blop

* Fix prefix option for FuzzyTermQuery

* Update changelog

CHANGELOG.md

@@ -1,3 +1,7 @@
+Tantivy 0.13.0
+======================
+- Bugfix in `FuzzyTermQuery` not matching terms by prefix when it should (@Peachball)
+
 Tantivy 0.12.0
 ======================
 - Removing static dispatch in tokenizers for simplicity. (#762)

Cargo.toml

@@ -18,7 +18,7 @@ byteorder = "1.0"
 crc32fast = "1.2.0"
 once_cell = "1.0"
 regex ={version = "1.3.0", default-features = false, features = ["std"]}
-tantivy-fst = "0.2.1"
+tantivy-fst = {path="../tantivy-fst", version="0.3"}
 memmap = {version = "0.7", optional=true}
 lz4 = {version="1.20", optional=true}
 snap = "1"
@@ -29,7 +29,7 @@ serde = {version="1.0", features=["derive"]}
 serde_json = "1.0"
 num_cpus = "1.2"
 fs2={version="0.4", optional=true}
-levenshtein_automata = "0.1"
+levenshtein_automata = "0.2"
 notify = {version="4", optional=true}
 uuid = { version = "0.8", features = ["v4", "serde"] }
 crossbeam = "0.7"
@@ -38,9 +38,9 @@ owning_ref = "0.4"
 stable_deref_trait = "1.0.0"
 rust-stemmers = "1.2"
 downcast-rs = { version="1.0" }
-tantivy-query-grammar = { version="0.12", path="./query-grammar" }
+tantivy-query-grammar = { version="0.13", path="./query-grammar" }
 bitpacking = {version="0.8", default-features = false, features=["bitpacker4x"]}
-census =  {path="../census"}
+census = "0.4"
 fnv = "1.0.6"
 owned-read = "0.4"
 failure = "0.1"

TODO.md

@@ -1,9 +0,0 @@
-- segment writer serializes if already flush
-- flush if exceed max doc. 
-- unit tests
-- reader from `IndexWriter`
-- configurable limit to flush 
-- bundle directory
-- add index worker when exceeds some doc limit
-- flush before prepare commit.
-- segment_writer should not receive a segment 

appveyor.yml

@@ -18,5 +18,5 @@ install:
 build: false
 
 test_script:
-  - REM SET RUST_LOG=tantivy,test & cargo test --verbose --no-default-features --features mmap
+  - REM SET RUST_LOG=tantivy,test & cargo test --all --verbose --no-default-features --features mmap
   - REM SET RUST_BACKTRACE=1 & cargo build --examples

query-grammar/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "tantivy-query-grammar"
-version = "0.12.0"
+version = "0.13.0"
 authors = ["Paul Masurel <paul.masurel@gmail.com>"]
 license = "MIT"
 categories = ["database-implementations", "data-structures"]

query-grammar/src/query_grammar.rs

@@ -154,17 +154,11 @@ fn negate(expr: UserInputAST) -> UserInputAST {
     expr.unary(Occur::MustNot)
 }
 
-fn must(expr: UserInputAST) -> UserInputAST {
-    expr.unary(Occur::Must)
-}
-
 fn leaf<'a>() -> impl Parser<&'a str, Output = UserInputAST> {
     parser(|input| {
-        char('-')
-            .with(leaf())
-            .map(negate)
-            .or(char('+').with(leaf()).map(must))
-            .or(char('(').with(ast()).skip(char(')')))
+        char('(')
+            .with(ast())
+            .skip(char(')'))
             .or(char('*').map(|_| UserInputAST::from(UserInputLeaf::All)))
             .or(attempt(
                 string("NOT").skip(spaces1()).with(leaf()).map(negate),
@@ -176,6 +170,16 @@ fn leaf<'a>() -> impl Parser<&'a str, Output = UserInputAST> {
     })
 }
 
+fn occur_symbol<'a>() -> impl Parser<&'a str, Output = Occur> {
+    char('-')
+        .map(|_| Occur::MustNot)
+        .or(char('+').map(|_| Occur::Must))
+}
+
+fn occur_leaf<'a>() -> impl Parser<&'a str, Output = (Option<Occur>, UserInputAST)> {
+    (optional(occur_symbol()), boosted_leaf())
+}
+
 fn positive_float_number<'a>() -> impl Parser<&'a str, Output = f32> {
     (many1(digit()), optional((char('.'), many1(digit())))).map(
         |(int_part, decimal_part_opt): (String, Option<(char, String)>)| {
@@ -239,21 +243,29 @@ fn aggregate_binary_expressions(
     }
 }
 
-pub fn ast<'a>() -> impl Parser<&'a str, Output = UserInputAST> {
-    let operand_leaf = (
+fn operand_leaf<'a>() -> impl Parser<&'a str, Output = (BinaryOperand, UserInputAST)> {
+    (
         binary_operand().skip(spaces()),
         boosted_leaf().skip(spaces()),
-    );
-    let boolean_expr = (boosted_leaf().skip(spaces().silent()), many1(operand_leaf))
+    )
+}
+
+pub fn ast<'a>() -> impl Parser<&'a str, Output = UserInputAST> {
+    let boolean_expr = (boosted_leaf().skip(spaces()), many1(operand_leaf()))
         .map(|(left, right)| aggregate_binary_expressions(left, right));
-    let whitespace_separated_leaves =
-        many1(boosted_leaf().skip(spaces().silent())).map(|subqueries: Vec<UserInputAST>| {
+    let whitespace_separated_leaves = many1(occur_leaf().skip(spaces().silent())).map(
+        |subqueries: Vec<(Option<Occur>, UserInputAST)>| {
             if subqueries.len() == 1 {
-                subqueries.into_iter().next().unwrap()
+                let (occur_opt, ast) = subqueries.into_iter().next().unwrap();
+                match occur_opt.unwrap_or(Occur::Should) {
+                    Occur::Must | Occur::Should => ast,
+                    Occur::MustNot => UserInputAST::Clause(vec![(Some(Occur::MustNot), ast)]),
+                }
             } else {
                 UserInputAST::Clause(subqueries.into_iter().collect())
             }
-        });
+        },
+    );
     let expr = attempt(boolean_expr).or(whitespace_separated_leaves);
     spaces().with(expr).skip(spaces())
 }
@@ -283,6 +295,12 @@ mod test {
         );
     }
 
+    #[test]
+    fn test_occur_symbol() {
+        assert_eq!(super::occur_symbol().parse("-"), Ok((Occur::MustNot, "")));
+        assert_eq!(super::occur_symbol().parse("+"), Ok((Occur::Must, "")));
+    }
+
     #[test]
     fn test_positive_float_number() {
         fn valid_parse(float_str: &str, expected_val: f32, expected_remaining: &str) {
@@ -330,7 +348,7 @@ mod test {
             "Err(UnexpectedParse)"
         );
         test_parse_query_to_ast_helper("NOTa", "\"NOTa\"");
-        test_parse_query_to_ast_helper("NOT a", "-(\"a\")");
+        test_parse_query_to_ast_helper("NOT a", "(-\"a\")");
     }
 
     #[test]
@@ -338,16 +356,16 @@ mod test {
         assert!(parse_to_ast().parse("a^2^3").is_err());
         assert!(parse_to_ast().parse("a^2^").is_err());
         test_parse_query_to_ast_helper("a^3", "(\"a\")^3");
-        test_parse_query_to_ast_helper("a^3 b^2", "((\"a\")^3 (\"b\")^2)");
+        test_parse_query_to_ast_helper("a^3 b^2", "(*(\"a\")^3 *(\"b\")^2)");
         test_parse_query_to_ast_helper("a^1", "\"a\"");
     }
 
     #[test]
     fn test_parse_query_to_ast_binary_op() {
-        test_parse_query_to_ast_helper("a AND b", "(+(\"a\") +(\"b\"))");
-        test_parse_query_to_ast_helper("a OR b", "(?(\"a\") ?(\"b\"))");
-        test_parse_query_to_ast_helper("a OR b AND c", "(?(\"a\") ?((+(\"b\") +(\"c\"))))");
-        test_parse_query_to_ast_helper("a AND b         AND c", "(+(\"a\") +(\"b\") +(\"c\"))");
+        test_parse_query_to_ast_helper("a AND b", "(+\"a\" +\"b\")");
+        test_parse_query_to_ast_helper("a OR b", "(?\"a\" ?\"b\")");
+        test_parse_query_to_ast_helper("a OR b AND c", "(?\"a\" ?(+\"b\" +\"c\"))");
+        test_parse_query_to_ast_helper("a AND b         AND c", "(+\"a\" +\"b\" +\"c\")");
         assert_eq!(
             format!("{:?}", parse_to_ast().parse("a OR b aaa")),
             "Err(UnexpectedParse)"
@@ -385,6 +403,13 @@ mod test {
         test_parse_query_to_ast_helper("weight: <= 70.5", "weight:{\"*\" TO \"70.5\"]");
     }
 
+    #[test]
+    fn test_occur_leaf() {
+        let ((occur, ast), _) = super::occur_leaf().parse("+abc").unwrap();
+        assert_eq!(occur, Some(Occur::Must));
+        assert_eq!(format!("{:?}", ast), "\"abc\"");
+    }
+
     #[test]
     fn test_range_parser() {
         // testing the range() parser separately
@@ -413,32 +438,67 @@ mod test {
     fn test_parse_query_to_triming_spaces() {
         test_parse_query_to_ast_helper("   abc", "\"abc\"");
         test_parse_query_to_ast_helper("abc ", "\"abc\"");
-        test_parse_query_to_ast_helper("(  a OR abc)", "(?(\"a\") ?(\"abc\"))");
-        test_parse_query_to_ast_helper("(a  OR abc)", "(?(\"a\") ?(\"abc\"))");
-        test_parse_query_to_ast_helper("(a OR  abc)", "(?(\"a\") ?(\"abc\"))");
-        test_parse_query_to_ast_helper("a OR abc ", "(?(\"a\") ?(\"abc\"))");
-        test_parse_query_to_ast_helper("(a OR abc )", "(?(\"a\") ?(\"abc\"))");
-        test_parse_query_to_ast_helper("(a OR  abc) ", "(?(\"a\") ?(\"abc\"))");
+        test_parse_query_to_ast_helper("(  a OR abc)", "(?\"a\" ?\"abc\")");
+        test_parse_query_to_ast_helper("(a  OR abc)", "(?\"a\" ?\"abc\")");
+        test_parse_query_to_ast_helper("(a OR  abc)", "(?\"a\" ?\"abc\")");
+        test_parse_query_to_ast_helper("a OR abc ", "(?\"a\" ?\"abc\")");
+        test_parse_query_to_ast_helper("(a OR abc )", "(?\"a\" ?\"abc\")");
+        test_parse_query_to_ast_helper("(a OR  abc) ", "(?\"a\" ?\"abc\")");
     }
 
