_range,
-                "convert_optional_u64_range_to_u64_range failed for {:?}. Val: {:?}, OptRange: \
-                 {:?}, U64Range: {:?}. Opt says {}, U64 says {}",
-                std::any::type_name::<C>(),
-                v,
-                range,
-                u64_range,
-                in_opt_range,
-                in_u64_range
-            );
-        }
-        Ok(())
-    }
 }

src/collector/sort_key_top_collector.rs

@@ -99,12 +99,7 @@ where
     TSegmentSortKeyComputer: SegmentSortKeyComputer,
     C: Comparator<TSegmentSortKeyComputer::SegmentSortKey>,
 {
-    pub(crate) topn_computer: TopNComputer<
-        TSegmentSortKeyComputer::SegmentSortKey,
-        DocId,
-        C,
-        TSegmentSortKeyComputer::Buffer,
-    >,
+    pub(crate) topn_computer: TopNComputer<TSegmentSortKeyComputer::SegmentSortKey, DocId, C>,
     pub(crate) segment_ord: u32,
     pub(crate) segment_sort_key_computer: TSegmentSortKeyComputer,
 }
@@ -125,11 +120,6 @@ where
         );
     }
 
-    fn collect_block(&mut self, docs: &[DocId]) {
-        self.segment_sort_key_computer
-            .compute_sort_keys_and_collect(docs, &mut self.topn_computer);
-    }
-
     fn harvest(self) -> Self::Fruit {
         let segment_ord = self.segment_ord;
         let segment_hits: Vec<(TSegmentSortKeyComputer::SortKey, DocAddress)> = self

src/collector/top_collector.rs

@@ -0,0 +1,64 @@
+use std::cmp::Ordering;
+
+use serde::{Deserialize, Serialize};
+
+/// Contains a feature (field, score, etc.) of a document along with the document address.
+///
+/// It guarantees stable sorting: in case of a tie on the feature, the document
+/// address is used.
+///
+/// The REVERSE_ORDER generic parameter controls whether the by-feature order
+/// should be reversed, which is useful for achieving for example largest-first
+/// semantics without having to wrap the feature in a `Reverse`.
+#[derive(Clone, Default, Serialize, Deserialize)]
+pub struct ComparableDoc<T, D, const REVERSE_ORDER: bool = false> {
+    /// The feature of the document. In practice, this is
+    /// is any type that implements `PartialOrd`.
+    pub sort_key: T,
+    /// The document address. In practice, this is any
+    /// type that implements `PartialOrd`, and is guaranteed
+    /// to be unique for each document.
+    pub doc: D,
+}
+impl<T: std::fmt::Debug, D: std::fmt::Debug, const R: bool> std::fmt::Debug
+    for ComparableDoc<T, D, R>
+{
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        f.debug_struct(format!("ComparableDoc<_, _ {R}").as_str())
+            .field("feature", &self.sort_key)
+            .field("doc", &self.doc)
+            .finish()
+    }
+}
+
+impl<T: PartialOrd, D: PartialOrd, const R: bool> PartialOrd for ComparableDoc<T, D, R> {
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        Some(self.cmp(other))
+    }
+}
+
+impl<T: PartialOrd, D: PartialOrd, const R: bool> Ord for ComparableDoc<T, D, R> {
+    #[inline]
+    fn cmp(&self, other: &Self) -> Ordering {
+        let by_feature = self
+            .sort_key
+            .partial_cmp(&other.sort_key)
+            .map(|ord| if R { ord.reverse() } else { ord })
+            .unwrap_or(Ordering::Equal);
+
+        let lazy_by_doc_address = || self.doc.partial_cmp(&other.doc).unwrap_or(Ordering::Equal);
+
+        // In case of a tie on the feature, we sort by ascending
+        // `DocAddress` in order to ensure a stable sorting of the
+        // documents.
+        by_feature.then_with(lazy_by_doc_address)
+    }
+}
+
+impl<T: PartialOrd, D: PartialOrd, const R: bool> PartialEq for ComparableDoc<T, D, R> {
+    fn eq(&self, other: &Self) -> bool {
+        self.cmp(other) == Ordering::Equal
+    }
+}
+
+impl<T: PartialOrd, D: PartialOrd, const R: bool> Eq for ComparableDoc<T, D, R> {}

src/collector/top_score_collector.rs

@@ -2,7 +2,6 @@ use std::cmp::Ordering;
 use std::fmt;
 use std::ops::Range;
 
-use columnar::ValueRange;
 use serde::{Deserialize, Serialize};
 
 use super::Collector;
@@ -11,7 +10,8 @@ use crate::collector::sort_key::{
     SortByStaticFastValue, SortByString,
 };
 use crate::collector::sort_key_top_collector::TopBySortKeyCollector;
-use crate::collector::{ComparableDoc, SegmentSortKeyComputer, SortKeyComputer};
+use crate::collector::top_collector::ComparableDoc;
+use crate::collector::{SegmentSortKeyComputer, SortKeyComputer};
 use crate::fastfield::FastValue;
 use crate::{DocAddress, DocId, Order, Score, SegmentReader};
 
@@ -23,9 +23,10 @@ use crate::{DocAddress, DocId, Order, Score, SegmentReader};
 /// The theoretical complexity for collecting the top `K` out of `N` documents
 /// is `O(N + K)`.
 ///
-/// This collector guarantees a stable sorting in case of a tie on the
-/// document score/sort key: The document address (`DocAddress`) is used as a tie breaker.
-/// In case of a tie on the sort key, documents are always sorted by ascending `DocAddress`.
+/// This collector does not guarantee a stable sorting in case of a tie on the
+/// document score, for stable sorting `PartialOrd` needs to resolve on other fields
+/// like docid in case of score equality.
+/// Only then, it is suitable for pagination.
 ///
 /// ```rust
 /// use tantivy::collector::TopDocs;
@@ -324,7 +325,7 @@ impl TopDocs {
         sort_key_computer: impl SortKeyComputer<SortKey = TSortKey> + Send + 'static,
     ) -> impl Collector<Fruit = Vec<(TSortKey, DocAddress)>>
     where
-        TSortKey: 'static + Clone + Send + Sync + std::fmt::Debug,
+        TSortKey: 'static + Clone + Send + Sync + PartialOrd + std::fmt::Debug,
     {
         TopBySortKeyCollector::new(sort_key_computer, self.doc_range())
     }
@@ -445,7 +446,7 @@ where
     F: 'static + Send + Sync + Fn(&SegmentReader) -> TTweakScoreSortKeyFn,
     TTweakScoreSortKeyFn: 'static + Fn(DocId, Score) -> TSortKey,
     TweakScoreSegmentSortKeyComputer<TTweakScoreSortKeyFn>:
-        SegmentSortKeyComputer<SortKey = TSortKey, SegmentSortKey = TSortKey>,
+        SegmentSortKeyComputer<SortKey = TSortKey>,
     TSortKey: 'static + PartialOrd + Clone + Send + Sync + std::fmt::Debug,
 {
     type SortKey = TSortKey;
@@ -480,23 +481,11 @@ where
 {
     type SortKey = TSortKey;
     type SegmentSortKey = TSortKey;
-    type SegmentComparator = NaturalComparator;
-    type Buffer = ();
 
     fn segment_sort_key(&mut self, doc: DocId, score: Score) -> TSortKey {
         (self.sort_key_fn)(doc, score)
     }
 
-    fn segment_sort_keys(
-        &mut self,
-        _input_docs: &[DocId],
-        _output: &mut Vec<ComparableDoc<Self::SegmentSortKey, DocId>>,
-        _buffer: &mut Self::Buffer,
-        _filter: ValueRange<Self::SegmentSortKey>,
-    ) {
-        unimplemented!("Batch computation is not supported for tweak score.")
-    }
-
     /// Convert a segment level score into the global level score.
     fn convert_segment_sort_key(&self, sort_key: Self::SegmentSortKey) -> Self::SortKey {
         sort_key
@@ -511,23 +500,16 @@ where
 ///
 /// For TopN == 0, it will be relative expensive.
 ///
-/// The TopNComputer will tiebreak by using ascending `D` (DocId or DocAddress):
-/// i.e., in case of a tie on the sort key, the `DocId|DocAddress` are always sorted in
-/// ascending order, regardless of the `Comparator` used for the `Score` type.
-///
-/// NOTE: Items must be `push`ed to the TopNComputer in ascending `DocId|DocAddress` order, as the
-/// threshold used to eliminate docs does not include the `DocId` or `DocAddress`: this provides
-/// the ascending `DocId|DocAddress` tie-breaking behavior without additional comparisons.
+/// When using the natural comparator, the top N computer returns the top N elements in
+/// descending order, as expected for a top N.
 #[derive(Serialize, Deserialize)]
 #[serde(from = "TopNComputerDeser<Score, D, C>")]
-pub struct TopNComputer<Score, D, C, Buffer = ()> {
+pub struct TopNComputer<Score, D, C> {
     /// The buffer reverses sort order to get top-semantics instead of bottom-semantics
     buffer: Vec<ComparableDoc<Score, D>>,
     top_n: usize,
     pub(crate) threshold: Option<Score>,
     comparator: C,
-    #[serde(skip)]
-    scratch: Buffer,
 }
 
 // Intermediate struct for TopNComputer for deserialization, to keep vec capacity
@@ -539,9 +521,7 @@ struct TopNComputerDeser<Score, D, C> {
     comparator: C,
 }
 
-impl<Score, D, C, Buffer> From<TopNComputerDeser<Score, D, C>> for TopNComputer<Score, D, C, Buffer>
-where Buffer: Default
-{
+impl<Score, D, C> From<TopNComputerDeser<Score, D, C>> for TopNComputer<Score, D, C> {
     fn from(mut value: TopNComputerDeser<Score, D, C>) -> Self {
         let expected_cap = value.top_n.max(1) * 2;
         let current_cap = value.buffer.capacity();
@@ -556,15 +536,12 @@ where Buffer: Default
             top_n: value.top_n,
             threshold: value.threshold,
             comparator: value.comparator,
-            scratch: Buffer::default(),
         }
     }
 }
 
