prepare for merge

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "tantivy"
-version = "0.19.1-quickwit"
+version = "0.19.0"
 authors = ["Paul Masurel <paul.masurel@gmail.com>"]
 license = "MIT"
 categories = ["database-implementations", "data-structures"]
@@ -23,7 +23,7 @@ regex = { version = "1.5.5", default-features = false, features = ["std", "unico
 aho-corasick = "0.7"
 tantivy-fst = "0.4.0"
 memmap2 = { version = "0.5.3", optional = true }
-lz4_flex = { version = "0.10", default-features = false, features = ["checked-decode"], optional = true }
+lz4_flex = { version = "0.9.2", default-features = false, features = ["checked-decode"], optional = true }
 brotli = { version = "3.3.4", optional = true }
 zstd = { version = "0.12", optional = true, default-features = false }
 snap = { version = "1.0.5", optional = true }
@@ -55,7 +55,7 @@ measure_time = "0.8.2"
 async-trait = "0.1.53"
 arc-swap = "1.5.0"
 
-#columnar = { version="0.1", path="./columnar", package ="tantivy-columnar" }
+columnar = { version="0.1", path="./columnar", package ="tantivy-columnar" }
 sstable = { version="0.1", path="./sstable", package ="tantivy-sstable", optional = true }
 stacker = { version="0.1", path="./stacker", package ="tantivy-stacker" }
 tantivy-query-grammar = { version= "0.19.0", path="./query-grammar" }

columnar/src/column/mod.rs

@@ -22,6 +22,9 @@ pub struct Column<T> {
 }
 
 impl<T: PartialOrd> Column<T> {
+    pub fn get_cardinality(&self) -> Cardinality {
+        self.idx.get_cardinality()
+    }
     pub fn num_rows(&self) -> RowId {
         match &self.idx {
             ColumnIndex::Full => self.values.num_vals() as u32,

columnar/src/columnar/merge.rs

@@ -1,9 +1,10 @@
 use std::collections::HashMap;
 use std::io;
 
+use super::writer::ColumnarSerializer;
 use crate::columnar::ColumnarReader;
 use crate::dynamic_column::DynamicColumn;
-use crate::ColumnType;
+use crate::{Cardinality, ColumnType};
 
 pub enum MergeDocOrder {
     /// Columnar tables are simply stacked one above the other.
@@ -19,20 +20,30 @@ pub enum MergeDocOrder {
 }
 
 pub fn merge_columnar(
-    _columnar_readers: &[ColumnarReader],
+    columnar_readers: &[ColumnarReader],
     mapping: MergeDocOrder,
-    _output: &mut impl io::Write,
+    output: &mut impl io::Write,
 ) -> io::Result<()> {
-    match mapping {
-        MergeDocOrder::Stack => {
-            // implement me :)
-            todo!();
-        }
-        MergeDocOrder::Complex(_) => {
-            // for later
-            todo!();
+    let mut serializer = ColumnarSerializer::new(output);
+
+    // TODO handle dictionary merge for Str/Bytes column
+    let field_name_to_group = group_columns_for_merge(columnar_readers)?;
+    for (column_name, category_to_columns) in field_name_to_group {
+        for (_category, columns_to_merge) in category_to_columns {
+            let column_type = columns_to_merge[0].column_type();
+            let mut column_serialzier =
+                serializer.serialize_column(column_name.as_bytes(), column_type);
+            merge_columns(
+                column_type,
+                &columns_to_merge,
+                &mapping,
+                &mut column_serialzier,
+            )?;
         }
     }
+    serializer.finalize()?;
+
+    Ok(())
 }
 
 /// Column types are grouped into different categories.
@@ -44,7 +55,7 @@ pub fn merge_columnar(
 /// See also [README.md].
 #[derive(Copy, Clone, Eq, PartialEq, Hash, Debug)]
 #[repr(u8)]
-enum ColumnTypeCategory {
+pub enum ColumnTypeCategory {
     Bool,
     Str,
     Numerical,
@@ -68,8 +79,41 @@ impl From<ColumnType> for ColumnTypeCategory {
     }
 }
 
