Removing iterators.

Introducing a ColumnReader trait and .reader() to Column,
hence removing the dreaded Mutex in the `MultiValueStartIndex`
thingy.

.gitattributes

@@ -0,0 +1 @@
+cpp/* linguist-vendored

.gitignore

@@ -9,6 +9,7 @@ target/release
 Cargo.lock
 benchmark
 .DS_Store
+cpp/simdcomp/bitpackingbenchmark
 *.bk
 .idea
 trace.dat

Cargo.toml

@@ -11,7 +11,6 @@ repository = "https://github.com/quickwit-oss/tantivy"
 readme = "README.md"
 keywords = ["search", "information", "retrieval"]
 edition = "2021"
-rust-version = "1.62"
 
 [dependencies]
 oneshot = "0.1.3"
@@ -20,11 +19,11 @@ byteorder = "1.4.3"
 crc32fast = "1.3.2"
 once_cell = "1.10.0"
 regex = { version = "1.5.5", default-features = false, features = ["std", "unicode"] }
-tantivy-fst = "0.4.0"
+tantivy-fst = "0.3.0"
 memmap2 = { version = "0.5.3", 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 = "0.11", optional = true, default-features = false }
+zstd = { version = "0.11", optional = true }
 snap = { version = "1.0.5", optional = true }
 tempfile = { version = "3.3.0", optional = true }
 log = "0.4.16"

README.md

@@ -58,7 +58,7 @@ Distributed search is out of the scope of Tantivy, but if you are looking for th
 
 # Getting started
 
-Tantivy works on stable Rust and supports Linux, macOS, and Windows.
+Tantivy works on stable Rust (>= 1.27) and supports Linux, macOS, and Windows.
 
 - [Tantivy's simple search example](https://tantivy-search.github.io/examples/basic_search.html)
 - [tantivy-cli and its tutorial](https://github.com/quickwit-oss/tantivy-cli) - `tantivy-cli` is an actual command-line interface that makes it easy for you to create a search engine,
@@ -81,13 +81,9 @@ There are many ways to support this project.
 
 We use the GitHub Pull Request workflow: reference a GitHub ticket and/or include a comprehensive commit message when opening a PR.
 
-## Minimum supported Rust version
-
-Tantivy currently requires at least Rust 1.62 or later to compile.
-
 ## Clone and build locally
 