     #[test]
-    fn test_parse_query_to_ast() {
+    fn test_parse_query_single_term() {
         test_parse_query_to_ast_helper("abc", "\"abc\"");
-        test_parse_query_to_ast_helper("a b", "(\"a\" \"b\")");
-        test_parse_query_to_ast_helper("+(a b)", "+((\"a\" \"b\"))");
-        test_parse_query_to_ast_helper("+d", "+(\"d\")");
-        test_parse_query_to_ast_helper("+(a b) +d", "(+((\"a\" \"b\")) +(\"d\"))");
-        test_parse_query_to_ast_helper("(+a +b) d", "((+(\"a\") +(\"b\")) \"d\")");
-        test_parse_query_to_ast_helper("(+a)", "+(\"a\")");
-        test_parse_query_to_ast_helper("(+a +b)", "(+(\"a\") +(\"b\"))");
+    }
+
+    #[test]
+    fn test_parse_query_default_clause() {
+        test_parse_query_to_ast_helper("a b", "(*\"a\" *\"b\")");
+    }
+
+    #[test]
+    fn test_parse_query_must_default_clause() {
+        test_parse_query_to_ast_helper("+(a b)", "(*\"a\" *\"b\")");
+    }
+
+    #[test]
+    fn test_parse_query_must_single_term() {
+        test_parse_query_to_ast_helper("+d", "\"d\"");
+    }
+
+    #[test]
+    fn test_single_term_with_field() {
         test_parse_query_to_ast_helper("abc:toto", "abc:\"toto\"");
+    }
+
+    #[test]
+    fn test_single_term_with_float() {
         test_parse_query_to_ast_helper("abc:1.1", "abc:\"1.1\"");
-        test_parse_query_to_ast_helper("+abc:toto", "+(abc:\"toto\")");
-        test_parse_query_to_ast_helper("(+abc:toto -titi)", "(+(abc:\"toto\") -(\"titi\"))");
-        test_parse_query_to_ast_helper("-abc:toto", "-(abc:\"toto\")");
-        test_parse_query_to_ast_helper("abc:a b", "(abc:\"a\" \"b\")");
+    }
+
+    #[test]
+    fn test_must_clause() {
+        test_parse_query_to_ast_helper("(+a +b)", "(+\"a\" +\"b\")");
+    }
+
+    #[test]
+    fn test_parse_test_query_plus_a_b_plus_d() {
+        test_parse_query_to_ast_helper("+(a b) +d", "(+(*\"a\" *\"b\") +\"d\")");
+    }
+
+    #[test]
+    fn test_parse_test_query_other() {
+        test_parse_query_to_ast_helper("(+a +b) d", "(*(+\"a\" +\"b\") *\"d\")");
+        test_parse_query_to_ast_helper("+abc:toto", "abc:\"toto\"");
+        test_parse_query_to_ast_helper("(+abc:toto -titi)", "(+abc:\"toto\" -\"titi\")");
+        test_parse_query_to_ast_helper("-abc:toto", "(-abc:\"toto\")");
+        test_parse_query_to_ast_helper("abc:a b", "(*abc:\"a\" *\"b\")");
         test_parse_query_to_ast_helper("abc:\"a b\"", "abc:\"a b\"");
         test_parse_query_to_ast_helper("foo:[1 TO 5]", "foo:[\"1\" TO \"5\"]");
+    }
+
+    #[test]
+    fn test_parse_query_with_range() {
         test_parse_query_to_ast_helper("[1 TO 5]", "[\"1\" TO \"5\"]");
         test_parse_query_to_ast_helper("foo:{a TO z}", "foo:{\"a\" TO \"z\"}");
         test_parse_query_to_ast_helper("foo:[1 TO toto}", "foo:[\"1\" TO \"toto\"}");

query-grammar/src/user_input_ast.rs

@@ -85,15 +85,14 @@ impl UserInputBound {
 }
 
 pub enum UserInputAST {
-    Clause(Vec<UserInputAST>),
-    Unary(Occur, Box<UserInputAST>),
+    Clause(Vec<(Option<Occur>, UserInputAST)>),
     Leaf(Box<UserInputLeaf>),
     Boost(Box<UserInputAST>, f32),
 }
 
 impl UserInputAST {
     pub fn unary(self, occur: Occur) -> UserInputAST {
-        UserInputAST::Unary(occur, Box::new(self))
+        UserInputAST::Clause(vec![(Some(occur), self)])
     }
 
     fn compose(occur: Occur, asts: Vec<UserInputAST>) -> UserInputAST {
@@ -104,7 +103,7 @@ impl UserInputAST {
         } else {
             UserInputAST::Clause(
                 asts.into_iter()
-                    .map(|ast: UserInputAST| ast.unary(occur))
+                    .map(|ast: UserInputAST| (Some(occur), ast))
                     .collect::<Vec<_>>(),
             )
         }
@@ -135,25 +134,36 @@ impl From<UserInputLeaf> for UserInputAST {
     }
 }
 
+fn print_occur_ast(
+    occur_opt: Option<Occur>,
+    ast: &UserInputAST,
+    formatter: &mut fmt::Formatter,
+) -> fmt::Result {
+    if let Some(occur) = occur_opt {
+        write!(formatter, "{}{:?}", occur, ast)?;
+    } else {
+        write!(formatter, "*{:?}", ast)?;
+    }
+    Ok(())
+}
+
 impl fmt::Debug for UserInputAST {
-    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
         match *self {
             UserInputAST::Clause(ref subqueries) => {
                 if subqueries.is_empty() {
                     write!(formatter, "<emptyclause>")?;
                 } else {
                     write!(formatter, "(")?;
-                    write!(formatter, "{:?}", &subqueries[0])?;
+                    print_occur_ast(subqueries[0].0, &subqueries[0].1, formatter)?;
                     for subquery in &subqueries[1..] {
-                        write!(formatter, " {:?}", subquery)?;
+                        write!(formatter, " ")?;
+                        print_occur_ast(subquery.0, &subquery.1, formatter)?;
                     }
                     write!(formatter, ")")?;
                 }
                 Ok(())
             }
-            UserInputAST::Unary(ref occur, ref subquery) => {
-                write!(formatter, "{}({:?})", occur, subquery)
-            }
             UserInputAST::Leaf(ref subquery) => write!(formatter, "{:?}", subquery),
             UserInputAST::Boost(ref leaf, boost) => write!(formatter, "({:?})^{}", leaf, boost),
         }

src/common/composite_file.rs

@@ -190,12 +190,11 @@ mod test {
     use crate::schema::Field;
     use std::io::Write;
     use std::path::Path;
-    
 
     #[test]
     fn test_composite_file() {
         let path = Path::new("test_path");
-        let mut directory = RAMDirectory::default();
+        let mut directory = RAMDirectory::create();
         {
             let w = directory.open_write(path).unwrap();
             let mut composite_write = CompositeWrite::wrap(w);

src/common/mod.rs

@@ -2,7 +2,6 @@ pub mod bitpacker;
 mod bitset;
 mod composite_file;
 mod counting_writer;
-mod mutable_enum;
 mod serialize;
 mod vint;
 
@@ -10,7 +9,6 @@ pub use self::bitset::BitSet;
 pub(crate) use self::bitset::TinySet;
 pub(crate) use self::composite_file::{CompositeFile, CompositeWrite};
 pub use self::counting_writer::CountingWriter;
-pub(crate) use self::mutable_enum::MutableEnum;
 pub use self::serialize::{BinarySerializable, FixedSize};
 pub use self::vint::{read_u32_vint, serialize_vint_u32, write_u32_vint, VInt};
 pub use byteorder::LittleEndian as Endianness;

src/common/mutable_enum.rs

@@ -1,37 +0,0 @@
-use std::ops::{Deref, DerefMut};
-
-pub(crate) struct MutableEnum<T>(Option<T>);
-
-impl<T> MutableEnum<T> {
-    pub fn wrap(val: T) -> Self {
-        MutableEnum(Some(val))
-    }
-
-    pub fn into(self) -> T {
-        self.0.unwrap()
-    }
-}
-
-impl<T> MutableEnum<T> {
-    pub fn map_mutate<E, F>(&mut self, transformation: F) -> Result<(), E>
-    where
-        F: FnOnce(T) -> Result<T, E>,
-    {
-        self.0 = self.0.take().map(transformation).transpose()?;
-        Ok(())
-    }
-}
-
-impl<T> Deref for MutableEnum<T> {
-    type Target = T;
-
-    fn deref(&self) -> &Self::Target {
-        self.0.as_ref().unwrap()
-    }
-}
-
-impl<T> DerefMut for MutableEnum<T> {
-    fn deref_mut(&mut self) -> &mut Self::Target {
-        self.0.as_mut().unwrap()
-    }
-}

src/core/index.rs

@@ -12,8 +12,8 @@ use crate::directory::INDEX_WRITER_LOCK;
 use crate::directory::{Directory, RAMDirectory};
 use crate::error::DataCorruption;
 use crate::error::TantivyError;
+use crate::indexer::index_writer::HEAP_SIZE_MIN;
 use crate::indexer::segment_updater::save_new_metas;
-use crate::indexer::IndexWriterConfig;
 use crate::reader::IndexReader;
 use crate::reader::IndexReaderBuilder;
 use crate::schema::Field;
@@ -273,14 +273,30 @@ impl Index {
     pub fn writer_with_num_threads(
         &self,
         num_threads: usize,
-        overall_heap_size_in_bytes: u64,
+        overall_heap_size_in_bytes: usize,
     ) -> crate::Result<IndexWriter> {
-        let config = IndexWriterConfig {
-            max_indexing_threads: num_threads,
-            memory_budget: overall_heap_size_in_bytes,
-            ..Default::default()
-        };
-        self.writer_from_config(config)
+        let directory_lock = self
+            .directory
+            .acquire_lock(&INDEX_WRITER_LOCK)
+            .map_err(|err| {
+                TantivyError::LockFailure(
+                    err,
+                    Some(
+                        "Failed to acquire index lock. If you are using\
+                         a regular directory, this means there is already an \
+                         `IndexWriter` working on this `Directory`, in this process \
+                         or in a different process."
+                            .to_string(),
+                    ),
+                )
+            })?;
+        let heap_size_in_bytes_per_thread = overall_heap_size_in_bytes / num_threads;
+        IndexWriter::new(
+            self,
+            num_threads,
+            heap_size_in_bytes_per_thread,
+            directory_lock,
+        )
     }
 
     /// Creates a multithreaded writer
@@ -293,36 +309,13 @@ impl Index {
     /// If the lockfile already exists, returns `Error::FileAlreadyExists`.
     /// # Panics
     /// If the heap size per thread is too small, panics.
-    pub fn writer(&self, overall_heap_size_in_bytes: u64) -> crate::Result<IndexWriter> {
-        let config = IndexWriterConfig {
-            max_indexing_threads: num_cpus::get(),
-            memory_budget: overall_heap_size_in_bytes,
-            ..Default::default()
-        };
-        self.writer_from_config(config)
-    }
-
-    /// Creates a new writer with a given configuration.
-    ///
-    /// See [`IndexWriterConfig`](./struct.IndexWriterConfig.html) for more information.
-    pub fn writer_from_config(&self, mut config: IndexWriterConfig) -> crate::Result<IndexWriter> {
-        config.validate()?;
-        let directory_lock = self
-            .directory
-            .acquire_lock(&INDEX_WRITER_LOCK)
-            .map_err(|err| {
-                TantivyError::LockFailure(
-                    err,
-                    Some(
-                        "Failed to acquire index lock. If you are using \
-                         a regular directory, this means there is already an \
-                         `IndexWriter` working on this `Directory`, in this process \
-                         or in a different process."
-                            .to_string(),
-                    ),
-                )
-            })?;
-        IndexWriter::new(self, config, directory_lock)
+    pub fn writer(&self, overall_heap_size_in_bytes: usize) -> crate::Result<IndexWriter> {
+        let mut num_threads = num_cpus::get();
+        let heap_size_in_bytes_per_thread = overall_heap_size_in_bytes / num_threads;
+        if heap_size_in_bytes_per_thread < HEAP_SIZE_MIN {
+            num_threads = (overall_heap_size_in_bytes / HEAP_SIZE_MIN).max(1);
+        }
+        self.writer_with_num_threads(num_threads, overall_heap_size_in_bytes)
     }
 