-fn collect_columns(
-    columnar_readers: &[&ColumnarReader],
+pub fn detect_cardinality(columns: &[DynamicColumn]) -> Cardinality {
+    if columns
+        .iter()
+        .any(|column| column.get_cardinality().is_multivalue())
+    {
+        return Cardinality::Multivalued;
+    }
+    if columns
+        .iter()
+        .any(|column| column.get_cardinality().is_optional())
+    {
+        return Cardinality::Optional;
+    }
+    Cardinality::Full
+}
+
+pub fn compute_num_docs(columns: &[DynamicColumn], mapping: &MergeDocOrder) -> usize {
+    // TODO handle deletes
+
+    0
+}
+
+pub fn merge_columns(
+    column_type: ColumnType,
+    columns: &[DynamicColumn],
+    mapping: &MergeDocOrder,
+    column_serializer: &mut impl io::Write,
+) -> io::Result<()> {
+    let cardinality = detect_cardinality(columns);
+
+    Ok(())
+}
+
+pub fn group_columns_for_merge(
+    columnar_readers: &[ColumnarReader],
 ) -> io::Result<HashMap<String, HashMap<ColumnTypeCategory, Vec<DynamicColumn>>>> {
     // Each column name may have multiple types of column associated.
     // For merging we are interested in the same column type category since they can be merged.
@@ -117,26 +161,20 @@ fn cast_to_common_numerical_column(columns: &[DynamicColumn]) -> Vec<DynamicColu
         .all(|column| column.column_type().numerical_type().is_some()));
     let coerce_to_i64: Vec<_> = columns
         .iter()
-        .map(|column| column.clone().coerce_to_i64())
+        .filter_map(|column| column.clone().coerce_to_i64())
         .collect();
 
-    if coerce_to_i64.iter().all(|column| column.is_some()) {
-        return coerce_to_i64
-            .into_iter()
-            .map(|column| column.unwrap())
-            .collect();
+    if coerce_to_i64.len() == columns.len() {
+        return coerce_to_i64;
     }
 
     let coerce_to_u64: Vec<_> = columns
         .iter()
-        .map(|column| column.clone().coerce_to_u64())
+        .filter_map(|column| column.clone().coerce_to_u64())
         .collect();
 
-    if coerce_to_u64.iter().all(|column| column.is_some()) {
-        return coerce_to_u64
-            .into_iter()
-            .map(|column| column.unwrap())
-            .collect();
+    if coerce_to_u64.len() == columns.len() {
+        return coerce_to_u64;
     }
 
     columns
@@ -183,7 +221,9 @@ mod tests {
             ColumnarReader::open(buffer).unwrap()
         };
 
-        let column_map = collect_columns(&[&columnar1, &columnar2, &columnar3]).unwrap();
+        let column_map =
+            group_columns_for_merge(&[columnar1.clone(), columnar2.clone(), columnar3.clone()])
+                .unwrap();
         assert_eq!(column_map.len(), 1);
         let cat_to_columns = column_map.get("numbers").unwrap();
         assert_eq!(cat_to_columns.len(), 1);
@@ -191,14 +231,14 @@ mod tests {
         let numerical = cat_to_columns.get(&ColumnTypeCategory::Numerical).unwrap();
         assert!(numerical.iter().all(|column| column.is_f64()));
 
-        let column_map = collect_columns(&[&columnar1, &columnar1]).unwrap();
+        let column_map = group_columns_for_merge(&[columnar1.clone(), columnar1.clone()]).unwrap();
         assert_eq!(column_map.len(), 1);
         let cat_to_columns = column_map.get("numbers").unwrap();
         assert_eq!(cat_to_columns.len(), 1);
         let numerical = cat_to_columns.get(&ColumnTypeCategory::Numerical).unwrap();
         assert!(numerical.iter().all(|column| column.is_i64()));
 
-        let column_map = collect_columns(&[&columnar2, &columnar2]).unwrap();
+        let column_map = group_columns_for_merge(&[columnar2.clone(), columnar2.clone()]).unwrap();
         assert_eq!(column_map.len(), 1);
         let cat_to_columns = column_map.get("numbers").unwrap();
         assert_eq!(cat_to_columns.len(), 1);

columnar/src/columnar/merge_index.rs

@@ -0,0 +1 @@
+

columnar/src/columnar/mod.rs

@@ -1,6 +1,7 @@
 mod column_type;
 mod format_version;
 mod merge;
+mod merge_index;
 mod reader;
 mod writer;
 