-Tantivy compiles on stable Rust.
+Tantivy compiles on stable Rust but requires `Rust >= 1.27`.
 To check out and run tests, you can simply run:
 
 ```bash

common/src/bitset.rs

@@ -259,7 +259,11 @@ impl BitSet {
         // we do not check saturated els.
         let higher = el / 64u32;
         let lower = el % 64u32;
-        self.len += u64::from(self.tinysets[higher as usize].insert_mut(lower));
+        self.len += if self.tinysets[higher as usize].insert_mut(lower) {
+            1
+        } else {
+            0
+        };
     }
 
     /// Inserts an element in the `BitSet`
@@ -268,7 +272,11 @@ impl BitSet {
         // we do not check saturated els.
         let higher = el / 64u32;
         let lower = el % 64u32;
-        self.len -= u64::from(self.tinysets[higher as usize].remove_mut(lower));
+        self.len -= if self.tinysets[higher as usize].remove_mut(lower) {
+            1
+        } else {
+            0
+        };
     }
 
     /// Returns true iff the elements is in the `BitSet`.
@@ -277,7 +285,7 @@ impl BitSet {
         self.tinyset(el / 64u32).contains(el % 64)
     }
 
-    /// Returns the first non-empty `TinySet` associated with a bucket lower
+    /// Returns the first non-empty `TinySet` associated to a bucket lower
     /// or greater than bucket.
     ///
     /// Reminder: the tiny set with the bucket `bucket`, represents the

common/src/serialize.rs

@@ -161,7 +161,8 @@ impl FixedSize for u8 {
 
 impl BinarySerializable for bool {
     fn serialize<W: Write>(&self, writer: &mut W) -> io::Result<()> {
-        writer.write_u8(u8::from(*self))
+        let val = if *self { 1 } else { 0 };
+        writer.write_u8(val)
     }
     fn deserialize<R: Read>(reader: &mut R) -> io::Result<bool> {
         let val = reader.read_u8()?;

doc/src/basis.md

@@ -50,7 +50,7 @@ to get tantivy to fit your use case:
 
 *Example 1* You could for instance use hadoop to build a very large search index in a timely manner, copy all of the resulting segment files in the same directory and edit the `meta.json` to get a functional index.[^2]
 
-*Example 2* You could also disable your merge policy and enforce daily segments. Removing data after one week can then be done very efficiently by just editing the `meta.json` and deleting the files associated with segment `D-7`.
+*Example 2* You could also disable your merge policy and enforce daily segments. Removing data after one week can then be done very efficiently by just editing the `meta.json` and deleting the files associated to segment `D-7`.
 
 ## Merging
 

examples/deleting_updating_documents.rs

@@ -113,7 +113,7 @@ fn main() -> tantivy::Result<()> {
     // on its id.
     //
     // Note that `tantivy` does nothing to enforce the idea that
-    // there is only one document associated with this id.
+    // there is only one document associated to this id.
     //
     // Also you might have noticed that we apply the delete before
     // having committed. This does not matter really...

examples/iterating_docs_and_positions.rs

@@ -44,7 +44,7 @@ fn main() -> tantivy::Result<()> {
         // A segment contains different data structure.
         // Inverted index stands for the combination of
         // - the term dictionary
-        // - the inverted lists associated with each terms and their positions
+        // - the inverted lists associated to each terms and their positions
         let inverted_index = segment_reader.inverted_index(title)?;
 
         // A `Term` is a text token associated with a field.
@@ -105,7 +105,7 @@ fn main() -> tantivy::Result<()> {
         // A segment contains different data structure.
         // Inverted index stands for the combination of
         // - the term dictionary
-        // - the inverted lists associated with each terms and their positions
+        // - the inverted lists associated to each terms and their positions
         let inverted_index = segment_reader.inverted_index(title)?;
 
         // This segment posting object is like a cursor over the documents matching the term.

fastfield_codecs/src/bitpacked.rs

@@ -68,14 +68,16 @@ impl FastFieldCodec for BitpackedCodec {
         assert_eq!(column.min_value(), 0u64);
         let num_bits = compute_num_bits(column.max_value());
         let mut bit_packer = BitPacker::new();
-        for val in column.iter() {
+        let mut reader = column.reader();
+        while reader.advance() {
+            let val = reader.get();
             bit_packer.write(val, num_bits, write)?;
         }
         bit_packer.close(write)?;
         Ok(())
     }
 
-    fn estimate(column: &dyn Column) -> Option<f32> {
+    fn estimate(column: &impl Column) -> Option<f32> {
         let num_bits = compute_num_bits(column.max_value());
         let num_bits_uncompressed = 64;
         Some(num_bits as f32 / num_bits_uncompressed as f32)

fastfield_codecs/src/blockwise_linear.rs

@@ -71,11 +71,13 @@ impl FastFieldCodec for BlockwiseLinearCodec {
     }
 
     // Estimate first_chunk and extrapolate
-    fn estimate(column: &dyn crate::Column) -> Option<f32> {
+    fn estimate(column: &impl crate::Column) -> Option<f32> {
         if column.num_vals() < 10 * CHUNK_SIZE as u64 {
             return None;
         }
-        let mut first_chunk: Vec<u64> = column.iter().take(CHUNK_SIZE as usize).collect();
+        let mut first_chunk: Vec<u64> = crate::iter_from_reader(column.reader())
+            .take(CHUNK_SIZE as usize)
+            .collect();
         let line = Line::train(&VecColumn::from(&first_chunk));
         for (i, buffer_val) in first_chunk.iter_mut().enumerate() {
             let interpolated_val = line.eval(i as u64);
@@ -100,7 +102,7 @@ impl FastFieldCodec for BlockwiseLinearCodec {
         Some(num_bits as f32 / num_bits_uncompressed as f32)
     }
 
-    fn serialize(column: &dyn Column, wrt: &mut impl io::Write) -> io::Result<()> {
+    fn serialize(column: &dyn crate::Column, wrt: &mut impl io::Write) -> io::Result<()> {
         // The BitpackedReader assumes a normalized vector.
         assert_eq!(column.min_value(), 0);
         let mut buffer = Vec::with_capacity(CHUNK_SIZE);
@@ -109,7 +111,7 @@ impl FastFieldCodec for BlockwiseLinearCodec {
         let num_blocks = compute_num_blocks(num_vals);
         let mut blocks = Vec::with_capacity(num_blocks);
 
-        let mut vals = column.iter();
+        let mut vals = crate::iter_from_reader(column.reader());
 
         let mut bit_packer = BitPacker::new();
 

fastfield_codecs/src/column.rs

@@ -3,14 +3,22 @@ use std::ops::RangeInclusive;
 
 use tantivy_bitpacker::minmax;
 
-pub trait Column<T: PartialOrd = u64>: Send + Sync {
-    /// Return the value associated with the given idx.
+pub trait Column<T: PartialOrd + Copy + 'static = u64>: Send + Sync {
+    /// Return a `ColumnReader`.
+    fn reader(&self) -> Box<dyn ColumnReader<T> + '_> {
+        // Box::new(ColumnReaderAdapter { column: self, idx: 0,  })
+        Box::new(ColumnReaderAdapter::from(self))
+    }
+
+    /// Return the value associated to the given idx.
     ///
     /// This accessor should return as fast as possible.
     ///
     /// # Panics
     ///
     /// May panic if `idx` is greater than the column length.
+    ///
+    /// TODO remove to force people to use `.reader()`.
     fn get_val(&self, idx: u64) -> T;
 
     /// Fills an output buffer with the fast field values
@@ -58,10 +66,70 @@ pub trait Column<T: PartialOrd = u64>: Send + Sync {
     fn max_value(&self) -> T;
 
     fn num_vals(&self) -> u64;
+}
 
-    /// Returns a iterator over the data
-    fn iter<'a>(&'a self) -> Box<dyn Iterator<Item = T> + 'a> {
-        Box::new((0..self.num_vals()).map(|idx| self.get_val(idx)))
+/// `ColumnReader` makes it possible to read forward through a column.
+pub trait ColumnReader<T = u64> {
+    /// Advance the reader to the target_idx.
+    ///
+    /// After a successful call to seek,
+    /// `.get()` should returns `column.get_val(target_idx)`.
+    fn seek(&mut self, target_idx: u64) -> T;
+
+    fn advance(&mut self) -> bool;
+
+    /// Get the current value without advancing the reader
+    fn get(&self) -> T;
+}
+
+pub fn iter_from_reader<'a, T: 'static>(
+    mut column_reader: Box<dyn ColumnReader<T> + 'a>,
+) -> impl Iterator<Item = T> + 'a {
+    std::iter::from_fn(move || {
+        if !column_reader.advance() {
+            return None;
+        }
+        Some(column_reader.get())
+    })
+}
+
+pub(crate) struct ColumnReaderAdapter<'a, C: ?Sized, T> {
+    column: &'a C,
+    idx: u64,
+    len: u64,
+    _phantom: PhantomData<T>,
+}
+
+impl<'a, C: Column<T> + ?Sized, T: Copy + PartialOrd + 'static> From<&'a C>
+    for ColumnReaderAdapter<'a, C, T>
+{
+    fn from(column: &'a C) -> Self {
+        ColumnReaderAdapter {
+            column,
+            idx: u64::MAX,
+            len: column.num_vals(),
+            _phantom: PhantomData,
+        }
+    }
+}
+
+impl<'a, T, C: ?Sized> ColumnReader<T> for ColumnReaderAdapter<'a, C, T>
+where
+    C: Column<T>,
+    T: PartialOrd<T> + Copy + 'static,
+{
+    fn seek(&mut self, idx: u64) -> T {
+        self.idx = idx;
+        self.get()
+    }
+
+    fn advance(&mut self) -> bool {
+        self.idx = self.idx.wrapping_add(1);
+        self.idx < self.len
+    }
+
+    fn get(&self) -> T {
+        self.column.get_val(self.idx)
     }
 }
 
@@ -71,7 +139,9 @@ pub struct VecColumn<'a, T = u64> {
     max_value: T,
 }
 
-impl<'a, C: Column<T>, T: Copy + PartialOrd> Column<T> for &'a C {
+impl<'a, C: Column<T>, T> Column<T> for &'a C
+where T: Copy + PartialOrd + 'static
+{
     fn get_val(&self, idx: u64) -> T {
         (*self).get_val(idx)
     }
@@ -88,8 +158,8 @@ impl<'a, C: Column<T>, T: Copy + PartialOrd> Column<T> for &'a C {
         (*self).num_vals()
     }
 
-    fn iter<'b>(&'b self) -> Box<dyn Iterator<Item = T> + 'b> {
-        (*self).iter()
+    fn reader(&self) -> Box<dyn ColumnReader<T> + '_> {
+        (*self).reader()
     }
 
     fn get_range(&self, start: u64, output: &mut [T]) {
@@ -97,15 +167,11 @@ impl<'a, C: Column<T>, T: Copy + PartialOrd> Column<T> for &'a C {
     }
 }
 
-impl<'a, T: Copy + PartialOrd + Send + Sync> Column<T> for VecColumn<'a, T> {
+impl<'a, T: Copy + PartialOrd + Send + Sync + 'static> Column<T> for VecColumn<'a, T> {
     fn get_val(&self, position: u64) -> T {
         self.values[position as usize]
     }
 
-    fn iter(&self) -> Box<dyn Iterator<Item = T> + '_> {
-        Box::new(self.values.iter().copied())
-    }
-
     fn min_value(&self) -> T {
         self.min_value
     }
@@ -144,15 +210,15 @@ struct MonotonicMappingColumn<C, T, Input> {
 }
 
 /// Creates a view of a column transformed by a monotonic mapping.
-pub fn monotonic_map_column<C, T, Input: PartialOrd, Output: PartialOrd>(
+pub fn monotonic_map_column<C, T, Input: PartialOrd + Copy, Output: PartialOrd + Copy>(
     from_column: C,
     monotonic_mapping: T,
 ) -> impl Column<Output>
 where
     C: Column<Input>,
     T: Fn(Input) -> Output + Send + Sync,
-    Input: Send + Sync,
-    Output: Send + Sync,
+    Input: Send + Sync + 'static,
+    Output: Send + Sync + 'static,
 {
     MonotonicMappingColumn {
         from_column,
@@ -161,13 +227,13 @@ where
     }
 }
 
-impl<C, T, Input: PartialOrd, Output: PartialOrd> Column<Output>
+impl<C, T, Input: PartialOrd + Copy, Output: PartialOrd + Copy> Column<Output>
     for MonotonicMappingColumn<C, T, Input>
 where
     C: Column<Input>,
     T: Fn(Input) -> Output + Send + Sync,
-    Input: Send + Sync,
-    Output: Send + Sync,
+    Input: Send + Sync + 'static,
+    Output: Send + Sync + 'static,
 {
     #[inline]
     fn get_val(&self, idx: u64) -> Output {
@@ -189,14 +255,44 @@ where
         self.from_column.num_vals()
     }
 
-    fn iter(&self) -> Box<dyn Iterator<Item = Output> + '_> {
-        Box::new(self.from_column.iter().map(&self.monotonic_mapping))
+    fn reader(&self) -> Box<dyn ColumnReader<Output> + '_> {
+        Box::new(MonotonicMappingColumnReader {
+            col_reader: self.from_column.reader(),
+            monotonic_mapping: &self.monotonic_mapping,
+            intermdiary_type: PhantomData,
+        })
     }
 
     // We voluntarily do not implement get_range as it yields a regression,
     // and we do not have any specialized implementation anyway.
 }
 
+struct MonotonicMappingColumnReader<'a, Transform, U> {
+    col_reader: Box<dyn ColumnReader<U> + 'a>,
+    monotonic_mapping: &'a Transform,
+    intermdiary_type: PhantomData<U>,
+}
+
+impl<'a, U, V, Transform> ColumnReader<V> for MonotonicMappingColumnReader<'a, Transform, U>
+where
+    U: Copy,
+    V: Copy,
+    Transform: Fn(U) -> V,
+{
+    fn seek(&mut self, idx: u64) -> V {
+        let intermediary_value = self.col_reader.seek(idx);
+        (*self.monotonic_mapping)(intermediary_value)
+    }
+
+    fn advance(&mut self) -> bool {
+        self.col_reader.advance()
+    }
+
+    fn get(&self) -> V {
+        (*self.monotonic_mapping)(self.col_reader.get())
+    }
+}
+
 pub struct IterColumn<T>(T);
 
 impl<T> From<T> for IterColumn<T>
@@ -210,7 +306,7 @@ where T: Iterator + Clone + ExactSizeIterator
 impl<T> Column<T::Item> for IterColumn<T>
 where
     T: Iterator + Clone + ExactSizeIterator + Send + Sync,
-    T::Item: PartialOrd,
+    T::Item: PartialOrd + Copy + 'static,
 {
     fn get_val(&self, idx: u64) -> T::Item {
         self.0.clone().nth(idx as usize).unwrap()
@@ -227,10 +323,6 @@ where
     fn num_vals(&self) -> u64 {
         self.0.len() as u64
     }
-
-    fn iter(&self) -> Box<dyn Iterator<Item = T::Item> + '_> {
-        Box::new(self.0.clone())
-    }
 }
 
 #[cfg(test)]
@@ -263,7 +355,7 @@ mod tests {
         let vals: Vec<u64> = (-1..99).map(i64::to_u64).collect();
         let col = VecColumn::from(&vals);
         let mapped = monotonic_map_column(col, |el| i64::from_u64(el) * 10i64);
-        let val_i64s: Vec<i64> = mapped.iter().collect();
+        let val_i64s: Vec<i64> = crate::iter_from_reader(mapped.reader()).collect();
         for i in 0..100 {
             assert_eq!(val_i64s[i as usize], mapped.get_val(i));
         }
@@ -277,7 +369,7 @@ mod tests {
         assert_eq!(mapped.min_value(), -10i64);
         assert_eq!(mapped.max_value(), 980i64);
         assert_eq!(mapped.num_vals(), 100);
-        let val_i64s: Vec<i64> = mapped.iter().collect();
+        let val_i64s: Vec<i64> = crate::iter_from_reader(mapped.reader()).collect();
         assert_eq!(val_i64s.len(), 100);
         for i in 0..100 {
             assert_eq!(val_i64s[i as usize], mapped.get_val(i));

fastfield_codecs/src/compact_space/mod.rs

@@ -22,7 +22,7 @@ use ownedbytes::OwnedBytes;
 use tantivy_bitpacker::{self, BitPacker, BitUnpacker};
 
 use crate::compact_space::build_compact_space::get_compact_space;
-use crate::Column;
+use crate::{iter_from_reader, Column, ColumnReader};
 
 mod blank_range;
 mod build_compact_space;
@@ -173,11 +173,14 @@ impl CompactSpaceCompressor {
     /// Taking the vals as Vec may cost a lot of memory. It is used to sort the vals.
     pub fn train_from(column: &impl Column<u128>) -> Self {
         let mut values_sorted = BTreeSet::new();
-        values_sorted.extend(column.iter());
+
         let total_num_values = column.num_vals();
 
+        values_sorted.extend(iter_from_reader(column.reader()));
+
         let compact_space =
             get_compact_space(&values_sorted, total_num_values, COST_PER_BLANK_IN_BITS);
+
         let amplitude_compact_space = compact_space.amplitude_compact_space();
 
         assert!(
@@ -218,11 +221,12 @@ impl CompactSpaceCompressor {
 
     pub fn compress_into(
         self,
-        vals: impl Iterator<Item = u128>,
+        mut vals: Box<dyn ColumnReader<u128> + '_>,
         write: &mut impl Write,
     ) -> io::Result<()> {
         let mut bitpacker = BitPacker::default();
-        for val in vals {
+        while vals.advance() {
+            let val = vals.get();
             let compact = self
                 .params
                 .compact_space
@@ -300,13 +304,13 @@ impl Column<u128> for CompactSpaceDecompressor {
         self.params.num_vals
     }
 
-    #[inline]
-    fn iter(&self) -> Box<dyn Iterator<Item = u128> + '_> {
-        Box::new(self.iter())
-    }
     fn get_between_vals(&self, range: RangeInclusive<u128>) -> Vec<u64> {
         self.get_between_vals(range)
     }
+
+    fn reader(&self) -> Box<dyn ColumnReader<u128> + '_> {
+        Box::new(self.specialized_reader())
+    }
 }
 
 impl CompactSpaceDecompressor {
@@ -410,18 +414,13 @@ impl CompactSpaceDecompressor {
         positions
     }
 
-    #[inline]
-    fn iter_compact(&self) -> impl Iterator<Item = u64> + '_ {
-        (0..self.params.num_vals)
-            .map(move |idx| self.params.bit_unpacker.get(idx as u64, &self.data) as u64)
-    }
-
-    #[inline]
-    fn iter(&self) -> impl Iterator<Item = u128> + '_ {
-        // TODO: Performance. It would be better to iterate on the ranges and check existence via
-        // the bit_unpacker.
-        self.iter_compact()
-            .map(|compact| self.compact_to_u128(compact))
+    fn specialized_reader(&self) -> CompactSpaceReader<'_> {
+        CompactSpaceReader {
+            data: self.data.as_slice(),
+            params: &self.params,
+            idx: 0u64,
+            len: self.params.num_vals,
+        }
     }
 
     #[inline]
@@ -439,6 +438,30 @@ impl CompactSpaceDecompressor {
     }
 }
 
+pub struct CompactSpaceReader<'a> {
+    data: &'a [u8],
+    params: &'a IPCodecParams,
+    idx: u64,
+    len: u64,
+}
+
+impl<'a> ColumnReader<u128> for CompactSpaceReader<'a> {
+    fn seek(&mut self, target_idx: u64) -> u128 {
+        self.idx = target_idx;
+        self.get()
+    }
+
+    fn advance(&mut self) -> bool {
+        self.idx = self.idx.wrapping_add(1);
+        self.idx < self.len
+    }
+
+    fn get(&self) -> u128 {
+        let compact_code = self.params.bit_unpacker.get(self.idx, self.data);
+        self.params.compact_space.compact_to_u128(compact_code)
+    }
+}
+
 #[cfg(test)]
 mod tests {
 

fastfield_codecs/src/lib.rs

@@ -29,7 +29,7 @@ mod serialize;
 
 use self::bitpacked::BitpackedCodec;
 use self::blockwise_linear::BlockwiseLinearCodec;
-pub use self::column::{monotonic_map_column, Column, VecColumn};
+pub use self::column::{iter_from_reader, monotonic_map_column, Column, ColumnReader, VecColumn};
 use self::linear::LinearCodec;
 pub use self::monotonic_mapping::MonotonicallyMappableToU64;
 pub use self::serialize::{
@@ -123,7 +123,7 @@ trait FastFieldCodec: 'static {
     ///
     /// The column iterator should be preferred over using column `get_val` method for
     /// performance reasons.
-    fn serialize(column: &dyn Column, write: &mut impl Write) -> io::Result<()>;
+    fn serialize(column: &dyn Column<u64>, write: &mut impl Write) -> io::Result<()>;
 
     /// Returns an estimate of the compression ratio.
     /// If the codec is not applicable, returns `None`.
@@ -132,7 +132,7 @@ trait FastFieldCodec: 'static {
     ///
     /// It could make sense to also return a value representing
     /// computational complexity.
-    fn estimate(column: &dyn Column) -> Option<f32>;
+    fn estimate(column: &impl Column) -> Option<f32>;
 }
 
 pub const ALL_CODEC_TYPES: [FastFieldCodecType; 3] = [
@@ -312,7 +312,7 @@ mod tests {
 
     #[test]
     fn estimation_test_bad_interpolation_case_monotonically_increasing() {
-        let mut data: Vec<u64> = (201..=20000_u64).collect();
+        let mut data: Vec<u64> = (200..=20000_u64).collect();
         data.push(1_000_000);
         let data: VecColumn = data.as_slice().into();
 

fastfield_codecs/src/line.rs

@@ -68,37 +68,24 @@ impl Line {
     }
 
     // Same as train, but the intercept is only estimated from provided sample positions
-    pub fn estimate(sample_positions_and_values: &[(u64, u64)]) -> Self {
-        let first_val = sample_positions_and_values[0].1;
-        let last_val = sample_positions_and_values[sample_positions_and_values.len() - 1].1;
-        let num_vals = sample_positions_and_values[sample_positions_and_values.len() - 1].0 + 1;
-        Self::train_from(
-            first_val,
-            last_val,
-            num_vals,
-            sample_positions_and_values.iter().cloned(),
-        )
+    pub fn estimate(ys: &dyn Column, sample_positions: &[u64]) -> Self {
+        Self::train_from(ys, sample_positions.iter().cloned())
     }
 
     // Intercept is only computed from provided positions
-    fn train_from(
-        first_val: u64,
-        last_val: u64,
-        num_vals: u64,
-        positions_and_values: impl Iterator<Item = (u64, u64)>,
-    ) -> Self {
-        // TODO replace with let else
-        let idx_last_val = if let Some(idx_last_val) = NonZeroU64::new(num_vals - 1) {
-            idx_last_val
+    fn train_from(ys: &dyn Column, positions: impl Iterator<Item = u64>) -> Self {
+        let last_idx = if let Some(last_idx) = NonZeroU64::new(ys.num_vals() - 1) {
+            last_idx
         } else {
             return Line::default();
         };
 
-        let y0 = first_val;
-        let y1 = last_val;
+        let mut ys_reader = ys.reader();
+        let y0 = ys_reader.seek(0);
+        let y1 = ys_reader.seek(last_idx.get());
 
         // We first independently pick our slope.
-        let slope = compute_slope(y0, y1, idx_last_val);
+        let slope = compute_slope(y0, y1, last_idx);
 
         // We picked our slope. Note that it does not have to be perfect.