     /// Accessor to the index schema
@@ -476,7 +469,7 @@ mod tests {
             .try_into()
             .unwrap();
         assert_eq!(reader.searcher().num_docs(), 0);
-        test_index_on_commit_reload_policy_aux(field, index.clone(), &index, &reader);
+        test_index_on_commit_reload_policy_aux(field, &index, &reader);
     }
 
     #[cfg(feature = "mmap")]
@@ -500,7 +493,7 @@ mod tests {
                 .try_into()
                 .unwrap();
             assert_eq!(reader.searcher().num_docs(), 0);
-            test_index_on_commit_reload_policy_aux(field, index.clone(), &index, &reader);
+            test_index_on_commit_reload_policy_aux(field, &index, &reader);
         }
 
         #[test]
@@ -542,16 +535,12 @@ mod tests {
                 .try_into()
                 .unwrap();
             assert_eq!(reader.searcher().num_docs(), 0);
-            test_index_on_commit_reload_policy_aux(field, read_index, &write_index, &reader);
+            test_index_on_commit_reload_policy_aux(field, &write_index, &reader);
         }
     }
 
-    fn test_index_on_commit_reload_policy_aux(
-        field: Field,
-        mut reader_index: Index,
-        index: &Index,
-        reader: &IndexReader,
-    ) {
+    fn test_index_on_commit_reload_policy_aux(field: Field, index: &Index, reader: &IndexReader) {
+        let mut reader_index = reader.index();
         let (sender, receiver) = crossbeam::channel::unbounded();
         let _watch_handle = reader_index.directory_mut().watch(Box::new(move || {
             let _ = sender.send(());

src/core/segment.rs

@@ -3,140 +3,41 @@ use crate::core::Index;
 use crate::core::SegmentId;
 use crate::core::SegmentMeta;
 use crate::directory::error::{OpenReadError, OpenWriteError};
-use crate::directory::{Directory, ManagedDirectory, RAMDirectory};
+use crate::directory::Directory;
 use crate::directory::{ReadOnlySource, WritePtr};
 use crate::indexer::segment_serializer::SegmentSerializer;
 use crate::schema::Schema;
 use crate::Opstamp;
 use std::fmt;
-use std::ops::{Deref, DerefMut};
 use std::path::PathBuf;
-use crate::indexer::{ResourceManager};
-
-#[derive(Clone)]
-pub(crate) enum SegmentDirectory {
-    Persisted(ManagedDirectory),
-    Volatile {
-        directory: RAMDirectory,
-    },
-}
-
-impl SegmentDirectory {
-    fn new_volatile(memory_manager: ResourceManager) -> SegmentDirectory {
-        SegmentDirectory::Volatile {
-            directory: RAMDirectory::create_with_memory_manager(memory_manager),
-        }
-    }
-}
-
-impl fmt::Debug for SegmentDirectory {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        match self {
-            SegmentDirectory::Volatile { .. } => write!(f, "volatile")?,
-            SegmentDirectory::Persisted(dir) => write!(f, "Persisted({:?})", dir)?,
-        }
-        Ok(())
-    }
-}
-
-impl From<ManagedDirectory> for SegmentDirectory {
-    fn from(directory: ManagedDirectory) -> Self {
-        SegmentDirectory::Persisted(directory)
-    }
-}
-
-impl Deref for SegmentDirectory {
-    type Target = dyn Directory;
-
-    fn deref(&self) -> &Self::Target {
-        match self {
-            SegmentDirectory::Volatile {
-                directory, ..
-            } => directory,
-            SegmentDirectory::Persisted(dir) => dir,
-        }
-    }
-}
-
-impl DerefMut for SegmentDirectory {
-    fn deref_mut(&mut self) -> &mut Self::Target {
-        match self {
-            SegmentDirectory::Volatile { directory, .. } => directory,
-            SegmentDirectory::Persisted(dir) => dir,
-        }
-    }
-}
 
 /// A segment is a piece of the index.
 #[derive(Clone)]
 pub struct Segment {
-    schema: Schema,
+    index: Index,
     meta: SegmentMeta,
-    directory: SegmentDirectory,
 }
 
 impl fmt::Debug for Segment {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(
-            f,
-            "Segment(id={:?}, directory={:?})",
-            self.id().uuid_string(),
-            self.directory
-        )
+        write!(f, "Segment({:?})", self.id().uuid_string())
     }
 }
 
 impl Segment {
-    pub(crate) fn new_persisted(
-        meta: SegmentMeta,
-        directory: ManagedDirectory,
-        schema: Schema,
-    ) -> Segment {
-        Segment {
-            meta,
-            schema,
-            directory: SegmentDirectory::from(directory),
-        }
-    }
-
-    /// Creates a new segment that embeds its own `RAMDirectory`.
-    ///
-    /// That segment is entirely dissociated from the index directory.
-    /// It will be persisted by a background thread in charge of IO.
-    pub fn new_volatile(meta: SegmentMeta, schema: Schema, resource_manager: ResourceManager) -> Segment {
-        Segment {
-            schema,
-            meta,
-            directory: SegmentDirectory::new_volatile(resource_manager),
-        }
-    }
-
     /// Creates a new segment given an `Index` and a `SegmentId`
     pub(crate) fn for_index(index: Index, meta: SegmentMeta) -> Segment {
-        let segment_directory = index.directory().clone();
-        Segment::new_persisted(meta, segment_directory, index.schema())
+        Segment { index, meta }
     }
 
-    /// Persists a given `Segment` to a directory.
-    pub fn persist(&mut self, mut dest_directory: ManagedDirectory) -> crate::Result<()> {
-        if let SegmentDirectory::Persisted(_) = self.directory {
-            // this segment is already persisted.
-            return Ok(());
-        }
-        if let SegmentDirectory::Volatile { directory, ..} = &self.directory {
-            directory.persist(&mut dest_directory)?;
-        }
-        self.directory = SegmentDirectory::Persisted(dest_directory);
-        Ok(())
-    }
-
-    pub fn into_volatile(&self, memory_manager: ResourceManager) -> Segment {
-        Segment::new_volatile(self.meta.clone(), self.schema.clone(), memory_manager)
+    /// Returns the index the segment belongs to.
+    pub fn index(&self) -> &Index {
+        &self.index
     }
 
     /// Returns our index's schema.
     pub fn schema(&self) -> Schema {
-        self.schema.clone()
+        self.index.schema()
     }
 
     /// Returns the segment meta-information
@@ -150,18 +51,16 @@ impl Segment {
     /// as we finalize a fresh new segment.
     pub(crate) fn with_max_doc(self, max_doc: u32) -> Segment {
         Segment {
-            schema: self.schema,
+            index: self.index,
             meta: self.meta.with_max_doc(max_doc),
-            directory: self.directory,
         }
     }
 
     #[doc(hidden)]
     pub fn with_delete_meta(self, num_deleted_docs: u32, opstamp: Opstamp) -> Segment {
         Segment {
-            schema: self.schema,
+            index: self.index,
             meta: self.meta.with_delete_meta(num_deleted_docs, opstamp),
-            directory: self.directory,
         }
     }
 
@@ -181,15 +80,15 @@ impl Segment {
     /// Open one of the component file for a *regular* read.
     pub fn open_read(&self, component: SegmentComponent) -> Result<ReadOnlySource, OpenReadError> {
         let path = self.relative_path(component);
-        let source = self.directory.open_read(&path)?;
+        let source = self.index.directory().open_read(&path)?;
         Ok(source)
     }
 
     /// Open one of the component file for *regular* write.
     pub fn open_write(&mut self, component: SegmentComponent) -> Result<WritePtr, OpenWriteError> {
         let path = self.relative_path(component);
-        let wrt = self.directory.open_write(&path)?;
-        Ok(wrt)
+        let write = self.index.directory_mut().open_write(&path)?;
+        Ok(write)
     }
 }
 

src/directory/mod.rs

@@ -13,10 +13,7 @@ mod footer;
 mod managed_directory;
 mod ram_directory;
 mod read_only_source;
-mod spilling_writer;
 mod watch_event_router;
-mod persistor;
-
 
 /// Errors specific to the directory module.
 pub mod error;
@@ -26,7 +23,6 @@ pub use self::directory::{Directory, DirectoryClone};
 pub use self::directory_lock::{Lock, INDEX_WRITER_LOCK, META_LOCK};
 pub use self::ram_directory::RAMDirectory;
 pub use self::read_only_source::ReadOnlySource;
-pub(crate) use self::spilling_writer::{SpillingResult, SpillingWriter};
 pub use self::watch_event_router::{WatchCallback, WatchCallbackList, WatchHandle};
 use std::io::{self, BufWriter, Write};
 use std::path::PathBuf;
@@ -83,16 +79,10 @@ impl<W: TerminatingWrite> TerminatingWrite for BufWriter<W> {
     }
 }
 
-impl TerminatingWrite for Vec<u8> {
-    fn terminate_ref(&mut self, _a: AntiCallToken) -> io::Result<()> {
-        Ok(())
-    }
-}
-
 #[cfg(test)]
 impl<'a> TerminatingWrite for &'a mut Vec<u8> {
     fn terminate_ref(&mut self, _a: AntiCallToken) -> io::Result<()> {
-        Ok(())
+        self.flush()
     }
 }
 

src/directory/persistor.rs

@@ -1,38 +0,0 @@
-use crate::indexer::{SegmentManager, ResourceManager, MergeOperationInventory};
-use std::thread::JoinHandle;
-use crate::{IndexWriterConfig, SegmentId};
-use std::collections::HashSet;
-
-pub(crate) struct Persistor {
-    memory_manager: ResourceManager,
-    thread_handle: JoinHandle<()>,
-}
-
-impl Persistor {
-    pub(crate) fn create_and_start(segment_manager: SegmentManager,
-                            memory_manager: ResourceManager,
-                            config: IndexWriterConfig) -> crate::Result<Persistor> {
-        let memory_manager_clone = memory_manager.clone();
-        let thread_handle = std::thread::Builder::new()
-            .name("persistor-thread".to_string())
-            .spawn(move || {
-                while let Ok(_) = memory_manager_clone.wait_until_in_range(config.persist_low..) {
-                    segment_manager.largest_segment_not_in_merge();
-                }
-            }).map_err(|_err| crate::TantivyError::ErrorInThread("Failed to start persistor thread.".to_string()))?;
-        Ok(Persistor {
-            memory_manager,
-            thread_handle
-        })
-    }
-
-    /// Stop the persisting thread.
-    ///
-    /// The memory manager will be terminated, which will unlock the thread from any waiting
-    /// position.
-    /// This method blocks for a short amount of tim until the persistor thread has terminated.
-    pub fn stop(self) {
-        self.memory_manager.terminate();
-        let _ = self.thread_handle.join();
-    }
-}

src/directory/ram_directory.rs

@@ -11,7 +11,6 @@ use std::io::{self, BufWriter, Cursor, Seek, SeekFrom, Write};
 use std::path::{Path, PathBuf};
 use std::result;
 use std::sync::{Arc, RwLock};
-use crate::indexer::ResourceManager;
 
 /// Writer associated with the `RAMDirectory`
 ///
@@ -83,12 +82,11 @@ impl TerminatingWrite for VecWriter {
 struct InnerDirectory {
     fs: HashMap<PathBuf, ReadOnlySource>,
     watch_router: WatchCallbackList,
-    memory_manager: ResourceManager,
 }
 
 impl InnerDirectory {
     fn write(&mut self, path: PathBuf, data: &[u8]) -> bool {
-        let data = ReadOnlySource::new_with_allocation(Vec::from(data), &self.memory_manager);
+        let data = ReadOnlySource::new(Vec::from(data));
         self.fs.insert(path, data).is_some()
     }
 