-impl<Score: std::fmt::Debug, D, C, Buffer> std::fmt::Debug for TopNComputer<Score, D, C, Buffer>
-where
-    C: Comparator<Score>,
-    Buffer: std::fmt::Debug,
+impl<Score: std::fmt::Debug, D, C> std::fmt::Debug for TopNComputer<Score, D, C>
+where C: Comparator<Score>
 {
     fn fmt(&self, f: &mut fmt::Formatter) -> std::fmt::Result {
         f.debug_struct("TopNComputer")
@@ -572,13 +549,12 @@ where
             .field("top_n", &self.top_n)
             .field("current_threshold", &self.threshold)
             .field("comparator", &self.comparator)
-            .field("scratch", &self.scratch)
             .finish()
     }
 }
 
 // Custom clone to keep capacity
-impl<Score: Clone, D: Clone, C: Clone, Buffer: Clone> Clone for TopNComputer<Score, D, C, Buffer> {
+impl<Score: Clone, D: Clone, C: Clone> Clone for TopNComputer<Score, D, C> {
     fn clone(&self) -> Self {
         let mut buffer_clone = Vec::with_capacity(self.buffer.capacity());
         buffer_clone.extend(self.buffer.iter().cloned());
@@ -587,17 +563,15 @@ impl<Score: Clone, D: Clone, C: Clone, Buffer: Clone> Clone for TopNComputer<Sco
             top_n: self.top_n,
             threshold: self.threshold.clone(),
             comparator: self.comparator.clone(),
-            scratch: self.scratch.clone(),
         }
     }
 }
 
-impl<TSortKey, D> TopNComputer<TSortKey, D, ReverseComparator, ()>
+impl<TSortKey, D> TopNComputer<TSortKey, D, ReverseComparator>
 where
     D: Ord,
     TSortKey: Clone,
     NaturalComparator: Comparator<TSortKey>,
-    ReverseComparator: Comparator<TSortKey>,
 {
     /// Create a new `TopNComputer`.
     /// Internally it will allocate a buffer of size `2 * top_n`.
@@ -606,38 +580,30 @@ where
     }
 }
 
-impl<TSortKey, D, C, Buffer> TopNComputer<TSortKey, D, C, Buffer>
+impl<TSortKey, D, C> TopNComputer<TSortKey, D, C>
 where
     D: Ord,
     TSortKey: Clone,
     C: Comparator<TSortKey>,
-    Buffer: Default,
 {
     /// Create a new `TopNComputer`.
-    /// Internally it will allocate a buffer of size `(top_n.max(1) * 2) +
-    /// COLLECT_BLOCK_BUFFER_LEN`.
+    /// Internally it will allocate a buffer of size `2 * top_n`.
     pub fn new_with_comparator(top_n: usize, comparator: C) -> Self {
-        // We ensure that there is always enough space to include an entire block in the buffer if
-        // need be, so that `push_block_lazy` can avoid checking capacity inside its loop.
-        let vec_cap = (top_n.max(1) * 2) + crate::COLLECT_BLOCK_BUFFER_LEN;
+        let vec_cap = top_n.max(1) * 2;
         TopNComputer {
             buffer: Vec::with_capacity(vec_cap),
             top_n,
             threshold: None,
             comparator,
-            scratch: Buffer::default(),
         }
     }
 
     /// Push a new document to the top n.
     /// If the document is below the current threshold, it will be ignored.
-    ///
-    /// NOTE: `push` must be called in ascending `DocId`/`DocAddress` order.
     #[inline]
     pub fn push(&mut self, sort_key: TSortKey, doc: D) {
         if let Some(last_median) = &self.threshold {
-            // See the struct docs for an explanation of why this comparison is strict.
-            if self.comparator.compare(&sort_key, last_median) != Ordering::Greater {
+            if self.comparator.compare(&sort_key, last_median) == Ordering::Less {
                 return;
             }
         }
@@ -649,34 +615,24 @@ where
     // At this point, we need to have established that the doc is above the threshold.
     #[inline(always)]
     pub(crate) fn append_doc(&mut self, doc: D, sort_key: TSortKey) {
-        self.reserve(1);
-        // This cannot panic, because we've reserved room for one element.
-        let comparable_doc = ComparableDoc { doc, sort_key };
-        push_assuming_capacity(comparable_doc, &mut self.buffer);
-    }
-
-    // Ensure that there is capacity to push `additional` more elements without resizing.
-    #[inline(always)]
-    pub(crate) fn reserve(&mut self, additional: usize) {
-        if self.buffer.len() + additional > self.buffer.capacity() {
+        if self.buffer.len() == self.buffer.capacity() {
             let median = self.truncate_top_n();
-            debug_assert!(self.buffer.len() + additional <= self.buffer.capacity());
             self.threshold = Some(median);
         }
-    }
-
-    pub(crate) fn buffer_and_scratch(
-        &mut self,
-    ) -> (&mut Vec<ComparableDoc<TSortKey, D>>, &mut Buffer) {
-        (&mut self.buffer, &mut self.scratch)
+        // This cannot panic, because we truncate_median will at least remove one element, since
+        // the min capacity is 2.
+        let comparable_doc = ComparableDoc { doc, sort_key };
+        push_assuming_capacity(comparable_doc, &mut self.buffer);
     }
 
     #[inline(never)]
     fn truncate_top_n(&mut self) -> TSortKey {
         // Use select_nth_unstable to find the top nth score
-        let (_, median_el, _) = self
-            .buffer
-            .select_nth_unstable_by(self.top_n, |lhs, rhs| self.comparator.compare_doc(lhs, rhs));
+        let (_, median_el, _) = self.buffer.select_nth_unstable_by(self.top_n, |lhs, rhs| {
+            self.comparator
+                .compare(&rhs.sort_key, &lhs.sort_key)
+                .then_with(|| lhs.doc.cmp(&rhs.doc))
+        });
 
         let median_score = median_el.sort_key.clone();
         // Remove all elements below the top_n
@@ -690,8 +646,11 @@ where
         if self.buffer.len() > self.top_n {
             self.truncate_top_n();
         }
-        self.buffer
-            .sort_unstable_by(|left, right| self.comparator.compare_doc(left, right));
+        self.buffer.sort_unstable_by(|left, right| {
+            self.comparator
+                .compare(&right.sort_key, &left.sort_key)
+                .then_with(|| left.doc.cmp(&right.doc))
+        });
         self.buffer
     }
 
@@ -710,7 +669,7 @@ where
 //
 // Panics if there is not enough capacity to add an element.
 #[inline(always)]
-pub fn push_assuming_capacity<T>(el: T, buf: &mut Vec<T>) {
+fn push_assuming_capacity<T>(el: T, buf: &mut Vec<T>) {
     let prev_len = buf.len();
     assert!(prev_len < buf.capacity());
     // This is mimicking the current (non-stabilized) implementation in std.
@@ -727,10 +686,9 @@ mod tests {
     use proptest::prelude::*;
 
     use super::{TopDocs, TopNComputer};
-    use crate::collector::sort_key::{
-        Comparator, ComparatorEnum, NaturalComparator, ReverseComparator,
-    };
-    use crate::collector::{Collector, ComparableDoc, DocSetCollector};
+    use crate::collector::sort_key::{ComparatorEnum, NaturalComparator, ReverseComparator};
+    use crate::collector::top_collector::ComparableDoc;
+    use crate::collector::{Collector, DocSetCollector};
     use crate::query::{AllQuery, Query, QueryParser};
     use crate::schema::{Field, Schema, FAST, STORED, TEXT};
     use crate::time::format_description::well_known::Rfc3339;
@@ -797,33 +755,6 @@ mod tests {
         );
     }
 
-    #[test]
-    fn test_topn_computer_duplicates() {
-        let mut computer: TopNComputer<u32, u32, NaturalComparator> =
-            TopNComputer::new_with_comparator(2, NaturalComparator);
-
-        computer.push(1u32, 1u32);
-        computer.push(1u32, 2u32);
-        computer.push(1u32, 3u32);
-        computer.push(1u32, 4u32);
-        computer.push(1u32, 5u32);
-
-        // In the presence of duplicates, DocIds are always ascending order.
-        assert_eq!(
-            computer.into_sorted_vec(),
-            &[
-                ComparableDoc {
-                    sort_key: 1u32,
-                    doc: 1u32,
-                },
-                ComparableDoc {
-                    sort_key: 1u32,
-                    doc: 2u32,
-                }
-            ]
-        );
-    }
-
     #[test]
     fn test_topn_computer_no_panic() {
         for top_n in 0..10 {
@@ -841,17 +772,14 @@ mod tests {
         #[test]
         fn test_topn_computer_asc_prop(
           limit in 0..10_usize,
-          mut docs in proptest::collection::vec((0..100_u64, 0..100_u64), 0..100_usize),
+          docs in proptest::collection::vec((0..100_u64, 0..100_u64), 0..100_usize),
         ) {
-            // NB: TopNComputer must receive inputs in ascending DocId order.
-            docs.sort_by_key(|(_, doc_id)| *doc_id);
             let mut computer: TopNComputer<_, _, ReverseComparator> = TopNComputer::new_with_comparator(limit, ReverseComparator);
             for (feature, doc) in &docs {
                 computer.push(*feature, *doc);
             }
-            let mut comparable_docs =
-                docs.into_iter().map(|(sort_key, doc)| ComparableDoc { sort_key, doc }).collect::<Vec<_>>();
-            comparable_docs.sort_by(|l, r| ReverseComparator.compare_doc(l, r));
+            let mut comparable_docs: Vec<ComparableDoc<u64, u64>> = docs.into_iter().map(|(sort_key, doc)| ComparableDoc { sort_key, doc }).collect::<Vec<_>>();
+            comparable_docs.sort();
             comparable_docs.truncate(limit);
             prop_assert_eq!(
                 computer.into_sorted_vec(),
@@ -1435,11 +1363,11 @@ mod tests {
         #[test]
         fn test_top_field_collect_string_prop(
           order in prop_oneof!(Just(Order::Desc), Just(Order::Asc)),
-          limit in 1..32_usize,
-          offset in 0..32_usize,
+          limit in 1..256_usize,
+          offset in 0..256_usize,
           segments_terms in
             proptest::collection::vec(
-                proptest::collection::vec(0..64_u8, 1..256_usize),
+                proptest::collection::vec(0..32_u8, 1..32_usize),
                 0..8_usize,
             )
         ) {
@@ -1478,14 +1406,15 @@ mod tests {
 