         // Now we need to compute the best intercept.
@@ -128,8 +115,12 @@ impl Line {
             intercept: 0,
         };
         let heuristic_shift = y0.wrapping_sub(MID_POINT);
-        line.intercept = positions_and_values
-            .map(|(pos, y)| y.wrapping_sub(line.eval(pos)))
+        let mut ys_reader = ys.reader();
+        line.intercept = positions
+            .map(|pos| {
+                let y = ys_reader.seek(pos);
+                y.wrapping_sub(line.eval(pos))
+            })
             .min_by_key(|&val| val.wrapping_sub(heuristic_shift))
             .unwrap_or(0u64); //< Never happens.
         line
@@ -146,14 +137,7 @@ impl Line {
     /// This function is only invariable by translation if all of the
     /// `ys` are packaged into half of the space. (See heuristic below)
     pub fn train(ys: &dyn Column) -> Self {
-        let first_val = ys.iter().next().unwrap();
-        let last_val = ys.iter().nth(ys.num_vals() as usize - 1).unwrap();
-        Self::train_from(
-            first_val,
-            last_val,
-            ys.num_vals(),
-            ys.iter().enumerate().map(|(pos, val)| (pos as u64, val)),
-        )
+        Self::train_from(ys, 0..ys.num_vals())
     }
 }
 

fastfield_codecs/src/linear.rs

@@ -89,8 +89,7 @@ impl FastFieldCodec for LinearCodec {
         assert_eq!(column.min_value(), 0);
         let line = Line::train(column);
 
-        let max_offset_from_line = column
-            .iter()
+        let max_offset_from_line = crate::iter_from_reader(column.reader())
             .enumerate()
             .map(|(pos, actual_value)| {
                 let calculated_value = line.eval(pos as u64);
@@ -107,7 +106,12 @@ impl FastFieldCodec for LinearCodec {
         linear_params.serialize(write)?;
 
         let mut bit_packer = BitPacker::new();
-        for (pos, actual_value) in column.iter().enumerate() {
+        let mut col_reader = column.reader();
+        for pos in 0.. {
+            if !col_reader.advance() {
+                break;
+            }
+            let actual_value = col_reader.get();
             let calculated_value = line.eval(pos as u64);
             let offset = actual_value.wrapping_sub(calculated_value);
             bit_packer.write(offset, num_bits, write)?;
@@ -121,25 +125,24 @@ impl FastFieldCodec for LinearCodec {
     /// where the local maxima for the deviation of the calculated value are and
     /// the offset to shift all values to >=0 is also unknown.
     #[allow(clippy::question_mark)]
-    fn estimate(column: &dyn Column) -> Option<f32> {
+    fn estimate(column: &impl Column) -> Option<f32> {
         if column.num_vals() < 3 {
             return None; // disable compressor for this case
         }
 
-        let limit_num_vals = column.num_vals().min(100_000);
+        // let's sample at 0%, 5%, 10% .. 95%, 100%
+        let num_vals = column.num_vals() as f32 / 100.0;
+        let sample_positions = (0..20)
+            .map(|pos| (num_vals * pos as f32 * 5.0) as u64)
+            .collect::<Vec<_>>();
 
-        let num_samples = 100;
-        let step_size = (limit_num_vals / num_samples).max(1); // 20 samples
-        let mut sample_positions_and_values: Vec<_> = Vec::new();
-        for (pos, val) in column.iter().enumerate().step_by(step_size as usize) {
-            sample_positions_and_values.push((pos as u64, val));
-        }
+        let line = Line::estimate(column, &sample_positions);
 
-        let line = Line::estimate(&sample_positions_and_values);
-
-        let estimated_bit_width = sample_positions_and_values
+        let mut column_reader = column.reader();
+        let estimated_bit_width = sample_positions
             .into_iter()
-            .map(|(pos, actual_value)| {
+            .map(|pos| {
+                let actual_value = column_reader.seek(pos);
                 let interpolated_val = line.eval(pos as u64);
                 actual_value.wrapping_sub(interpolated_val)
             })
@@ -148,7 +151,6 @@ impl FastFieldCodec for LinearCodec {
             .max()
             .unwrap_or(0);
 
-        // Extrapolate to whole column
         let num_bits = (estimated_bit_width as u64 * column.num_vals() as u64) + 64;
         let num_bits_uncompressed = 64 * column.num_vals();
         Some(num_bits as f32 / num_bits_uncompressed as f32)

fastfield_codecs/src/monotonic_mapping.rs

@@ -36,7 +36,11 @@ impl MonotonicallyMappableToU64 for i64 {
 impl MonotonicallyMappableToU64 for bool {
     #[inline(always)]
     fn to_u64(self) -> u64 {
-        u64::from(self)
+        if self {
+            1
+        } else {
+            0
+        }
     }
 
     #[inline(always)]

fastfield_codecs/src/monotonic_mapping_u128.rs

@@ -1,42 +0,0 @@
-use std::net::{IpAddr, Ipv6Addr};
-
-pub trait MonotonicallyMappableToU128: 'static + PartialOrd + Copy + Send + Sync {
-    /// Converts a value to u128.
-    ///
-    /// Internally all fast field values are encoded as u64.
-    fn to_u128(self) -> u128;
-
-    /// Converts a value from u128
-    ///
-    /// Internally all fast field values are encoded as u64.
-    /// **Note: To be used for converting encoded Term, Posting values.**
-    fn from_u128(val: u128) -> Self;
-}
-
-impl MonotonicallyMappableToU128 for u128 {
-    fn to_u128(self) -> u128 {
-        self
-    }
-
-    fn from_u128(val: u128) -> Self {
-        val
-    }
-}
-
-impl MonotonicallyMappableToU128 for IpAddr {
-    fn to_u128(self) -> u128 {
-        ip_to_u128(self)
-    }
-
-    fn from_u128(val: u128) -> Self {
-        IpAddr::from(val.to_be_bytes())
-    }
-}
-
-fn ip_to_u128(ip_addr: IpAddr) -> u128 {
-    let ip_addr_v6: Ipv6Addr = match ip_addr {
-        IpAddr::V4(v4) => v4.to_ipv6_mapped(),
-        IpAddr::V6(v6) => v6,
-    };
-    u128::from_be_bytes(ip_addr_v6.octets())
-}

fastfield_codecs/src/serialize.rs

@@ -31,8 +31,8 @@ use crate::blockwise_linear::BlockwiseLinearCodec;
 use crate::compact_space::CompactSpaceCompressor;
 use crate::linear::LinearCodec;
 use crate::{
-    monotonic_map_column, Column, FastFieldCodec, FastFieldCodecType, MonotonicallyMappableToU64,
-    VecColumn, ALL_CODEC_TYPES,
+    iter_from_reader, monotonic_map_column, Column, FastFieldCodec, FastFieldCodecType,
+    MonotonicallyMappableToU64, VecColumn, ALL_CODEC_TYPES,
 };
 
 /// The normalized header gives some parameters after applying the following
@@ -79,8 +79,9 @@ impl Header {
         let num_vals = column.num_vals();
         let min_value = column.min_value();
         let max_value = column.max_value();
-        let gcd = crate::gcd::find_gcd(column.iter().map(|val| val - min_value))
-            .filter(|gcd| gcd.get() > 1u64);
+        let gcd =
+            crate::gcd::find_gcd(iter_from_reader(column.reader()).map(|val| val - min_value))
+                .filter(|gcd| gcd.get() > 1u64);
         let divider = DividerU64::divide_by(gcd.map(|gcd| gcd.get()).unwrap_or(1u64));
         let shifted_column = monotonic_map_column(&column, |val| divider.divide(val - min_value));
         let codec_type = detect_codec(shifted_column, codecs)?;
@@ -131,7 +132,7 @@ pub fn estimate<T: MonotonicallyMappableToU64>(
 ) -> Option<f32> {
     let column = monotonic_map_column(typed_column, T::to_u64);
     let min_value = column.min_value();
-    let gcd = crate::gcd::find_gcd(column.iter().map(|val| val - min_value))
+    let gcd = crate::gcd::find_gcd(iter_from_reader(column.reader()).map(|val| val - min_value))
         .filter(|gcd| gcd.get() > 1u64);
     let divider = DividerU64::divide_by(gcd.map(|gcd| gcd.get()).unwrap_or(1u64));
     let normalized_column = monotonic_map_column(&column, |val| divider.divide(val - min_value));
@@ -149,7 +150,7 @@ pub fn serialize_u128(
     // TODO write header, to later support more codecs
     let compressor = CompactSpaceCompressor::train_from(&typed_column);
     compressor
-        .compress_into(typed_column.iter(), output)
+        .compress_into(typed_column.reader(), output)
         .unwrap();
 
     Ok(())
@@ -240,7 +241,8 @@ mod tests {
     #[test]
     fn test_serialize_deserialize() {
         let original = [1u64, 5u64, 10u64];
-        let restored: Vec<u64> = serialize_and_load(&original[..]).iter().collect();
+        let restored: Vec<u64> =
+            crate::iter_from_reader(serialize_and_load(&original[..]).reader()).collect();
         assert_eq!(&restored, &original[..]);
     }
 

src/aggregation/bucket/histogram/histogram.rs

@@ -425,7 +425,7 @@ impl SegmentHistogramCollector {
         let bucket = &mut self.buckets[bucket_pos];
         bucket.doc_count += 1;
         if let Some(sub_aggregation) = self.sub_aggregations.as_mut() {
-            sub_aggregation[bucket_pos].collect(doc, bucket_with_accessor)?;
+            (&mut sub_aggregation[bucket_pos]).collect(doc, bucket_with_accessor)?;
         }
         Ok(())
     }

src/aggregation/bucket/range.rs

@@ -323,8 +323,8 @@ impl SegmentRangeCollector {
 /// Converts the user provided f64 range value to fast field value space.
 ///
 /// Internally fast field values are always stored as u64.
-/// If the fast field has u64 `[1, 2, 5]`, these values are stored as is in the fast field.
-/// A fast field with f64 `[1.0, 2.0, 5.0]` is converted to u64 space, using a
+/// If the fast field has u64 [1,2,5], these values are stored as is in the fast field.
+/// A fast field with f64 [1.0, 2.0, 5.0] is converted to u64 space, using a
 /// monotonic mapping function, so the order is preserved.
 ///
 /// Consequently, a f64 user range 1.0..3.0 needs to be converted to fast field value space using

src/collector/custom_score_top_collector.rs

@@ -38,7 +38,7 @@ pub trait CustomSegmentScorer<TScore>: 'static {
 pub trait CustomScorer<TScore>: Sync {
     /// Type of the associated [`CustomSegmentScorer`].
     type Child: CustomSegmentScorer<TScore>;
-    /// Builds a child scorer for a specific segment. The child scorer is associated with
+    /// Builds a child scorer for a specific segment. The child scorer is associated to
     /// a specific segment.
     fn segment_scorer(&self, segment_reader: &SegmentReader) -> crate::Result<Self::Child>;
 }

src/collector/facet_collector.rs

@@ -91,7 +91,7 @@ fn facet_depth(facet_bytes: &[u8]) -> usize {
 ///     let index = Index::create_in_ram(schema);
 ///     {
 ///         let mut index_writer = index.writer(3_000_000)?;
-///         // a document can be associated with any number of facets
+///         // a document can be associated to any number of facets
 ///         index_writer.add_document(doc!(
 ///             title => "The Name of the Wind",
 ///             facet => Facet::from("/lang/en"),
@@ -338,7 +338,11 @@ impl SegmentCollector for FacetSegmentCollector {
         let mut previous_collapsed_ord: usize = usize::MAX;
         for &facet_ord in &self.facet_ords_buf {
             let collapsed_ord = self.collapse_mapping[facet_ord as usize];
-            self.counts[collapsed_ord] += u64::from(collapsed_ord != previous_collapsed_ord);
+            self.counts[collapsed_ord] += if collapsed_ord == previous_collapsed_ord {
+                0
+            } else {
+                1
+            };
             previous_collapsed_ord = collapsed_ord;
         }
     }

src/collector/histogram_collector.rs

@@ -37,7 +37,7 @@ impl HistogramCollector {
     /// The scale/range of the histogram is not dynamic. It is required to
     /// define it by supplying following parameter:
     ///  - `min_value`: the minimum value that can be recorded in the histogram.
-    ///  - `bucket_width`: the length of the interval that is associated with each buckets.
+    ///  - `bucket_width`: the length of the interval that is associated to each buckets.
     ///  - `num_buckets`: The overall number of buckets.
     ///
     /// Together, this parameters define a partition of `[min_value, min_value + num_buckets *

src/collector/mod.rs

@@ -142,7 +142,7 @@ pub trait Collector: Sync + Send {
     /// e.g. `usize` for the `Count` collector.
     type Fruit: Fruit;
 
-    /// Type of the `SegmentCollector` associated with this collector.
+    /// Type of the `SegmentCollector` associated to this collector.
     type Child: SegmentCollector;
 
     /// `set_segment` is called before beginning to enumerate
@@ -156,7 +156,7 @@ pub trait Collector: Sync + Send {
     /// Returns true iff the collector requires to compute scores for documents.
     fn requires_scoring(&self) -> bool;
 
-    /// Combines the fruit associated with the collection of each segments
+    /// Combines the fruit associated to the collection of each segments
     /// into one fruit.
     fn merge_fruits(
         &self,

src/collector/top_score_collector.rs

@@ -693,7 +693,7 @@ impl Collector for TopDocs {
     }
 }
 
-/// Segment Collector associated with `TopDocs`.
+/// Segment Collector associated to `TopDocs`.
 pub struct TopScoreSegmentCollector(TopSegmentCollector<Score>);
 
 impl SegmentCollector for TopScoreSegmentCollector {

src/collector/tweak_score_top_collector.rs

@@ -40,7 +40,7 @@ pub trait ScoreTweaker<TScore>: Sync {
     /// Type of the associated [`ScoreSegmentTweaker`].
     type Child: ScoreSegmentTweaker<TScore>;
 
-    /// Builds a child tweaker for a specific segment. The child scorer is associated with
+    /// Builds a child tweaker for a specific segment. The child scorer is associated to
     /// a specific segment.
     fn segment_tweaker(&self, segment_reader: &SegmentReader) -> Result<Self::Child>;
 }

src/core/index.rs

@@ -19,7 +19,7 @@ use crate::error::{DataCorruption, TantivyError};
 use crate::indexer::index_writer::{MAX_NUM_THREAD, MEMORY_ARENA_NUM_BYTES_MIN};
 use crate::indexer::segment_updater::save_metas;
 use crate::reader::{IndexReader, IndexReaderBuilder};
-use crate::schema::{Cardinality, Field, FieldType, Schema};
+use crate::schema::{Field, FieldType, Schema};
 use crate::tokenizer::{TextAnalyzer, TokenizerManager};
 use crate::IndexWriter;
 
@@ -152,7 +152,9 @@ impl IndexBuilder {
     /// This should only be used for unit tests.
     pub fn create_in_ram(self) -> Result<Index, TantivyError> {
         let ram_directory = RamDirectory::create();
-        self.create(ram_directory)
+        Ok(self
+            .create(ram_directory)
+            .expect("Creating a RamDirectory should never fail"))
     }
 
     /// Creates a new index in a given filepath.
@@ -226,44 +228,10 @@ impl IndexBuilder {
             ))
         }
     }
-
-    fn validate(&self) -> crate::Result<()> {
-        if let Some(schema) = self.schema.as_ref() {
-            if let Some(sort_by_field) = self.index_settings.sort_by_field.as_ref() {
-                let schema_field = schema.get_field(&sort_by_field.field).ok_or_else(|| {
-                    TantivyError::InvalidArgument(format!(
-                        "Field to sort index {} not found in schema",
-                        sort_by_field.field
-                    ))
-                })?;
-                let entry = schema.get_field_entry(schema_field);
-                if !entry.is_fast() {
-                    return Err(TantivyError::InvalidArgument(format!(
-                        "Field {} is no fast field. Field needs to be a single value fast field \
-                         to be used to sort an index",
-                        sort_by_field.field
-                    )));
-                }
-                if entry.field_type().fastfield_cardinality() != Some(Cardinality::SingleValue) {
-                    return Err(TantivyError::InvalidArgument(format!(
-                        "Only single value fast field Cardinality supported for sorting index {}",
-                        sort_by_field.field
-                    )));
-                }
-            }
-            Ok(())
-        } else {
-            Err(TantivyError::InvalidArgument(
-                "no schema passed".to_string(),
-            ))
-        }
-    }
-
     /// Creates a new index given an implementation of the trait `Directory`.
     ///
     /// If a directory previously existed, it will be erased.
     fn create<T: Into<Box<dyn Directory>>>(self, dir: T) -> crate::Result<Index> {
-        self.validate()?;
         let dir = dir.into();
         let directory = ManagedDirectory::wrap(dir)?;
         save_new_metas(

src/core/index_meta.rs

@@ -130,7 +130,7 @@ impl SegmentMeta {
     /// Returns the relative path of a component of our segment.
     ///
     /// It just joins the segment id with the extension
-    /// associated with a segment component.
+    /// associated to a segment component.
     pub fn relative_path(&self, component: SegmentComponent) -> PathBuf {
         let mut path = self.id().uuid_string();
         path.push_str(&*match component {
@@ -326,13 +326,13 @@ pub struct IndexMeta {
     /// `IndexSettings` to configure index options.
     #[serde(default)]
     pub index_settings: IndexSettings,
-    /// List of `SegmentMeta` information associated with each finalized segment of the index.
+    /// List of `SegmentMeta` information associated to each finalized segment of the index.
     pub segments: Vec<SegmentMeta>,
     /// Index `Schema`
     pub schema: Schema,
-    /// Opstamp associated with the last `commit` operation.
+    /// Opstamp associated to the last `commit` operation.
     pub opstamp: Opstamp,
-    /// Payload associated with the last commit.
+    /// Payload associated to the last commit.
     ///
     /// Upon commit, clients can optionally add a small `String` payload to their commit
     /// to help identify this commit.

src/core/inverted_index_reader.rs

@@ -9,11 +9,11 @@ use crate::schema::{IndexRecordOption, Term};
 use crate::termdict::TermDictionary;
 
 /// The inverted index reader is in charge of accessing
-/// the inverted index associated with a specific field.
+/// the inverted index associated to a specific field.
 ///
 /// # Note
 ///
-/// It is safe to delete the segment associated with
+/// It is safe to delete the segment associated to
 /// an `InvertedIndexReader`. As long as it is open,
 /// the `FileSlice` it is relying on should
 /// stay available.
@@ -30,7 +30,7 @@ pub struct InvertedIndexReader {
 }
 
 impl InvertedIndexReader {
-    #[allow(clippy::needless_pass_by_value)] // for symmetry
+    #[cfg_attr(feature = "cargo-clippy", allow(clippy::needless_pass_by_value))] // for symmetry
     pub(crate) fn new(
         termdict: TermDictionary,
         postings_file_slice: FileSlice,

src/core/searcher.rs

@@ -69,7 +69,7 @@ pub struct Searcher {
 }
 
 impl Searcher {
-    /// Returns the `Index` associated with the `Searcher`
+    /// Returns the `Index` associated to the `Searcher`
     pub fn index(&self) -> &Index {
         &self.inner.index
     }
@@ -108,7 +108,7 @@ impl Searcher {
         store_reader.get_async(doc_address.doc_id).await
     }
 
-    /// Access the schema associated with the index of this searcher.
+    /// Access the schema associated to the index of this searcher.
     pub fn schema(&self) -> &Schema {
         &self.inner.schema
     }
@@ -161,11 +161,11 @@ impl Searcher {
     ///
     /// Search works as follows :
     ///
-    ///  First the weight object associated with the query is created.
+    ///  First the weight object associated to the query is created.
     ///
     ///  Then, the query loops over the segments and for each segment :
     ///  - setup the collector and informs it that the segment being processed has changed.
-    ///  - creates a SegmentCollector for collecting documents associated with the segment
+    ///  - creates a SegmentCollector for collecting documents associated to the segment
     ///  - creates a `Scorer` object associated for this segment
     ///  - iterate through the matched documents and push them to the segment collector.
     ///

src/core/segment.rs

@@ -70,7 +70,7 @@ impl Segment {
     /// Returns the relative path of a component of our segment.
     ///
     /// It just joins the segment id with the extension
-    /// associated with a segment component.
+    /// associated to a segment component.
     pub fn relative_path(&self, component: SegmentComponent) -> PathBuf {
         self.meta.relative_path(component)
     }

src/core/segment_component.rs

@@ -6,7 +6,7 @@ use std::slice;
 /// except the delete component that takes an `segment_uuid`.`delete_opstamp`.`component_extension`
 #[derive(Copy, Clone, Eq, PartialEq)]
 pub enum SegmentComponent {
-    /// Postings (or inverted list). Sorted lists of document ids, associated with terms
+    /// Postings (or inverted list). Sorted lists of document ids, associated to terms
     Postings,
     /// Positions of terms in each document.
     Positions,

src/core/segment_id.rs

@@ -57,7 +57,7 @@ impl SegmentId {
     /// Picking the first 8 chars is ok to identify
     /// segments in a display message (e.g. a5c4dfcb).
     pub fn short_uuid_string(&self) -> String {
-        self.0.as_simple().to_string()[..8].to_string()
+        (&self.0.as_simple().to_string()[..8]).to_string()
     }
 
     /// Returns a segment uuid string.

src/core/segment_reader.rs

@@ -89,7 +89,7 @@ impl SegmentReader {
         &self.fast_fields_readers
     }
 
-    /// Accessor to the `FacetReader` associated with a given `Field`.
+    /// Accessor to the `FacetReader` associated to a given `Field`.
     pub fn facet_reader(&self, field: Field) -> crate::Result<FacetReader> {
         let field_entry = self.schema.get_field_entry(field);
 
@@ -208,13 +208,13 @@ impl SegmentReader {
         })