@@ -114,8 +112,8 @@ impl InnerDirectory {
         self.watch_router.subscribe(watch_handle)
     }
 
-    fn total_mem_usage(&self) -> u64 {
-        self.fs.values().map(|source| source.len() as u64).sum()
+    fn total_mem_usage(&self) -> usize {
+        self.fs.values().map(|f| f.len()).sum()
     }
 }
 
@@ -136,30 +134,14 @@ pub struct RAMDirectory {
 }
 
 impl RAMDirectory {
-
-    /// Creates a new RAMDirectory.
-    ///
-    /// Check `.create_with_memory_manager(..)` if you want to associate an external memory
-    /// manager to your RAMDirectory.
-    pub fn create() -> RAMDirectory {
-        RAMDirectory::default()
-    }
-
     /// Constructor
-    pub fn create_with_memory_manager(memory_manager: ResourceManager) -> RAMDirectory {
-        let inner_directory = InnerDirectory {
-            fs: Default::default(),
-            watch_router: Default::default(),
-            memory_manager
-        };
-        RAMDirectory {
-            fs: Arc::new(RwLock::new(inner_directory))
-        }
+    pub fn create() -> RAMDirectory {
+        Self::default()
     }
 
     /// Returns the sum of the size of the different files
     /// in the RAMDirectory.
-    pub fn total_mem_usage(&self) -> u64 {
+    pub fn total_mem_usage(&self) -> usize {
         self.fs.read().unwrap().total_mem_usage()
     }
 
@@ -245,9 +227,6 @@ mod tests {
     use crate::Directory;
     use std::io::Write;
     use std::path::Path;
-    use crate::indexer::ResourceManager;
-    use crate::directory::TerminatingWrite;
-    use std::mem;
 
     #[test]
     fn test_persist() {
@@ -265,59 +244,4 @@ 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_memory_manager_several_path() {
-        let memory_manager = ResourceManager::default();
-        let mut ram_directory = RAMDirectory::create_with_memory_manager(memory_manager.clone());
-        assert!(ram_directory.atomic_write(Path::new("/titi"), b"abcd").is_ok());
-        assert_eq!(memory_manager.total_amount(), 4u64);
-        assert!(ram_directory.atomic_write(Path::new("/toto"), b"abcde").is_ok());
-        assert_eq!(memory_manager.total_amount(), 9u64);
-    }
-
-    #[test]
-    fn test_memory_manager_override() {
-        let memory_manager = ResourceManager::default();
-        let mut ram_directory = RAMDirectory::create_with_memory_manager(memory_manager.clone());
-        assert!(ram_directory.atomic_write(Path::new("/titi"), b"abcde").is_ok());
-        assert_eq!(memory_manager.total_amount(), 5u64);
-        assert!(ram_directory.atomic_write(Path::new("/titi"), b"abcdef").is_ok());
-        assert_eq!(memory_manager.total_amount(), 6u64);
-    }
-
-    #[test]
-    fn test_memory_manager_seq_wrt() {
-        let memory_manager = ResourceManager::default();
-        let mut ram_directory = RAMDirectory::create_with_memory_manager(memory_manager.clone());
-        let mut wrt = ram_directory.open_write(Path::new("/titi")).unwrap();
-        assert!(wrt.write_all(b"abcde").is_ok());
-        assert!(wrt.terminate().is_ok());
-        assert_eq!(memory_manager.total_amount(), 5u64);
-        assert!(ram_directory.atomic_write(Path::new("/titi"), b"abcdef").is_ok());
-        assert_eq!(memory_manager.total_amount(), 6u64);
-    }
-
-    #[test]
-    fn test_release_on_drop() {
-        let memory_manager = ResourceManager::default();
-        let mut ram_directory = RAMDirectory::create_with_memory_manager(memory_manager.clone());
-        let mut wrt = ram_directory.open_write(Path::new("/titi")).unwrap();
-        assert!(wrt.write_all(b"abcde").is_ok());
-        assert!(wrt.terminate().is_ok());
-        assert_eq!(memory_manager.total_amount(), 5u64);
-        let mut wrt2 = ram_directory.open_write(Path::new("/toto")).unwrap();
-        assert!(wrt2.write_all(b"abcdefghijkl").is_ok());
-        assert!(wrt2.terminate().is_ok());
-        assert_eq!(memory_manager.total_amount(), 17u64);
-        let source = ram_directory.open_read(Path::new("/titi")).unwrap();
-        let source_clone = source.clone();
-        assert_eq!(memory_manager.total_amount(), 17u64);
-        mem::drop(ram_directory);
-        assert_eq!(memory_manager.total_amount(), 5u64);
-        mem::drop(source);
-        assert_eq!(memory_manager.total_amount(), 5u64);
-        mem::drop(source_clone);
-        assert_eq!(memory_manager.total_amount(), 0u64);
-    }
 }

src/directory/read_only_source.rs

@@ -2,7 +2,6 @@ use crate::common::HasLen;
 use stable_deref_trait::{CloneStableDeref, StableDeref};
 use std::ops::Deref;
 use std::sync::Arc;
-use crate::indexer::{Allocation, ResourceManager};
 
 pub type BoxedData = Box<dyn Deref<Target = [u8]> + Send + Sync + 'static>;
 
@@ -16,7 +15,6 @@ pub struct ReadOnlySource {
     data: Arc<BoxedData>,
     start: usize,
     stop: usize,
-    allocation: Option<Arc<Allocation>>
 }
 
 unsafe impl StableDeref for ReadOnlySource {}
@@ -37,13 +35,11 @@ impl From<Arc<BoxedData>> for ReadOnlySource {
             data,
             start: 0,
             stop: len,
-            allocation: None
         }
     }
 }
 
 impl ReadOnlySource {
-
     pub(crate) fn new<D>(data: D) -> ReadOnlySource
     where
         D: Deref<Target = [u8]> + Send + Sync + 'static,
@@ -53,24 +49,9 @@ impl ReadOnlySource {
             data: Arc::new(Box::new(data)),
             start: 0,
             stop: len,
-            allocation: None
         }
     }
 
-    pub(crate) fn new_with_allocation<D>(data: D, memory_manager: &ResourceManager) -> ReadOnlySource
-        where
-            D: Deref<Target = [u8]> + Send + Sync + 'static,
-    {
-        let len = data.len();
-        ReadOnlySource {
-            data: Arc::new(Box::new(data)),
-            start: 0,
-            stop: len,
-            allocation: Some(Arc::new(memory_manager.allocate(len as u64)))
-        }
-    }
-
-
     /// Creates an empty ReadOnlySource
     pub fn empty() -> ReadOnlySource {
         ReadOnlySource::new(&[][..])
@@ -117,7 +98,6 @@ impl ReadOnlySource {
             data: self.data.clone(),
             start: self.start + start,
             stop: self.start + stop,
-            allocation: self.allocation.clone()
         }
     }
 

src/directory/spilling_writer.rs

@@ -1,186 +0,0 @@
-use crate::common::MutableEnum;
-use crate::directory::{TerminatingWrite, WritePtr};
-use std::io::{self, Write};
-
-/// Represents the state of the `SpillingWriter`.
-enum SpillingState {
-    Buffer {
-        buffer: Vec<u8>,
-        capacity: usize,
-        write_factory: Box<dyn FnOnce() -> io::Result<WritePtr>>,
-    },
-    Spilled(WritePtr),
-}
-
-impl SpillingState {
-    fn new(
-        limit: usize,
-        write_factory: Box<dyn FnOnce() -> io::Result<WritePtr>>,
-    ) -> SpillingState {
-        SpillingState::Buffer {
-            buffer: Vec::with_capacity(limit),
-            capacity: limit,
-            write_factory,
-        }
-    }
-
-    // Change the state in such a way that it is ready to accept
-    // `extra_capacity` bytes.
-    //
-    fn reserve(self, extra_capacity: usize) -> io::Result<SpillingState> {
-        match self {
-            SpillingState::Buffer {
-                buffer,
-                capacity,
-                write_factory,
-            } => {
-                if capacity >= extra_capacity {
-                    Ok(SpillingState::Buffer {
-                        buffer,
-                        capacity: capacity - extra_capacity,
-                        write_factory,
-                    })
-                } else {
-                    let mut wrt = write_factory()?;
-                    wrt.write_all(&buffer[..])?;
-                    Ok(SpillingState::Spilled(wrt))
-                }
-            }
-            SpillingState::Spilled(wrt) => Ok(SpillingState::Spilled(wrt)),
-        }
-    }
-}
-
-/// The `SpillingWriter` is a writer that start by writing in a
-/// buffer.
-///
-/// Once a memory limit is reached, the spilling writer will
-/// call a given `WritePtr` factory and start spilling into it.
-///
-/// Spilling here includes:
-/// - writing all of the data that were written in the in-memory buffer so far
-/// - writing subsequent data as well.
-///
-/// Once entering "spilling" mode, the `SpillingWriter` stays in this mode.
-pub struct SpillingWriter {
-    state: MutableEnum<SpillingState>,
-}
-
-impl SpillingWriter {
-    //// Creates a new `Spilling Writer`.
-    pub fn new(
-        limit: usize,
-        write_factory: Box<dyn FnOnce() -> io::Result<WritePtr>>,
-    ) -> SpillingWriter {
-        let state = SpillingState::new(limit, write_factory);
-        SpillingWriter {
-            state: MutableEnum::wrap(state),
-        }
-    }
-
-    /// Finalizes the `SpillingWriter`.
-    ///
-    /// The `SpillingResult` object is an enum specific
-    /// to whether the `SpillingWriter` reached the spilling limit
-    /// (In that case, the buffer is returned).
-    ///
-    /// If the writer reached the spilling mode, the underlying `WritePtr`
-    /// is terminated and SpillingResult::Spilled is returned.
-    pub fn finalize(self) -> io::Result<SpillingResult> {
-        match self.state.into() {
-            SpillingState::Spilled(wrt) => {
-                wrt.terminate()?;
-                Ok(SpillingResult::Spilled)
-            }
-            SpillingState::Buffer { buffer, .. } => Ok(SpillingResult::Buffer(buffer)),
-        }
-    }
-}
-
-/// enum used as the result of `.finalize()`.
-pub enum SpillingResult {
-    Spilled,
-    Buffer(Vec<u8>),
-}
-
-impl io::Write for SpillingWriter {
-    fn write(&mut self, payload: &[u8]) -> io::Result<usize> {
-        self.write_all(payload)?;
-        Ok(payload.len())
-    }
-
-    fn flush(&mut self) -> io::Result<()> {
-        if let SpillingState::Spilled(wrt) = &mut *self.state {
-            wrt.flush()?;
-        }
-        Ok(())
-    }
-
-    fn write_all(&mut self, payload: &[u8]) -> io::Result<()> {
-        self.state.map_mutate(|mut state| {
-            state = state.reserve(payload.len())?;
-            match &mut state {
-                SpillingState::Buffer { buffer, .. } => {
-                    buffer.extend_from_slice(payload);
-                }
-                SpillingState::Spilled(wrt) => {
-                    wrt.write_all(payload)?;
-                }
-            }
-            Ok(state)
-        })
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::SpillingWriter;
-    use crate::directory::spilling_writer::SpillingResult;
-    use crate::directory::RAMDirectory;
-    use crate::Directory;
-    use std::io::{self, Write};
-    use std::path::Path;
-
-    #[test]
-    fn test_no_spilling() {
-        let ram_directory = RAMDirectory::create();
-        let mut ram_directory_clone = ram_directory.clone();
-        let path = Path::new("test");
-        let write_factory = Box::new(move || {
-            ram_directory_clone
-                .open_write(path)
-                .map_err(|err| io::Error::new(io::ErrorKind::Other, err))
-        });
-        let mut spilling_wrt = SpillingWriter::new(10, write_factory);
-        assert!(spilling_wrt.write_all(b"abcd").is_ok());
-        if let SpillingResult::Buffer(buf) = spilling_wrt.finalize().unwrap() {
-            assert_eq!(buf, b"abcd")
-        } else {
-            panic!("spill writer should not have spilled");
-        }
-        assert!(!ram_directory.exists(path));
-    }
-
-    #[test]
-    fn test_spilling() {
-        let ram_directory = RAMDirectory::create();
-        let mut ram_directory_clone = ram_directory.clone();
-        let path = Path::new("test");
-        let write_factory = Box::new(move || {
-            ram_directory_clone
-                .open_write(path)
-                .map_err(|err| io::Error::new(io::ErrorKind::Other, err))
-        });
-        let mut spilling_wrt = SpillingWriter::new(10, write_factory);
-        assert!(spilling_wrt.write_all(b"abcd").is_ok());
-        assert!(spilling_wrt.write_all(b"efghijklmnop").is_ok());
-        if let SpillingResult::Spilled = spilling_wrt.finalize().unwrap() {
-        } else {
-            panic!("spill writer should have spilled");
-        }
-        assert_eq!(
-            ram_directory.atomic_read(path).unwrap(),
-            b"abcdefghijklmnop"
-        );
-    }
-}