             // Using the TopDocs collector should always be equivalent to sorting, skipping the
             // offset, and then taking the limit.
-            let sorted_docs: Vec<_> = {
-                let mut comparable_docs: Vec<ComparableDoc<_, _>> =
+            let sorted_docs: Vec<_> = if order.is_desc() {
+                let mut comparable_docs: Vec<ComparableDoc<_, _, true>> =
                     all_results.into_iter().map(|(sort_key, doc)| ComparableDoc { sort_key, doc}).collect();
-                if order.is_desc() {
-                    comparable_docs.sort_by(|l, r| NaturalComparator.compare_doc(l, r));
-                } else {
-                    comparable_docs.sort_by(|l, r| ReverseComparator.compare_doc(l, r));
-                }
+                comparable_docs.sort();
+                comparable_docs.into_iter().map(|cd| (cd.sort_key, cd.doc)).collect()
+            } else {
+                let mut comparable_docs: Vec<ComparableDoc<_, _, false>> =
+                    all_results.into_iter().map(|(sort_key, doc)| ComparableDoc { sort_key, doc}).collect();
+                comparable_docs.sort();
                 comparable_docs.into_iter().map(|cd| (cd.sort_key, cd.doc)).collect()
             };
             let expected_docs = sorted_docs.into_iter().skip(offset).take(limit).collect::<Vec<_>>();
@@ -1764,8 +1693,7 @@ mod tests {
 
     #[test]
     fn test_top_n_computer_not_at_capacity() {
-        let mut top_n_computer: TopNComputer<f32, u32, _, ()> =
-            TopNComputer::new_with_comparator(4, NaturalComparator);
+        let mut top_n_computer = TopNComputer::new_with_comparator(4, NaturalComparator);
         top_n_computer.append_doc(1, 0.8);
         top_n_computer.append_doc(3, 0.2);
         top_n_computer.append_doc(5, 0.3);
@@ -1790,8 +1718,7 @@ mod tests {
 
     #[test]
     fn test_top_n_computer_at_capacity() {
-        let mut top_collector: TopNComputer<f32, u32, _, ()> =
-            TopNComputer::new_with_comparator(4, NaturalComparator);
+        let mut top_collector = TopNComputer::new_with_comparator(4, NaturalComparator);
         top_collector.append_doc(1, 0.8);
         top_collector.append_doc(3, 0.2);
         top_collector.append_doc(5, 0.3);
@@ -1828,14 +1755,12 @@ mod tests {
         let doc_ids_collection = [4, 5, 6];
         let score = 3.3f32;
 
-        let mut top_collector_limit_2: TopNComputer<f32, u32, _, ()> =
-            TopNComputer::new_with_comparator(2, NaturalComparator);
+        let mut top_collector_limit_2 = TopNComputer::new_with_comparator(2, NaturalComparator);
         for id in &doc_ids_collection {
             top_collector_limit_2.append_doc(*id, score);
         }
 
-        let mut top_collector_limit_3: TopNComputer<f32, u32, _, ()> =
-            TopNComputer::new_with_comparator(3, NaturalComparator);
+        let mut top_collector_limit_3 = TopNComputer::new_with_comparator(3, NaturalComparator);
         for id in &doc_ids_collection {
             top_collector_limit_3.append_doc(*id, score);
         }
@@ -1856,16 +1781,15 @@ mod bench {
 
     #[bench]
     fn bench_top_segment_collector_collect_at_capacity(b: &mut Bencher) {
-        let mut top_collector: TopNComputer<f32, u32, _, ()> =
-            TopNComputer::new_with_comparator(100, NaturalComparator);
+        let mut top_collector = TopNComputer::new_with_comparator(100, NaturalComparator);
 
         for i in 0..100 {
-            top_collector.append_doc(i as u32, 0.8);
+            top_collector.append_doc(i, 0.8);
         }
 
         b.iter(|| {
             for i in 0..100 {
-                top_collector.append_doc(i as u32, 0.8);
+                top_collector.append_doc(i, 0.8);
             }
         });
     }

src/compat_tests.rs

@@ -36,7 +36,6 @@ fn path_for_version(version: &str) -> String {
 /// feature flag quickwit uses a different dictionary type
 #[test]
 #[cfg(not(feature = "quickwit"))]
-#[ignore = "test incompatible with fixed-width footer changes"]
 fn test_format_6() {
     let path = path_for_version("6");
 
@@ -48,7 +47,6 @@ fn test_format_6() {
 /// feature flag quickwit uses a different dictionary type
 #[test]
 #[cfg(not(feature = "quickwit"))]
-#[ignore = "test incompatible with fixed-width footer changes"]
 fn test_format_7() {
     let path = path_for_version("7");
 

src/core/executor.rs

@@ -48,7 +48,15 @@ impl Executor {
         F: Sized + Sync + Fn(A) -> crate::Result<R>,
     {
         match self {
-            Executor::SingleThread => args.map(f).collect::<crate::Result<_>>(),
+            Executor::SingleThread => {
+                // Avoid `collect`, since the stacktrace is blown up by it, which makes profiling
+                // harder.
+                let mut result = Vec::with_capacity(args.size_hint().0);
+                for arg in args {
+                    result.push(f(arg)?);
+                }
+                Ok(result)
+            }
             Executor::ThreadPool(pool) => {
                 let args: Vec<A> = args.collect();
                 let num_fruits = args.len();

src/core/json_utils.rs

@@ -406,7 +406,7 @@ mod tests {
         let mut term = Term::from_field_json_path(field, "color", false);
         term.append_type_and_str("red");
 
-        assert_eq!(term.serialized_value_bytes(), b"color\x00sred".to_vec())
+        assert_eq!(term.serialized_term(), b"\x00\x00\x00\x01jcolor\x00sred")
     }
 
     #[test]
@@ -416,8 +416,8 @@ mod tests {
         term.append_type_and_fast_value(-4i64);
 
         assert_eq!(
-            term.serialized_value_bytes(),
-            b"color\x00i\x7f\xff\xff\xff\xff\xff\xff\xfc".to_vec()
+            term.serialized_term(),
+            b"\x00\x00\x00\x01jcolor\x00i\x7f\xff\xff\xff\xff\xff\xff\xfc"
         )
     }
 
@@ -428,8 +428,8 @@ mod tests {
         term.append_type_and_fast_value(4u64);
 
         assert_eq!(
-            term.serialized_value_bytes(),
-            b"color\x00u\x00\x00\x00\x00\x00\x00\x00\x04".to_vec()
+            term.serialized_term(),
+            b"\x00\x00\x00\x01jcolor\x00u\x00\x00\x00\x00\x00\x00\x00\x04"
         )
     }
 
@@ -439,8 +439,8 @@ mod tests {
         let mut term = Term::from_field_json_path(field, "color", false);
         term.append_type_and_fast_value(4.0f64);
         assert_eq!(
-            term.serialized_value_bytes(),
-            b"color\x00f\xc0\x10\x00\x00\x00\x00\x00\x00".to_vec()
+            term.serialized_term(),
+            b"\x00\x00\x00\x01jcolor\x00f\xc0\x10\x00\x00\x00\x00\x00\x00"
         )
     }
 
@@ -450,8 +450,8 @@ mod tests {
         let mut term = Term::from_field_json_path(field, "color", false);
         term.append_type_and_fast_value(true);
         assert_eq!(
-            term.serialized_value_bytes(),
-            b"color\x00o\x00\x00\x00\x00\x00\x00\x00\x01".to_vec()
+            term.serialized_term(),
+            b"\x00\x00\x00\x01jcolor\x00o\x00\x00\x00\x00\x00\x00\x00\x01"
         )
     }
 

src/core/searcher.rs

@@ -1,5 +1,5 @@
 use std::collections::BTreeMap;
-use std::sync::{Arc, OnceLock};
+use std::sync::Arc;
 use std::{fmt, io};
 
 use crate::collector::Collector;
@@ -86,7 +86,7 @@ impl Searcher {
     /// The searcher uses the segment ordinal to route the
     /// request to the right `Segment`.
     pub fn doc<D: DocumentDeserialize>(&self, doc_address: DocAddress) -> crate::Result<D> {
-        let store_reader = &self.inner.store_readers()[doc_address.segment_ord as usize];
+        let store_reader = &self.inner.store_readers[doc_address.segment_ord as usize];
         store_reader.get(doc_address.doc_id)
     }
 
@@ -96,7 +96,7 @@ impl Searcher {
     pub fn doc_store_cache_stats(&self) -> CacheStats {
         let cache_stats: CacheStats = self
             .inner
-            .store_readers()
+            .store_readers
             .iter()
             .map(|reader| reader.cache_stats())
             .sum();
@@ -110,7 +110,7 @@ impl Searcher {
         doc_address: DocAddress,
     ) -> crate::Result<D> {
         let executor = self.inner.index.search_executor();
-        let store_reader = &self.inner.store_readers()[doc_address.segment_ord as usize];
+        let store_reader = &self.inner.store_readers[doc_address.segment_ord as usize];
         store_reader.get_async(doc_address.doc_id, executor).await
     }
 
@@ -259,9 +259,8 @@ impl From<Arc<SearcherInner>> for Searcher {
 pub(crate) struct SearcherInner {
     schema: Schema,
     index: Index,
-    doc_store_cache_num_blocks: usize,
     segment_readers: Vec<SegmentReader>,
-    store_readers: OnceLock<Vec<StoreReader>>,
+    store_readers: Vec<StoreReader>,
     generation: TrackedObject<SearcherGeneration>,
 }
 