     }
 
-    /// Returns a field reader associated with the field given in argument.
+    /// Returns a field reader associated to the field given in argument.
     /// If the field was not present in the index during indexing time,
     /// the InvertedIndexReader is empty.
     ///
     /// The field reader is in charge of iterating through the
-    /// term dictionary associated with a specific field,
-    /// and opening the posting list associated with any term.
+    /// term dictionary associated to a specific field,
+    /// and opening the posting list associated to any term.
     ///
     /// If the field is not marked as index, a warn is logged and an empty `InvertedIndexReader`
     /// is returned.
@@ -241,7 +241,7 @@ impl SegmentReader {
 
         if postings_file_opt.is_none() || record_option_opt.is_none() {
             // no documents in the segment contained this field.
-            // As a result, no data is associated with the inverted index.
+            // As a result, no data is associated to the inverted index.
             //
             // Returns an empty inverted index.
             let record_option = record_option_opt.unwrap_or(IndexRecordOption::Basic);

src/directory/composite_file.rs

@@ -154,14 +154,14 @@ impl CompositeFile {
         }
     }
 
-    /// Returns the `FileSlice` associated with
-    /// a given `Field` and stored in a `CompositeFile`.
+    /// Returns the `FileSlice` associated
+    /// to a given `Field` and stored in a `CompositeFile`.
     pub fn open_read(&self, field: Field) -> Option<FileSlice> {
         self.open_read_with_idx(field, 0)
     }
 
-    /// Returns the `FileSlice` associated with
-    /// a given `Field` and stored in a `CompositeFile`.
+    /// Returns the `FileSlice` associated
+    /// to a given `Field` and stored in a `CompositeFile`.
     pub fn open_read_with_idx(&self, field: Field, idx: usize) -> Option<FileSlice> {
         self.offsets_index
             .get(&FileAddr { field, idx })

src/directory/directory.rs

@@ -39,7 +39,7 @@ impl RetryPolicy {
 
 /// The `DirectoryLock` is an object that represents a file lock.
 ///
-/// It is associated with a lock file, that gets deleted on `Drop.`
+/// It is associated to a lock file, that gets deleted on `Drop.`
 pub struct DirectoryLock(Box<dyn Send + Sync + 'static>);
 
 struct DirectoryLockGuard {

src/directory/file_slice.rs

@@ -1,5 +1,5 @@
 use std::ops::{Deref, Range};
-use std::sync::Arc;
+use std::sync::{Arc, Weak};
 use std::{fmt, io};
 
 use async_trait::async_trait;
@@ -8,6 +8,9 @@ use stable_deref_trait::StableDeref;
 
 use crate::directory::OwnedBytes;
 
+pub type ArcBytes = Arc<dyn Deref<Target = [u8]> + Send + Sync + 'static>;
+pub type WeakArcBytes = Weak<dyn Deref<Target = [u8]> + Send + Sync + 'static>;
+
 /// Objects that represents files sections in tantivy.
 ///
 /// By contract, whatever happens to the directory file, as long as a FileHandle

src/directory/file_watcher.rs

@@ -9,7 +9,7 @@ use crc32fast::Hasher;
 
 use crate::directory::{WatchCallback, WatchCallbackList, WatchHandle};
 
-const POLLING_INTERVAL: Duration = Duration::from_millis(if cfg!(test) { 1 } else { 500 });
+pub 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.
 pub struct FileWatcher {

src/directory/mmap_directory.rs

@@ -3,7 +3,7 @@ use std::fs::{self, File, OpenOptions};
 use std::io::{self, BufWriter, Read, Seek, Write};
 use std::ops::Deref;
 use std::path::{Path, PathBuf};
-use std::sync::{Arc, RwLock, Weak};
+use std::sync::{Arc, RwLock};
 use std::{fmt, result};
 
 use fs2::FileExt;
@@ -18,13 +18,10 @@ use crate::directory::error::{
 };
 use crate::directory::file_watcher::FileWatcher;
 use crate::directory::{
-    AntiCallToken, Directory, DirectoryLock, FileHandle, Lock, OwnedBytes, TerminatingWrite,
-    WatchCallback, WatchHandle, WritePtr,
+    AntiCallToken, ArcBytes, Directory, DirectoryLock, FileHandle, Lock, OwnedBytes,
+    TerminatingWrite, WatchCallback, WatchHandle, WeakArcBytes, WritePtr,
 };
 
-pub type ArcBytes = Arc<dyn Deref<Target = [u8]> + Send + Sync + 'static>;
-pub type WeakArcBytes = Weak<dyn Deref<Target = [u8]> + Send + Sync + 'static>;
-
 /// Create a default io error given a string.
 pub(crate) fn make_io_err(msg: String) -> io::Error {
     io::Error::new(io::ErrorKind::Other, msg)
@@ -304,7 +301,7 @@ pub(crate) fn atomic_write(path: &Path, content: &[u8]) -> io::Result<()> {
             "Path {:?} does not have parent directory.",
         )
     })?;
-    let mut tempfile = tempfile::Builder::new().tempfile_in(parent_path)?;
+    let mut tempfile = tempfile::Builder::new().tempfile_in(&parent_path)?;
     tempfile.write_all(content)?;
     tempfile.flush()?;
     tempfile.as_file_mut().sync_data()?;
@@ -337,7 +334,7 @@ impl Directory for MmapDirectory {
         Ok(Arc::new(owned_bytes))
     }
 
-    /// Any entry associated with the path in the mmap will be
+    /// Any entry associated to the path in the mmap will be
     /// removed before the file is deleted.
     fn delete(&self, path: &Path) -> result::Result<(), DeleteError> {
         let full_path = self.resolve_path(path);
@@ -475,8 +472,6 @@ mod tests {
     // There are more tests in directory/mod.rs
     // The following tests are specific to the MmapDirectory
 
-    use std::time::Duration;
-
     use common::HasLen;
 
     use super::*;
@@ -615,14 +610,7 @@ mod tests {
                 mmap_directory.get_cache_info().mmapped.len()
             );
         }
-        // This test failed on CI. The last Mmap is dropped from the merging thread so there might
-        // be a race condition indeed.
-        for _ in 0..10 {
-            if mmap_directory.get_cache_info().mmapped.is_empty() {
-                return Ok(());
-            }
-            std::thread::sleep(Duration::from_millis(200));
-        }
-        panic!("The cache still contains information. One of the Mmap has not been dropped.");
+        assert!(mmap_directory.get_cache_info().mmapped.is_empty());
+        Ok(())
     }
 }

src/directory/mod.rs

@@ -26,6 +26,7 @@ pub use ownedbytes::OwnedBytes;
 pub(crate) use self::composite_file::{CompositeFile, CompositeWrite};
 pub use self::directory::{Directory, DirectoryClone, DirectoryLock};
 pub use self::directory_lock::{Lock, INDEX_WRITER_LOCK, META_LOCK};
+pub(crate) use self::file_slice::{ArcBytes, WeakArcBytes};
 pub use self::file_slice::{FileHandle, FileSlice};
 pub use self::ram_directory::RamDirectory;
 pub use self::watch_event_router::{WatchCallback, WatchCallbackList, WatchHandle};

src/directory/ram_directory.rs

@@ -136,20 +136,6 @@ impl RamDirectory {
         Self::default()
     }
 
-    /// Deep clones the directory.
-    ///
-    /// Ulterior writes on one of the copy
-    /// will not affect the other copy.
-    pub fn deep_clone(&self) -> RamDirectory {
-        let inner_clone = InnerDirectory {
-            fs: self.fs.read().unwrap().fs.clone(),
-            watch_router: Default::default(),
-        };
-        RamDirectory {
-            fs: Arc::new(RwLock::new(inner_clone)),
-        }
-    }
-
     /// Returns the sum of the size of the different files
     /// in the [`RamDirectory`].
     pub fn total_mem_usage(&self) -> usize {
@@ -270,23 +256,4 @@ mod tests {
         assert_eq!(directory_copy.atomic_read(path_atomic).unwrap(), msg_atomic);
         assert_eq!(directory_copy.atomic_read(path_seq).unwrap(), msg_seq);
     }
-
-    #[test]
-    fn test_ram_directory_deep_clone() {
-        let dir = RamDirectory::default();
-        let test = Path::new("test");
-        let test2 = Path::new("test2");
-        dir.atomic_write(test, b"firstwrite").unwrap();
-        let dir_clone = dir.deep_clone();
-        assert_eq!(
-            dir_clone.atomic_read(test).unwrap(),
-            dir.atomic_read(test).unwrap()
-        );
-        dir.atomic_write(test, b"original").unwrap();
-        dir_clone.atomic_write(test, b"clone").unwrap();
-        dir_clone.atomic_write(test2, b"clone2").unwrap();
-        assert_eq!(dir.atomic_read(test).unwrap(), b"original");
-        assert_eq!(&dir_clone.atomic_read(test).unwrap(), b"clone");
-        assert_eq!(&dir_clone.atomic_read(test2).unwrap(), b"clone2");
-    }
 }

src/fastfield/bytes/reader.rs

@@ -1,4 +1,3 @@
-use std::ops::Range;
 use std::sync::Arc;
 
 use fastfield_codecs::Column;
@@ -32,39 +31,36 @@ impl BytesFastFieldReader {
         Ok(BytesFastFieldReader { idx_reader, values })
     }
 
-    fn range(&self, doc: DocId) -> Range<u64> {
+    fn range(&self, doc: DocId) -> (usize, usize) {
         let idx = doc as u64;
-        let start = self.idx_reader.get_val(idx);
-        let end = self.idx_reader.get_val(idx + 1);
-        start..end
+        let start = self.idx_reader.get_val(idx) as usize;
+        let stop = self.idx_reader.get_val(idx + 1) as usize;
+        (start, stop)
     }
 
-    /// Returns the bytes associated with the given `doc`
+    /// Returns the bytes associated to the given `doc`
     pub fn get_bytes(&self, doc: DocId) -> &[u8] {
-        let range = self.range(doc);
-        &self.values.as_slice()[range.start as usize..range.end as usize]
+        let (start, stop) = self.range(doc);
+        &self.values.as_slice()[start..stop]
     }
 
-    /// Returns the length of the bytes associated with the given `doc`
-    pub fn num_bytes(&self, doc: DocId) -> u64 {
-        let range = self.range(doc);
-        range.end - range.start
+    /// Returns the length of the bytes associated to the given `doc`
+    pub fn num_bytes(&self, doc: DocId) -> usize {
+        let (start, stop) = self.range(doc);
+        stop - start
     }
 
     /// Returns the overall number of bytes in this bytes fast field.
-    pub fn total_num_bytes(&self) -> u64 {
-        self.values.len() as u64
+    pub fn total_num_bytes(&self) -> usize {
+        self.values.len()
     }
 }
 
 impl MultiValueLength for BytesFastFieldReader {
-    fn get_range(&self, doc_id: DocId) -> std::ops::Range<u64> {
-        self.range(doc_id)
-    }
     fn get_len(&self, doc_id: DocId) -> u64 {
-        self.num_bytes(doc_id)
+        self.num_bytes(doc_id) as u64
     }
     fn get_total_len(&self) -> u64 {
-        self.total_num_bytes()
+        self.total_num_bytes() as u64
     }
 }

src/fastfield/bytes/writer.rs

@@ -24,7 +24,7 @@ use crate::DocId;
 ///
 /// Once acquired, writing is done by calling
 /// [`.add_document_val(&[u8])`](BytesFastFieldWriter::add_document_val)
-/// once per document, even if there are no bytes associated with it.
+/// once per document, even if there are no bytes associated to it.
 pub struct BytesFastFieldWriter {
     field: Field,
     vals: Vec<u8>,
@@ -45,7 +45,7 @@ impl BytesFastFieldWriter {
     pub fn mem_usage(&self) -> usize {
         self.vals.capacity() + self.doc_index.capacity() * std::mem::size_of::<u64>()
     }
-    /// Access the field associated with the `BytesFastFieldWriter`
+    /// Access the field associated to the `BytesFastFieldWriter`
     pub fn field(&self) -> Field {
         self.field
     }
@@ -67,7 +67,7 @@ impl BytesFastFieldWriter {
         }
     }
 
-    /// Register the bytes associated with a document.
+    /// Register the bytes associated to a document.
     ///
     /// The method returns the `DocId` of the document that was
     /// just written.

src/fastfield/facet_reader.rs

@@ -7,7 +7,7 @@ use crate::termdict::{TermDictionary, TermOrdinal};
 use crate::DocId;
 
 /// The facet reader makes it possible to access the list of
-/// facets associated with a given document in a specific
+/// facets associated to a given document in a specific
 /// segment.
 ///
 /// Rather than manipulating `Facet` object directly, the API
@@ -58,7 +58,7 @@ impl FacetReader {
         &self.term_dict
     }
 
-    /// Given a term ordinal returns the term associated with it.
+    /// Given a term ordinal returns the term associated to it.
     pub fn facet_from_ord(
         &mut self,
         facet_ord: TermOrdinal,
@@ -74,7 +74,7 @@ impl FacetReader {
         Ok(())
     }
 
-    /// Return the list of facet ordinals associated with a document.
+    /// Return the list of facet ordinals associated to a document.
     pub fn facet_ords(&self, doc: DocId, output: &mut Vec<u64>) {
         self.term_ords.get_vals(doc, output);
     }

src/fastfield/mod.rs

@@ -41,15 +41,14 @@ mod error;
 mod facet_reader;
 mod multivalued;
 mod readers;
+mod remapped_column;
 mod serializer;
 mod writer;
 
 /// Trait for `BytesFastFieldReader` and `MultiValuedFastFieldReader` to return the length of data
 /// for a doc_id
 pub trait MultiValueLength {
-    /// returns the positions for a docid
-    fn get_range(&self, doc_id: DocId) -> std::ops::Range<u64>;
-    /// returns the num of values associated with a doc_id
+    /// returns the num of values associated to a doc_id
     fn get_len(&self, doc_id: DocId) -> u64;
     /// returns the sum of num values for all doc_ids
     fn get_total_len(&self) -> u64;
@@ -426,7 +425,7 @@ mod tests {
         permutation
     }
 
-    fn test_intfastfield_permutation_with_data(permutation: Vec<u64>) -> crate::Result<()> {
+    fn test_intfastfield_permutation_with_data(permutation: &[u64]) -> crate::Result<()> {
         let path = Path::new("test");
         let n = permutation.len();
         let directory = RamDirectory::create();
@@ -434,7 +433,7 @@ mod tests {
             let write: WritePtr = directory.open_write(Path::new("test"))?;
             let mut serializer = CompositeFastFieldSerializer::from_write(write)?;
             let mut fast_field_writers = FastFieldsWriter::from_schema(&SCHEMA);
-            for &x in &permutation {
+            for &x in permutation {
                 fast_field_writers.add_document(&doc!(*FIELD=>x));
             }
             fast_field_writers.serialize(&mut serializer, &HashMap::new(), None)?;
@@ -448,7 +447,6 @@ mod tests {
                 .unwrap()
                 .read_bytes()?;
             let fast_field_reader = open::<u64>(data)?;
-
             for a in 0..n {
                 assert_eq!(fast_field_reader.get_val(a as u64), permutation[a as usize]);
             }
@@ -457,16 +455,23 @@ mod tests {
     }
 
     #[test]
-    fn test_intfastfield_permutation_gcd() -> crate::Result<()> {
-        let permutation = generate_permutation_gcd();
-        test_intfastfield_permutation_with_data(permutation)?;
+    fn test_intfastfield_simple() -> crate::Result<()> {
+        let permutation = &[1, 2, 3];
+        test_intfastfield_permutation_with_data(&permutation[..])?;
         Ok(())
     }
 
     #[test]
     fn test_intfastfield_permutation() -> crate::Result<()> {
         let permutation = generate_permutation();
-        test_intfastfield_permutation_with_data(permutation)?;
+        test_intfastfield_permutation_with_data(&permutation)?;
+        Ok(())
+    }
+
+    #[test]
+    fn test_intfastfield_permutation_gcd() -> crate::Result<()> {
+        let permutation = generate_permutation_gcd();
+        test_intfastfield_permutation_with_data(&permutation)?;
         Ok(())
     }
 

src/fastfield/multivalued/mod.rs

@@ -1,9 +1,10 @@
+mod multivalue_start_index;
 mod reader;
 mod writer;
 
+pub(crate) use self::multivalue_start_index::MultivalueStartIndex;
 pub use self::reader::MultiValuedFastFieldReader;
 pub use self::writer::MultiValuedFastFieldWriter;
-pub(crate) use self::writer::MultivalueStartIndex;
 
 #[cfg(test)]
 mod tests {
@@ -402,74 +403,6 @@ mod bench {
     use crate::schema::{Cardinality, NumericOptions, Schema};
     use crate::Document;
 
-    fn bench_multi_value_ff_merge_opt(
-        num_docs: usize,
-        segments_every_n_docs: usize,
-        merge_policy: impl crate::indexer::MergePolicy + 'static,
-    ) {
-        let mut builder = crate::schema::SchemaBuilder::new();
-
-        let fast_multi =
-            crate::schema::NumericOptions::default().set_fast(Cardinality::MultiValues);
-        let multi_field = builder.add_f64_field("f64s", fast_multi);
-
-        let index = crate::Index::create_in_ram(builder.build());
-
-        let mut writer = index.writer_for_tests().unwrap();
-        writer.set_merge_policy(Box::new(merge_policy));
-
-        for i in 0..num_docs {
-            let mut doc = crate::Document::new();
-            doc.add_f64(multi_field, 0.24);
-            doc.add_f64(multi_field, 0.27);
-            doc.add_f64(multi_field, 0.37);
-            if i % 3 == 0 {
-                doc.add_f64(multi_field, 0.44);
-            }
-
-            writer.add_document(doc).unwrap();
-            if i % segments_every_n_docs == 0 {
-                writer.commit().unwrap();
-            }
-        }
-
-        {
-            writer.wait_merging_threads().unwrap();
-            let mut writer = index.writer_for_tests().unwrap();
-            let segment_ids = index.searchable_segment_ids().unwrap();
-            writer.merge(&segment_ids).wait().unwrap();
-        }
-
-        // If a merging thread fails, we should end up with more
-        // than one segment here
-        assert_eq!(1, index.searchable_segments().unwrap().len());
-    }
-
-    #[bench]
-    fn bench_multi_value_ff_merge_many_segments(b: &mut Bencher) {
-        let num_docs = 100_000;
-        b.iter(|| {
-            bench_multi_value_ff_merge_opt(num_docs, 1_000, crate::indexer::NoMergePolicy);
-        });
-    }
-
-    #[bench]
-    fn bench_multi_value_ff_merge_many_segments_log_merge(b: &mut Bencher) {
-        let num_docs = 100_000;
-        b.iter(|| {
-            let merge_policy = crate::indexer::LogMergePolicy::default();
-            bench_multi_value_ff_merge_opt(num_docs, 1_000, merge_policy);
-        });
-    }
-
-    #[bench]
-    fn bench_multi_value_ff_merge_few_segments(b: &mut Bencher) {
-        let num_docs = 100_000;
-        b.iter(|| {
-            bench_multi_value_ff_merge_opt(num_docs, 33_000, crate::indexer::NoMergePolicy);
-        });
-    }
-
     fn multi_values(num_docs: usize, vals_per_doc: usize) -> Vec<Vec<u64>> {
         let mut vals = vec![];
         for _i in 0..num_docs {

src/fastfield/multivalued/multivalue_start_index.rs

@@ -0,0 +1,195 @@
+use fastfield_codecs::{Column, ColumnReader};
+
+use crate::indexer::doc_id_mapping::DocIdMapping;
+use crate::DocId;
+
+pub(crate) struct MultivalueStartIndex<'a, C: Column> {
+    column: &'a C,
+    doc_id_map: &'a DocIdMapping,
+    min_value: u64,
+    max_value: u64,
+}
+
+struct MultivalueStartIndexReader<'a, C: Column> {
+    column: &'a C,
+    doc_id_map: &'a DocIdMapping,
+    idx: u64,
+    val: u64,
+    len: u64,
+}
+
+impl<'a, C: Column> MultivalueStartIndexReader<'a, C> {
+    fn new(column: &'a C, doc_id_map: &'a DocIdMapping) -> Self {
+        Self {
+            column,
+            doc_id_map,
+            idx: u64::MAX,
+            val: 0,
+            len: doc_id_map.num_new_doc_ids() as u64 + 1,
+        }
+    }
+
+    fn reset(&mut self) {
+        self.idx = u64::MAX;
+        self.val = 0;
+    }
+}
+
+impl<'a, C: Column> ColumnReader for MultivalueStartIndexReader<'a, C> {
+    fn seek(&mut self, idx: u64) -> u64 {
+        if self.idx > idx {
+            self.reset();
+            self.advance();
+        }
+        for _ in self.idx..idx {
+            self.advance();
+        }
+        self.get()
+    }
+
+    fn advance(&mut self) -> bool {
+        if self.idx == u64::MAX {
+            self.idx = 0;
+            self.val = 0;
+            return true;
+        }
+        let new_doc_id: DocId = self.idx as DocId;
+        self.idx += 1;
+        if self.idx >= self.len {
+            self.idx = self.len;
+            return false;
+        }
+        let old_doc: DocId = self.doc_id_map.get_old_doc_id(new_doc_id);
+        let num_vals_for_doc =
+            self.column.get_val(old_doc as u64 + 1) - self.column.get_val(old_doc as u64);
+        self.val += num_vals_for_doc;
+        true
+    }
+
+    fn get(&self) -> u64 {
+        self.val
+    }
+}
+
+impl<'a, C: Column> MultivalueStartIndex<'a, C> {
+    pub fn new(column: &'a C, doc_id_map: &'a DocIdMapping) -> Self {
+        assert_eq!(column.num_vals(), doc_id_map.num_old_doc_ids() as u64 + 1);
+        let iter = MultivalueStartIndexIter::new(column, doc_id_map);
+        let (min_value, max_value) = tantivy_bitpacker::minmax(iter).unwrap_or((0, 0));
+        MultivalueStartIndex {
+            column,
+            doc_id_map,
+            min_value,
+            max_value,
+        }
+    }
+
+    fn specialized_reader(&self) -> MultivalueStartIndexReader<'a, C> {
+        MultivalueStartIndexReader::new(self.column, self.doc_id_map)
+    }
+}
+impl<'a, C: Column> Column for MultivalueStartIndex<'a, C> {
+    fn reader(&self) -> Box<dyn ColumnReader + '_> {
+        Box::new(self.specialized_reader())
+    }
+
+    fn get_val(&self, idx: u64) -> u64 {
+        let mut reader = self.specialized_reader();
+        reader.seek(idx)
+    }
+
+    fn min_value(&self) -> u64 {
+        self.min_value
+    }
+
+    fn max_value(&self) -> u64 {
+        self.max_value
+    }
+
+    fn num_vals(&self) -> u64 {
+        (self.doc_id_map.num_new_doc_ids() + 1) as u64
+    }
+}
+
+struct MultivalueStartIndexIter<'a, C: Column> {
+    column: &'a C,
+    doc_id_map: &'a DocIdMapping,
+    new_doc_id: usize,
+    offset: u64,
+}
+
+impl<'a, C: Column> MultivalueStartIndexIter<'a, C> {
+    fn new(column: &'a C, doc_id_map: &'a DocIdMapping) -> Self {
+        Self {
+            column,
+            doc_id_map,
+            new_doc_id: 0,