src/fastfield/delete.rs

@@ -89,7 +89,7 @@ mod tests {
 
     fn test_delete_bitset_helper(bitset: &BitSet, max_doc: u32) {
         let test_path = PathBuf::from("test");
-        let mut directory = RAMDirectory::default();
+        let mut directory = RAMDirectory::create();
         {
             let mut writer = directory.open_write(&*test_path).unwrap();
             write_delete_bitset(bitset, max_doc, &mut writer).unwrap();

src/indexer/index_writer.rs

@@ -8,26 +8,22 @@ use crate::core::SegmentComponent;
 use crate::core::SegmentId;
 use crate::core::SegmentMeta;
 use crate::core::SegmentReader;
+use crate::directory::TerminatingWrite;
 use crate::directory::{DirectoryLock, GarbageCollectionResult};
-use crate::directory::{TerminatingWrite, WatchCallbackList};
 use crate::docset::DocSet;
 use crate::error::TantivyError;
 use crate::fastfield::write_delete_bitset;
 use crate::indexer::delete_queue::{DeleteCursor, DeleteQueue};
 use crate::indexer::doc_opstamp_mapping::DocToOpstampMapping;
 use crate::indexer::operation::DeleteOperation;
-use crate::indexer::segment_manager::SegmentRegisters;
-use crate::indexer::segment_register::SegmentRegister;
 use crate::indexer::stamper::Stamper;
-use crate::indexer::{SegmentEntry, ResourceManager};
+use crate::indexer::MergePolicy;
+use crate::indexer::SegmentEntry;
 use crate::indexer::SegmentWriter;
-use crate::indexer::{IndexWriterConfig, MergePolicy};
-use crate::reader::NRTReader;
 use crate::schema::Document;
 use crate::schema::IndexRecordOption;
 use crate::schema::Term;
-use crate::tokenizer::TokenizerManager;
-use crate::{IndexReader, Opstamp};
+use crate::Opstamp;
 use crossbeam::channel;
 use futures::executor::block_on;
 use futures::future::Future;
@@ -35,10 +31,18 @@ use smallvec::smallvec;
 use smallvec::SmallVec;
 use std::mem;
 use std::ops::Range;
-use std::sync::{Arc, RwLock};
+use std::sync::Arc;
 use std::thread;
 use std::thread::JoinHandle;
 
+// Size of the margin for the heap. A segment is closed when the remaining memory
+// in the heap goes below MARGIN_IN_BYTES.
+pub const MARGIN_IN_BYTES: usize = 1_000_000;
+
+// We impose the memory per thread to be at least 3 MB.
+pub const HEAP_SIZE_MIN: usize = ((MARGIN_IN_BYTES as u32) * 3u32) as usize;
+pub const HEAP_SIZE_MAX: usize = u32::max_value() as usize - MARGIN_IN_BYTES;
+
 // Add document will block if the number of docs waiting in the queue to be indexed
 // reaches `PIPELINE_MAX_SIZE_IN_DOCS`
 const PIPELINE_MAX_SIZE_IN_DOCS: usize = 10_000;
@@ -65,9 +69,8 @@ pub struct IndexWriter {
     _directory_lock: Option<DirectoryLock>,
 
     index: Index,
-    config: IndexWriterConfig,
 
-    segment_registers: Arc<RwLock<SegmentRegisters>>,
+    heap_size_in_bytes_per_thread: usize,
 
     workers_join_handle: Vec<JoinHandle<crate::Result<()>>>,
 
@@ -77,14 +80,13 @@ pub struct IndexWriter {
     segment_updater: SegmentUpdater,
 
     worker_id: usize,
+
+    num_threads: usize,
+
     delete_queue: DeleteQueue,
 
     stamper: Stamper,
     committed_opstamp: Opstamp,
-
-    on_commit: WatchCallbackList,
-
-    memory_manager: ResourceManager,
 }
 
 fn compute_deleted_bitset(
@@ -131,6 +133,7 @@ fn compute_deleted_bitset(
 /// For instance, there was no delete operation between the state of the `segment_entry` and
 /// the `target_opstamp`, `segment_entry` is not updated.
 pub(crate) fn advance_deletes(
+    mut segment: Segment,
     segment_entry: &mut SegmentEntry,
     target_opstamp: Opstamp,
 ) -> crate::Result<()> {
@@ -139,33 +142,25 @@ pub(crate) fn advance_deletes(
         return Ok(());
     }
 
-    let delete_bitset_opt = segment_entry.take_delete_bitset();
-
-    // We avoid directly advancing the `SegmentEntry` delete cursor, because
-    // we do not want to end up in an invalid state if the delete bitset
-    // serialization fails.
-    let mut delete_cursor = segment_entry.delete_cursor();
-
-    if delete_bitset_opt.is_none() && segment_entry.delete_cursor().get().is_none() {
+    if segment_entry.delete_bitset().is_none() && segment_entry.delete_cursor().get().is_none() {
         // There has been no `DeleteOperation` between the segment status and `target_opstamp`.
         return Ok(());
     }
 
-    // We open our current serialized segment to compute the new deleted bitset.
-    let segment = segment_entry.segment().clone();
     let segment_reader = SegmentReader::open(&segment)?;
 
     let max_doc = segment_reader.max_doc();
-
-    let mut delete_bitset: BitSet =
-        delete_bitset_opt.unwrap_or_else(|| BitSet::with_max_value(max_doc));
+    let mut delete_bitset: BitSet = match segment_entry.delete_bitset() {
+        Some(previous_delete_bitset) => (*previous_delete_bitset).clone(),
+        None => BitSet::with_max_value(max_doc),
+    };
 
     let num_deleted_docs_before = segment.meta().num_deleted_docs();
 
     compute_deleted_bitset(
         &mut delete_bitset,
         &segment_reader,
-        &mut delete_cursor,
+        segment_entry.delete_cursor(),
         &DocToOpstampMapping::None,
         target_opstamp,
     )?;
@@ -184,40 +179,32 @@ pub(crate) fn advance_deletes(
     let num_deleted_docs: u32 = delete_bitset.len() as u32;
     if num_deleted_docs > num_deleted_docs_before {
         // There are new deletes. We need to write a new delete file.
-        let mut delete_file = segment
-            .with_delete_meta(num_deleted_docs as u32, target_opstamp)
-            .open_write(SegmentComponent::DELETE)?;
+        segment = segment.with_delete_meta(num_deleted_docs as u32, target_opstamp);
+        let mut delete_file = segment.open_write(SegmentComponent::DELETE)?;
         write_delete_bitset(&delete_bitset, max_doc, &mut delete_file)?;
         delete_file.terminate()?;
-        segment_entry.reset_delete_meta(num_deleted_docs as u32, target_opstamp);
     }
 
-    // Regardless of whether we did end up having to write a new file or not
-    // we advance the `delete_cursor`. This is an optimisation. We want to ensure we do not
-    // check that a given deleted term does not match any of our docs more than once.
-    segment_entry.set_delete_cursor(delete_cursor);
+    segment_entry.set_meta(segment.meta().clone());
     Ok(())
 }
 
 fn index_documents(
-    config: IndexWriterConfig,
+    memory_budget: usize,
     segment: Segment,
     grouped_document_iterator: &mut dyn Iterator<Item = OperationGroup>,
     segment_updater: &mut SegmentUpdater,
-    tokenizers: &TokenizerManager,
     mut delete_cursor: DeleteCursor,
-    memory_manager: ResourceManager
 ) -> crate::Result<bool> {
     let schema = segment.schema();
 
-    let mut segment_writer = SegmentWriter::for_segment(
-        &config, segment, &schema, tokenizers, memory_manager)?;
+    let mut segment_writer = SegmentWriter::for_segment(memory_budget, segment.clone(), &schema)?;
     for document_group in grouped_document_iterator {
         for doc in document_group {
             segment_writer.add_document(doc, &schema)?;
         }
         let mem_usage = segment_writer.mem_usage();
-        if mem_usage >= config.heap_size_before_flushing() {
+        if mem_usage >= memory_budget - MARGIN_IN_BYTES {
             info!(
                 "Buffer limit reached, flushing segment with maxdoc={}.",
                 segment_writer.max_doc()
@@ -236,14 +223,24 @@ fn index_documents(
     // the worker thread.
     assert!(max_doc > 0);
 
-    let (segment, doc_opstamps): (Segment, Vec<Opstamp>) = segment_writer.finalize()?;
+    let doc_opstamps: Vec<Opstamp> = segment_writer.finalize()?;
+
+    let segment_with_max_doc = segment.with_max_doc(max_doc);
 
     let last_docstamp: Opstamp = *(doc_opstamps.last().unwrap());
 
-    let delete_bitset_opt =
-        apply_deletes(&segment, &mut delete_cursor, &doc_opstamps, last_docstamp)?;
+    let delete_bitset_opt = apply_deletes(
+        &segment_with_max_doc,
+        &mut delete_cursor,
+        &doc_opstamps,
+        last_docstamp,
+    )?;
 
-    let segment_entry = SegmentEntry::new(segment, delete_cursor, delete_bitset_opt);
+    let segment_entry = SegmentEntry::new(
+        segment_with_max_doc.meta().clone(),
+        delete_cursor,
+        delete_bitset_opt,
+    );
     block_on(segment_updater.schedule_add_segment(segment_entry))?;
     Ok(true)
 }
@@ -295,10 +292,21 @@ impl IndexWriter {
     /// If the heap size per thread is too small, panics.
     pub(crate) fn new(
         index: &Index,
-        mut config: IndexWriterConfig,
+        num_threads: usize,
+        heap_size_in_bytes_per_thread: usize,
         directory_lock: DirectoryLock,
     ) -> crate::Result<IndexWriter> {
-        config.validate()?;
+        if heap_size_in_bytes_per_thread < HEAP_SIZE_MIN {
+            let err_msg = format!(
+                "The heap size per thread needs to be at least {}.",
+                HEAP_SIZE_MIN
+            );
+            return Err(TantivyError::InvalidArgument(err_msg));
+        }
+        if heap_size_in_bytes_per_thread >= HEAP_SIZE_MAX {
+            let err_msg = format!("The heap size per thread cannot exceed {}", HEAP_SIZE_MAX);
+            return Err(TantivyError::InvalidArgument(err_msg));
+        }
         let (document_sender, document_receiver): (OperationSender, OperationReceiver) =
             channel::bounded(PIPELINE_MAX_SIZE_IN_DOCS);
 