@@ -282,30 +281,19 @@ impl SearcherInner {
             generation.segments(),
             "Set of segments referenced by this Searcher and its SearcherGeneration must match"
         );
+        let store_readers: Vec<StoreReader> = segment_readers
+            .iter()
+            .map(|segment_reader| segment_reader.get_store_reader(doc_store_cache_num_blocks))
+            .collect::<io::Result<Vec<_>>>()?;
 
         Ok(SearcherInner {
             schema,
             index,
-            doc_store_cache_num_blocks,
             segment_readers,
-            store_readers: OnceLock::default(),
+            store_readers,
             generation,
         })
     }
-
-    #[inline]
-    fn store_readers(&self) -> &[StoreReader] {
-        self.store_readers.get_or_init(|| {
-            self.segment_readers
-                .iter()
-                .map(|segment_reader| {
-                    segment_reader
-                        .get_store_reader(self.doc_store_cache_num_blocks)
-                        .expect("should be able to get store reader")
-                })
-                .collect()
-        })
-    }
 }
 
 impl fmt::Debug for Searcher {

src/directory/composite_file.rs

@@ -5,7 +5,7 @@ use std::ops::Range;
 use common::{BinarySerializable, CountingWriter, HasLen, VInt};
 
 use crate::directory::{FileSlice, TerminatingWrite, WritePtr};
-use crate::schema::{Field, Schema};
+use crate::schema::Field;
 use crate::space_usage::{FieldUsage, PerFieldSpaceUsage};
 
 #[derive(Eq, PartialEq, Hash, Copy, Ord, PartialOrd, Clone, Debug)]
@@ -167,11 +167,10 @@ impl CompositeFile {
             .map(|byte_range| self.data.slice(byte_range.clone()))
     }
 
-    pub fn space_usage(&self, schema: &Schema) -> PerFieldSpaceUsage {
+    pub fn space_usage(&self) -> PerFieldSpaceUsage {
         let mut fields = Vec::new();
         for (&field_addr, byte_range) in &self.offsets_index {
-            let field_name = schema.get_field_name(field_addr.field).to_string();
-            let mut field_usage = FieldUsage::empty(field_name);
+            let mut field_usage = FieldUsage::empty(field_addr.field);
             field_usage.add_field_idx(field_addr.idx, byte_range.len().into());
             fields.push(field_usage);
         }

src/directory/directory.rs

@@ -1,20 +1,12 @@
-use std::any::Any;
-use std::collections::HashSet;
 use std::io::Write;
 use std::path::{Path, PathBuf};
 use std::sync::Arc;
 use std::time::Duration;
 use std::{fmt, io, thread};
 
-use log::Level;
-
 use crate::directory::directory_lock::Lock;
 use crate::directory::error::{DeleteError, LockError, OpenReadError, OpenWriteError};
-use crate::directory::{
-    FileHandle, FileSlice, TerminatingWrite, WatchCallback, WatchHandle, WritePtr,
-};
-use crate::index::SegmentMetaInventory;
-use crate::IndexMeta;
+use crate::directory::{FileHandle, FileSlice, WatchCallback, WatchHandle, WritePtr};
 
 /// Retry the logic of acquiring locks is pretty simple.
 /// We just retry `n` times after a given `duratio`, both
@@ -64,7 +56,7 @@ impl<T: Send + Sync + 'static> From<Box<T>> for DirectoryLock {
 impl Drop for DirectoryLockGuard {
     fn drop(&mut self) {
         if let Err(e) = self.directory.delete(&self.path) {
-            error!("Failed to remove the lock file. {:?}", e);
+            error!("Failed to remove the lock file. {e:?}");
         }
     }
 }
@@ -105,8 +97,6 @@ fn retry_policy(is_blocking: bool) -> RetryPolicy {
     }
 }
 
-pub type DirectoryPanicHandler = Arc<dyn Fn(Box<dyn Any + Send>) + Send + Sync + 'static>;
-
 /// Write-once read many (WORM) abstraction for where
 /// tantivy's data should be stored.
 ///
@@ -145,10 +135,6 @@ pub trait Directory: DirectoryClone + fmt::Debug + Send + Sync + 'static {
     /// Returns true if and only if the file exists
     fn exists(&self, path: &Path) -> Result<bool, OpenReadError>;
 
-    /// Returns a boxed `TerminatingWrite` object, to be passed into `open_write`
-    /// which wraps it in a `BufWriter`
-    fn open_write_inner(&self, path: &Path) -> Result<Box<dyn TerminatingWrite>, OpenWriteError>;
-
     /// Opens a writer for the *virtual file* associated with
     /// a [`Path`].
     ///
@@ -175,12 +161,7 @@ pub trait Directory: DirectoryClone + fmt::Debug + Send + Sync + 'static {
     /// panic! if `flush` was not called.
     ///
     /// The file may not previously exist.
-    fn open_write(&self, path: &Path) -> Result<WritePtr, OpenWriteError> {
-        Ok(io::BufWriter::with_capacity(
-            self.bufwriter_capacity(),
-            self.open_write_inner(path)?,
-        ))
-    }
+    fn open_write(&self, path: &Path) -> Result<WritePtr, OpenWriteError>;
 
     /// Reads the full content file that has been written using
     /// [`Directory::atomic_write()`].
@@ -242,75 +223,6 @@ pub trait Directory: DirectoryClone + fmt::Debug + Send + Sync + 'static {
     /// `OnCommitWithDelay` `ReloadPolicy`. Not implementing watch in a `Directory` only prevents
     /// the `OnCommitWithDelay` `ReloadPolicy` to work properly.
     fn watch(&self, watch_callback: WatchCallback) -> crate::Result<WatchHandle>;
-
-    /// Allows the directory to list managed files, overriding the ManagedDirectory's default
-    /// list_managed_files
-    fn list_managed_files(&self) -> crate::Result<HashSet<PathBuf>> {
-        Err(crate::TantivyError::InternalError(
-            "list_managed_files not implemented".to_string(),
-        ))
-    }
-
-    /// Allows the directory to register a file as managed, overriding the ManagedDirectory's
-    /// default register_file_as_managed
-    fn register_files_as_managed(
-        &self,
-        _files: Vec<PathBuf>,
-        _overwrite: bool,
-    ) -> crate::Result<()> {
-        Err(crate::TantivyError::InternalError(
-            "register_files_as_managed not implemented".to_string(),
-        ))
-    }
-
-    /// Allows the directory to save IndexMeta, overriding the SegmentUpdater's default save_meta
-    fn save_metas(
-        &self,
-        _metas: &IndexMeta,
-        _previous_metas: &IndexMeta,
-        _payload: &mut (dyn Any + '_),
-    ) -> crate::Result<()> {
-        Err(crate::TantivyError::InternalError(
-            "save_meta not implemented".to_string(),
-        ))
-    }
-
-    /// Allows the directory to load IndexMeta, overriding the SegmentUpdater's default load_meta
-    fn load_metas(&self, _inventory: &SegmentMetaInventory) -> crate::Result<IndexMeta> {
-        Err(crate::TantivyError::InternalError(
-            "load_metas not implemented".to_string(),
-        ))
-    }
-
-    /// Returns true if this directory supports garbage collection.  The default assumption is
-    /// `true`
-    fn supports_garbage_collection(&self) -> bool {
-        true
-    }
-
-    /// Return a panic handler to be assigned to the various thread pools that may be created
-    ///
-    /// The default is [`None`], which indicates that an unhandled panic from a thread pool will
-    /// abort the process
-    fn panic_handler(&self) -> Option<DirectoryPanicHandler> {
-        None
-    }
-
-    /// Returns true if this directory is in a position of requiring that tantivy cancel
-    /// whatever operation(s) it might be doing  Typically this is just for the background
-    /// merge processes but could be used for anything
-    fn wants_cancel(&self) -> bool {
-        false
-    }
-
-    /// Send a logging message to the Directory to handle in its own way
-    fn log(&self, message: &str) {
-        log!(Level::Info, "{message}");
-    }
-
-    fn bufwriter_capacity(&self) -> usize {
-        8192
-    }
 }
 
 /// DirectoryClone

src/directory/directory_lock.rs

@@ -58,9 +58,3 @@ pub static META_LOCK: Lazy<Lock> = Lazy::new(|| Lock {
     filepath: PathBuf::from(".tantivy-meta.lock"),
     is_blocking: true,
 });
-
-#[allow(missing_docs)]
-pub static MANAGED_LOCK: Lazy<Lock> = Lazy::new(|| Lock {
-    filepath: PathBuf::from(".tantivy-managed.lock"),
-    is_blocking: true,
-});

src/directory/file_watcher.rs

@@ -9,7 +9,6 @@ use crc32fast::Hasher;
 
 use crate::directory::{WatchCallback, WatchCallbackList, WatchHandle};
 
-#[allow(dead_code)]
 const POLLING_INTERVAL: Duration = Duration::from_millis(if cfg!(test) { 1 } else { 500 });
 
 // Watches a file and executes registered callbacks when the file is modified.
@@ -19,7 +18,6 @@ pub struct FileWatcher {
     state: Arc<AtomicUsize>, // 0: new, 1: runnable, 2: terminated
 }
 
-#[allow(dead_code)]
 impl FileWatcher {
     pub fn new(path: &Path) -> FileWatcher {
         FileWatcher {

src/directory/footer.rs

@@ -7,14 +7,15 @@
 use std::io;
 use std::io::Write;
 
-use common::{BinarySerializable, HasLen};
+use common::{BinarySerializable, CountingWriter, DeserializeFrom, FixedSize, HasLen};
 use crc32fast::Hasher;
+use serde::{Deserialize, Serialize};
 
 use crate::directory::error::Incompatibility;
 use crate::directory::{AntiCallToken, FileSlice, TerminatingWrite};
 use crate::{Version, INDEX_FORMAT_OLDEST_SUPPORTED_VERSION, INDEX_FORMAT_VERSION};
 
-pub const FOOTER_LEN: usize = 24;
+const FOOTER_MAX_LEN: u32 = 50_000;
 