+            offset: 0,
+        }
+    }
+}
+
+impl<'a, C: Column> Iterator for MultivalueStartIndexIter<'a, C> {
+    type Item = u64;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        if self.new_doc_id > self.doc_id_map.num_new_doc_ids() {
+            return None;
+        }
+        let new_doc_id = self.new_doc_id;
+        self.new_doc_id += 1;
+        let start_offset = self.offset;
+        if new_doc_id < self.doc_id_map.num_new_doc_ids() {
+            let old_doc = self.doc_id_map.get_old_doc_id(new_doc_id as u32) as u64;
+            let num_vals_for_doc = self.column.get_val(old_doc + 1) - self.column.get_val(old_doc);
+            self.offset += num_vals_for_doc;
+        }
+        Some(start_offset)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use fastfield_codecs::VecColumn;
+
+    use super::*;
+
+    #[test]
+    fn test_multivalue_start_index() {
+        let doc_id_mapping = DocIdMapping::from_new_id_to_old_id(vec![4, 1, 2]);
+        assert_eq!(doc_id_mapping.num_old_doc_ids(), 5);
+        let col = VecColumn::from(&[0u64, 3, 5, 10, 12, 16][..]);
+        let multivalue_start_index = MultivalueStartIndex::new(
+            &col, // 3, 2, 5, 2, 4
+            &doc_id_mapping,
+        );
+        assert_eq!(multivalue_start_index.num_vals(), 4);
+        assert_eq!(
+            fastfield_codecs::iter_from_reader(multivalue_start_index.reader())
+                .collect::<Vec<u64>>(),
+            vec![0, 4, 6, 11]
+        ); // 4, 2, 5
+    }
+
+    #[test]
+    fn test_multivalue_get_vals() {
+        let doc_id_mapping =
+            DocIdMapping::from_new_id_to_old_id(vec![0, 1, 2, 3, 4, 5, 6, 7, 8, 9]);
+        assert_eq!(doc_id_mapping.num_old_doc_ids(), 10);
+        let col = VecColumn::from(&[0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55][..]);
+        let multivalue_start_index = MultivalueStartIndex::new(&col, &doc_id_mapping);
+        assert_eq!(
+            fastfield_codecs::iter_from_reader(multivalue_start_index.reader())
+                .collect::<Vec<u64>>(),
+            vec![0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55]
+        );
+        assert_eq!(multivalue_start_index.num_vals(), 11);
+        let mut multivalue_start_index_reader = multivalue_start_index.reader();
+        assert_eq!(multivalue_start_index_reader.seek(3), 2);
+        assert_eq!(multivalue_start_index_reader.seek(5), 5);
+        assert_eq!(multivalue_start_index_reader.seek(8), 21);
+        assert_eq!(multivalue_start_index_reader.seek(4), 3);
+        assert_eq!(multivalue_start_index_reader.seek(0), 0);
+        assert_eq!(multivalue_start_index_reader.seek(10), 55);
+    }
+}

src/fastfield/multivalued/reader.rs

@@ -30,8 +30,8 @@ impl<Item: FastValue> MultiValuedFastFieldReader<Item> {
         }
     }
 
-    /// Returns `[start, end)`, such that the values associated with
-    /// the given document are `start..end`.
+    /// Returns `[start, end)`, such that the values associated
+    /// to the given document are `start..end`.
     #[inline]
     fn range(&self, doc: DocId) -> Range<u64> {
         let idx = doc as u64;
@@ -40,7 +40,7 @@ impl<Item: FastValue> MultiValuedFastFieldReader<Item> {
         start..end
     }
 
-    /// Returns the array of values associated with the given `doc`.
+    /// Returns the array of values associated to the given `doc`.
     #[inline]
     fn get_vals_for_range(&self, range: Range<u64>, vals: &mut Vec<Item>) {
         let len = (range.end - range.start) as usize;
@@ -48,7 +48,7 @@ impl<Item: FastValue> MultiValuedFastFieldReader<Item> {
         self.vals_reader.get_range(range.start, &mut vals[..]);
     }
 
-    /// Returns the array of values associated with the given `doc`.
+    /// Returns the array of values associated to the given `doc`.
     #[inline]
     pub fn get_vals(&self, doc: DocId, vals: &mut Vec<Item>) {
         let range = self.range(doc);
@@ -88,9 +88,6 @@ impl<Item: FastValue> MultiValuedFastFieldReader<Item> {
 }
 
 impl<Item: FastValue> MultiValueLength for MultiValuedFastFieldReader<Item> {
-    fn get_range(&self, doc_id: DocId) -> Range<u64> {
-        self.range(doc_id)
-    }
     fn get_len(&self, doc_id: DocId) -> u64 {
         self.num_vals(doc_id) as u64
     }

src/fastfield/multivalued/writer.rs

@@ -1,9 +1,11 @@
 use std::io;
 
-use fastfield_codecs::{Column, MonotonicallyMappableToU64, VecColumn};
+use fastfield_codecs::{MonotonicallyMappableToU64, VecColumn};
 use fnv::FnvHashMap;
 
-use crate::fastfield::{value_to_u64, CompositeFastFieldSerializer, FastFieldType};
+use crate::fastfield::{
+    value_to_u64, CompositeFastFieldSerializer, FastFieldType, MultivalueStartIndex,
+};
 use crate::indexer::doc_id_mapping::DocIdMapping;
 use crate::postings::UnorderedTermId;
 use crate::schema::{Document, Field, Value};
@@ -61,7 +63,7 @@ impl MultiValuedFastFieldWriter {
             + self.doc_index.capacity() * std::mem::size_of::<u64>()
     }
 
-    /// Access the field associated with the `MultiValuedFastFieldWriter`
+    /// Access the field associated to the `MultiValuedFastFieldWriter`
     pub fn field(&self) -> Field {
         self.field
     }
@@ -199,100 +201,3 @@ impl MultiValuedFastFieldWriter {
         Ok(())
     }
 }
-
-pub(crate) struct MultivalueStartIndex<'a, C: Column> {
-    column: &'a C,
-    doc_id_map: &'a DocIdMapping,
-    min: u64,
-    max: u64,
-}
-
-impl<'a, C: Column> MultivalueStartIndex<'a, C> {
-    pub fn new(column: &'a C, doc_id_map: &'a DocIdMapping) -> Self {
-        assert_eq!(column.num_vals(), doc_id_map.num_old_doc_ids() as u64 + 1);
-        let (min, max) =
-            tantivy_bitpacker::minmax(iter_remapped_multivalue_index(doc_id_map, column))
-                .unwrap_or((0u64, 0u64));
-        MultivalueStartIndex {
-            column,
-            doc_id_map,
-            min,
-            max,
-        }
-    }
-}
-impl<'a, C: Column> Column for MultivalueStartIndex<'a, C> {
-    fn get_val(&self, _idx: u64) -> u64 {
-        unimplemented!()
-    }
-
-    fn min_value(&self) -> u64 {
-        self.min
-    }
-
-    fn max_value(&self) -> u64 {
-        self.max
-    }
-
-    fn num_vals(&self) -> u64 {
-        (self.doc_id_map.num_new_doc_ids() + 1) as u64
-    }
-
-    fn iter(&self) -> Box<dyn Iterator<Item = u64> + '_> {
-        Box::new(iter_remapped_multivalue_index(
-            self.doc_id_map,
-            &self.column,
-        ))
-    }
-}
-
-fn iter_remapped_multivalue_index<'a, C: Column>(
-    doc_id_map: &'a DocIdMapping,
-    column: &'a C,
-) -> impl Iterator<Item = u64> + 'a {
-    let mut offset = 0;
-    let offsets = doc_id_map
-        .iter_old_doc_ids()
-        .map(move |old_doc| {
-            let num_vals_for_doc =
-                column.get_val(old_doc as u64 + 1) - column.get_val(old_doc as u64);
-            offset += num_vals_for_doc;
-            offset
-        });
-    std::iter::once(0u64).chain(offsets)
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn test_multivalue_start_index() {
-        let doc_id_mapping = DocIdMapping::from_new_id_to_old_id(vec![4, 1, 2]);
-        assert_eq!(doc_id_mapping.num_old_doc_ids(), 5);
-        let col = VecColumn::from(&[0u64, 3, 5, 10, 12, 16][..]);
-        let multivalue_start_index = MultivalueStartIndex::new(
-            &col, // 3, 2, 5, 2, 4
-            &doc_id_mapping,
-        );
-        assert_eq!(multivalue_start_index.num_vals(), 4);
-        assert_eq!(
-            multivalue_start_index.iter().collect::<Vec<u64>>(),
-            vec![0, 4, 6, 11]
-        ); // 4, 2, 5
-    }
-
-    #[test]
-    fn test_multivalue_get_vals() {
-        let doc_id_mapping =
-            DocIdMapping::from_new_id_to_old_id(vec![0, 1, 2, 3, 4, 5, 6, 7, 8, 9]);
-        assert_eq!(doc_id_mapping.num_old_doc_ids(), 10);
-        let col = VecColumn::from(&[0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55][..]);
-        let multivalue_start_index = MultivalueStartIndex::new(&col, &doc_id_mapping);
-        assert_eq!(
-            multivalue_start_index.iter().collect::<Vec<u64>>(),
-            vec![0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55]
-        );
-        assert_eq!(multivalue_start_index.num_vals(), 11);
-    }
-}

src/fastfield/readers.rs

@@ -135,7 +135,7 @@ impl FastFieldReaders {
         Ok(MultiValuedFastFieldReader::open(idx_reader, vals_reader))
     }
 
-    /// Returns the `u64` fast field reader reader associated with `field`.
+    /// Returns the `u64` fast field reader reader associated to `field`.
     ///
     /// If `field` is not a u64 fast field, this method returns an Error.
     pub fn u64(&self, field: Field) -> crate::Result<Arc<dyn Column<u64>>> {
@@ -143,16 +143,16 @@ impl FastFieldReaders {
         self.typed_fast_field_reader(field)
     }
 
-    /// Returns the `u64` fast field reader reader associated with `field`, regardless of whether
-    /// the given field is effectively of type `u64` or not.
+    /// Returns the `u64` fast field reader reader associated to `field`, regardless of whether the
+    /// given field is effectively of type `u64` or not.
     ///
-    /// If not, the fastfield reader will returns the u64-value associated with the original
+    /// If not, the fastfield reader will returns the u64-value associated to the original
     /// FastValue.
     pub fn u64_lenient(&self, field: Field) -> crate::Result<Arc<dyn Column<u64>>> {
         self.typed_fast_field_reader(field)
     }
 
-    /// Returns the `i64` fast field reader reader associated with `field`.
+    /// Returns the `i64` fast field reader reader associated to `field`.
     ///
     /// If `field` is not a i64 fast field, this method returns an Error.
     pub fn i64(&self, field: Field) -> crate::Result<Arc<dyn Column<i64>>> {
@@ -160,7 +160,7 @@ impl FastFieldReaders {
         self.typed_fast_field_reader(field)
     }
 
-    /// Returns the `date` fast field reader reader associated with `field`.
+    /// Returns the `date` fast field reader reader associated to `field`.
     ///
     /// If `field` is not a date fast field, this method returns an Error.
     pub fn date(&self, field: Field) -> crate::Result<Arc<dyn Column<DateTime>>> {
@@ -168,7 +168,7 @@ impl FastFieldReaders {
         self.typed_fast_field_reader(field)
     }
 
-    /// Returns the `f64` fast field reader reader associated with `field`.
+    /// Returns the `f64` fast field reader reader associated to `field`.
     ///
     /// If `field` is not a f64 fast field, this method returns an Error.
     pub fn f64(&self, field: Field) -> crate::Result<Arc<dyn Column<f64>>> {
@@ -176,7 +176,7 @@ impl FastFieldReaders {
         self.typed_fast_field_reader(field)
     }
 
-    /// Returns the `bool` fast field reader reader associated with `field`.
+    /// Returns the `bool` fast field reader reader associated to `field`.
     ///
     /// If `field` is not a bool fast field, this method returns an Error.
     pub fn bool(&self, field: Field) -> crate::Result<Arc<dyn Column<bool>>> {
@@ -184,7 +184,7 @@ impl FastFieldReaders {
         self.typed_fast_field_reader(field)
     }
 
-    /// Returns a `u64s` multi-valued fast field reader reader associated with `field`.
+    /// Returns a `u64s` multi-valued fast field reader reader associated to `field`.
     ///
     /// If `field` is not a u64 multi-valued fast field, this method returns an Error.
     pub fn u64s(&self, field: Field) -> crate::Result<MultiValuedFastFieldReader<u64>> {
@@ -192,15 +192,15 @@ impl FastFieldReaders {
         self.typed_fast_field_multi_reader(field)
     }
 
-    /// Returns a `u64s` multi-valued fast field reader reader associated with `field`, regardless
-    /// of whether the given field is effectively of type `u64` or not.
+    /// Returns a `u64s` multi-valued fast field reader reader associated to `field`, regardless of
+    /// whether the given field is effectively of type `u64` or not.
     ///
     /// If `field` is not a u64 multi-valued fast field, this method returns an Error.
     pub fn u64s_lenient(&self, field: Field) -> crate::Result<MultiValuedFastFieldReader<u64>> {
         self.typed_fast_field_multi_reader(field)
     }
 
-    /// Returns a `i64s` multi-valued fast field reader reader associated with `field`.
+    /// Returns a `i64s` multi-valued fast field reader reader associated to `field`.
     ///
     /// If `field` is not a i64 multi-valued fast field, this method returns an Error.
     pub fn i64s(&self, field: Field) -> crate::Result<MultiValuedFastFieldReader<i64>> {
@@ -208,7 +208,7 @@ impl FastFieldReaders {
         self.typed_fast_field_multi_reader(field)
     }
 
-    /// Returns a `f64s` multi-valued fast field reader reader associated with `field`.
+    /// Returns a `f64s` multi-valued fast field reader reader associated to `field`.
     ///
     /// If `field` is not a f64 multi-valued fast field, this method returns an Error.
     pub fn f64s(&self, field: Field) -> crate::Result<MultiValuedFastFieldReader<f64>> {
@@ -216,7 +216,7 @@ impl FastFieldReaders {
         self.typed_fast_field_multi_reader(field)
     }
 
-    /// Returns a `bools` multi-valued fast field reader reader associated with `field`.
+    /// Returns a `bools` multi-valued fast field reader reader associated to `field`.
     ///
     /// If `field` is not a bool multi-valued fast field, this method returns an Error.
     pub fn bools(&self, field: Field) -> crate::Result<MultiValuedFastFieldReader<bool>> {
@@ -224,7 +224,7 @@ impl FastFieldReaders {
         self.typed_fast_field_multi_reader(field)
     }
 
-    /// Returns a `time::OffsetDateTime` multi-valued fast field reader reader associated with
+    /// Returns a `time::OffsetDateTime` multi-valued fast field reader reader associated to
     /// `field`.
     ///
     /// If `field` is not a `time::OffsetDateTime` multi-valued fast field, this method returns an
@@ -234,7 +234,7 @@ impl FastFieldReaders {
         self.typed_fast_field_multi_reader(field)
     }
 
-    /// Returns the `bytes` fast field reader associated with `field`.
+    /// Returns the `bytes` fast field reader associated to `field`.
     ///
     /// If `field` is not a bytes fast field, returns an Error.
     pub fn bytes(&self, field: Field) -> crate::Result<BytesFastFieldReader> {

src/fastfield/remapped_column.rs

@@ -0,0 +1,112 @@
+use fastfield_codecs::{Column, ColumnReader};
+use tantivy_bitpacker::BlockedBitpacker;
+
+use crate::indexer::doc_id_mapping::DocIdMapping;
+use crate::DocId;
+
+#[derive(Clone)]
+pub(crate) struct WriterFastFieldColumn<'map, 'bitp> {
+    pub(crate) doc_id_mapping_opt: Option<&'map DocIdMapping>,
+    pub(crate) vals: &'bitp BlockedBitpacker,
+    pub(crate) min_value: u64,
+    pub(crate) max_value: u64,
+    pub(crate) num_vals: u64,
+}
+
+impl<'map, 'bitp> Column for WriterFastFieldColumn<'map, 'bitp> {
+    /// Return the value associated to the given doc.
+    ///
+    /// Whenever possible use the Iterator passed to the fastfield creation instead, for performance
+    /// reasons.
+    ///
+    /// # Panics
+    ///
+    /// May panic if `doc` is greater than the index.
+    fn get_val(&self, doc: u64) -> u64 {
+        if let Some(doc_id_map) = self.doc_id_mapping_opt {
+            self.vals
+                .get(doc_id_map.get_old_doc_id(doc as u32) as usize) // consider extra
+                                                                     // FastFieldReader wrapper for
+                                                                     // non doc_id_map
+        } else {
+            self.vals.get(doc as usize)
+        }
+    }
+
+    fn reader(&self) -> Box<dyn ColumnReader + '_> {
+        if let Some(doc_id_mapping) = self.doc_id_mapping_opt {
+            Box::new(RemappedColumnReader {
+                doc_id_mapping,
+                vals: self.vals,
+                idx: u64::MAX,
+                len: doc_id_mapping.num_new_doc_ids() as u64,
+            })
+        } else {
+            Box::new(BitpackedColumnReader {
+                vals: self.vals,
+                idx: u64::MAX,
+                len: self.num_vals,
+            })
+        }
+    }
+
+    fn min_value(&self) -> u64 {
+        self.min_value
+    }
+
+    fn max_value(&self) -> u64 {
+        self.max_value
+    }
+
+    fn num_vals(&self) -> u64 {
+        self.num_vals
+    }
+}
+
+struct RemappedColumnReader<'a> {
+    doc_id_mapping: &'a DocIdMapping,
+    vals: &'a BlockedBitpacker,
+    idx: u64,
+    len: u64,
+}
+
+impl<'a> ColumnReader for RemappedColumnReader<'a> {
+    fn seek(&mut self, target_idx: u64) -> u64 {
+        assert!(target_idx < self.len);
+        self.idx = target_idx;
+        self.get()
+    }
+
+    fn advance(&mut self) -> bool {
+        self.idx = self.idx.wrapping_add(1);
+        self.idx < self.len
+    }
+
+    fn get(&self) -> u64 {
+        let old_doc_id: DocId = self.doc_id_mapping.get_old_doc_id(self.idx as DocId);
+        self.vals.get(old_doc_id as usize)
+    }
+}
+
+struct BitpackedColumnReader<'a> {
+    vals: &'a BlockedBitpacker,
+    idx: u64,
+    len: u64,
+}
+
+impl<'a> ColumnReader for BitpackedColumnReader<'a> {
+    fn seek(&mut self, target_idx: u64) -> u64 {
+        assert!(target_idx < self.len);
+        self.idx = target_idx;
+        self.get()
+    }
+
+    fn advance(&mut self) -> bool {
+        self.idx = self.idx.wrapping_add(1);
+        self.idx < self.len
+    }
+
+    fn get(&self) -> u64 {
+        self.vals.get(self.idx as usize)
+    }
+}

src/fastfield/writer.rs

@@ -2,12 +2,13 @@ use std::collections::HashMap;
 use std::io;
 
 use common;
-use fastfield_codecs::{Column, MonotonicallyMappableToU64};
+use fastfield_codecs::MonotonicallyMappableToU64;
 use fnv::FnvHashMap;
 use tantivy_bitpacker::BlockedBitpacker;
 
 use super::multivalued::MultiValuedFastFieldWriter;
 use super::FastFieldType;
+use crate::fastfield::remapped_column::WriterFastFieldColumn;
 use crate::fastfield::{BytesFastFieldWriter, CompositeFastFieldSerializer};
 use crate::indexer::doc_id_mapping::DocIdMapping;
 use crate::postings::UnorderedTermId;
@@ -131,7 +132,7 @@ impl FastFieldsWriter {
                 .sum::<usize>()
     }
 
-    /// Get the `FastFieldWriter` associated with a field.
+    /// Get the `FastFieldWriter` associated to a field.
     pub fn get_term_id_writer(&self, field: Field) -> Option<&MultiValuedFastFieldWriter> {
         // TODO optimize
         self.term_id_writers
@@ -139,7 +140,7 @@ impl FastFieldsWriter {
             .find(|field_writer| field_writer.field() == field)
     }
 
-    /// Get the `FastFieldWriter` associated with a field.
+    /// Get the `FastFieldWriter` associated to a field.
     pub fn get_field_writer(&self, field: Field) -> Option<&IntFastFieldWriter> {
         // TODO optimize
         self.single_value_writers
@@ -147,7 +148,7 @@ impl FastFieldsWriter {
             .find(|field_writer| field_writer.field() == field)
     }
 
-    /// Get the `FastFieldWriter` associated with a field.
+    /// Get the `FastFieldWriter` associated to a field.
     pub fn get_field_writer_mut(&mut self, field: Field) -> Option<&mut IntFastFieldWriter> {
         // TODO optimize
         self.single_value_writers
@@ -155,7 +156,7 @@ impl FastFieldsWriter {
             .find(|field_writer| field_writer.field() == field)
     }
 
-    /// Get the `FastFieldWriter` associated with a field.
+    /// Get the `FastFieldWriter` associated to a field.
     pub fn get_term_id_writer_mut(
         &mut self,
         field: Field,
@@ -294,7 +295,7 @@ impl IntFastFieldWriter {
     /// Records a new value.
     ///
     /// The n-th value being recorded is implicitly
-    /// associated with the document with the `DocId` n.
+    /// associated to the document with the `DocId` n.
     /// (Well, `n-1` actually because of 0-indexing)
     pub fn add_val(&mut self, val: u64) {
         self.vals.add(val);
@@ -313,7 +314,7 @@ impl IntFastFieldWriter {
     /// (or use the default value) and records it.
     ///
     ///
-    /// Extract the value associated with the fast field for
+    /// Extract the value associated to the fast field for
     /// this document.
     ///
     /// i64 and f64 are remapped to u64 using the logic
@@ -351,7 +352,7 @@ impl IntFastFieldWriter {
     pub fn serialize(
         &self,
         serializer: &mut CompositeFastFieldSerializer,
-        doc_id_map: Option<&DocIdMapping>,
+        doc_id_mapping_opt: Option<&DocIdMapping>,
     ) -> io::Result<()> {
         let (min, max) = if self.val_min > self.val_max {
             (0, 0)
@@ -359,8 +360,8 @@ impl IntFastFieldWriter {
             (self.val_min, self.val_max)
         };
 
-        let fastfield_accessor = WriterFastFieldAccessProvider {
-            doc_id_map,
+        let fastfield_accessor = WriterFastFieldColumn {
+            doc_id_mapping_opt,
             vals: &self.vals,
             min_value: min,
             max_value: max,
@@ -372,50 +373,3 @@ impl IntFastFieldWriter {
         Ok(())
     }
 }
-
-#[derive(Clone)]
-struct WriterFastFieldAccessProvider<'map, 'bitp> {
-    doc_id_map: Option<&'map DocIdMapping>,
-    vals: &'bitp BlockedBitpacker,
-    min_value: u64,
-    max_value: u64,
-    num_vals: u64,
-}
-
-impl<'map, 'bitp> Column for WriterFastFieldAccessProvider<'map, 'bitp> {
-    /// Return the value associated with the given doc.
-    ///
-    /// Whenever possible use the Iterator passed to the fastfield creation instead, for performance