columnar/src/columnar/reader/mod.rs

@@ -13,6 +13,7 @@ fn io_invalid_data(msg: String) -> io::Error {
 
 /// The ColumnarReader makes it possible to access a set of columns
 /// associated to field names.
+#[derive(Clone)]
 pub struct ColumnarReader {
     column_dictionary: Dictionary<RangeSSTable>,
     column_data: FileSlice,

columnar/src/columnar/writer/mod.rs

@@ -8,7 +8,7 @@ use std::net::Ipv6Addr;
 
 use column_operation::ColumnOperation;
 use common::CountingWriter;
-use serializer::ColumnarSerializer;
+pub(crate) use serializer::ColumnarSerializer;
 use stacker::{Addr, ArenaHashMap, MemoryArena};
 
 use crate::column_index::SerializableColumnIndex;

columnar/src/dynamic_column.rs

@@ -8,7 +8,7 @@ use common::{HasLen, OwnedBytes};
 use crate::column::{BytesColumn, Column, StrColumn};
 use crate::column_values::{monotonic_map_column, StrictlyMonotonicFn};
 use crate::columnar::ColumnType;
-use crate::{DateTime, NumericalType};
+use crate::{Cardinality, DateTime, NumericalType};
 
 #[derive(Clone)]
 pub enum DynamicColumn {
@@ -23,6 +23,18 @@ pub enum DynamicColumn {
 }
 
 impl DynamicColumn {
+    pub fn get_cardinality(&self) -> Cardinality {
+        match self {
+            DynamicColumn::Bool(c) => c.get_cardinality(),
+            DynamicColumn::I64(c) => c.get_cardinality(),
+            DynamicColumn::U64(c) => c.get_cardinality(),
+            DynamicColumn::F64(c) => c.get_cardinality(),
+            DynamicColumn::IpAddr(c) => c.get_cardinality(),
+            DynamicColumn::DateTime(c) => c.get_cardinality(),
+            DynamicColumn::Bytes(c) => c.ords().get_cardinality(),
+            DynamicColumn::Str(c) => c.ords().get_cardinality(),
+        }
+    }
     pub fn column_type(&self) -> ColumnType {
         match self {
             DynamicColumn::Bool(_) => ColumnType::Bool,

columnar/src/lib.rs

@@ -62,6 +62,12 @@ pub enum Cardinality {
 }
 
 impl Cardinality {
+    pub fn is_optional(&self) -> bool {
+        matches!(self, Cardinality::Optional)
+    }
+    pub fn is_multivalue(&self) -> bool {
+        matches!(self, Cardinality::Multivalued)
+    }
     pub(crate) fn to_code(self) -> u8 {
         self as u8
     }

src/aggregation/bucket/term_agg.rs

@@ -362,19 +362,13 @@ impl SegmentTermCollector {
         let mut entries: Vec<(u32, TermBucketEntry)> =
             self.term_buckets.entries.into_iter().collect();
 
+        let order_by_key = self.req.order.target == OrderTarget::Key;
         let order_by_sub_aggregation =
             matches!(self.req.order.target, OrderTarget::SubAggregation(_));
 
         match self.req.order.target {
             OrderTarget::Key => {
-                // We rely on the fact, that term ordinals match the order of the strings
-                // TODO: We could have a special collector, that keeps only TOP n results at any
-                // time.
-                if self.req.order.order == Order::Desc {
-                    entries.sort_unstable_by_key(|bucket| std::cmp::Reverse(bucket.0));
-                } else {
-                    entries.sort_unstable_by_key(|bucket| bucket.0);
-                }
+                // defer order and cut_off after loading the texts from the dictionary
             }
             OrderTarget::SubAggregation(_name) => {
                 // don't sort and cut off since it's hard to make assumptions on the quality of the
@@ -390,11 +384,12 @@ impl SegmentTermCollector {
             }
         }
 
-        let (term_doc_count_before_cutoff, sum_other_doc_count) = if order_by_sub_aggregation {
-            (0, 0)
-        } else {
-            cut_off_buckets(&mut entries, self.req.segment_size as usize)
-        };
+        let (term_doc_count_before_cutoff, mut sum_other_doc_count) =
+            if order_by_key || order_by_sub_aggregation {
+                (0, 0)
+            } else {
+                cut_off_buckets(&mut entries, self.req.segment_size as usize)
+            };
 
         let inverted_index = agg_with_accessor
             .inverted_index
@@ -417,10 +412,6 @@ impl SegmentTermCollector {
         if self.req.min_doc_count == 0 {
             let mut stream = term_dict.stream()?;
             while let Some((key, _ord)) = stream.next() {
-                if dict.len() >= self.req.segment_size as usize {
-                    break;
-                }
-
                 let key = std::str::from_utf8(key)
                     .map_err(|utf8_err| DataCorruption::comment_only(utf8_err.to_string()))?;
                 if !dict.contains_key(key) {
@@ -429,6 +420,20 @@ impl SegmentTermCollector {
             }
         }
 