 /// The magic byte of the footer to identify corruption
 /// or an old version of the footer.
@@ -23,7 +24,7 @@ const FOOTER_MAGIC_NUMBER: u32 = 1337;
 type CrcHashU32 = u32;
 
 /// A Footer is appended to every file
-#[derive(Debug, Clone, PartialEq)]
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
 pub struct Footer {
     /// The version of the index format
     pub version: Version,
@@ -40,45 +41,34 @@ impl Footer {
     pub(crate) fn crc(&self) -> CrcHashU32 {
         self.crc
     }
-    pub fn append_footer<W: io::Write>(&self, write: &mut W) -> io::Result<()> {
-        // 24 bytes
-        BinarySerializable::serialize(&self.version.major, write)?;
-        BinarySerializable::serialize(&self.version.minor, write)?;
-        BinarySerializable::serialize(&self.version.patch, write)?;
-        BinarySerializable::serialize(&self.version.index_format_version, write)?;
-        BinarySerializable::serialize(&self.crc, write)?;
+    pub(crate) fn append_footer<W: io::Write>(&self, mut write: &mut W) -> io::Result<()> {
+        let mut counting_write = CountingWriter::wrap(&mut write);
+        counting_write.write_all(serde_json::to_string(&self)?.as_ref())?;
+        let footer_payload_len = counting_write.written_bytes();
+        BinarySerializable::serialize(&(footer_payload_len as u32), write)?;
         BinarySerializable::serialize(&FOOTER_MAGIC_NUMBER, write)?;
         Ok(())
     }
 
     /// Extracts the tantivy Footer from the file and returns the footer and the rest of the file
     pub fn extract_footer(file: FileSlice) -> io::Result<(Footer, FileSlice)> {
-        if file.len() < FOOTER_LEN {
+        if file.len() < 4 {
             return Err(io::Error::new(
                 io::ErrorKind::UnexpectedEof,
                 format!(
-                    "File corrupted. The file is too small to contain the {FOOTER_LEN} byte \
-                     footer (len={}).",
+                    "File corrupted. The file is smaller than 4 bytes (len={}).",
                     file.len()
                 ),
             ));
         }
 
-        let (body_slice, footer_slice) = file.split_from_end(FOOTER_LEN);
-        let footer_bytes = footer_slice.read_bytes()?;
-        let mut footer_bytes = footer_bytes.as_slice();
+        let footer_metadata_len = <(u32, u32)>::SIZE_IN_BYTES;
+        let (footer_len, footer_magic_byte): (u32, u32) = file
+            .slice_from_end(footer_metadata_len)
+            .read_bytes()?
+            .as_ref()
+            .deserialize()?;
 
-        let footer = Footer {
-            version: Version {
-                major: u32::deserialize(&mut footer_bytes)?,
-                minor: u32::deserialize(&mut footer_bytes)?,
-                patch: u32::deserialize(&mut footer_bytes)?,
-                index_format_version: u32::deserialize(&mut footer_bytes)?,
-            },
-            crc: u32::deserialize(&mut footer_bytes)?,
-        };
-
-        let footer_magic_byte = u32::deserialize(&mut footer_bytes)?;
         if footer_magic_byte != FOOTER_MAGIC_NUMBER {
             return Err(io::Error::new(
                 io::ErrorKind::InvalidData,
@@ -88,12 +78,38 @@ impl Footer {
             ));
         }
 
-        Ok((footer, body_slice))
+        if footer_len > FOOTER_MAX_LEN {
+            return Err(io::Error::new(
+                io::ErrorKind::InvalidData,
+                format!(
+                    "Footer seems invalid as it suggests a footer len of {footer_len}. File is \
+                     corrupted, or the index was created with a different & old version of \
+                     tantivy."
+                ),
+            ));
+        }
+        let total_footer_size = footer_len as usize + footer_metadata_len;
+        if file.len() < total_footer_size {
+            return Err(io::Error::new(
+                io::ErrorKind::UnexpectedEof,
+                format!(
+                    "File corrupted. The file is smaller than it's footer bytes \
+                     (len={total_footer_size})."
+                ),
+            ));
+        }
+
+        let footer: Footer =
+            serde_json::from_slice(&file.read_bytes_slice(
+                file.len() - total_footer_size..file.len() - footer_metadata_len,
+            )?)?;
+
+        let body = file.slice_to(file.len() - total_footer_size);
+        Ok((footer, body))
     }
 
     /// Confirms that the index will be read correctly by this version of tantivy
     /// Has to be called after `extract_footer` to make sure it's not accessing uninitialised memory
-    #[allow(dead_code)]
     pub fn is_compatible(&self) -> Result<(), Incompatibility> {
         const SUPPORTED_INDEX_FORMAT_VERSION_RANGE: std::ops::RangeInclusive<u32> =
             INDEX_FORMAT_OLDEST_SUPPORTED_VERSION..=INDEX_FORMAT_VERSION;
@@ -172,10 +188,6 @@ mod tests {
     fn test_deserialize_footer_missing_magic_byte() {
         let mut buf: Vec<u8> = vec![];
         BinarySerializable::serialize(&0_u32, &mut buf).unwrap();
-        BinarySerializable::serialize(&0_u32, &mut buf).unwrap();
-        BinarySerializable::serialize(&0_u32, &mut buf).unwrap();
-        BinarySerializable::serialize(&0_u32, &mut buf).unwrap();
-        BinarySerializable::serialize(&0_u32, &mut buf).unwrap();
         let wrong_magic_byte: u32 = 5555;
         BinarySerializable::serialize(&wrong_magic_byte, &mut buf).unwrap();
 
@@ -193,6 +205,7 @@ mod tests {
     #[test]
     fn test_deserialize_footer_wrong_filesize() {
         let mut buf: Vec<u8> = vec![];
+        BinarySerializable::serialize(&100_u32, &mut buf).unwrap();
         BinarySerializable::serialize(&FOOTER_MAGIC_NUMBER, &mut buf).unwrap();
 
         let owned_bytes = OwnedBytes::new(buf);
@@ -202,7 +215,27 @@ mod tests {
         assert_eq!(err.kind(), io::ErrorKind::UnexpectedEof);
         assert_eq!(
             err.to_string(),
-            "File corrupted. The file is too small to contain the 24 byte footer (len=4)."
+            "File corrupted. The file is smaller than it\'s footer bytes (len=108)."
+        );
+    }
+
+    #[test]
+    fn test_deserialize_too_large_footer() {
+        let mut buf: Vec<u8> = vec![];
+
+        let footer_length = super::FOOTER_MAX_LEN + 1;
+        BinarySerializable::serialize(&footer_length, &mut buf).unwrap();
+        BinarySerializable::serialize(&FOOTER_MAGIC_NUMBER, &mut buf).unwrap();
+
+        let owned_bytes = OwnedBytes::new(buf);
+
+        let fileslice = FileSlice::new(Arc::new(owned_bytes));
+        let err = Footer::extract_footer(fileslice).unwrap_err();
+        assert_eq!(err.kind(), io::ErrorKind::InvalidData);
+        assert_eq!(
+            err.to_string(),
+            "Footer seems invalid as it suggests a footer len of 50001. File is corrupted, or the \
+             index was created with a different & old version of tantivy."
         );
     }
 }

src/directory/managed_directory.rs

@@ -1,22 +1,20 @@
-use std::any::Any;
 use std::collections::HashSet;
 use std::io::Write;
 use std::path::{Path, PathBuf};
-use std::sync::Arc;
+use std::sync::{Arc, RwLock, RwLockWriteGuard};
 use std::{io, result};
 
 use crc32fast::Hasher;
 
 use crate::core::MANAGED_FILEPATH;
 use crate::directory::error::{DeleteError, LockError, OpenReadError, OpenWriteError};
-use crate::directory::footer::{Footer, FooterProxy, FOOTER_LEN};
+use crate::directory::footer::{Footer, FooterProxy};
 use crate::directory::{
-    DirectoryLock, DirectoryPanicHandler, FileHandle, FileSlice, GarbageCollectionResult, Lock,
-    TerminatingWrite, WatchCallback, WatchHandle, MANAGED_LOCK, META_LOCK,
+    DirectoryLock, FileHandle, FileSlice, GarbageCollectionResult, Lock, WatchCallback,
+    WatchHandle, WritePtr, META_LOCK,
 };
 use crate::error::DataCorruption;
-use crate::index::SegmentMetaInventory;
-use crate::{Directory, IndexMeta};
+use crate::Directory;
 
 /// Returns true if the file is "managed".
 /// Non-managed file are not subject to garbage collection.
@@ -41,9 +39,9 @@ fn is_managed(path: &Path) -> bool {
 #[derive(Debug)]
 pub struct ManagedDirectory {
     directory: Box<dyn Directory>,
+    meta_informations: Arc<RwLock<MetaInformation>>,
 }
 