@@ -306,26 +314,16 @@ impl IndexWriter {
 
         let current_opstamp = index.load_metas()?.opstamp;
 
-        let meta = index.load_metas()?;
-
         let stamper = Stamper::new(current_opstamp);
 
-        let commited_segments = SegmentRegister::new(
-            index.directory(),
-            &index.schema(),
-            meta.segments,
-            &delete_queue.cursor(),
-        );
-        let segment_registers = Arc::new(RwLock::new(SegmentRegisters::new(commited_segments)));
-
         let segment_updater =
-            SegmentUpdater::create(segment_registers.clone(), index.clone(), stamper.clone())?;
+            SegmentUpdater::create(index.clone(), stamper.clone(), &delete_queue.cursor())?;
 
         let mut index_writer = IndexWriter {
             _directory_lock: Some(directory_lock),
 
+            heap_size_in_bytes_per_thread,
             index: index.clone(),
-            config,
 
             operation_receiver: document_receiver,
             operation_sender: document_sender,
@@ -333,6 +331,7 @@ impl IndexWriter {
             segment_updater,
 
             workers_join_handle: vec![],
+            num_threads,
 
             delete_queue,
 
@@ -340,10 +339,6 @@ impl IndexWriter {
             stamper,
 
             worker_id: 0,
-            segment_registers,
-            on_commit: Default::default(),
-
-            memory_manager: Default::default()
         };
         index_writer.start_workers()?;
         Ok(index_writer)
@@ -371,11 +366,23 @@ impl IndexWriter {
                 })?;
         }
 
-        self
+        let result = self
             .segment_updater
-            .wait_merging_thread();
+            .wait_merging_thread()
+            .map_err(|_| TantivyError::ErrorInThread("Failed to join merging thread.".into()));
 
-        Ok(())
+        if let Err(ref e) = result {
+            error!("Some merging thread failed {:?}", e);
+        }
+
+        result
+    }
+
+    #[doc(hidden)]
+    pub fn add_segment(&self, segment_meta: SegmentMeta) -> crate::Result<()> {
+        let delete_cursor = self.delete_queue.cursor();
+        let segment_entry = SegmentEntry::new(segment_meta, delete_cursor, None);
+        block_on(self.segment_updater.schedule_add_segment(segment_entry))
     }
 
     /// Creates a new segment.
@@ -398,9 +405,8 @@ impl IndexWriter {
 
         let mut delete_cursor = self.delete_queue.cursor();
 
+        let mem_budget = self.heap_size_in_bytes_per_thread;
         let index = self.index.clone();
-        let config = self.config.clone();
-        let memory_manager = self.memory_manager.clone();
         let join_handle: JoinHandle<crate::Result<()>> = thread::Builder::new()
             .name(format!("thrd-tantivy-index{}", self.worker_id))
             .spawn(move || {
@@ -429,13 +435,11 @@ impl IndexWriter {
                     }
                     let segment = index.new_segment();
                     index_documents(
-                        config.clone(),
+                        mem_budget,
                         segment,
                         &mut document_iterator,
                         &mut segment_updater,
-                        index.tokenizers(),
                         delete_cursor.clone(),
-                        memory_manager.clone()
                     )?;
                 }
             })?;
@@ -455,7 +459,7 @@ impl IndexWriter {
     }
 
     fn start_workers(&mut self) -> crate::Result<()> {
-        for _ in 0..self.config.max_indexing_threads {
+        for _ in 0..self.num_threads {
             self.add_indexing_worker()?;
         }
         Ok(())
@@ -560,8 +564,12 @@ impl IndexWriter {
             .take()
             .expect("The IndexWriter does not have any lock. This is a bug, please report.");
 
-        let new_index_writer: IndexWriter =
-            IndexWriter::new(&self.index, self.config.clone(), directory_lock)?;
+        let new_index_writer: IndexWriter = IndexWriter::new(
+            &self.index,
+            self.num_threads,
+            self.heap_size_in_bytes_per_thread,
+            directory_lock,
+        )?;
 
         // the current `self` is dropped right away because of this call.
         //
@@ -600,7 +608,7 @@ impl IndexWriter {
     /// It is also possible to add a payload to the `commit`
     /// using this API.
     /// See [`PreparedCommit::set_payload()`](PreparedCommit.html)
-    pub fn prepare_commit(&mut self, soft_commit: bool) -> crate::Result<PreparedCommit> {
+    pub fn prepare_commit(&mut self) -> crate::Result<PreparedCommit> {
         // Here, because we join all of the worker threads,
         // all of the segment update for this commit have been
         // sent.
@@ -628,7 +636,7 @@ impl IndexWriter {
         }
 
         let commit_opstamp = self.stamper.stamp();
-        let prepared_commit = PreparedCommit::new(self, commit_opstamp, soft_commit);
+        let prepared_commit = PreparedCommit::new(self, commit_opstamp);
         info!("Prepared commit {}", commit_opstamp);
         Ok(prepared_commit)
     }
@@ -648,25 +656,7 @@ impl IndexWriter {
     /// that made it in the commit.
     ///
     pub fn commit(&mut self) -> crate::Result<Opstamp> {
-        self.prepare_commit(false)?.commit()
-    }
-
-    pub fn soft_commit(&mut self) -> crate::Result<Opstamp> {
-        self.prepare_commit(true)?.commit()
-    }
-
-    pub(crate) fn trigger_commit(&self) -> impl Future<Output = ()> {
-        self.on_commit.broadcast()
-    }
-
-    pub fn reader(&self, num_searchers: usize) -> crate::Result<IndexReader> {
-        let nrt_reader = NRTReader::create(
-            num_searchers,
-            self.index.clone(),
-            self.segment_registers.clone(),
-            &self.on_commit,
-        )?;
-        Ok(IndexReader::NRT(nrt_reader))
+        self.prepare_commit()?.commit()
     }
 
     pub(crate) fn segment_updater(&self) -> &SegmentUpdater {
@@ -1064,8 +1054,7 @@ mod tests {
                 index_writer.add_document(doc!(text_field => "a"));
             }
             {
-                let mut prepared_commit =
-                    index_writer.prepare_commit(false).expect("commit failed");
+                let mut prepared_commit = index_writer.prepare_commit().expect("commit failed");
                 prepared_commit.set_payload("first commit");
                 prepared_commit.commit().expect("commit failed");
             }
@@ -1098,8 +1087,7 @@ mod tests {
                 index_writer.add_document(doc!(text_field => "a"));
             }
             {
-                let mut prepared_commit =
-                    index_writer.prepare_commit(false).expect("commit failed");
+                let mut prepared_commit = index_writer.prepare_commit().expect("commit failed");
                 prepared_commit.set_payload("first commit");
                 prepared_commit.abort().expect("commit failed");
             }
@@ -1277,41 +1265,4 @@ mod tests {
         let commit = index_writer.commit();
         assert!(commit.is_ok());
     }
-
-    #[test]
-    fn test_index_writer_reader() {
-        let mut schema_builder = schema::Schema::builder();
-        let idfield = schema_builder.add_text_field("id", STRING);
-        schema_builder.add_text_field("optfield", STRING);
-        let index = Index::create_in_ram(schema_builder.build());
-        let mut index_writer = index.writer_with_num_threads(1, 3_000_000).unwrap();
-        index_writer.add_document(doc!(idfield=>"myid"));
-        assert!(index_writer.commit().is_ok());
-        let reader = index_writer.reader(2).unwrap();
-        let searcher = reader.searcher();
-        assert_eq!(searcher.num_docs(), 1u64);
-        index_writer.add_document(doc!(idfield=>"myid"));
-        assert!(index_writer.commit().is_ok());
-        assert_eq!(reader.searcher().num_docs(), 2u64);
-        assert_eq!(searcher.num_docs(), 1u64);
-    }
-
-    #[test]
-    fn test_index_writer_reader_soft_commit() {
-        let mut schema_builder = schema::Schema::builder();
-        let idfield = schema_builder.add_text_field("id", STRING);
-        schema_builder.add_text_field("optfield", STRING);
-        let index = Index::create_in_ram(schema_builder.build());
-        let mut index_writer = index.writer_with_num_threads(1, 3_000_000).unwrap();
-        index_writer.add_document(doc!(idfield=>"myid"));
-        assert!(index_writer.soft_commit().is_ok());
-        let nrt_reader = index_writer.reader(2).unwrap();
-        let normal_reader = index.reader_builder().try_into().unwrap();
-        assert_eq!(nrt_reader.searcher().num_docs(), 1u64);
-        assert_eq!(normal_reader.searcher().num_docs(), 0u64);
-        assert!(index_writer.commit().is_ok());
-        assert!(normal_reader.reload().is_ok());
-        assert_eq!(nrt_reader.searcher().num_docs(), 1u64);
-        assert_eq!(normal_reader.searcher().num_docs(), 1u64);
-    }
 }