+        if order_by_key {
+            let mut dict_entries = dict.into_iter().collect_vec();
+            if self.req.order.order == Order::Desc {
+                dict_entries.sort_unstable_by(|(key1, _), (key2, _)| key1.cmp(key2));
+            } else {
+                dict_entries.sort_unstable_by(|(key1, _), (key2, _)| key2.cmp(key1));
+            }
+            let (_, sum_other_docs) =
+                cut_off_buckets(&mut dict_entries, self.req.segment_size as usize);
+
+            sum_other_doc_count += sum_other_docs;
+            dict = dict_entries.into_iter().collect();
+        }
+
         Ok(IntermediateBucketResult::Terms(
             IntermediateTermBucketResult {
                 entries: dict,
@@ -918,14 +923,14 @@ mod tests {
         ];
         let index = get_test_index_from_values_and_terms(merge_segments, &segment_and_terms)?;
 
-        // key asc
+        // key desc
         let agg_req: Aggregations = vec![(
             "my_texts".to_string(),
             Aggregation::Bucket(BucketAggregation {
                 bucket_agg: BucketAggregationType::Terms(TermsAggregation {
                     field: "string_id".to_string(),
                     order: Some(CustomOrder {
-                        order: Order::Asc,
+                        order: Order::Desc,
                         target: OrderTarget::Key,
                     }),
                     ..Default::default()
@@ -952,7 +957,7 @@ mod tests {
                 bucket_agg: BucketAggregationType::Terms(TermsAggregation {
                     field: "string_id".to_string(),
                     order: Some(CustomOrder {
-                        order: Order::Asc,
+                        order: Order::Desc,
                         target: OrderTarget::Key,
                     }),
                     size: Some(2),
@@ -976,14 +981,14 @@ mod tests {
 
         assert_eq!(res["my_texts"]["sum_other_doc_count"], 3);
 
-        // key asc and segment_size cut_off
+        // key desc and segment_size cut_off
         let agg_req: Aggregations = vec![(
             "my_texts".to_string(),
             Aggregation::Bucket(BucketAggregation {
                 bucket_agg: BucketAggregationType::Terms(TermsAggregation {
                     field: "string_id".to_string(),
                     order: Some(CustomOrder {
-                        order: Order::Asc,
+                        order: Order::Desc,
                         target: OrderTarget::Key,
                     }),
                     size: Some(2),
@@ -1006,14 +1011,14 @@ mod tests {
             serde_json::Value::Null
         );
 
-        // key desc
+        // key asc
         let agg_req: Aggregations = vec![(
             "my_texts".to_string(),
             Aggregation::Bucket(BucketAggregation {
                 bucket_agg: BucketAggregationType::Terms(TermsAggregation {
                     field: "string_id".to_string(),
                     order: Some(CustomOrder {
-                        order: Order::Desc,
+                        order: Order::Asc,
                         target: OrderTarget::Key,
                     }),
                     ..Default::default()
@@ -1033,14 +1038,14 @@ mod tests {
         assert_eq!(res["my_texts"]["buckets"][2]["doc_count"], 5);
         assert_eq!(res["my_texts"]["sum_other_doc_count"], 0);
 
-        // key desc, size cut_off
+        // key asc, size cut_off
         let agg_req: Aggregations = vec![(
             "my_texts".to_string(),
             Aggregation::Bucket(BucketAggregation {
                 bucket_agg: BucketAggregationType::Terms(TermsAggregation {
                     field: "string_id".to_string(),
                     order: Some(CustomOrder {
-                        order: Order::Desc,
+                        order: Order::Asc,
                         target: OrderTarget::Key,
                     }),
                     size: Some(2),
@@ -1063,14 +1068,14 @@ mod tests {
         );
         assert_eq!(res["my_texts"]["sum_other_doc_count"], 5);
 