-#[allow(unused)]
 #[derive(Debug, Default)]
 struct MetaInformation {
     managed_paths: HashSet<PathBuf>,
@@ -53,9 +51,9 @@ struct MetaInformation {
 /// that were created by tantivy.
 fn save_managed_paths(
     directory: &dyn Directory,
-    managed_paths: &HashSet<PathBuf>,
+    wlock: &RwLockWriteGuard<'_, MetaInformation>,
 ) -> io::Result<()> {
-    let mut w = serde_json::to_vec(managed_paths)?;
+    let mut w = serde_json::to_vec(&wlock.managed_paths)?;
     writeln!(&mut w)?;
     directory.atomic_write(&MANAGED_FILEPATH, &w[..])?;
     Ok(())
@@ -64,37 +62,33 @@ fn save_managed_paths(
 impl ManagedDirectory {
     /// Wraps a directory as managed directory.
     pub fn wrap(directory: Box<dyn Directory>) -> crate::Result<ManagedDirectory> {
-        Ok(ManagedDirectory { directory })
-    }
-
-    pub fn list_managed_files(&self) -> crate::Result<HashSet<PathBuf>> {
-        match self.directory.list_managed_files() {
-            Ok(managed_files) => Ok(managed_files),
-            Err(crate::TantivyError::InternalError(_)) => {
-                match self.directory.atomic_read(&MANAGED_FILEPATH) {
-                    Ok(data) => {
-                        let managed_files_json = String::from_utf8_lossy(&data);
-                        let managed_files: HashSet<PathBuf> =
-                            serde_json::from_str(&managed_files_json).map_err(|e| {
-                                DataCorruption::new(
-                                    MANAGED_FILEPATH.to_path_buf(),
-                                    format!("Managed file cannot be deserialized: {e:?}. "),
-                                )
-                            })?;
-                        Ok(managed_files)
-                    }
-                    Err(OpenReadError::FileDoesNotExist(_)) => Ok(HashSet::new()),
-                    io_err @ Err(OpenReadError::IoError { .. }) => {
-                        Err(io_err.err().unwrap().into())
-                    }
-                    Err(OpenReadError::IncompatibleIndex(incompatibility)) => {
-                        // For the moment, this should never happen  `meta.json`
-                        // do not have any footer and cannot detect incompatibility.
-                        Err(crate::TantivyError::IncompatibleIndex(incompatibility))
-                    }
-                }
+        match directory.atomic_read(&MANAGED_FILEPATH) {
+            Ok(data) => {
+                let managed_files_json = String::from_utf8_lossy(&data);
+                let managed_files: HashSet<PathBuf> = serde_json::from_str(&managed_files_json)
+                    .map_err(|e| {
+                        DataCorruption::new(
+                            MANAGED_FILEPATH.to_path_buf(),
+                            format!("Managed file cannot be deserialized: {e:?}. "),
+                        )
+                    })?;
+                Ok(ManagedDirectory {
+                    directory,
+                    meta_informations: Arc::new(RwLock::new(MetaInformation {
+                        managed_paths: managed_files,
+                    })),
+                })
+            }
+            Err(OpenReadError::FileDoesNotExist(_)) => Ok(ManagedDirectory {
+                directory,
+                meta_informations: Arc::default(),
+            }),
+            io_err @ Err(OpenReadError::IoError { .. }) => Err(io_err.err().unwrap().into()),
+            Err(OpenReadError::IncompatibleIndex(incompatibility)) => {
+                // For the moment, this should never happen  `meta.json`
+                // do not have any footer and cannot detect incompatibility.
+                Err(crate::TantivyError::IncompatibleIndex(incompatibility))
             }
-            Err(err) => Err(err),
         }
     }
 
@@ -116,26 +110,9 @@ impl ManagedDirectory {
         &mut self,
         get_living_files: L,
     ) -> crate::Result<GarbageCollectionResult> {
-        if !self.supports_garbage_collection() {
-            // the underlying directory does not support garbage collection.
-            return Ok(GarbageCollectionResult {
-                deleted_files: vec![],
-                failed_to_delete_files: vec![],
-            });
-        }
+        info!("Garbage collect");
         let mut files_to_delete = vec![];
 
-        // We're about to do an atomic write to managed.json, lock it down
-        let _lock = self.acquire_lock(&MANAGED_LOCK)?;
-        let managed_paths = match self.directory.list_managed_files() {
-            Ok(managed_paths) => managed_paths,
-            Err(crate::TantivyError::InternalError(_)) => {
-                // If the managed.json file does not exist, we consider
-                // that there is no managed file.
-                self.list_managed_files()?
-            }
-            Err(err) => return Err(err),
-        };
         // It is crucial to get the living files after acquiring the
         // read lock of meta information. That way, we
         // avoid the following scenario.
@@ -147,6 +124,11 @@ impl ManagedDirectory {
         //
         // releasing the lock as .delete() will use it too.
         {
+            let meta_informations_rlock = self
+                .meta_informations
+                .read()
+                .expect("Managed directory rlock poisoned in garbage collect.");
+
             // The point of this second "file" lock is to enforce the following scenario
             // 1) process B tries to load a new set of searcher.
             // The list of segments is loaded
@@ -156,7 +138,7 @@ impl ManagedDirectory {
             match self.acquire_lock(&META_LOCK) {
                 Ok(_meta_lock) => {
                     let living_files = get_living_files();
-                    for managed_path in &managed_paths {
+                    for managed_path in &meta_informations_rlock.managed_paths {
                         if !living_files.contains(managed_path) {
                             files_to_delete.push(managed_path.clone());
                         }
@@ -199,18 +181,16 @@ impl ManagedDirectory {
         if !deleted_files.is_empty() {
             // update the list of managed files by removing
             // the file that were removed.
-            let mut managed_paths_write = managed_paths;
+            let mut meta_informations_wlock = self
+                .meta_informations
+                .write()
+                .expect("Managed directory wlock poisoned (2).");
+            let managed_paths_write = &mut meta_informations_wlock.managed_paths;
             for delete_file in &deleted_files {
                 managed_paths_write.remove(delete_file);
             }
             self.directory.sync_directory()?;
-
-            if let Err(crate::TantivyError::InternalError(_)) = self
-                .directory
-                .register_files_as_managed(managed_paths_write.clone().into_iter().collect(), true)
-            {
-                save_managed_paths(self.directory.as_mut(), &managed_paths_write)?;
-            }
+            save_managed_paths(self.directory.as_mut(), &meta_informations_wlock)?;
         }
 
         Ok(GarbageCollectionResult {
@@ -235,39 +215,27 @@ impl ManagedDirectory {
         if !is_managed(filepath) {
             return Ok(());
         }
-
-        // We're about to do an atomic write to managed.json, lock it down
-        let _lock = self
-            .acquire_lock(&MANAGED_LOCK)
-            .expect("must be able to acquire lock for managed.json");
-
-        if let Err(crate::TantivyError::InternalError(_)) = self
-            .directory
-            .register_files_as_managed(vec![filepath.to_owned()], false)
-        {
-            let mut managed_paths = self
-                .list_managed_files()
-                .expect("reading managed files should not fail");
-            let has_changed = managed_paths.insert(filepath.to_owned());
-            if !has_changed {
-                return Ok(());
-            }
-            save_managed_paths(self.directory.as_ref(), &managed_paths)?;
-            // This is not the first file we add.
-            // Therefore, we are sure that `.managed.json` has been already
-            // properly created and we do not need to sync its parent directory.
-            //
-            // (It might seem like a nicer solution to create the managed_json on the
-            // creation of the ManagedDirectory instance but it would actually
-            // prevent the use of read-only directories..)
-            let managed_file_definitely_already_exists = managed_paths.len() > 1;
-            if managed_file_definitely_already_exists {
-                return Ok(());
-            }
+        let mut meta_wlock = self
+            .meta_informations
+            .write()
+            .expect("Managed file lock poisoned");
+        let has_changed = meta_wlock.managed_paths.insert(filepath.to_owned());
+        if !has_changed {
+            return Ok(());
+        }
+        save_managed_paths(self.directory.as_ref(), &meta_wlock)?;
+        // This is not the first file we add.
+        // Therefore, we are sure that `.managed.json` has been already
+        // properly created and we do not need to sync its parent directory.
+        //
+        // (It might seem like a nicer solution to create the managed_json on the
+        // creation of the ManagedDirectory instance but it would actually
+        // prevent the use of read-only directories..)
+        let managed_file_definitely_already_exists = meta_wlock.managed_paths.len() > 1;
+        if managed_file_definitely_already_exists {
+            return Ok(());
         }
-
         self.directory.sync_directory()?;
-
         Ok(())
     }
 
@@ -287,6 +255,17 @@ impl ManagedDirectory {
         let crc = hasher.finalize();
         Ok(footer.crc() == crc)
     }
+
+    /// List all managed files
+    pub fn list_managed_files(&self) -> HashSet<PathBuf> {
+        let managed_paths = self
+            .meta_informations
+            .read()
+            .expect("Managed directory rlock poisoned in list damaged.")
+            .managed_paths
+            .clone();
+        managed_paths
+    }
 }
 
 impl Directory for ManagedDirectory {
@@ -297,32 +276,22 @@ impl Directory for ManagedDirectory {
 
     fn open_read(&self, path: &Path) -> result::Result<FileSlice, OpenReadError> {
         let file_slice = self.directory.open_read(path)?;
-        debug_assert!(
-            {
-                use common::HasLen;
-                file_slice.len() >= FOOTER_LEN
-            },
-            "{} is too short",
-            path.display()
-        );
-        let (reader, _) = file_slice.split_from_end(FOOTER_LEN);
-        // NB:  We do not read/validate the footer here -- we blindly skip it entirely
+        let (footer, reader) = Footer::extract_footer(file_slice)
+            .map_err(|io_error| OpenReadError::wrap_io_error(io_error, path.to_path_buf()))?;
+        footer.is_compatible()?;
         Ok(reader)
     }
 