-    /// reasons.
-    ///
-    /// # Panics
-    ///
-    /// May panic if `doc` is greater than the index.
-    fn get_val(&self, _doc: u64) -> u64 {
-        unimplemented!()
-    }
-
-    fn iter(&self) -> Box<dyn Iterator<Item = u64> + '_> {
-        if let Some(doc_id_map) = self.doc_id_map {
-            Box::new(
-                doc_id_map
-                    .iter_old_doc_ids()
-                    .map(|doc_id| self.vals.get(doc_id as usize)),
-            )
-        } else {
-            Box::new(self.vals.iter())
-        }
-    }
-
-    fn min_value(&self) -> u64 {
-        self.min_value
-    }
-
-    fn max_value(&self) -> u64 {
-        self.max_value
-    }
-
-    fn num_vals(&self) -> u64 {
-        self.num_vals
-    }
-}

src/fieldnorm/mod.rs

@@ -1,4 +1,4 @@
-//! The fieldnorm represents the length associated with
+//! The fieldnorm represents the length associated to
 //! a given Field of a given document.
 //!
 //! This metric is important to compute the score of a

src/fieldnorm/reader.rs

@@ -47,9 +47,9 @@ impl FieldNormReaders {
     }
 }
 
-/// Reads the fieldnorm associated with a document.
+/// Reads the fieldnorm associated to a document.
 ///
-/// The [fieldnorm](FieldNormReader::fieldnorm) represents the length associated with
+/// The [fieldnorm](FieldNormReader::fieldnorm) represents the length associated to
 /// a given Field of a given document.
 #[derive(Clone)]
 pub struct FieldNormReader(ReaderImplEnum);
@@ -104,7 +104,7 @@ impl FieldNormReader {
         }
     }
 
-    /// Returns the `fieldnorm` associated with a doc id.
+    /// Returns the `fieldnorm` associated to a doc id.
     /// The fieldnorm is a value approximating the number
     /// of tokens in a given field of the `doc_id`.
     ///
@@ -123,7 +123,7 @@ impl FieldNormReader {
         }
     }
 
-    /// Returns the `fieldnorm_id` associated with a document.
+    /// Returns the `fieldnorm_id` associated to a document.
     #[inline]
     pub fn fieldnorm_id(&self, doc_id: DocId) -> u8 {
         match &self.0 {

src/indexer/delete_queue.rs

@@ -188,7 +188,7 @@ impl DeleteCursor {
         }
     }
 
-    #[allow(clippy::wrong_self_convention)]
+    #[cfg_attr(feature = "cargo-clippy", allow(clippy::wrong_self_convention))]
     fn is_behind_opstamp(&mut self, target_opstamp: Opstamp) -> bool {
         self.get()
             .map(|operation| operation.opstamp < target_opstamp)
@@ -246,27 +246,18 @@ impl DeleteCursor {
 mod tests {
 
     use super::{DeleteOperation, DeleteQueue};
-    use crate::query::{Explanation, Scorer, Weight};
-    use crate::{DocId, Score, SegmentReader};
-
-    struct DummyWeight;
-    impl Weight for DummyWeight {
-        fn scorer(&self, _reader: &SegmentReader, _boost: Score) -> crate::Result<Box<dyn Scorer>> {
-            Err(crate::TantivyError::InternalError("dummy impl".to_owned()))
-        }
-
-        fn explain(&self, _reader: &SegmentReader, _doc: DocId) -> crate::Result<Explanation> {
-            Err(crate::TantivyError::InternalError("dummy impl".to_owned()))
-        }
-    }
+    use crate::schema::{Field, Term};
 
     #[test]
     fn test_deletequeue() {
         let delete_queue = DeleteQueue::new();
 
-        let make_op = |i: usize| DeleteOperation {
-            opstamp: i as u64,
-            target: Box::new(DummyWeight),
+        let make_op = |i: usize| {
+            let field = Field::from_field_id(1u32);
+            DeleteOperation {
+                opstamp: i as u64,
+                term: Term::from_field_u64(field, i as u64),
+            }
         };
 
         delete_queue.push(make_op(1));

src/indexer/doc_id_mapping.rs

@@ -24,7 +24,7 @@ impl SegmentDocIdMapping {
 
     /// Returns an iterator over the old document addresses, ordered by the new document ids.
     ///
-    /// In the returned `DocAddress`, the `segment_ord` is the ordinal of targeted segment
+    /// In the returned `DocAddress`, the `segment_ord` is the ordinal of targetted segment
     /// in the list of merged segments.
     pub(crate) fn iter_old_doc_addrs(&self) -> impl Iterator<Item = DocAddress> + '_ {
         self.new_doc_id_to_old_doc_addr.iter().copied()
@@ -34,6 +34,10 @@ impl SegmentDocIdMapping {
         self.new_doc_id_to_old_doc_addr.len()
     }
 
+    pub(crate) fn get_old_doc_addr(&self, new_doc_id: DocId) -> DocAddress {
+        self.new_doc_id_to_old_doc_addr[new_doc_id as usize]
+    }
+
     /// This flags means the segments are simply stacked in the order of their ordinal.
     /// e.g. [(0, 1), .. (n, 1), (0, 2)..., (m, 2)]
     ///

src/indexer/index_writer.rs

@@ -11,6 +11,7 @@ use super::segment_updater::SegmentUpdater;
 use super::{AddBatch, AddBatchReceiver, AddBatchSender, PreparedCommit};
 use crate::core::{Index, Segment, SegmentComponent, SegmentId, SegmentMeta, SegmentReader};
 use crate::directory::{DirectoryLock, GarbageCollectionResult, TerminatingWrite};
+use crate::docset::{DocSet, TERMINATED};
 use crate::error::TantivyError;
 use crate::fastfield::write_alive_bitset;
 use crate::indexer::delete_queue::{DeleteCursor, DeleteQueue};
@@ -19,9 +20,8 @@ use crate::indexer::index_writer_status::IndexWriterStatus;
 use crate::indexer::operation::DeleteOperation;
 use crate::indexer::stamper::Stamper;
 use crate::indexer::{MergePolicy, SegmentEntry, SegmentWriter};
-use crate::query::{Query, TermQuery};
 use crate::schema::{Document, IndexRecordOption, Term};
-use crate::{FutureResult, IndexReader, Opstamp};
+use crate::{FutureResult, Opstamp};
 
 // Size of the margin for the `memory_arena`. A segment is closed when the remaining memory
 // in the `memory_arena` goes below MARGIN_IN_BYTES.
@@ -57,7 +57,6 @@ pub struct IndexWriter {
     _directory_lock: Option<DirectoryLock>,
 
     index: Index,
-    index_reader: IndexReader,
 
     memory_arena_in_bytes_per_thread: usize,
 
@@ -93,14 +92,19 @@ fn compute_deleted_bitset(
 
         // A delete operation should only affect
         // document that were inserted before it.
-        delete_op
-            .target
-            .for_each(segment_reader, &mut |doc_matching_delete_query, _| {
-                if doc_opstamps.is_deleted(doc_matching_delete_query, delete_op.opstamp) {
-                    alive_bitset.remove(doc_matching_delete_query);
+        let inverted_index = segment_reader.inverted_index(delete_op.term.field())?;
+        if let Some(mut docset) =
+            inverted_index.read_postings(&delete_op.term, IndexRecordOption::Basic)?
+        {
+            let mut doc_matching_deleted_term = docset.doc();
+            while doc_matching_deleted_term != TERMINATED {
+                if doc_opstamps.is_deleted(doc_matching_deleted_term, delete_op.opstamp) {
+                    alive_bitset.remove(doc_matching_deleted_term);
                     might_have_changed = true;
                 }
-            })?;
+                doc_matching_deleted_term = docset.advance();
+            }
+        }
         delete_cursor.advance();
     }
     Ok(might_have_changed)
@@ -298,7 +302,6 @@ impl IndexWriter {
 
             memory_arena_in_bytes_per_thread,
             index: index.clone(),
-            index_reader: index.reader()?,
 
             index_writer_status: IndexWriterStatus::from(document_receiver),
             operation_sender: document_sender,
@@ -370,9 +373,9 @@ impl IndexWriter {
     /// This method is useful only for users trying to do complex
     /// operations, like converting an index format to another.
     ///
-    /// It is safe to start writing file associated with the new `Segment`.
+    /// It is safe to start writing file associated to the new `Segment`.
     /// These will not be garbage collected as long as an instance object of
-    /// `SegmentMeta` object associated with the new `Segment` is "alive".
+    /// `SegmentMeta` object associated to the new `Segment` is "alive".
     pub fn new_segment(&self) -> Segment {
         self.index.new_segment()
     }
@@ -663,33 +666,10 @@ impl IndexWriter {
     /// Like adds, the deletion itself will be visible
     /// only after calling `commit()`.
     pub fn delete_term(&self, term: Term) -> Opstamp {
-        let query = TermQuery::new(term, IndexRecordOption::Basic);
-        // For backward compatibility, if Term is invalid for the index, do nothing but return an
-        // Opstamp
-        self.delete_query(Box::new(query))
-            .unwrap_or_else(|_| self.stamper.stamp())
-    }
-
-    /// Delete all documents matching a given query.
-    /// Returns an `Err` if the query can't be executed.
-    ///
-    /// Delete operation only affects documents that
-    /// were added in previous commits, and documents
-    /// that were added previously in the same commit.
-    ///
-    /// Like adds, the deletion itself will be visible
-    /// only after calling `commit()`.
-    #[doc(hidden)]
-    pub fn delete_query(&self, query: Box<dyn Query>) -> crate::Result<Opstamp> {
-        let weight = query.weight(&self.index_reader.searcher(), false)?;
-
         let opstamp = self.stamper.stamp();
-        let delete_operation = DeleteOperation {
-            opstamp,
-            target: weight,
-        };
+        let delete_operation = DeleteOperation { opstamp, term };
         self.delete_queue.push(delete_operation);
-        Ok(opstamp)
+        opstamp
     }
 
     /// Returns the opstamp of the last successful commit.
@@ -758,17 +738,10 @@ impl IndexWriter {
         let (batch_opstamp, stamps) = self.get_batch_opstamps(count);
 
         let mut adds = AddBatch::default();
-
         for (user_op, opstamp) in user_operations_it.zip(stamps) {
             match user_op {
                 UserOperation::Delete(term) => {
-                    let query = TermQuery::new(term, IndexRecordOption::Basic);
-                    let weight = query.weight(&self.index_reader.searcher(), false)?;
-
-                    let delete_operation = DeleteOperation {
-                        opstamp,
-                        target: weight,
-                    };
+                    let delete_operation = DeleteOperation { opstamp, term };
                     self.delete_queue.push(delete_operation);
                 }
                 UserOperation::Add(document) => {
@@ -813,7 +786,7 @@ mod tests {
     use crate::directory::error::LockError;
     use crate::error::*;
     use crate::indexer::NoMergePolicy;
-    use crate::query::{BooleanQuery, Occur, Query, QueryParser, TermQuery};
+    use crate::query::{QueryParser, TermQuery};
     use crate::schema::{
         self, Cardinality, Facet, FacetOptions, IndexRecordOption, NumericOptions,
         TextFieldIndexing, TextOptions, FAST, INDEXED, STORED, STRING, TEXT,
@@ -1395,35 +1368,6 @@ mod tests {
         assert!(commit_again.is_ok());
     }
 
-    #[test]
-    fn test_sort_by_multivalue_field_error() -> crate::Result<()> {
-        let mut schema_builder = schema::Schema::builder();
-        let options = NumericOptions::default().set_fast(Cardinality::MultiValues);
-        schema_builder.add_u64_field("id", options);
-        let schema = schema_builder.build();
-
-        let settings = IndexSettings {
-            sort_by_field: Some(IndexSortByField {
-                field: "id".to_string(),
-                order: Order::Desc,
-            }),
-            ..Default::default()
-        };
-
-        let err = Index::builder()
-            .schema(schema)
-            .settings(settings)
-            .create_in_ram()
-            .unwrap_err();
-        assert_eq!(
-            err.to_string(),
-            "An invalid argument was passed: 'Only single value fast field Cardinality supported \
-             for sorting index id'"
-        );
-
-        Ok(())
-    }
-
     #[test]
     fn test_delete_with_sort_by_field() -> crate::Result<()> {
         let mut schema_builder = schema::Schema::builder();
@@ -1474,72 +1418,10 @@ mod tests {
         Ok(())
     }
 
-    #[test]
-    fn test_delete_query_with_sort_by_field() -> crate::Result<()> {
-        let mut schema_builder = schema::Schema::builder();
-        let id_field =
-            schema_builder.add_u64_field("id", schema::INDEXED | schema::STORED | schema::FAST);
-        let schema = schema_builder.build();
-
-        let settings = IndexSettings {
-            sort_by_field: Some(IndexSortByField {
-                field: "id".to_string(),
-                order: Order::Desc,
-            }),
-            ..Default::default()
-        };
-
-        let index = Index::builder()
-            .schema(schema)
-            .settings(settings)
-            .create_in_ram()?;
-        let index_reader = index.reader()?;
-        let mut index_writer = index.writer_for_tests()?;
-
-        // create and delete docs in same commit
-        for id in 0u64..5u64 {
-            index_writer.add_document(doc!(id_field => id))?;
-        }
-        for id in 1u64..4u64 {
-            let term = Term::from_field_u64(id_field, id);
-            let not_term = Term::from_field_u64(id_field, 2);
-            let term = Box::new(TermQuery::new(term, Default::default()));
-            let not_term = Box::new(TermQuery::new(not_term, Default::default()));
-
-            let query: BooleanQuery = vec![
-                (Occur::Must, term as Box<dyn Query>),
-                (Occur::MustNot, not_term as Box<dyn Query>),
-            ]
-            .into();
-
-            index_writer.delete_query(Box::new(query))?;
-        }
-        for id in 5u64..10u64 {
-            index_writer.add_document(doc!(id_field => id))?;
-        }
-        index_writer.commit()?;
-        index_reader.reload()?;
-
-        let searcher = index_reader.searcher();
-        assert_eq!(searcher.segment_readers().len(), 1);
-
-        let segment_reader = searcher.segment_reader(0);
-        assert_eq!(segment_reader.num_docs(), 8);
-        assert_eq!(segment_reader.max_doc(), 10);
-        let fast_field_reader = segment_reader.fast_fields().u64(id_field)?;
-        let in_order_alive_ids: Vec<u64> = segment_reader
-            .doc_ids_alive()
-            .map(|doc| fast_field_reader.get_val(doc as u64))
-            .collect();
-        assert_eq!(&in_order_alive_ids[..], &[9, 8, 7, 6, 5, 4, 2, 0]);
-        Ok(())
-    }
-
     #[derive(Debug, Clone, Copy)]
     enum IndexingOp {
         AddDoc { id: u64 },
         DeleteDoc { id: u64 },
-        DeleteDocQuery { id: u64 },
         Commit,
         Merge,
     }
@@ -1547,7 +1429,6 @@ mod tests {
     fn balanced_operation_strategy() -> impl Strategy<Value = IndexingOp> {
         prop_oneof![
             (0u64..20u64).prop_map(|id| IndexingOp::DeleteDoc { id }),
-            (0u64..20u64).prop_map(|id| IndexingOp::DeleteDocQuery { id }),
             (0u64..20u64).prop_map(|id| IndexingOp::AddDoc { id }),
             (0u64..1u64).prop_map(|_| IndexingOp::Commit),
             (0u64..1u64).prop_map(|_| IndexingOp::Merge),
@@ -1556,8 +1437,7 @@ mod tests {
 
     fn adding_operation_strategy() -> impl Strategy<Value = IndexingOp> {
         prop_oneof![
-            5 => (0u64..100u64).prop_map(|id| IndexingOp::DeleteDoc { id }),
-            5 => (0u64..100u64).prop_map(|id| IndexingOp::DeleteDocQuery { id }),
+            10 => (0u64..100u64).prop_map(|id| IndexingOp::DeleteDoc { id }),
             50 => (0u64..100u64).prop_map(|id| IndexingOp::AddDoc { id }),
             2 => (0u64..1u64).prop_map(|_| IndexingOp::Commit),
             1 => (0u64..1u64).prop_map(|_| IndexingOp::Merge),
@@ -1577,10 +1457,6 @@ mod tests {
                     existing_ids.remove(&id);
                     deleted_ids.insert(id);
                 }
-                IndexingOp::DeleteDocQuery { id } => {
-                    existing_ids.remove(&id);
-                    deleted_ids.insert(id);
-                }
                 _ => {}
             }
         }
@@ -1663,11 +1539,6 @@ mod tests {
                 IndexingOp::DeleteDoc { id } => {
                     index_writer.delete_term(Term::from_field_u64(id_field, id));
                 }
-                IndexingOp::DeleteDocQuery { id } => {
-                    let term = Term::from_field_u64(id_field, id);
-                    let query = TermQuery::new(term, Default::default());
-                    index_writer.delete_query(Box::new(query))?;
-                }
                 IndexingOp::Commit => {
                     index_writer.commit()?;
                 }

src/indexer/merger.rs

@@ -14,8 +14,8 @@ use crate::fastfield::{
 };
 use crate::fieldnorm::{FieldNormReader, FieldNormReaders, FieldNormsSerializer, FieldNormsWriter};
 use crate::indexer::doc_id_mapping::{expect_field_id_for_sort_field, SegmentDocIdMapping};
-use crate::indexer::sorted_doc_id_column::RemappedDocIdColumn;
-use crate::indexer::sorted_doc_id_multivalue_column::RemappedDocIdMultiValueColumn;
+use crate::indexer::sorted_doc_id_column::SortedDocIdColumn;
+use crate::indexer::sorted_doc_id_multivalue_column::SortedDocIdMultiValueColumn;
 use crate::indexer::SegmentSerializer;
 use crate::postings::{InvertedIndexSerializer, Postings, SegmentPostings};
 use crate::schema::{Cardinality, Field, FieldType, Schema};
@@ -310,7 +310,7 @@ impl IndexMerger {
         fast_field_serializer: &mut CompositeFastFieldSerializer,
         doc_id_mapping: &SegmentDocIdMapping,
     ) -> crate::Result<()> {
-        let fast_field_accessor = RemappedDocIdColumn::new(&self.readers, doc_id_mapping, field);
+        let fast_field_accessor = SortedDocIdColumn::new(&self.readers, doc_id_mapping, field);
         fast_field_serializer.create_auto_detect_u64_fast_field(field, fast_field_accessor)?;
 
         Ok(())
@@ -428,8 +428,14 @@ impl IndexMerger {
         fast_field_serializer: &mut CompositeFastFieldSerializer,
         doc_id_mapping: &SegmentDocIdMapping,
         reader_and_field_accessors: &[(&SegmentReader, T)],
-    ) -> crate::Result<()> {
-        // TODO Use `Column` implementation instead
+    ) -> crate::Result<Vec<u64>> {
+        // We can now create our `idx` serializer, and in a second pass,
+        // can effectively push the different indexes.
+
+        // copying into a temp vec is not ideal, but the fast field codec api requires random
+        // access, which is used in the estimation. It's possible to 1. calculate random
+        // access on the fly or 2. change the codec api to make random access optional, but
+        // they both have also major drawbacks.
 
         let mut offsets = Vec::with_capacity(doc_id_mapping.len());
         let mut offset = 0;
@@ -443,7 +449,7 @@ impl IndexMerger {
         let fastfield_accessor = VecColumn::from(&offsets[..]);
 
         fast_field_serializer.create_auto_detect_u64_fast_field(field, fastfield_accessor)?;
-        Ok(())
+        Ok(offsets)
     }
     /// Returns the fastfield index (index for the data, not the data).
     fn write_multi_value_fast_field_idx(
@@ -451,7 +457,7 @@ impl IndexMerger {
         field: Field,
         fast_field_serializer: &mut CompositeFastFieldSerializer,
         doc_id_mapping: &SegmentDocIdMapping,
-    ) -> crate::Result<()> {
+    ) -> crate::Result<Vec<u64>> {
         let reader_ordinal_and_field_accessors = self
             .readers
             .iter()
@@ -555,16 +561,16 @@ impl IndexMerger {
         fast_field_serializer: &mut CompositeFastFieldSerializer,
         doc_id_mapping: &SegmentDocIdMapping,
     ) -> crate::Result<()> {
-        // Multifastfield consists of 2 fastfields.
+        // Multifastfield consists in 2 fastfields.
         // The first serves as an index into the second one and is strictly increasing.
         // The second contains the actual values.
 
         // First we merge the idx fast field.
-
-        self.write_multi_value_fast_field_idx(field, fast_field_serializer, doc_id_mapping)?;
+        let offsets =
+            self.write_multi_value_fast_field_idx(field, fast_field_serializer, doc_id_mapping)?;
 
         let fastfield_accessor =
-            RemappedDocIdMultiValueColumn::new(&self.readers, doc_id_mapping, field);
+            SortedDocIdMultiValueColumn::new(&self.readers, doc_id_mapping, &offsets, field);
         fast_field_serializer.create_auto_detect_u64_fast_field_with_idx(
             field,
             fastfield_accessor,

src/indexer/operation.rs

@@ -1,11 +1,20 @@
-use crate::query::Weight;
 use crate::schema::{Document, Term};
 use crate::Opstamp;
 
 /// Timestamped Delete operation.
+#[derive(Clone, Eq, PartialEq, Debug)]
 pub struct DeleteOperation {
     pub opstamp: Opstamp,
-    pub target: Box<dyn Weight>,
+    pub term: Term,
+}
+
+impl Default for DeleteOperation {
+    fn default() -> Self {
+        DeleteOperation {
+            opstamp: 0u64,
+            term: Term::new(),
+        }
+    }
 }
 
 /// Timestamped Add operation.

src/indexer/prepared_commit.rs

@@ -17,7 +17,7 @@ impl<'a> PreparedCommit<'a> {
         }
     }
 
-    /// Returns the opstamp associated with the prepared commit.
+    /// Returns the opstamp associated to the prepared commit.
     pub fn opstamp(&self) -> Opstamp {
         self.opstamp
     }

src/indexer/segment_serializer.rs

@@ -24,25 +24,12 @@ impl SegmentSerializer {
         // In the merge case this is not necessary because we can kmerge the already sorted
         // segments
         let remapping_required = segment.index().settings().sort_by_field.is_some() && !is_in_merge;
-        let settings = segment.index().settings().clone();
-        let store_writer = if remapping_required {