-        // key desc, segment_size cut_off
+        // key asc, segment_size cut_off
         let agg_req: Aggregations = vec![(
             "my_texts".to_string(),
             Aggregation::Bucket(BucketAggregation {
                 bucket_agg: BucketAggregationType::Terms(TermsAggregation {
                     field: "string_id".to_string(),
                     order: Some(CustomOrder {
-                        order: Order::Desc,
+                        order: Order::Asc,
                         target: OrderTarget::Key,
                     }),
                     size: Some(2),
@@ -1347,3 +1352,68 @@ mod tests {
         Ok(())
     }
 }
+
+#[cfg(all(test, feature = "unstable"))]
+mod bench {
+
+    use itertools::Itertools;
+    use rand::seq::SliceRandom;
+    use rand::thread_rng;
+
+    use super::*;
+
+    fn get_collector_with_buckets(num_docs: u64) -> TermBuckets {
+        TermBuckets::from_req_and_validate(&Default::default(), num_docs as usize).unwrap()
+    }
+
+    fn get_rand_terms(total_terms: u64, num_terms_returned: u64) -> Vec<u64> {
+        let mut rng = thread_rng();
+
+        let all_terms = (0..total_terms - 1).collect_vec();
+
+        let mut vals = vec![];
+        for _ in 0..num_terms_returned {
+            let val = all_terms.as_slice().choose(&mut rng).unwrap();
+            vals.push(*val);
+        }
+
+        vals
+    }
+
+    fn bench_term_buckets(b: &mut test::Bencher, num_terms: u64, total_terms: u64) {
+        let mut collector = get_collector_with_buckets(total_terms);
+        let vals = get_rand_terms(total_terms, num_terms);
+        let aggregations_with_accessor: AggregationsWithAccessor = Default::default();
+        let bucket_count: BucketCount = BucketCount {
+            bucket_count: Default::default(),
+            max_bucket_count: 1_000_001u32,
+        };
+        b.iter(|| {
+            for &val in &vals {
+                collector
+                    .increment_bucket(&[val], 0, &aggregations_with_accessor, &bucket_count, &None)
+                    .unwrap();
+            }
+        })
+    }
+
+    #[bench]
+    fn bench_term_buckets_500_of_1_000_000(b: &mut test::Bencher) {
+        bench_term_buckets(b, 500u64, 1_000_000u64)
+    }
+
+    #[bench]
+    fn bench_term_buckets_1_000_000_of_50_000(b: &mut test::Bencher) {
+        bench_term_buckets(b, 1_000_000u64, 50_000u64)
+    }
+
+    #[bench]
+    fn bench_term_buckets_1_000_000_of_50(b: &mut test::Bencher) {
+        bench_term_buckets(b, 1_000_000u64, 50u64)
+    }
+
+    #[bench]
+    fn bench_term_buckets_1_000_000_of_1_000_000(b: &mut test::Bencher) {
+        bench_term_buckets(b, 1_000_000u64, 1_000_000u64)
+    }
+}

src/aggregation/intermediate_agg_result.rs

@@ -499,7 +499,7 @@ impl IntermediateTermBucketResult {
         match req.order.target {
             OrderTarget::Key => {
                 buckets.sort_by(|left, right| {
-                    if req.order.order == Order::Asc {
+                    if req.order.order == Order::Desc {
                         left.key.partial_cmp(&right.key)
                     } else {
                         right.key.partial_cmp(&left.key)

src/aggregation/mod.rs

@@ -1156,6 +1156,12 @@ mod tests {
             r#"FieldNotFound("not_exist_field")"#
         );
 
+        let agg_res = avg_on_field("scores_i64");
+        assert_eq!(
+            format!("{:?}", agg_res),
+            r#"InvalidArgument("Invalid field cardinality on field scores_i64 expected SingleValue, but got MultiValues")"#
+        );
+
         Ok(())
     }
 

src/core/inverted_index_reader.rs

@@ -135,8 +135,6 @@ impl InvertedIndexReader {
         term_info: &TermInfo,
         option: IndexRecordOption,
     ) -> io::Result<SegmentPostings> {
-        let option = option.downgrade(self.record_option);
-
         let block_postings = self.read_block_postings_from_terminfo(term_info, option)?;
         let position_reader = {
             if option.has_positions() {