-    fn open_write_inner(
-        &self,
-        path: &Path,
-    ) -> result::Result<Box<dyn TerminatingWrite>, OpenWriteError> {
+    fn open_write(&self, path: &Path) -> result::Result<WritePtr, OpenWriteError> {
         self.register_file_as_managed(path)
             .map_err(|io_error| OpenWriteError::wrap_io_error(io_error, path.to_path_buf()))?;
-        Ok(Box::new(FooterProxy::new(
+        Ok(io::BufWriter::new(Box::new(FooterProxy::new(
             self.directory
                 .open_write(path)?
                 .into_inner()
                 .map_err(|_| ())
                 .expect("buffer should be empty"),
-        )))
+        ))))
     }
 
     fn atomic_write(&self, path: &Path, data: &[u8]) -> io::Result<()> {
@@ -354,45 +323,13 @@ impl Directory for ManagedDirectory {
         self.directory.sync_directory()?;
         Ok(())
     }
-
-    fn save_metas(
-        &self,
-        metas: &IndexMeta,
-        previous_metas: &IndexMeta,
-        payload: &mut (dyn Any + '_),
-    ) -> crate::Result<()> {
-        self.directory.save_metas(metas, previous_metas, payload)
-    }
-
-    fn load_metas(&self, inventory: &SegmentMetaInventory) -> crate::Result<IndexMeta> {
-        self.directory.load_metas(inventory)
-    }
-
-    fn supports_garbage_collection(&self) -> bool {
-        self.directory.supports_garbage_collection()
-    }
-
-    fn panic_handler(&self) -> Option<DirectoryPanicHandler> {
-        self.directory.panic_handler()
-    }
-
-    fn wants_cancel(&self) -> bool {
-        self.directory.wants_cancel()
-    }
-
-    fn log(&self, message: &str) {
-        self.directory.log(message);
-    }
-
-    fn bufwriter_capacity(&self) -> usize {
-        self.directory.bufwriter_capacity()
-    }
 }
 
 impl Clone for ManagedDirectory {
     fn clone(&self) -> ManagedDirectory {
         ManagedDirectory {
             directory: self.directory.box_clone(),
+            meta_informations: Arc::clone(&self.meta_informations),
         }
     }
 }
@@ -400,6 +337,7 @@ impl Clone for ManagedDirectory {
 #[cfg(feature = "mmap")]
 #[cfg(test)]
 mod tests_mmap_specific {
+
     use std::collections::HashSet;
     use std::io::Write;
     use std::path::{Path, PathBuf};

src/directory/mmap_directory.rs

@@ -1,7 +1,7 @@
 use std::collections::HashMap;
 use std::fmt;
 use std::fs::{self, File, OpenOptions};
-use std::io::{self, Read, Write};
+use std::io::{self, BufWriter, Read, Write};
 use std::ops::Deref;
 use std::path::{Path, PathBuf};
 use std::sync::{Arc, RwLock, Weak};
@@ -21,7 +21,7 @@ use crate::directory::error::{
 use crate::directory::file_watcher::FileWatcher;
 use crate::directory::{
     AntiCallToken, Directory, DirectoryLock, FileHandle, Lock, OwnedBytes, TerminatingWrite,
-    WatchCallback, WatchHandle,
+    WatchCallback, WatchHandle, WritePtr,
 };
 
 pub type ArcBytes = Arc<dyn Deref<Target = [u8]> + Send + Sync + 'static>;
@@ -413,8 +413,8 @@ impl Directory for MmapDirectory {
             .map_err(|io_err| OpenReadError::wrap_io_error(io_err, path.to_path_buf()))
     }
 
-    fn open_write_inner(&self, path: &Path) -> Result<Box<dyn TerminatingWrite>, OpenWriteError> {
-        debug!("Open Write {:?}", path);
+    fn open_write(&self, path: &Path) -> Result<WritePtr, OpenWriteError> {
+        debug!("Open Write {path:?}");
         let full_path = self.resolve_path(path);
 
         let open_res = OpenOptions::new()
@@ -443,7 +443,7 @@ impl Directory for MmapDirectory {
         // sync_directory() is called.
 
         let writer = SafeFileWriter::new(file);
-        Ok(Box::new(writer))
+        Ok(BufWriter::new(Box::new(writer)))
     }
 
     fn atomic_read(&self, path: &Path) -> Result<Vec<u8>, OpenReadError> {

src/directory/mod.rs

@@ -19,13 +19,12 @@ mod composite_file;
 use std::io::BufWriter;
 use std::path::PathBuf;
 
-pub use common::buffered_file_slice::BufferedFileSlice;
 pub use common::file_slice::{FileHandle, FileSlice};
 pub use common::{AntiCallToken, OwnedBytes, TerminatingWrite};
 
 pub(crate) use self::composite_file::{CompositeFile, CompositeWrite};
-pub use self::directory::{Directory, DirectoryClone, DirectoryLock, DirectoryPanicHandler};
-pub use self::directory_lock::{Lock, INDEX_WRITER_LOCK, MANAGED_LOCK, META_LOCK};
+pub use self::directory::{Directory, DirectoryClone, DirectoryLock};
+pub use self::directory_lock::{Lock, INDEX_WRITER_LOCK, META_LOCK};
 pub use self::ram_directory::RamDirectory;
 pub use self::watch_event_router::{WatchCallback, WatchCallbackList, WatchHandle};
 

src/directory/ram_directory.rs

@@ -1,5 +1,5 @@
 use std::collections::HashMap;
-use std::io::{self, Cursor, Write};
+use std::io::{self, BufWriter, Cursor, Write};
 use std::path::{Path, PathBuf};
 use std::sync::{Arc, RwLock};
 use std::{fmt, result};
@@ -11,7 +11,7 @@ use crate::core::META_FILEPATH;
 use crate::directory::error::{DeleteError, OpenReadError, OpenWriteError};
 use crate::directory::{
     AntiCallToken, Directory, FileSlice, TerminatingWrite, WatchCallback, WatchCallbackList,
-    WatchHandle,
+    WatchHandle, WritePtr,
 };
 
 /// Writer associated with the [`RamDirectory`].
@@ -197,7 +197,7 @@ impl Directory for RamDirectory {
             .exists(path))
     }
 
-    fn open_write_inner(&self, path: &Path) -> Result<Box<dyn TerminatingWrite>, OpenWriteError> {
+    fn open_write(&self, path: &Path) -> Result<WritePtr, OpenWriteError> {
         let mut fs = self.fs.write().unwrap();
         let path_buf = PathBuf::from(path);
         let vec_writer = VecWriter::new(path_buf.clone(), self.clone());
@@ -206,7 +206,7 @@ impl Directory for RamDirectory {
         if exists {
             Err(OpenWriteError::FileAlreadyExists(path_buf))
         } else {
-            Ok(Box::new(vec_writer))
+            Ok(BufWriter::new(Box::new(vec_writer)))
         }
     }
 

src/error.rs

@@ -110,11 +110,6 @@ pub enum TantivyError {
     #[error("Deserialize error: {0}")]
     /// An error occurred while attempting to deserialize a document.
     DeserializeError(DeserializeError),
-    /// The user requested the current operation be cancelled
-    #[error("User requested cancel")]
-    Cancelled,
-    #[error("Segment Merging failed: {0:#?}")]
-    MergeErrors(Vec<TantivyError>),
 }
 
 impl From<io::Error> for TantivyError {

src/fastfield/mod.rs

@@ -79,7 +79,7 @@ mod tests {
     use std::ops::{Range, RangeInclusive};
     use std::path::Path;
 
-    use columnar::{StrColumn, ValueRange};
+    use columnar::StrColumn;
     use common::{ByteCount, DateTimePrecision, HasLen, TerminatingWrite};
     use once_cell::sync::Lazy;
     use rand::prelude::SliceRandom;
@@ -395,7 +395,7 @@ mod tests {
             .unwrap()
             .first_or_default_col(0);
         for a in 0..n {
-            assert_eq!(col.get_val(a as u32), permutation[a], "for doc {a}");
+            assert_eq!(col.get_val(a as u32), permutation[a]);
         }
     }
 
@@ -944,7 +944,7 @@ mod tests {
         let test_range = |range: RangeInclusive<u64>| {
             let expected_count = numbers.iter().filter(|num| range.contains(*num)).count();
             let mut vec = vec![];
-            field.get_row_ids_for_value_range(ValueRange::Inclusive(range), 0..u32::MAX, &mut vec);
+            field.get_row_ids_for_value_range(range, 0..u32::MAX, &mut vec);
             assert_eq!(vec.len(), expected_count);
         };
         test_range(50..=50);
@@ -1022,7 +1022,7 @@ mod tests {
         let test_range = |range: RangeInclusive<u64>| {
             let expected_count = numbers.iter().filter(|num| range.contains(*num)).count();
             let mut vec = vec![];
-            field.get_row_ids_for_value_range(ValueRange::Inclusive(range), 0..u32::MAX, &mut vec);
+            field.get_row_ids_for_value_range(range, 0..u32::MAX, &mut vec);
             assert_eq!(vec.len(), expected_count);
         };
         let test_range_variant = |start, stop| {

src/fastfield/readers.rs

@@ -8,7 +8,7 @@ use columnar::{
 };
 use common::ByteCount;
 
-use crate::core::json_utils::{encode_column_name, json_path_sep_to_dot};
+use crate::core::json_utils::encode_column_name;
 use crate::directory::FileSlice;
 use crate::schema::{Field, FieldEntry, FieldType, Schema};
 use crate::space_usage::{FieldUsage, PerFieldSpaceUsage};
@@ -39,15 +39,19 @@ impl FastFieldReaders {
         self.resolve_column_name_given_default_field(column_name, default_field_opt)
     }
 
-    pub(crate) fn space_usage(&self) -> io::Result<PerFieldSpaceUsage> {
+    pub(crate) fn space_usage(&self, schema: &Schema) -> io::Result<PerFieldSpaceUsage> {
         let mut per_field_usages: Vec<FieldUsage> = Default::default();
-        for (mut field_name, column_handle) in self.columnar.iter_columns()? {
-            json_path_sep_to_dot(&mut field_name);
-            let space_usage = column_handle.space_usage()?;
-            let mut field_usage = FieldUsage::empty(field_name);
-            field_usage.set_column_usage(space_usage);
+        for (field, field_entry) in schema.fields() {
+            let column_handles = self.columnar.read_columns(field_entry.name())?;
+            let num_bytes: ByteCount = column_handles
+                .iter()
+                .map(|column_handle| column_handle.num_bytes())
+                .sum();
+            let mut field_usage = FieldUsage::empty(field);
+            field_usage.add_field_idx(0, num_bytes);
             per_field_usages.push(field_usage);
         }
+        // TODO fix space usage for JSON fields.
         Ok(PerFieldSpaceUsage::new(per_field_usages))
     }
 

src/fieldnorm/reader.rs

@@ -2,7 +2,7 @@ use std::sync::Arc;
 
 use super::{fieldnorm_to_id, id_to_fieldnorm};
 use crate::directory::{CompositeFile, FileSlice, OwnedBytes};
-use crate::schema::{Field, Schema};
+use crate::schema::Field;
 use crate::space_usage::PerFieldSpaceUsage;
 use crate::DocId;
 