-            let store_write = segment.open_write(SegmentComponent::TempStore)?;
-            StoreWriter::new(
-                store_write,
-                crate::store::Compressor::None,
-                0, // we want random access on the docs, so we choose a minimal block size. Every
-                // doc will get its own block.
-                settings.docstore_compress_dedicated_thread,
-            )?
+        let store_component = if remapping_required {
+            SegmentComponent::TempStore
         } else {
-            let store_write = segment.open_write(SegmentComponent::Store)?;
-            StoreWriter::new(
-                store_write,
-                settings.docstore_compression,
-                settings.docstore_blocksize,
-                settings.docstore_compress_dedicated_thread,
-            )?
+            SegmentComponent::Store
         };
+        let store_write = segment.open_write(store_component)?;
 
         let fast_field_write = segment.open_write(SegmentComponent::FastFields)?;
         let fast_field_serializer = CompositeFastFieldSerializer::from_write(fast_field_write)?;
@@ -51,6 +38,13 @@ impl SegmentSerializer {
         let fieldnorms_serializer = FieldNormsSerializer::from_write(fieldnorms_write)?;
 
         let postings_serializer = InvertedIndexSerializer::open(&mut segment)?;
+        let settings = segment.index().settings();
+        let store_writer = StoreWriter::new(
+            store_write,
+            settings.docstore_compression,
+            settings.docstore_blocksize,
+            settings.docstore_compress_dedicated_thread,
+        )?;
         Ok(SegmentSerializer {
             segment,
             store_writer,

src/indexer/segment_writer.rs

@@ -1,5 +1,4 @@
 use fastfield_codecs::MonotonicallyMappableToU64;
-use itertools::Itertools;
 
 use super::doc_id_mapping::{get_doc_id_mapping_from_field, DocIdMapping};
 use super::operation::AddOperation;
@@ -158,13 +157,7 @@ impl SegmentWriter {
 
     fn index_document(&mut self, doc: &Document) -> crate::Result<()> {
         let doc_id = self.max_doc;
-        let vals_grouped_by_field = doc
-            .field_values()
-            .iter()
-            .sorted_by_key(|el| el.field())
-            .group_by(|el| el.field());
-        for (field, field_values) in &vals_grouped_by_field {
-            let values = field_values.map(|field_value| field_value.value());
+        for (field, values) in doc.get_sorted_field_values() {
             let field_entry = self.schema.get_field_entry(field);
             let make_schema_error = || {
                 crate::TantivyError::SchemaError(format!(
@@ -205,16 +198,24 @@ impl SegmentWriter {
                 }
                 FieldType::Str(_) => {
                     let mut token_streams: Vec<BoxTokenStream> = vec![];
+                    let mut offsets = vec![];
+                    let mut total_offset = 0;
 
                     for value in values {
                         match value {
                             Value::PreTokStr(tok_str) => {
+                                offsets.push(total_offset);
+                                if let Some(last_token) = tok_str.tokens.last() {
+                                    total_offset += last_token.offset_to;
+                                }
                                 token_streams
                                     .push(PreTokenizedStream::from(tok_str.clone()).into());
                             }
                             Value::Str(ref text) => {
                                 let text_analyzer =
                                     &self.per_field_text_analyzers[field.field_id() as usize];
+                                offsets.push(total_offset);
+                                total_offset += text.len();
                                 token_streams.push(text_analyzer.token_stream(text));
                             }
                             _ => (),
@@ -283,8 +284,9 @@ impl SegmentWriter {
                 }
                 FieldType::JsonObject(_) => {
                     let text_analyzer = &self.per_field_text_analyzers[field.field_id() as usize];
-                    let json_values_it =
-                        values.map(|value| value.as_json().ok_or_else(make_schema_error));
+                    let json_values_it = values
+                        .iter()
+                        .map(|value| value.as_json().ok_or_else(make_schema_error));
                     index_json_values(
                         doc_id,
                         json_values_it,
@@ -372,9 +374,9 @@ fn remap_and_write(
         doc_id_map,
     )?;
 
+    debug!("resort-docstore");
     // finalize temp docstore and create version, which reflects the doc_id_map
     if let Some(doc_id_map) = doc_id_map {
-        debug!("resort-docstore");
         let store_write = serializer
             .segment_mut()
             .open_write(SegmentComponent::Store)?;
@@ -391,8 +393,7 @@ fn remap_and_write(
             serializer
                 .segment()
                 .open_read(SegmentComponent::TempStore)?,
-            1, /* The docstore is configured to have one doc per block, and each doc is accessed
-                * only once: we don't need caching. */
+            50,
         )?;
         for old_doc_id in doc_id_map.iter_old_doc_ids() {
             let doc_bytes = store_read.get_document_bytes(old_doc_id)?;

src/indexer/sorted_doc_id_column.rs

@@ -1,13 +1,13 @@
 use std::sync::Arc;
 
-use fastfield_codecs::Column;
+use fastfield_codecs::{Column, ColumnReader};
 use itertools::Itertools;
 
 use crate::indexer::doc_id_mapping::SegmentDocIdMapping;
 use crate::schema::Field;
-use crate::SegmentReader;
+use crate::{DocAddress, DocId, SegmentReader};
 
-pub(crate) struct RemappedDocIdColumn<'a> {
+pub(crate) struct SortedDocIdColumn<'a> {
     doc_id_mapping: &'a SegmentDocIdMapping,
     fast_field_readers: Vec<Arc<dyn Column<u64>>>,
     min_value: u64,
@@ -37,7 +37,7 @@ fn compute_min_max_val(
         .into_option()
 }
 
-impl<'a> RemappedDocIdColumn<'a> {
+impl<'a> SortedDocIdColumn<'a> {
     pub(crate) fn new(
         readers: &'a [SegmentReader],
         doc_id_mapping: &'a SegmentDocIdMapping,
@@ -68,7 +68,7 @@ impl<'a> RemappedDocIdColumn<'a> {
             })
             .collect::<Vec<_>>();
 
-        RemappedDocIdColumn {
+        SortedDocIdColumn {
             doc_id_mapping,
             fast_field_readers,
             min_value,
@@ -78,22 +78,23 @@ impl<'a> RemappedDocIdColumn<'a> {
     }
 }
 
-impl<'a> Column for RemappedDocIdColumn<'a> {
-    fn get_val(&self, _doc: u64) -> u64 {
-        unimplemented!()
+impl<'a> Column for SortedDocIdColumn<'a> {
+    fn get_val(&self, doc: u64) -> u64 {
+        let DocAddress {
+            doc_id,
+            segment_ord,
+        } = self.doc_id_mapping.get_old_doc_addr(doc as u32);
+        self.fast_field_readers[segment_ord as usize].get_val(doc_id as u64)
     }
 
-    fn iter(&self) -> Box<dyn Iterator<Item = u64> + '_> {
-        Box::new(
-            self.doc_id_mapping
-                .iter_old_doc_addrs()
-                .map(|old_doc_addr| {
-                    let fast_field_reader =
-                        &self.fast_field_readers[old_doc_addr.segment_ord as usize];
-                    fast_field_reader.get_val(old_doc_addr.doc_id as u64)
-                }),
-        )
+    fn reader(&self) -> Box<dyn ColumnReader<u64> + '_> {
+        Box::new(SortedDocIdColumnReader {
+            doc_id_mapping: self.doc_id_mapping,
+            fast_field_readers: &self.fast_field_readers[..],
+            new_doc_id: u32::MAX,
+        })
     }
+
     fn min_value(&self) -> u64 {
         self.min_value
     }
@@ -106,3 +107,27 @@ impl<'a> Column for RemappedDocIdColumn<'a> {
         self.num_vals
     }
 }
+
+struct SortedDocIdColumnReader<'a> {
+    doc_id_mapping: &'a SegmentDocIdMapping,
+    fast_field_readers: &'a [Arc<dyn Column>],
+    new_doc_id: DocId,
+}
+
+impl<'a> ColumnReader for SortedDocIdColumnReader<'a> {
+    fn seek(&mut self, target_idx: u64) -> u64 {
+        assert!(target_idx < self.doc_id_mapping.len() as u64);
+        self.new_doc_id = target_idx as u32;
+        self.get()
+    }
+
+    fn advance(&mut self) -> bool {
+        self.new_doc_id = self.new_doc_id.wrapping_add(1);
+        self.new_doc_id < self.doc_id_mapping.len() as u32
+    }
+
+    fn get(&self) -> u64 {
+        let old_doc = self.doc_id_mapping.get_old_doc_addr(self.new_doc_id);
+        self.fast_field_readers[old_doc.segment_ord as usize].get_val(old_doc.doc_id as u64)
+    }
+}

src/indexer/sorted_doc_id_multivalue_column.rs

@@ -1,24 +1,27 @@
 use std::cmp;
 
-use fastfield_codecs::Column;
+use fastfield_codecs::{Column, ColumnReader};
 
-use crate::fastfield::MultiValuedFastFieldReader;
+use crate::fastfield::{MultiValueLength, MultiValuedFastFieldReader};
 use crate::indexer::doc_id_mapping::SegmentDocIdMapping;
 use crate::schema::Field;
-use crate::SegmentReader;
+use crate::{DocId, SegmentReader};
 
-pub(crate) struct RemappedDocIdMultiValueColumn<'a> {
+// We can now initialize our serializer, and push it the different values
+pub(crate) struct SortedDocIdMultiValueColumn<'a> {
     doc_id_mapping: &'a SegmentDocIdMapping,
     fast_field_readers: Vec<MultiValuedFastFieldReader<u64>>,
+    offsets: &'a [u64],
     min_value: u64,
     max_value: u64,
     num_vals: u64,
 }
 
-impl<'a> RemappedDocIdMultiValueColumn<'a> {
+impl<'a> SortedDocIdMultiValueColumn<'a> {
     pub(crate) fn new(
         readers: &'a [SegmentReader],
         doc_id_mapping: &'a SegmentDocIdMapping,
+        offsets: &'a [u64],
         field: Field,
     ) -> Self {
         // Our values are bitpacked and we need to know what should be
@@ -55,9 +58,10 @@ impl<'a> RemappedDocIdMultiValueColumn<'a> {
             min_value = 0;
             max_value = 0;
         }
-        RemappedDocIdMultiValueColumn {
+        SortedDocIdMultiValueColumn {
             doc_id_mapping,
             fast_field_readers,
+            offsets,
             min_value,
             max_value,
             num_vals: num_vals as u64,
@@ -65,23 +69,32 @@ impl<'a> RemappedDocIdMultiValueColumn<'a> {
     }
 }
 
-impl<'a> Column for RemappedDocIdMultiValueColumn<'a> {
-    fn get_val(&self, _pos: u64) -> u64 {
-        unimplemented!()
+impl<'a> Column for SortedDocIdMultiValueColumn<'a> {
+    fn get_val(&self, pos: u64) -> u64 {
+        // use the offsets index to find the doc_id which will contain the position.
+        // the offsets are strictly increasing so we can do a simple search on it.
+        let new_doc_id: DocId = self
+            .offsets
+            .iter()
+            .position(|&offset| offset > pos)
+            .expect("pos is out of bounds") as DocId
+            - 1u32;
+
+        // now we need to find the position of `pos` in the multivalued bucket
+        let num_pos_covered_until_now = self.offsets[new_doc_id as usize];
+        let pos_in_values = pos - num_pos_covered_until_now;
+
+        let old_doc_addr = self.doc_id_mapping.get_old_doc_addr(new_doc_id);
+        let num_vals =
+            self.fast_field_readers[old_doc_addr.segment_ord as usize].get_len(old_doc_addr.doc_id);
+        assert!(num_vals >= pos_in_values);
+        let mut vals = Vec::new();
+        self.fast_field_readers[old_doc_addr.segment_ord as usize]
+            .get_vals(old_doc_addr.doc_id, &mut vals);
+
+        vals[pos_in_values as usize]
     }
 
-    fn iter(&self) -> Box<dyn Iterator<Item = u64> + '_> {
-        Box::new(
-            self.doc_id_mapping
-                .iter_old_doc_addrs()
-                .flat_map(|old_doc_addr| {
-                    let ff_reader = &self.fast_field_readers[old_doc_addr.segment_ord as usize];
-                    let mut vals = Vec::new();
-                    ff_reader.get_vals(old_doc_addr.doc_id, &mut vals);
-                    vals.into_iter()
-                }),
-        )
-    }
     fn min_value(&self) -> u64 {
         self.min_value
     }
@@ -93,4 +106,80 @@ impl<'a> Column for RemappedDocIdMultiValueColumn<'a> {
     fn num_vals(&self) -> u64 {
         self.num_vals
     }
+
+    fn reader(&self) -> Box<dyn ColumnReader<u64> + '_> {
+        let mut reader = SortedDocMultiValueColumnReader {
+            doc_id_mapping: self.doc_id_mapping,
+            fast_field_readers: &self.fast_field_readers[..],
+            new_doc_id: u32::MAX,
+            in_buffer_idx: 0,
+            buffer: Vec::new(),
+            idx: u64::MAX,
+        };
+        reader.reset();
+        Box::new(reader)
+    }
+}
+
+struct SortedDocMultiValueColumnReader<'a> {
+    doc_id_mapping: &'a SegmentDocIdMapping,
+    fast_field_readers: &'a [MultiValuedFastFieldReader<u64>],
+
+    new_doc_id: DocId,
+    in_buffer_idx: usize,
+    buffer: Vec<u64>,
+    idx: u64,
+}
+
+impl<'a> SortedDocMultiValueColumnReader<'a> {
+    fn fill(&mut self) {
+        let old_doc = self.doc_id_mapping.get_old_doc_addr(self.new_doc_id);
+        let ff_reader = &self.fast_field_readers[old_doc.segment_ord as usize];
+        ff_reader.get_vals(old_doc.doc_id, &mut self.buffer);
+        self.in_buffer_idx = 0;
+    }
+
+    fn reset(&mut self) {
+        self.buffer.clear();
+        self.idx = u64::MAX;
+        self.in_buffer_idx = 0;
+        self.new_doc_id = u32::MAX;
+    }
+}
+
+impl<'a> ColumnReader for SortedDocMultiValueColumnReader<'a> {
+    fn seek(&mut self, target_idx: u64) -> u64 {
+        if target_idx < self.idx {
+            self.reset();
+            self.advance();
+        }
+        for _ in self.idx..target_idx {
+            // TODO could be optimized.
+            assert!(self.advance());
+        }
+        self.get()
+    }
+
+    fn advance(&mut self) -> bool {
+        loop {
+            self.in_buffer_idx += 1;
+            if self.in_buffer_idx < self.buffer.len() {
+                self.idx = self.idx.wrapping_add(1);
+                return true;
+            }
+            self.new_doc_id = self.new_doc_id.wrapping_add(1);
+            if self.new_doc_id >= self.doc_id_mapping.len() as u32 {
+                return false;
+            }
+            self.fill();
+            if !self.buffer.is_empty() {
+                self.idx = self.idx.wrapping_add(1);
+                return true;
+            }
+        }
+    }
+
+    fn get(&self) -> u64 {
+        self.buffer[self.in_buffer_idx]
+    }
 }

src/postings/compression/mod.rs

@@ -106,7 +106,7 @@ impl BlockDecoder {
 
 pub trait VIntEncoder {
     /// Compresses an array of `u32` integers,
-    /// using [delta-encoding](https://en.wikipedia.org/wiki/Delta_encoding)
+    /// using [delta-encoding](https://en.wikipedia.org/wiki/Delta_ encoding)
     /// and variable bytes encoding.
     ///
     /// The method takes an array of ints to compress, and returns

src/postings/mod.rs

@@ -31,7 +31,7 @@ pub use self::term_info::TermInfo;
 
 pub(crate) type UnorderedTermId = u64;
 
-#[allow(clippy::enum_variant_names)]
+#[cfg_attr(feature = "cargo-clippy", allow(clippy::enum_variant_names))]
 #[derive(Debug, PartialEq, Clone, Copy, Eq)]
 pub(crate) enum FreqReadingOption {
     NoFreq,

src/postings/recorder.rs

@@ -50,7 +50,7 @@ impl<'a> Iterator for VInt32Reader<'a> {
 /// Recorder is in charge of recording relevant information about
 /// the presence of a term in a document.
 ///
-/// Depending on the `TextIndexingOptions` associated with the
+/// Depending on the `TextIndexingOptions` associated to the
 /// field, the recorder may records
 ///   * the document frequency
 ///   * the document id

src/postings/segment_postings.rs

@@ -7,7 +7,7 @@ use crate::postings::compression::COMPRESSION_BLOCK_SIZE;
 use crate::postings::{branchless_binary_search, BlockSegmentPostings, Postings};
 use crate::{DocId, TERMINATED};
 
-/// `SegmentPostings` represents the inverted list or postings associated with
+/// `SegmentPostings` represents the inverted list or postings associated to
 /// a term in a `Segment`.
 ///
 /// As we iterate through the `SegmentPostings`, the frequencies are optionally decoded.
@@ -216,7 +216,7 @@ impl HasLen for SegmentPostings {
 }
 
 impl Postings for SegmentPostings {
-    /// Returns the frequency associated with the current document.
+    /// Returns the frequency associated to the current document.
     /// If the schema is set up so that no frequency have been encoded,
     /// this method should always return 1.
     ///

src/postings/term_info.rs

@@ -4,7 +4,7 @@ use std::ops::Range;
 
 use common::{BinarySerializable, FixedSize};
 
-/// `TermInfo` wraps the metadata associated with a Term.
+/// `TermInfo` wraps the metadata associated to a Term.
 /// It is segment-local.
 #[derive(Debug, Default, Eq, PartialEq, Clone)]
 pub struct TermInfo {

src/query/all_query.rs

@@ -17,7 +17,7 @@ impl Query for AllQuery {
     }
 }
 
-/// Weight associated with the `AllQuery` query.
+/// Weight associated to the `AllQuery` query.
 pub struct AllWeight;
 
 impl Weight for AllWeight {
@@ -37,7 +37,7 @@ impl Weight for AllWeight {
     }
 }
 
-/// Scorer associated with the `AllQuery` query.
+/// Scorer associated to the `AllQuery` query.
 pub struct AllScorer {
     doc: DocId,
     max_doc: DocId,

src/query/bitset/mod.rs

@@ -14,7 +14,7 @@ use crate::DocId;
 /// when the bitset is sparse
 pub struct BitSetDocSet {
     docs: BitSet,
-    cursor_bucket: u32, //< index associated with the current tiny bitset
+    cursor_bucket: u32, //< index associated to the current tiny bitset
     cursor_tinybitset: TinySet,
     doc: u32,
 }

src/query/boolean_query/block_wand.rs

@@ -144,7 +144,7 @@ fn advance_all_scorers_on_pivot(term_scorers: &mut Vec<TermScorerWithMaxScore>,
 
 /// Implements the WAND (Weak AND) algorithm for dynamic pruning
 /// described in the paper "Faster Top-k Document Retrieval Using Block-Max Indexes".
-/// Link: <http://engineering.nyu.edu/~suel/papers/bmw.pdf>
+/// Link: http://engineering.nyu.edu/~suel/papers/bmw.pdf
 pub fn block_wand(
     mut scorers: Vec<TermScorer>,
     mut threshold: Score,

src/query/boolean_query/boolean_weight.rs

@@ -174,9 +174,9 @@ impl<TScoreCombiner: ScoreCombiner + Sync> Weight for BooleanWeight<TScoreCombin
                     into_box_scorer(specialized_scorer, &self.score_combiner_fn)
                 })
         } else {
-            self.complex_scorer(reader, boost, DoNothingCombiner::default)
+            self.complex_scorer(reader, boost, &DoNothingCombiner::default)
                 .map(|specialized_scorer| {
-                    into_box_scorer(specialized_scorer, DoNothingCombiner::default)
+                    into_box_scorer(specialized_scorer, &DoNothingCombiner::default)
                 })
         }
     }

src/query/explanation.rs

@@ -39,7 +39,7 @@ impl Explanation {
         }
     }
 
-    /// Returns the value associated with the current node.
+    /// Returns the value associated to the current node.
     pub fn value(&self) -> Score {
         self.value
     }

src/query/intersection.rs

@@ -5,7 +5,7 @@ use crate::{DocId, Score};
 
 /// Returns the intersection scorer.
 ///
-/// The score associated with the documents is the sum of the
+/// The score associated to the documents is the sum of the
 /// score of the `Scorer`s given in argument.
 ///
 /// For better performance, the function uses a

src/query/mod.rs

@@ -21,7 +21,6 @@ mod range_query;
 mod regex_query;
 mod reqopt_scorer;
 mod scorer;
-mod set_query;
 mod term_query;
 mod union;
 mod weight;
@@ -59,7 +58,6 @@ pub use self::score_combiner::{
     DisjunctionMaxCombiner, ScoreCombiner, SumCombiner, SumWithCoordsCombiner,
 };
 pub use self::scorer::Scorer;
-pub use self::set_query::TermSetQuery;
 pub use self::term_query::TermQuery;
 pub use self::union::Union;
 #[cfg(test)]

src/query/more_like_this/more_like_this.rs

@@ -33,9 +33,9 @@ impl Ord for ScoreTerm {
     }
 }
 
-/// A struct used as helper to build [`MoreLikeThisQuery`](crate::query::MoreLikeThisQuery)
-/// This more-like-this implementation is inspired by the Apache Lucene
-/// and closely follows the same implementation with adaptation to Tantivy vocabulary and API.
+/// A struct used as helper to build [`MoreLikeThisQuery`]
+/// This more-like-this implementation is inspired by the Appache Lucene
+/// amd closely follows the same implementation with adaptabtion to Tantivy vocabulary and API.
 ///
 /// [MoreLikeThis](https://github.com/apache/lucene/blob/main/lucene/queries/src/java/org/apache/lucene/queries/mlt/MoreLikeThis.java#L147)
 /// [MoreLikeThisQuery](https://github.com/apache/lucene/blob/main/lucene/queries/src/java/org/apache/lucene/queries/mlt/MoreLikeThisQuery.java#L36)

src/query/phrase_query/phrase_query.rs

@@ -119,7 +119,7 @@ impl PhraseQuery {
 }
 
 impl Query for PhraseQuery {
-    /// Create the weight associated with a query.
+    /// Create the weight associated to a query.
     ///
     /// See [`Weight`].
     fn weight(&self, searcher: &Searcher, scoring_enabled: bool) -> crate::Result<Box<dyn Weight>> {

src/query/query.rs

@@ -42,7 +42,7 @@ use crate::{DocAddress, Term};
 /// [`Scorer`]: crate::query::Scorer
 /// [`SegmentReader`]: crate::SegmentReader
 pub trait Query: QueryClone + Send + Sync + downcast_rs::Downcast + fmt::Debug {
-    /// Create the weight associated with a query.
+    /// Create the weight associated to a query.
     ///
     /// If scoring is not required, setting `scoring_enabled` to `false`