src/core/searcher.rs

@@ -249,7 +249,7 @@ impl SearcherInner {
         index: Index,
         segment_readers: Vec<SegmentReader>,
         generation: TrackedObject<SearcherGeneration>,
-        doc_store_cache_num_blocks: usize,
+        doc_store_cache_size: usize,
     ) -> io::Result<SearcherInner> {
         assert_eq!(
             &segment_readers
@@ -261,7 +261,7 @@ impl SearcherInner {
         );
         let store_readers: Vec<StoreReader> = segment_readers
             .iter()
-            .map(|segment_reader| segment_reader.get_store_reader(doc_store_cache_num_blocks))
+            .map(|segment_reader| segment_reader.get_store_reader(doc_store_cache_size))
             .collect::<io::Result<Vec<_>>>()?;
 
         Ok(SearcherInner {

src/core/segment_reader.rs

@@ -134,12 +134,9 @@ impl SegmentReader {
         &self.fieldnorm_readers
     }
 
-    /// Accessor to the segment's [`StoreReader`](crate::store::StoreReader).
-    ///
-    /// `cache_num_blocks` sets the number of decompressed blocks to be cached in an LRU.
-    /// The size of blocks is configurable, this should be reflexted in the
-    pub fn get_store_reader(&self, cache_num_blocks: usize) -> io::Result<StoreReader> {
-        StoreReader::open(self.store_file.clone(), cache_num_blocks)
+    /// Accessor to the segment's `StoreReader`.
+    pub fn get_store_reader(&self, cache_size: usize) -> io::Result<StoreReader> {
+        StoreReader::open(self.store_file.clone(), cache_size)
     }
 
     /// Open a new segment for reading.

src/indexer/segment_writer.rs

@@ -834,23 +834,20 @@ mod tests {
         // This is a bit of a contrived example.
         let tokens = PreTokenizedString {
             text: "contrived-example".to_string(), //< I can't think of a use case where this corner case happens in real life.
-            tokens: vec![
-                Token {
-                    // Not the last token, yet ends after the last token.
-                    offset_from: 0,
-                    offset_to: 14,
-                    position: 0,
-                    text: "long_token".to_string(),
-                    position_length: 3,
-                },
-                Token {
-                    offset_from: 0,
-                    offset_to: 14,
-                    position: 1,
-                    text: "short".to_string(),
-                    position_length: 1,
-                },
-            ],
+            tokens: vec![Token { // Not the last token, yet ends after the last token.
+                offset_from: 0,
+                offset_to: 14,
+                position: 0,
+                text: "long_token".to_string(),
+                position_length: 3,
+            },
+            Token {
+                offset_from: 0,
+                offset_to: 14,
+                position: 1,
+                text: "short".to_string(),
+                position_length: 1,
+            }],
         };
         doc.add_pre_tokenized_text(text, tokens);
         doc.add_text(text, "hello");

src/query/term_query/term_query.rs

@@ -109,7 +109,6 @@ impl TermQuery {
         } else {
             IndexRecordOption::Basic
         };
-
         Ok(TermWeight::new(
             self.term.clone(),
             index_record_option,

src/reader/mod.rs

@@ -44,7 +44,7 @@ pub struct IndexReaderBuilder {
     index: Index,
     warmers: Vec<Weak<dyn Warmer>>,
     num_warming_threads: usize,
-    doc_store_cache_num_blocks: usize,
+    doc_store_cache_size: usize,
 }
 
 impl IndexReaderBuilder {
@@ -55,7 +55,7 @@ impl IndexReaderBuilder {
             index,
             warmers: Vec::new(),
             num_warming_threads: 1,
-            doc_store_cache_num_blocks: DOCSTORE_CACHE_CAPACITY,
+            doc_store_cache_size: DOCSTORE_CACHE_CAPACITY,
         }
     }
 
@@ -72,7 +72,7 @@ impl IndexReaderBuilder {
             searcher_generation_inventory.clone(),
         )?;
         let inner_reader = InnerIndexReader::new(
-            self.doc_store_cache_num_blocks,
+            self.doc_store_cache_size,
             self.index,
             warming_state,
             searcher_generation_inventory,
@@ -119,11 +119,8 @@ impl IndexReaderBuilder {
     ///
     /// The doc store readers cache by default DOCSTORE_CACHE_CAPACITY(100) decompressed blocks.
     #[must_use]
-    pub fn doc_store_cache_num_blocks(
-        mut self,
-        doc_store_cache_num_blocks: usize,
-    ) -> IndexReaderBuilder {
-        self.doc_store_cache_num_blocks = doc_store_cache_num_blocks;
+    pub fn doc_store_cache_size(mut self, doc_store_cache_size: usize) -> IndexReaderBuilder {
+        self.doc_store_cache_size = doc_store_cache_size;
         self
     }
 