src/indexer/index_writer_config.rs

@@ -1,133 +0,0 @@
-use serde::{Deserialize, Serialize};
-
-// Size of the margin for the heap. A segment is closed when the remaining memory
-// in the heap goes below MARGIN_IN_BYTES.
-const MARGIN_IN_BYTES: u64 = 1_000_000;
-
-// We impose the memory per thread to be at least 3 MB.
-const HEAP_SIZE_MIN: u64 = MARGIN_IN_BYTES * 3u64;
-const HEAP_SIZE_MAX: u64 = u32::max_value() as u64 - MARGIN_IN_BYTES;
-
-#[derive(Debug, Clone, Serialize, Deserialize)]
-pub struct IndexWriterConfig {
-    pub max_indexing_threads: usize,
-    pub max_merging_threads: usize,
-    pub memory_budget: u64,
-    pub store_flush_num_bytes: u64,
-    pub persist_low: u64,
-    pub persist_high: u64,
-}
-
-impl Default for IndexWriterConfig {
-    fn default() -> Self {
-        IndexWriterConfig {
-            max_indexing_threads: 1,
-            max_merging_threads: 3,
-            memory_budget: 50_000_000u64,
-            store_flush_num_bytes: 10_000_000u64,
-            persist_low: 10_000_000u64,
-            persist_high: 50_000_000u64
-        }
-    }
-}
-
-impl IndexWriterConfig {
-    #[cfg(test)]
-    pub fn for_test() -> IndexWriterConfig {
-        IndexWriterConfig {
-            max_indexing_threads: 1,
-            max_merging_threads: 5,
-            memory_budget: 4_000_000u64,
-            store_flush_num_bytes: 500_000u64,
-            persist_low: 2_000_000u64,
-            persist_high: 3_000_000u64,
-        }
-    }
-
-    // Ensures the `IndexWriterConfig` is correct.
-    //
-    // This method checks that the values in the `IndexWriterConfig`
-    // are valid. If it is not, it may mutate some of the values (like `max_num_threads`) to
-    // fit the contracts or return an error with an explicit error message.
-    //
-    // If called twice, the config is guaranteed to not be updated the second time.
-    pub fn validate(&mut self) -> crate::Result<()> {
-        if self.memory_budget < HEAP_SIZE_MIN {
-            let err_msg = format!(
-                "The heap size per thread needs to be at least {}.",
-                HEAP_SIZE_MIN
-            );
-            return Err(crate::TantivyError::InvalidArgument(err_msg));
-        }
-        let heap_size_in_bytes_per_thread = self.heap_size_in_byte_per_thread();
-        if heap_size_in_bytes_per_thread >= HEAP_SIZE_MAX {
-            let err_msg = format!("The heap size per thread cannot exceed {}", HEAP_SIZE_MAX);
-            return Err(crate::TantivyError::InvalidArgument(err_msg));
-        }
-        if heap_size_in_bytes_per_thread < HEAP_SIZE_MIN {
-            self.max_indexing_threads = (self.memory_budget / HEAP_SIZE_MIN) as usize;
-        }
-        Ok(())
-    }
-
-    pub fn heap_size_in_byte_per_thread(&self) -> u64 {
-        self.memory_budget / self.max_indexing_threads as u64
-    }
-
-    pub fn heap_size_before_flushing(&self) -> u64 {
-        self.heap_size_in_byte_per_thread() - MARGIN_IN_BYTES
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use crate::IndexWriterConfig;
-
-    #[test]
-    fn test_index_writer_config_simple() {
-        let mut index = IndexWriterConfig {
-            max_indexing_threads: 3,
-            memory_budget: super::HEAP_SIZE_MIN * 3,
-            ..Default::default()
-        };
-        assert!(index.validate().is_ok());
-        assert_eq!(index.max_indexing_threads, 3);
-        assert_eq!(index.heap_size_in_byte_per_thread(), super::HEAP_SIZE_MIN);
-    }
-
-    #[test]
-    fn test_index_writer_config_reduce_num_threads() {
-        let mut index = IndexWriterConfig {
-            max_indexing_threads: 3,
-            memory_budget: super::HEAP_SIZE_MIN,
-            ..Default::default()
-        };
-        assert!(index.validate().is_ok());
-        assert_eq!(index.max_indexing_threads, 1);
-        assert_eq!(index.heap_size_in_byte_per_thread(), super::HEAP_SIZE_MIN);
-    }
-
-    #[test]
-    fn test_index_writer_config_not_enough_memory() {
-        let mut index = IndexWriterConfig {
-            max_indexing_threads: 1,
-            memory_budget: super::HEAP_SIZE_MIN - 1,
-            ..Default::default()
-        };
-        assert!(
-            matches!(index.validate(), Err(crate::TantivyError::InvalidArgument(msg) ) if msg.contains("The heap size per thread needs to be at least"))
-        );
-    }
-
-    #[test]
-    fn test_index_writer_config_too_much_memory() {
-        let mut index = IndexWriterConfig {
-            max_indexing_threads: 1,
-            memory_budget: (u32::max_value() as u64) + 1,
-            ..Default::default()
-        };
-        assert!(
-            matches!(index.validate(), Err(crate::TantivyError::InvalidArgument(msg) ) if msg.contains("The heap size per thread cannot exceed"))
-        );
-    }
-}

src/indexer/merge_operation.rs

@@ -1,22 +1,17 @@
-use crate::indexer::resource_manager::{Allocation, ResourceManager};
 use crate::Opstamp;
 use crate::SegmentId;
 use census::{Inventory, TrackedObject};
 use std::collections::HashSet;
-use std::fmt;
 use std::ops::Deref;
 
-#[derive(Default, Clone)]
-pub(crate) struct MergeOperationInventory {
-    inventory: Inventory<InnerMergeOperation>,
-    num_merge_watcher: ResourceManager,
-}
+#[derive(Default)]
+pub(crate) struct MergeOperationInventory(Inventory<InnerMergeOperation>);
 
 impl Deref for MergeOperationInventory {
     type Target = Inventory<InnerMergeOperation>;
 
     fn deref(&self) -> &Self::Target {
-        &self.inventory
+        &self.0
     }
 }
 
@@ -30,10 +25,6 @@ impl MergeOperationInventory {
         }
         segment_in_merge
     }
-
-    pub fn wait_until_empty(&self) {
-        let _ = self.num_merge_watcher.wait_until_in_range(0..1);
-    }
 }
 
 /// A `MergeOperation` has two roles.
@@ -56,17 +47,6 @@ pub struct MergeOperation {
 pub(crate) struct InnerMergeOperation {
     target_opstamp: Opstamp,
     segment_ids: Vec<SegmentId>,
-    _allocation: Allocation,
-}
-
-impl fmt::Debug for InnerMergeOperation {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(
-            f,
-            "MergeOp(target_opstamp={:?}, segment_ids={:?})",
-            self.target_opstamp, self.segment_ids
-        )
-    }
 }
 
 impl MergeOperation {
@@ -75,11 +55,9 @@ impl MergeOperation {
         target_opstamp: Opstamp,
         segment_ids: Vec<SegmentId>,
     ) -> MergeOperation {
-        let allocation = inventory.num_merge_watcher.allocate(1);
         let inner_merge_operation = InnerMergeOperation {
             target_opstamp,
             segment_ids,
-            _allocation: allocation,
         };
         MergeOperation {
             inner: inventory.track(inner_merge_operation),

src/indexer/merger.rs

@@ -2,8 +2,6 @@ use crate::common::MAX_DOC_LIMIT;
 use crate::core::Segment;
 use crate::core::SegmentReader;
 use crate::core::SerializableSegment;
-use crate::directory::TerminatingWrite;
-use crate::directory::WritePtr;
 use crate::docset::DocSet;
 use crate::fastfield::BytesFastFieldReader;
 use crate::fastfield::DeleteBitSet;
@@ -662,8 +660,7 @@ impl IndexMerger {
         Ok(term_ordinal_mappings)
     }
 
-    pub fn write_storable_fields(&self, store_wrt: WritePtr) -> crate::Result<()> {
-        let mut store_writer = StoreWriter::new(store_wrt);
+    fn write_storable_fields(&self, store_writer: &mut StoreWriter) -> crate::Result<()> {
         for reader in &self.readers {
             let store_reader = reader.get_store_reader();
             if reader.num_deleted_docs() > 0 {
@@ -675,8 +672,6 @@ impl IndexMerger {
                 store_writer.stack(&store_reader)?;
             }
         }
-        let store_wrt = store_writer.close()?;
-        store_wrt.terminate()?;
         Ok(())
     }
 }
@@ -686,6 +681,7 @@ impl SerializableSegment for IndexMerger {
         let term_ord_mappings = self.write_postings(serializer.get_postings_serializer())?;
         self.write_fieldnorms(serializer.get_fieldnorms_serializer())?;
         self.write_fast_fields(serializer.get_fast_field_serializer(), term_ord_mappings)?;
+        self.write_storable_fields(serializer.get_store_writer())?;
         serializer.close()?;
         Ok(self.max_doc)
     }

src/indexer/mod.rs

@@ -2,14 +2,12 @@ pub mod delete_queue;
 
 mod doc_opstamp_mapping;
 pub mod index_writer;
-mod index_writer_config;
 mod log_merge_policy;
 mod merge_operation;
 pub mod merge_policy;
 pub mod merger;
 pub mod operation;
 mod prepared_commit;
-mod resource_manager;
 mod segment_entry;
 mod segment_manager;
 mod segment_register;
@@ -18,17 +16,13 @@ pub mod segment_updater;
 mod segment_writer;
 mod stamper;
 
-pub(crate) use self::resource_manager::{Allocation, ResourceManager};
-pub(crate) use self::merge_operation::MergeOperationInventory;
 pub use self::index_writer::IndexWriter;
-pub use self::index_writer_config::IndexWriterConfig;
 pub use self::log_merge_policy::LogMergePolicy;
 pub use self::merge_operation::MergeOperation;
 pub use self::merge_policy::{MergeCandidate, MergePolicy, NoMergePolicy};
 pub use self::prepared_commit::PreparedCommit;
 pub use self::segment_entry::SegmentEntry;
 pub use self::segment_manager::SegmentManager;
-pub(crate) use self::segment_manager::SegmentRegisters;
 pub use self::segment_serializer::SegmentSerializer;
 pub use self::segment_writer::SegmentWriter;
 

src/indexer/prepared_commit.rs

@@ -7,20 +7,14 @@ pub struct PreparedCommit<'a> {
     index_writer: &'a mut IndexWriter,
     payload: Option<String>,
     opstamp: Opstamp,
-    soft_commit: bool,
 }
 
 impl<'a> PreparedCommit<'a> {
-    pub(crate) fn new(
-        index_writer: &'a mut IndexWriter,
-        opstamp: Opstamp,
-        soft_commit: bool,
-    ) -> PreparedCommit<'_> {
+    pub(crate) fn new(index_writer: &'a mut IndexWriter, opstamp: Opstamp) -> PreparedCommit<'_> {
         PreparedCommit {
             index_writer,
             payload: None,
             opstamp,
-            soft_commit,
         }
     }
 
@@ -38,12 +32,11 @@ impl<'a> PreparedCommit<'a> {
 
     pub fn commit(self) -> crate::Result<Opstamp> {
         info!("committing {}", self.opstamp);
-        block_on(self.index_writer.segment_updater().schedule_commit(
-            self.opstamp,
-            self.payload,
-            self.soft_commit,
-        ))?;
-        block_on(self.index_writer.trigger_commit());
+        let _ = block_on(
+            self.index_writer
+                .segment_updater()
+                .schedule_commit(self.opstamp, self.payload),
+        );
         Ok(self.opstamp)
     }
 }