@@ -37,8 +37,8 @@ impl FieldNormReaders {
     }
 
     /// Return a break down of the space usage per field.
-    pub fn space_usage(&self, schema: &Schema) -> PerFieldSpaceUsage {
-        self.data.space_usage(schema)
+    pub fn space_usage(&self) -> PerFieldSpaceUsage {
+        self.data.space_usage()
     }
 
     /// Returns a handle to inner file

src/index/index.rs

@@ -30,30 +30,22 @@ fn load_metas(
     directory: &dyn Directory,
     inventory: &SegmentMetaInventory,
 ) -> crate::Result<IndexMeta> {
-    match directory.load_metas(inventory) {
-        Ok(metas) => Ok(metas),
-        Err(crate::TantivyError::InternalError(_)) => {
-            let meta_data = directory.atomic_read(&META_FILEPATH)?;
-            let meta_string = String::from_utf8(meta_data).map_err(|_utf8_err| {
-                error!("Meta data is not valid utf8.");
-                DataCorruption::new(
-                    META_FILEPATH.to_path_buf(),
-                    "Meta file does not contain valid utf8 file.".to_string(),
-                )
-            })?;
-            IndexMeta::deserialize(&meta_string, inventory)
-                .map_err(|e| {
-                    DataCorruption::new(
-                        META_FILEPATH.to_path_buf(),
-                        format!(
-                            "Meta file cannot be deserialized. {e:?}. Content: {meta_string:?}"
-                        ),
-                    )
-                })
-                .map_err(From::from)
-        }
-        Err(err) => Err(err),
-    }
+    let meta_data = directory.atomic_read(&META_FILEPATH)?;
+    let meta_string = String::from_utf8(meta_data).map_err(|_utf8_err| {
+        error!("Meta data is not valid utf8.");
+        DataCorruption::new(
+            META_FILEPATH.to_path_buf(),
+            "Meta file does not contain valid utf8 file.".to_string(),
+        )
+    })?;
+    IndexMeta::deserialize(&meta_string, inventory)
+        .map_err(|e| {
+            DataCorruption::new(
+                META_FILEPATH.to_path_buf(),
+                format!("Meta file cannot be deserialized. {e:?}. Content: {meta_string:?}"),
+            )
+        })
+        .map_err(From::from)
 }
 
 /// Save the index meta file.
@@ -68,14 +60,16 @@ fn save_new_metas(
     index_settings: IndexSettings,
     directory: &dyn Directory,
 ) -> crate::Result<()> {
-    let empty_metas = IndexMeta {
-        index_settings,
-        segments: Vec::new(),
-        schema,
-        opstamp: 0u64,
-        payload: None,
-    };
-    save_metas(&empty_metas, &empty_metas, directory)?;
+    save_metas(
+        &IndexMeta {
+            index_settings,
+            segments: Vec::new(),
+            schema,
+            opstamp: 0u64,
+            payload: None,
+        },
+        directory,
+    )?;
     directory.sync_directory()?;
     Ok(())
 }
@@ -588,7 +582,7 @@ impl Index {
         num_threads: usize,
         overall_memory_budget_in_bytes: usize,
     ) -> crate::Result<IndexWriter<D>> {
-        let memory_arena_in_bytes_per_thread = overall_memory_budget_in_bytes / num_threads.max(1);
+        let memory_arena_in_bytes_per_thread = overall_memory_budget_in_bytes / num_threads;
         let options = IndexWriterOptions::builder()
             .num_worker_threads(num_threads)
             .memory_budget_per_thread(memory_arena_in_bytes_per_thread)
@@ -661,11 +655,9 @@ impl Index {
 
     /// Creates a new segment.
     pub fn new_segment(&self) -> Segment {
-        self.new_segment_with_id(SegmentId::generate_random())
-    }
-
-    pub fn new_segment_with_id(&self, segment_id: SegmentId) -> Segment {
-        let segment_meta = self.inventory.new_segment_meta(segment_id, 0);
+        let segment_meta = self
+            .inventory
+            .new_segment_meta(SegmentId::generate_random(), 0);
         self.segment(segment_meta)
     }
 
@@ -696,7 +688,7 @@ impl Index {
 
     /// Returns the set of corrupted files
     pub fn validate_checksum(&self) -> crate::Result<HashSet<PathBuf>> {
-        let managed_files = self.directory.list_managed_files()?;
+        let managed_files = self.directory.list_managed_files();
         let active_segments_files: HashSet<PathBuf> = self
             .searchable_segment_metas()?
             .iter()

src/index/index_meta.rs

@@ -1,6 +1,5 @@
 use std::collections::HashSet;
 use std::fmt;
-use std::fmt::{Debug, Formatter};
 use std::path::PathBuf;
 use std::sync::atomic::AtomicBool;
 use std::sync::Arc;
@@ -14,24 +13,16 @@ use crate::store::Compressor;
 use crate::{Inventory, Opstamp, TrackedObject};
 
 #[derive(Clone, Debug, Serialize, Deserialize)]
-pub struct DeleteMeta {
-    pub num_deleted_docs: u32,
-    pub opstamp: Opstamp,
+struct DeleteMeta {
+    num_deleted_docs: u32,
+    opstamp: Opstamp,
 }
 
 #[derive(Clone, Default)]
-pub struct SegmentMetaInventory {
+pub(crate) struct SegmentMetaInventory {
     inventory: Inventory<InnerSegmentMeta>,
 }
 
-impl Debug for SegmentMetaInventory {
-    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
-        f.debug_struct("SegmentMetaInventory")
-            .field("inventory", &self.inventory.list())
-            .finish()
-    }
-}
-
 impl SegmentMetaInventory {
     /// Lists all living `SegmentMeta` object at the time of the call.
     pub fn all(&self) -> Vec<SegmentMeta> {
@@ -59,7 +50,7 @@ impl SegmentMetaInventory {
 /// how many are deleted, etc.
 #[derive(Clone)]
 pub struct SegmentMeta {
-    pub tracked: TrackedObject<InnerSegmentMeta>,
+    tracked: TrackedObject<InnerSegmentMeta>,
 }
 
 impl fmt::Debug for SegmentMeta {
@@ -219,15 +210,15 @@ impl SegmentMeta {
 }
 
 #[derive(Debug, Clone, Serialize, Deserialize)]
-pub struct InnerSegmentMeta {
-    pub segment_id: SegmentId,
-    pub max_doc: u32,
-    pub deletes: Option<DeleteMeta>,
+struct InnerSegmentMeta {
+    segment_id: SegmentId,
+    max_doc: u32,
+    deletes: Option<DeleteMeta>,
     /// If you want to avoid the SegmentComponent::TempStore file to be covered by
     /// garbage collection and deleted, set this to true. This is used during merge.
     #[serde(skip)]
     #[serde(default = "default_temp_store")]
-    pub include_temp_doc_store: Arc<AtomicBool>,
+    pub(crate) include_temp_doc_store: Arc<AtomicBool>,
 }
 fn default_temp_store() -> Arc<AtomicBool> {
     Arc::new(AtomicBool::new(false))

src/index/inverted_index_reader.rs

@@ -1,6 +1,5 @@
 use std::io;
 
-use common::file_slice::DeferredFileSlice;
 use common::json_path_writer::JSON_END_OF_PATH;
 use common::{BinarySerializable, ByteCount};
 #[cfg(feature = "quickwit")]
@@ -31,7 +30,7 @@ use crate::termdict::TermDictionary;
 pub struct InvertedIndexReader {
     termdict: TermDictionary,
     postings_file_slice: FileSlice,
-    positions_file_slice: DeferredFileSlice,
+    positions_file_slice: FileSlice,
     record_option: IndexRecordOption,
     total_num_tokens: u64,
 }
@@ -67,7 +66,7 @@ impl InvertedIndexReader {
     pub(crate) fn new(
         termdict: TermDictionary,
         postings_file_slice: FileSlice,
-        positions_file_slice: DeferredFileSlice,
+        positions_file_slice: FileSlice,
         record_option: IndexRecordOption,
     ) -> io::Result<InvertedIndexReader> {
         let (total_num_tokens_slice, postings_body) = postings_file_slice.split(8);
@@ -87,7 +86,7 @@ impl InvertedIndexReader {
         InvertedIndexReader {
             termdict: TermDictionary::empty(),
             postings_file_slice: FileSlice::empty(),
-            positions_file_slice: DeferredFileSlice::new(|| Ok(FileSlice::empty())),
+            positions_file_slice: FileSlice::empty(),
             record_option,
             total_num_tokens: 0u64,
         }
@@ -212,7 +211,7 @@ impl InvertedIndexReader {
             .slice(term_info.postings_range.clone());
         BlockSegmentPostings::open(
             term_info.doc_freq,
-            postings_data.read_bytes()?,
+            postings_data,
             self.record_option,
             requested_option,
         )
@@ -234,7 +233,6 @@ impl InvertedIndexReader {
             if option.has_positions() {
                 let positions_data = self
                     .positions_file_slice
-                    .open()?
                     .read_bytes_slice(term_info.positions_range.clone())?;
                 let position_reader = PositionReader::open(positions_data)?;
                 Some(position_reader)
@@ -344,7 +342,6 @@ impl InvertedIndexReader {
             if with_positions {
                 let positions = self
                     .positions_file_slice
-                    .open()?
                     .read_bytes_slice_async(term_info.positions_range.clone());
                 futures_util::future::try_join(postings, positions).await?;
             } else {
@@ -387,7 +384,6 @@ impl InvertedIndexReader {
         if with_positions {
             let positions = self
                 .positions_file_slice
-                .open()?
                 .read_bytes_slice_async(positions_range);
             futures_util::future::try_join(postings, positions).await?;
         } else {
@@ -482,7 +478,7 @@ impl InvertedIndexReader {
     pub async fn warm_postings_full(&self, with_positions: bool) -> io::Result<()> {
         self.postings_file_slice.read_bytes_async().await?;
         if with_positions {
-            self.positions_file_slice.open()?.read_bytes_async().await?;
+            self.positions_file_slice.read_bytes_async().await?;
         }
         Ok(())
     }