     /// can increase performances.
@@ -67,7 +67,7 @@ pub trait Query: QueryClone + Send + Sync + downcast_rs::Downcast + fmt::Debug {
         Ok(result)
     }
 
-    /// Extract all of the terms associated with the query and pass them to the
+    /// Extract all of the terms associated to the query and pass them to the
     /// given closure.
     ///
     /// Each term is associated with a boolean indicating whether

src/query/query_parser/query_parser.rs

@@ -610,7 +610,7 @@ impl QueryParser {
         if let Some((field, path)) = self.split_full_path(full_path) {
             return Ok(vec![(field, path, literal.phrase.as_str())]);
         }
-        // We need to add terms associated with json default fields.
+        // We need to add terms associated to json default fields.
         let triplets: Vec<(Field, &str, &str)> = self
             .default_indexed_json_fields()
             .map(|json_field| (json_field, full_path.as_str(), literal.phrase.as_str()))

src/query/set_query.rs

@@ -1,222 +0,0 @@
-use std::collections::HashMap;
-
-use tantivy_fst::raw::CompiledAddr;
-use tantivy_fst::{Automaton, Map};
-
-use crate::query::score_combiner::DoNothingCombiner;
-use crate::query::{AutomatonWeight, BooleanWeight, Occur, Query, Weight};
-use crate::schema::Field;
-use crate::{Searcher, Term};
-
-/// A Term Set Query matches all of the documents containing any of the Term provided
-#[derive(Debug, Clone)]
-pub struct TermSetQuery {
-    terms_map: HashMap<Field, Vec<Term>>,
-}
-
-impl TermSetQuery {
-    /// Create a Term Set Query
-    pub fn new<T: IntoIterator<Item = Term>>(terms: T) -> Self {
-        let mut terms_map: HashMap<_, Vec<_>> = HashMap::new();
-        for term in terms {
-            terms_map.entry(term.field()).or_default().push(term);
-        }
-
-        for terms in terms_map.values_mut() {
-            terms.sort_unstable();
-            terms.dedup();
-        }
-
-        TermSetQuery { terms_map }
-    }
-
-    fn specialized_weight(
-        &self,
-        searcher: &Searcher,
-    ) -> crate::Result<BooleanWeight<DoNothingCombiner>> {
-        let mut sub_queries: Vec<(_, Box<dyn Weight>)> = Vec::with_capacity(self.terms_map.len());
-
-        for (&field, sorted_terms) in self.terms_map.iter() {
-            let field_entry = searcher.schema().get_field_entry(field);
-            let field_type = field_entry.field_type();
-            if !field_type.is_indexed() {
-                let error_msg = format!("Field {:?} is not indexed.", field_entry.name());
-                return Err(crate::TantivyError::SchemaError(error_msg));
-            }
-
-            // In practice this won't fail because:
-            // - we are writing to memory, so no IoError
-            // - Terms are ordered
-            let map = Map::from_iter(sorted_terms.iter().map(|key| (key.value_bytes(), 0)))
-                .map_err(|e| std::io::Error::new(std::io::ErrorKind::Other, e))?;
-
-            sub_queries.push((
-                Occur::Should,
-                Box::new(AutomatonWeight::new(field, SetDfaWrapper(map))),
-            ));
-        }
-
-        Ok(BooleanWeight::new(
-            sub_queries,
-            false,
-            Box::new(|| DoNothingCombiner),
-        ))
-    }
-}
-
-impl Query for TermSetQuery {
-    fn weight(
-        &self,
-        searcher: &Searcher,
-        _scoring_enabled: bool,
-    ) -> crate::Result<Box<dyn Weight>> {
-        Ok(Box::new(self.specialized_weight(searcher)?))
-    }
-}
-
-struct SetDfaWrapper(Map<Vec<u8>>);
-
-impl Automaton for SetDfaWrapper {
-    type State = Option<CompiledAddr>;
-
-    fn start(&self) -> Option<CompiledAddr> {
-        Some(self.0.as_ref().root().addr())
-    }
-
-    fn is_match(&self, state_opt: &Option<CompiledAddr>) -> bool {
-        if let Some(state) = state_opt {
-            self.0.as_ref().node(*state).is_final()
-        } else {
-            false
-        }
-    }
-
-    fn accept(&self, state_opt: &Option<CompiledAddr>, byte: u8) -> Option<CompiledAddr> {
-        let state = state_opt.as_ref()?;
-        let node = self.0.as_ref().node(*state);
-        let transition = node.find_input(byte)?;
-        Some(node.transition_addr(transition))
-    }
-
-    fn can_match(&self, state: &Self::State) -> bool {
-        state.is_some()
-    }
-}
-
-#[cfg(test)]
-mod tests {
-
-    use crate::collector::TopDocs;
-    use crate::query::TermSetQuery;
-    use crate::schema::{Schema, TEXT};
-    use crate::{assert_nearly_equals, Index, Term};
-
-    #[test]
-    pub fn test_term_set_query() -> crate::Result<()> {
-        let mut schema_builder = Schema::builder();
-        let field1 = schema_builder.add_text_field("field1", TEXT);
-        let field2 = schema_builder.add_text_field("field1", TEXT);
-        let schema = schema_builder.build();
-        let index = Index::create_in_ram(schema);
-        {
-            let mut index_writer = index.writer_for_tests()?;
-            index_writer.add_document(doc!(
-                field1 => "doc1",
-                field2 => "val1",
-            ))?;
-            index_writer.add_document(doc!(
-                field1 => "doc2",
-                field2 => "val2",
-            ))?;
-            index_writer.add_document(doc!(
-                field1 => "doc3",
-                field2 => "val3",
-            ))?;
-            index_writer.add_document(doc!(
-                field1 => "val3",
-                field2 => "doc3",
-            ))?;
-            index_writer.commit()?;
-        }
-        let reader = index.reader()?;
-        let searcher = reader.searcher();
-
-        {
-            // single element
-            let terms = vec![Term::from_field_text(field1, "doc1")];
-
-            let term_set_query = TermSetQuery::new(terms);
-            let top_docs = searcher.search(&term_set_query, &TopDocs::with_limit(2))?;
-            assert_eq!(top_docs.len(), 1, "Expected 1 document");
-            let (score, _) = top_docs[0];
-            assert_nearly_equals!(1.0, score);
-        }
-
-        {
-            // single element, absent
-            let terms = vec![Term::from_field_text(field1, "doc4")];
-
-            let term_set_query = TermSetQuery::new(terms);
-            let top_docs = searcher.search(&term_set_query, &TopDocs::with_limit(1))?;
-            assert!(top_docs.is_empty(), "Expected 0 document");
-        }
-
-        {
-            // multiple elements
-            let terms = vec![
-                Term::from_field_text(field1, "doc1"),
-                Term::from_field_text(field1, "doc2"),
-            ];
-
-            let term_set_query = TermSetQuery::new(terms);
-            let top_docs = searcher.search(&term_set_query, &TopDocs::with_limit(2))?;
-            assert_eq!(top_docs.len(), 2, "Expected 2 documents");
-            for (score, _) in top_docs {
-                assert_nearly_equals!(1.0, score);
-            }
-        }
-
-        {
-            // multiple elements, mixed fields
-            let terms = vec![
-                Term::from_field_text(field1, "doc1"),
-                Term::from_field_text(field1, "doc1"),
-                Term::from_field_text(field2, "val2"),
-            ];
-
-            let term_set_query = TermSetQuery::new(terms);
-            let top_docs = searcher.search(&term_set_query, &TopDocs::with_limit(3))?;
-
-            assert_eq!(top_docs.len(), 2, "Expected 2 document");
-            for (score, _) in top_docs {
-                assert_nearly_equals!(1.0, score);
-            }
-        }
-
-        {
-            // no field crosstalk
-            let terms = vec![Term::from_field_text(field1, "doc3")];
-
-            let term_set_query = TermSetQuery::new(terms);
-            let top_docs = searcher.search(&term_set_query, &TopDocs::with_limit(3))?;
-            assert_eq!(top_docs.len(), 1, "Expected 1 document");
-
-            let terms = vec![Term::from_field_text(field2, "doc3")];
-
-            let term_set_query = TermSetQuery::new(terms);
-            let top_docs = searcher.search(&term_set_query, &TopDocs::with_limit(3))?;
-            assert_eq!(top_docs.len(), 1, "Expected 1 document");
-
-            let terms = vec![
-                Term::from_field_text(field1, "doc3"),
-                Term::from_field_text(field2, "doc3"),
-            ];
-
-            let term_set_query = TermSetQuery::new(terms);
-            let top_docs = searcher.search(&term_set_query, &TopDocs::with_limit(3))?;
-            assert_eq!(top_docs.len(), 2, "Expected 2 document");
-        }
-
-        Ok(())
-    }
-}

src/schema/bytes_options.rs

@@ -83,7 +83,7 @@ impl BytesOptions {
     ///
     /// Fast fields are designed for random access.
     /// Access time are similar to a random lookup in an array.
-    /// If more than one value is associated with a fast field, only the last one is
+    /// If more than one value is associated to a fast field, only the last one is
     /// kept.
     #[must_use]
     pub fn set_fast(mut self) -> BytesOptions {

src/schema/date_time_options.rs

@@ -104,7 +104,7 @@ impl DateOptions {
     ///
     /// Fast fields are designed for random access.
     /// Access time are similar to a random lookup in an array.
-    /// If more than one value is associated with a fast field, only the last one is
+    /// If more than one value is associated to a fast field, only the last one is
     /// kept.
     #[must_use]
     pub fn set_fast(mut self, cardinality: Cardinality) -> DateOptions {

src/schema/facet.rs

@@ -35,7 +35,7 @@ pub enum FacetParseError {
 /// For instance, an e-commerce website could
 /// have a `Facet` for `/electronics/tv_and_video/led_tv`.
 ///
-/// A document can be associated with any number of facets.
+/// A document can be associated to any number of facets.
 /// The hierarchy implicitly imply that a document
 /// belonging to a facet also belongs to the ancestor of
 /// its facet. In the example above, `/electronics/tv_and_video/`

src/schema/field_type.rs

@@ -2,7 +2,6 @@ use serde::{Deserialize, Serialize};
 use serde_json::Value as JsonValue;
 use thiserror::Error;
 
-use super::Cardinality;
 use crate::schema::bytes_options::BytesOptions;
 use crate::schema::facet_options::FacetOptions;
 use crate::schema::{
@@ -215,26 +214,6 @@ impl FieldType {
         }
     }
 
-    /// returns true if the field is fast.
-    pub fn fastfield_cardinality(&self) -> Option<Cardinality> {
-        match *self {
-            FieldType::Bytes(ref bytes_options) if bytes_options.is_fast() => {
-                Some(Cardinality::SingleValue)
-            }
-            FieldType::Str(ref text_options) if text_options.is_fast() => {
-                Some(Cardinality::MultiValues)
-            }
-            FieldType::U64(ref int_options)
-            | FieldType::I64(ref int_options)
-            | FieldType::F64(ref int_options)
-            | FieldType::Bool(ref int_options) => int_options.get_fastfield_cardinality(),
-            FieldType::Date(ref date_options) => date_options.get_fastfield_cardinality(),
-            FieldType::Facet(_) => Some(Cardinality::MultiValues),
-            FieldType::JsonObject(_) => None,
-            _ => None,
-        }
-    }
-
     /// returns true if the field is normed (see [fieldnorms](crate::fieldnorm)).
     pub fn has_fieldnorms(&self) -> bool {
         match *self {

src/schema/ip_options.rs

@@ -1,109 +0,0 @@
-use std::ops::BitOr;
-
-use serde::{Deserialize, Serialize};
-
-use super::flags::{FastFlag, IndexedFlag, SchemaFlagList, StoredFlag};
-use super::Cardinality;
-
-/// Define how an ip field should be handled by tantivy.
-#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Default)]
-pub struct IpOptions {
-    #[serde(skip_serializing_if = "Option::is_none")]
-    fast: Option<Cardinality>,
-    stored: bool,
-}
-
-impl IpOptions {
-    /// Returns true iff the value is a fast field.
-    pub fn is_fast(&self) -> bool {
-        self.fast.is_some()
-    }
-
-    /// Returns `true` if the json object should be stored.
-    pub fn is_stored(&self) -> bool {
-        self.stored
-    }
-
-    /// Returns the cardinality of the fastfield.
-    ///
-    /// If the field has not been declared as a fastfield, then
-    /// the method returns None.
-    pub fn get_fastfield_cardinality(&self) -> Option<Cardinality> {
-        self.fast
-    }
-
-    /// Sets the field as stored
-    #[must_use]
-    pub fn set_stored(mut self) -> Self {
-        self.stored = true;
-        self
-    }
-
-    /// Set the field as a fast field.
-    ///
-    /// Fast fields are designed for random access.
-    /// Access time are similar to a random lookup in an array.
-    /// If more than one value is associated with a fast field, only the last one is
-    /// kept.
-    #[must_use]
-    pub fn set_fast(mut self, cardinality: Cardinality) -> Self {
-        self.fast = Some(cardinality);
-        self
-    }
-}
-
-impl From<()> for IpOptions {
-    fn from(_: ()) -> IpOptions {
-        IpOptions::default()
-    }
-}
-
-impl From<FastFlag> for IpOptions {
-    fn from(_: FastFlag) -> Self {
-        IpOptions {
-            stored: false,
-            fast: Some(Cardinality::SingleValue),
-        }
-    }
-}
-
-impl From<StoredFlag> for IpOptions {
-    fn from(_: StoredFlag) -> Self {
-        IpOptions {
-            stored: true,
-            fast: None,
-        }
-    }
-}
-
-impl From<IndexedFlag> for IpOptions {
-    fn from(_: IndexedFlag) -> Self {
-        IpOptions {
-            stored: false,
-            fast: None,
-        }
-    }
-}
-
-impl<T: Into<IpOptions>> BitOr<T> for IpOptions {
-    type Output = IpOptions;
-
-    fn bitor(self, other: T) -> IpOptions {
-        let other = other.into();
-        IpOptions {
-            stored: self.stored | other.stored,
-            fast: self.fast.or(other.fast),
-        }
-    }
-}
-
-impl<Head, Tail> From<SchemaFlagList<Head, Tail>> for IpOptions
-where
-    Head: Clone,
-    Tail: Clone,
-    Self: BitOr<Output = Self> + From<Head> + From<Tail>,
-{
-    fn from(head_tail: SchemaFlagList<Head, Tail>) -> Self {
-        Self::from(head_tail.head) | Self::from(head_tail.tail)
-    }
-}

src/schema/mod.rs

@@ -120,7 +120,6 @@ mod date_time_options;
 mod field;
 mod flags;
 mod index_record_option;
-mod ip_options;
 mod json_object_options;
 mod named_field_document;
 mod numeric_options;
@@ -139,7 +138,6 @@ pub use self::field_type::{FieldType, Type};
 pub use self::field_value::FieldValue;
 pub use self::flags::{FAST, INDEXED, STORED};
 pub use self::index_record_option::IndexRecordOption;
-pub use self::ip_options::IpOptions;
 pub use self::json_object_options::JsonObjectOptions;
 pub use self::named_field_document::NamedFieldDocument;
 pub use self::numeric_options::NumericOptions;

src/schema/numeric_options.rs

@@ -7,10 +7,10 @@ use crate::schema::flags::{FastFlag, IndexedFlag, SchemaFlagList, StoredFlag};
 /// Express whether a field is single-value or multi-valued.
 #[derive(Clone, Copy, PartialEq, Eq, Debug, Serialize, Deserialize)]
 pub enum Cardinality {
-    /// The document must have exactly one value associated with the document.
+    /// The document must have exactly one value associated to the document.
     #[serde(rename = "single")]
     SingleValue,
-    /// The document can have any number of values associated with the document.
+    /// The document can have any number of values associated to the document.
     /// This is more memory and CPU expensive than the `SingleValue` solution.
     #[serde(rename = "multi")]
     MultiValues,
@@ -124,7 +124,7 @@ impl NumericOptions {
     ///
     /// Fast fields are designed for random access.
     /// Access time are similar to a random lookup in an array.
-    /// If more than one value is associated with a fast field, only the last one is
+    /// If more than one value is associated to a fast field, only the last one is
     /// kept.
     #[must_use]
     pub fn set_fast(mut self, cardinality: Cardinality) -> NumericOptions {

src/schema/schema.rs

@@ -258,7 +258,7 @@ impl Eq for InnerSchema {}
 pub struct Schema(Arc<InnerSchema>);
 
 impl Schema {
-    /// Return the `FieldEntry` associated with a `Field`.
+    /// Return the `FieldEntry` associated to a `Field`.
     pub fn get_field_entry(&self, field: Field) -> &FieldEntry {
         &self.0.fields[field.field_id() as usize]
     }
@@ -422,8 +422,12 @@ pub enum DocParsingError {
 impl DocParsingError {
     /// Builds a NotJson DocParsingError
     fn invalid_json(invalid_json: &str) -> Self {
-        let sample = invalid_json.chars().take(20).collect();
-        DocParsingError::InvalidJson(sample)
+        let sample_json: String = if invalid_json.len() < 20 {
+            invalid_json.to_string()
+        } else {
+            format!("{:?}...", &invalid_json[0..20])
+        };
+        DocParsingError::InvalidJson(sample_json)
     }
 }
 
@@ -789,11 +793,6 @@ mod tests {
                 ))
             );
         }
-        {
-            // Short JSON, under the 20 char take.
-            let json_err = schema.parse_document(r#"{"count": 50,}"#);
-            assert_matches!(json_err, Err(InvalidJson(_)));
-        }
         {
             let json_err = schema.parse_document(
                 r#"{

src/schema/text_options.rs

@@ -161,7 +161,7 @@ impl TextFieldIndexing {
         self
     }
 
-    /// Returns the indexing options associated with this field.
+    /// Returns the indexing options associated to this field.
     ///
     /// See [`IndexRecordOption`] for more detail.
     pub fn index_option(&self) -> IndexRecordOption {

src/snippet/mod.rs

@@ -342,7 +342,7 @@ impl SnippetGenerator {
 
     /// Generates a snippet for the given `Document`.
     ///
-    /// This method extract the text associated with the `SnippetGenerator`'s field
+    /// This method extract the text associated to the `SnippetGenerator`'s field
     /// and computes a snippet.
     pub fn snippet_from_doc(&self, doc: &Document) -> Snippet {
         let text: String = doc

src/store/compressors.rs

@@ -104,13 +104,6 @@ impl ZstdCompressor {
                             value, opt_name, err
                         )
                     })?;
-                    if value >= 15 {
-                        warn!(
-                            "High zstd compression level detected: {:?}. High compression levels \
-                             (>=15) are slow and will limit indexing speed.",
-                            value
-                        )
-                    }
                     compressor.compression_level = Some(value);
                 }
                 _ => {

src/termdict/fst_termdict/streamer.rs

@@ -136,7 +136,7 @@ where A: Automaton
     }
 
     /// Return the next `(key, value)` pair.
-    #[allow(clippy::should_implement_trait)]
+    #[cfg_attr(feature = "cargo-clippy", allow(clippy::should_implement_trait))]
     pub fn next(&mut self) -> Option<(&[u8], &TermInfo)> {
         if self.advance() {
             Some((self.key(), self.value()))

src/termdict/fst_termdict/termdict.rs

@@ -138,12 +138,12 @@ impl TermDictionary {
         self.term_info_store.num_terms()
     }
 
-    /// Returns the ordinal associated with a given term.
+    /// Returns the ordinal associated to a given term.
     pub fn term_ord<K: AsRef<[u8]>>(&self, key: K) -> io::Result<Option<TermOrdinal>> {
         Ok(self.fst_index.get(key))
     }
 
-    /// Stores the term associated with a given term ordinal in
+    /// Stores the term associated to a given term ordinal in
     /// a `bytes` buffer.
     ///
     /// Term ordinals are defined as the position of the term in

src/termdict/sstable_termdict/streamer.rs

@@ -179,7 +179,7 @@ where
     }
 
     /// Return the next `(key, value)` pair.
-    #[allow(clippy::should_implement_trait)]
+    #[cfg_attr(feature = "cargo-clippy", allow(clippy::should_implement_trait))]
     pub fn next(&mut self) -> Option<(&[u8], &TermInfo)> {
         if self.advance() {
             Some((self.key(), self.value()))

src/termdict/sstable_termdict/termdict.rs

@@ -52,7 +52,7 @@ impl<W: io::Write> TermDictionaryBuilder<W> {
     /// to insert_key and insert_value.
     ///
     /// Prefer using `.insert(key, value)`
-    #[allow(clippy::unnecessary_wraps)]
+    #[allow(clippy::clippy::clippy::unnecessary_wraps)]
     pub(crate) fn insert_key(&mut self, key: &[u8]) -> io::Result<()> {
         self.sstable_writer.write_key(key);
         Ok(())
@@ -153,7 +153,7 @@ impl TermDictionary {
         self.num_terms as usize
     }
 
-    /// Returns the ordinal associated with a given term.
+    /// Returns the ordinal associated to a given term.
     pub fn term_ord<K: AsRef<[u8]>>(&self, key: K) -> io::Result<Option<TermOrdinal>> {
         let mut term_ord = 0u64;
         let key_bytes = key.as_ref();
@@ -167,7 +167,7 @@ impl TermDictionary {
         Ok(None)
     }
 
-    /// Returns the term associated with a given term ordinal.
+    /// Returns the term associated to a given term ordinal.
     ///
     /// Term ordinals are defined as the position of the term in
     /// the sorted list of terms.

src/tokenizer/ngram_tokenizer.rs

@@ -255,7 +255,7 @@ where T: Iterator<Item = usize>
 /// Emits all of the offsets where a codepoint starts
 /// or a codepoint ends.
 ///
-/// By convention, we emit `[0]` for the empty string.
+/// By convention, we emit [0] for the empty string.
 struct CodepointFrontiers<'a> {
     s: &'a str,
     next_el: Option<usize>,