@@ -154,7 +151,7 @@ impl TryInto<IndexReader> for IndexReaderBuilder {
 }
 
 struct InnerIndexReader {
-    doc_store_cache_num_blocks: usize,
+    doc_store_cache_size: usize,
     index: Index,
     warming_state: WarmingState,
     searcher: arc_swap::ArcSwap<SearcherInner>,
@@ -164,7 +161,7 @@ struct InnerIndexReader {
 
 impl InnerIndexReader {
     fn new(
-        doc_store_cache_num_blocks: usize,
+        doc_store_cache_size: usize,
         index: Index,
         warming_state: WarmingState,
         // The searcher_generation_inventory is not used as source, but as target to track the
@@ -175,13 +172,13 @@ impl InnerIndexReader {
 
         let searcher = Self::create_searcher(
             &index,
-            doc_store_cache_num_blocks,
+            doc_store_cache_size,
             &warming_state,
             &searcher_generation_counter,
             &searcher_generation_inventory,
         )?;
         Ok(InnerIndexReader {
-            doc_store_cache_num_blocks,
+            doc_store_cache_size,
             index,
             warming_state,
             searcher: ArcSwap::from(searcher),
@@ -217,7 +214,7 @@ impl InnerIndexReader {
 
     fn create_searcher(
         index: &Index,
-        doc_store_cache_num_blocks: usize,
+        doc_store_cache_size: usize,
         warming_state: &WarmingState,
         searcher_generation_counter: &Arc<AtomicU64>,
         searcher_generation_inventory: &Inventory<SearcherGeneration>,
@@ -235,7 +232,7 @@ impl InnerIndexReader {
             index.clone(),
             segment_readers,
             searcher_generation,
-            doc_store_cache_num_blocks,
+            doc_store_cache_size,
         )?);
 
         warming_state.warm_new_searcher_generation(&searcher.clone().into())?;
@@ -245,7 +242,7 @@ impl InnerIndexReader {
     fn reload(&self) -> crate::Result<()> {
         let searcher = Self::create_searcher(
             &self.index,
-            self.doc_store_cache_num_blocks,
+            self.doc_store_cache_size,
             &self.warming_state,
             &self.searcher_generation_counter,
             &self.searcher_generation_inventory,

src/schema/index_record_option.rs

@@ -49,17 +49,4 @@ impl IndexRecordOption {
             IndexRecordOption::WithFreqsAndPositions => true,
         }
     }
-
-    /// Downgrades to the next level if provided `IndexRecordOption` is unavailable.
-    pub fn downgrade(&self, other: IndexRecordOption) -> IndexRecordOption {
-        use IndexRecordOption::*;
-
-        match (other, self) {
-            (WithFreqsAndPositions, WithFreqsAndPositions) => WithFreqsAndPositions,
-            (WithFreqs, WithFreqs) => WithFreqs,
-            (WithFreqsAndPositions, WithFreqs) => WithFreqs,
-            (WithFreqs, WithFreqsAndPositions) => WithFreqs,
-            _ => Basic,
-        }
-    }
 }

src/schema/term.rs

@@ -375,8 +375,7 @@ where B: AsRef<[u8]>
     ///
     /// Do NOT rely on this byte representation in the index.
     /// This value is likely to change in the future.
-    #[inline(always)]
-    pub fn as_slice(&self) -> &[u8] {
+    pub(crate) fn as_slice(&self) -> &[u8] {
         self.0.as_ref()
     }
 }

src/store/index/block.rs

@@ -90,7 +90,7 @@ impl CheckpointBlock {
             return Ok(());
         }
         let mut doc = read_u32_vint(data);
-        let mut start_offset = VInt::deserialize_u64(data)? as usize;
+        let mut start_offset = read_u32_vint(data) as usize;
         for _ in 0..len {
             let num_docs = read_u32_vint(data);
             let block_num_bytes = read_u32_vint(data) as usize;
@@ -147,15 +147,6 @@ mod tests {
         test_aux_ser_deser(&checkpoints)
     }
 
-    #[test]
-    fn test_block_serialize_large_byte_range() -> io::Result<()> {
-        let checkpoints = vec![Checkpoint {
-            doc_range: 10..12,
-            byte_range: 8_000_000_000..9_000_000_000,
-        }];
-        test_aux_ser_deser(&checkpoints)
-    }
-
     #[test]
     fn test_block_serialize() -> io::Result<()> {
         let offsets: Vec<usize> = (0..11).map(|i| i * i * i).collect();

src/store/mod.rs

@@ -4,8 +4,8 @@
 //! order to be handled in the `Store`.
 //!
 //! Internally, documents (or rather their stored fields) are serialized to a buffer.
-//! When the buffer exceeds `block_size` (defaults to 16K), the buffer is compressed using `brotli`,
-//! `LZ4` or `snappy` and the resulting block is written to disk.
+//! When the buffer exceeds 16K, the buffer is compressed using `brotli`, `LZ4` or `snappy`
+//! and the resulting block is written to disk.
 //!
 //! One can then request for a specific `DocId`.
 //! A skip list helps navigating to the right block,
@@ -28,6 +28,8 @@
 //! - at the segment level, the
 //! [`SegmentReader`'s `doc` method](../struct.SegmentReader.html#method.doc)
 //! - at the index level, the [`Searcher::doc()`](crate::Searcher::doc) method
+//!
+//! !
 
 mod compressors;
 mod decompressors;

src/store/reader.rs

@@ -114,10 +114,7 @@ impl Sum for CacheStats {
 
 impl StoreReader {
     /// Opens a store reader
-    ///
-    /// `cache_num_blocks` sets the number of decompressed blocks to be cached in an LRU.
-    /// The size of blocks is configurable, this should be reflexted in the
-    pub fn open(store_file: FileSlice, cache_num_blocks: usize) -> io::Result<StoreReader> {
+    pub fn open(store_file: FileSlice, cache_size: usize) -> io::Result<StoreReader> {
         let (footer, data_and_offset) = DocStoreFooter::extract_footer(store_file)?;
 
         let (data_file, offset_index_file) = data_and_offset.split(footer.offset as usize);
@@ -128,8 +125,8 @@ impl StoreReader {
             decompressor: footer.decompressor,
             data: data_file,
             cache: BlockCache {
-                cache: NonZeroUsize::new(cache_num_blocks)
-                    .map(|cache_num_blocks| Mutex::new(LruCache::new(cache_num_blocks))),
+                cache: NonZeroUsize::new(cache_size)
+                    .map(|cache_size| Mutex::new(LruCache::new(cache_size))),
                 cache_hits: Default::default(),
                 cache_misses: Default::default(),
             },

sstable/src/dictionary.rs

@@ -30,6 +30,7 @@ use crate::{BlockAddr, DeltaReader, Reader, SSTable, SSTableIndex, TermOrdinal};
 /// block boundary.
 ///
 /// (See also README.md)
+#[derive(Debug, Clone)]
 pub struct Dictionary<TSSTable: SSTable> {
     pub sstable_slice: FileSlice,
     pub sstable_index: SSTableIndex,

sstable/src/lib.rs

@@ -117,6 +117,7 @@ impl SSTable for MonotonicU64SSTable {
 /// `range_sstable[k1].end == range_sstable[k2].start`.
 ///
 /// The first range is not required to start at `0`.
+#[derive(Clone, Copy, Debug)]
 pub struct RangeSSTable;
 
 impl SSTable for RangeSSTable {

sstable/src/sstable_index.rs

@@ -5,7 +5,7 @@ use serde::{Deserialize, Serialize};
 
 use crate::{common_prefix_len, SSTableDataCorruption, TermOrdinal};
 
-#[derive(Default, Debug, Serialize, Deserialize)]
+#[derive(Default, Debug, Clone, Serialize, Deserialize)]
 pub struct SSTableIndex {
     blocks: Vec<BlockMeta>,
 }
@@ -75,7 +75,7 @@ pub struct BlockAddr {
     pub first_ordinal: u64,
 }
 
-#[derive(Debug, Serialize, Deserialize)]
+#[derive(Debug, Clone, Serialize, Deserialize)]
 pub(crate) struct BlockMeta {
     /// Any byte string that is lexicographically greater or equal to
     /// the last key in the block,