src/indexer/resource_manager.rs

@@ -1,213 +0,0 @@
-use std::ops::RangeBounds;
-use std::sync::{Arc, Condvar, Mutex, MutexGuard, RwLock};
-
-struct LockedData {
-    count: u64,
-    enabled: bool
-}
-
-impl Default for LockedData {
-    fn default() -> Self {
-        LockedData {
-            count: 0u64,
-            enabled: true
-        }
-    }
-}
-
-#[derive(Default)]
-struct Inner {
-    resource_level: Mutex<LockedData>,
-    convdvar: Condvar,
-}
-
-
-/// The resource manager makes it possible to track the amount of level of a given resource.
-/// There is no magic here : it is to the description of the user to declare how much
-/// of the resource is being held.
-///
-/// Allocation of a resource is bound to the lifetime of a `Allocation` instance.
-///
-/// ```rust
-/// let resource_manager = ResourceManager::default();
-///
-/// ```
-///
-/// In tantivy, this is used to check the number of merging thread and the number of memory
-/// used by the volatile segments.
-///
-#[derive(Clone, Default)]
-pub struct ResourceManager {
-    inner: Arc<Inner>,
-}
-
-impl ResourceManager {
-    /// Return the total amount of reousrce allocated
-    pub fn total_amount(&self) -> u64 {
-        self.lock().count
-    }
-
-    fn lock(&self) -> MutexGuard<LockedData> {
-        self.inner
-            .resource_level
-            .lock()
-            .expect("Failed to obtain lock for ReservedMemory. This should never happen.")
-    }
-
-    fn record_delta(&self, delta: i64) {
-        if delta == 0i64 {
-            return;
-        }
-        let mut lock = self.lock();
-        let new_val = lock.count as i64 + delta;
-        lock.count = new_val as u64;
-        self.inner.convdvar.notify_all();
-    }
-
-    /// Records a new allocation.
-    ///
-    /// The returned allocate object is used to automatically release the allocated resource
-    /// on drop.
-    pub fn allocate(&self, amount: u64) -> Allocation {
-        self.record_delta(amount as i64);
-        Allocation {
-            resource_manager: self.clone(),
-            amount: RwLock::new(amount),
-        }
-    }
-
-    /// Stops the resource manager.
-    ///
-    /// If any thread is waiting via `.wait_until_in_range(...)`, the method will stop
-    /// being blocking and will return an error.
-    pub fn terminate(&self) {
-        self.lock().enabled = false;
-        self.inner.convdvar.notify_all();
-    }
-
-    /// Blocks the current thread until the resource level reaches the given range,
-    /// in a cpu-efficient way.
-    ///
-    /// This method does not necessarily wakes up the current thread at every transition
-    /// into the targetted range, but any durable entry in the range will be detected.
-    pub fn wait_until_in_range<R: RangeBounds<u64>>(&self, range: R) -> Result<u64, u64> {
-        let mut levels = self.lock();
-        if !levels.enabled {
-            return Err(levels.count)
-        }
-        while !range.contains(&levels.count) {
-           levels = self.inner.convdvar.wait(levels).unwrap();
-            if !levels.enabled {
-                return Err(levels.count)
-            }
-        }
-        Ok(levels.count)
-    }
-}
-
-pub struct Allocation {
-    resource_manager: ResourceManager,
-    amount: RwLock<u64>,
-}
-
-impl Allocation {
-    pub fn amount(&self) -> u64 {
-        *self.amount.read().unwrap()
-    }
-
-    pub fn modify(&self, new_amount: u64) {
-        let mut wlock = self.amount.write().unwrap();
-        let delta = new_amount as i64 - *wlock as i64;
-        *wlock = new_amount;
-        self.resource_manager.record_delta(delta);
-    }
-}
-
-impl Drop for Allocation {
-    fn drop(&mut self) {
-        let amount = self.amount();
-        self.resource_manager.record_delta(-(amount as i64))
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::ResourceManager;
-    use futures::channel::oneshot;
-    use futures::executor::block_on;
-    use std::{mem, thread};
-
-    #[test]
-    fn test_simple_allocation() {
-        let memory = ResourceManager::default();
-        assert_eq!(memory.total_amount(), 0u64);
-        let _allocation = memory.allocate(10u64);
-        assert_eq!(memory.total_amount(), 10u64);
-    }
-
-    #[test]
-    fn test_multiple_allocation() {
-        let memory = ResourceManager::default();
-        assert_eq!(memory.total_amount(), 0u64);
-        let _allocation = memory.allocate(10u64);
-        let _allocation_2 = memory.allocate(11u64);
-        assert_eq!(memory.total_amount(), 21u64);
-    }
-
-    #[test]
-    fn test_release_on_drop() {
-        let memory = ResourceManager::default();
-        assert_eq!(memory.total_amount(), 0u64);
-        let allocation = memory.allocate(10u64);
-        let allocation_2 = memory.allocate(11u64);
-        assert_eq!(memory.total_amount(), 21u64);
-        mem::drop(allocation);
-        assert_eq!(memory.total_amount(), 11u64);
-        mem::drop(allocation_2);
-        assert_eq!(memory.total_amount(), 0u64);
-    }
-
-    #[test]
-    fn test_wait_until() {
-        let memory = ResourceManager::default();
-        let (send, recv) = oneshot::channel::<()>();
-        let memory_clone = memory.clone();
-        thread::spawn(move || {
-            let _allocation1 = memory_clone.allocate(2u64);
-            let _allocation2 = memory_clone.allocate(3u64);
-            let _allocation3 = memory_clone.allocate(4u64);
-            std::mem::drop(_allocation3);
-            assert!(block_on(recv).is_ok());
-        });
-        assert_eq!(memory.wait_until_in_range(5u64..8u64), Ok(5u64));
-        assert!(send.send(()).is_ok());
-    }
-
-    #[test]
-    fn test_modify_amount() {
-        let memory = ResourceManager::default();
-        let alloc = memory.allocate(2u64);
-        assert_eq!(memory.total_amount(), 2u64);
-        assert_eq!(alloc.amount(), 2u64);
-        let alloc2 = memory.allocate(3u64);
-        assert_eq!(memory.total_amount(), 2u64 + 3u64);
-        assert_eq!(alloc2.amount(), 3u64);
-        alloc.modify(14u64);
-        assert_eq!(alloc.amount(), 14u64);
-        assert_eq!(memory.total_amount(), 14u64 + 3u64)
-    }
-    
-    #[test]
-    fn test_stop_resource_manager() {
-        let resource_manager = ResourceManager::default();
-        let resource_manager_clone = resource_manager.clone();
-        let (sender, recv) = oneshot::channel();
-        let join_handle = thread::spawn(move || {
-            assert!(sender.send(()).is_ok());
-            resource_manager_clone.wait_until_in_range(10..20)
-        });
-        let _ = block_on(recv);
-        resource_manager.terminate();
-        assert_eq!(join_handle.join().unwrap(), Err(0u64));
-    }
-}

src/indexer/segment_entry.rs

@@ -1,9 +1,7 @@
 use crate::common::BitSet;
 use crate::core::SegmentId;
 use crate::core::SegmentMeta;
-use crate::directory::ManagedDirectory;
 use crate::indexer::delete_queue::DeleteCursor;
-use crate::{Opstamp, Segment};
 use std::fmt;
 
 /// A segment entry describes the state of
@@ -21,7 +19,7 @@ use std::fmt;
 /// in the .del file or in the `delete_bitset`.
 #[derive(Clone)]
 pub struct SegmentEntry {
-    segment: Segment,
+    meta: SegmentMeta,
     delete_bitset: Option<BitSet>,
     delete_cursor: DeleteCursor,
 }
@@ -29,67 +27,47 @@ pub struct SegmentEntry {
 impl SegmentEntry {
     /// Create a new `SegmentEntry`
     pub fn new(
-        segment: Segment,
+        segment_meta: SegmentMeta,
         delete_cursor: DeleteCursor,
         delete_bitset: Option<BitSet>,
     ) -> SegmentEntry {
         SegmentEntry {
-            segment,
+            meta: segment_meta,
             delete_bitset,
             delete_cursor,
         }
     }
 
-    pub fn persist(&mut self, dest_directory: ManagedDirectory) -> crate::Result<()> {
-        // TODO take in account delete bitset?
-        self.segment.persist(dest_directory)?;
-        Ok(())
-    }
-
-    pub fn set_delete_cursor(&mut self, delete_cursor: DeleteCursor) {
-        self.delete_cursor = delete_cursor;
-    }
-
-    /// `Takes` (as in Option::take) the delete bitset of a segment entry.
-    /// `DocId` in this bitset are flagged as deleted.
-    pub fn take_delete_bitset(&mut self) -> Option<BitSet> {
-        self.delete_bitset.take()
-    }
-
-    /// Reset the delete information in this segment.
+    /// Return a reference to the segment entry deleted bitset.
     ///
-    /// The `SegmentEntry` segment's `SegmentMeta` gets updated, and
-    /// any delete bitset is drop and set to None.
-    pub fn reset_delete_meta(&mut self, num_deleted_docs: u32, target_opstamp: Opstamp) {
-        self.segment = self
-            .segment
-            .clone()
-            .with_delete_meta(num_deleted_docs, target_opstamp);
-        self.delete_bitset = None;
+    /// `DocId` in this bitset are flagged as deleted.
+    pub fn delete_bitset(&self) -> Option<&BitSet> {
+        self.delete_bitset.as_ref()
+    }
+
+    /// Set the `SegmentMeta` for this segment.
+    pub fn set_meta(&mut self, segment_meta: SegmentMeta) {
+        self.meta = segment_meta;
     }
 
     /// Return a reference to the segment_entry's delete cursor
-    pub fn delete_cursor(&mut self) -> DeleteCursor {
-        self.delete_cursor.clone()
+    pub fn delete_cursor(&mut self) -> &mut DeleteCursor {
+        &mut self.delete_cursor
     }
 
     /// Returns the segment id.
     pub fn segment_id(&self) -> SegmentId {
-        self.meta().id()
+        self.meta.id()
     }
 
-    /// Returns the `segment` associated to the `SegmentEntry`.
-    pub fn segment(&self) -> &Segment {
-        &self.segment
-    }
     /// Accessor to the `SegmentMeta`
     pub fn meta(&self) -> &SegmentMeta {
-        self.segment.meta()
+        &self.meta
     }
 }
 
 impl fmt::Debug for SegmentEntry {
     fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(formatter, "SegmentEntry({:?})", self.meta())
+        write!(formatter, "SegmentEntry({:?})", self.meta)
     }
 }

src/indexer/segment_manager.rs

@@ -2,15 +2,15 @@ use super::segment_register::SegmentRegister;
 use crate::core::SegmentId;
 use crate::core::SegmentMeta;
 use crate::error::TantivyError;
-use crate::indexer::{SegmentEntry, MergeOperationInventory, MergeCandidate, MergeOperation};
-use crate::{Segment, Opstamp};
+use crate::indexer::delete_queue::DeleteCursor;
+use crate::indexer::SegmentEntry;
 use std::collections::hash_set::HashSet;
 use std::fmt::{self, Debug, Formatter};
-use std::sync::{Arc, RwLock};
+use std::sync::RwLock;
 use std::sync::{RwLockReadGuard, RwLockWriteGuard};
 
 #[derive(Default)]
-pub(crate) struct SegmentRegisters {
+struct SegmentRegisters {
     uncommitted: SegmentRegister,
     committed: SegmentRegister,
 }
@@ -22,17 +22,6 @@ pub(crate) enum SegmentsStatus {
 }
 
 impl SegmentRegisters {
-    pub fn new(committed: SegmentRegister) -> SegmentRegisters {
-        SegmentRegisters {
-            uncommitted: Default::default(),
-            committed,
-        }
-    }
-
-    pub fn committed_segment(&self) -> Vec<Segment> {
-        self.committed.segments()
-    }
-
     /// Check if all the segments are committed or uncommited.
     ///
     /// If some segment is missing or segments are in a different state (this should not happen
@@ -55,8 +44,7 @@ impl SegmentRegisters {
 /// changes (merges especially)
 #[derive(Default)]
 pub struct SegmentManager {
-    registers: Arc<RwLock<SegmentRegisters>>,
-    merge_operations: MergeOperationInventory,
+    registers: RwLock<SegmentRegisters>,
 }
 
 impl Debug for SegmentManager {
@@ -70,28 +58,34 @@ impl Debug for SegmentManager {
     }
 }
 
+pub fn get_mergeable_segments(
+    in_merge_segment_ids: &HashSet<SegmentId>,
+    segment_manager: &SegmentManager,
+) -> (Vec<SegmentMeta>, Vec<SegmentMeta>) {
+    let registers_lock = segment_manager.read();
+    (
+        registers_lock
+            .committed
+            .get_mergeable_segments(in_merge_segment_ids),
+        registers_lock
+            .uncommitted
+            .get_mergeable_segments(in_merge_segment_ids),
+    )
+}
 
 impl SegmentManager {
-    pub(crate) fn new(registers: Arc<RwLock<SegmentRegisters>>) -> SegmentManager {
+    pub fn from_segments(
+        segment_metas: Vec<SegmentMeta>,
+        delete_cursor: &DeleteCursor,
+    ) -> SegmentManager {
         SegmentManager {
-            registers,
-            merge_operations: Default::default()
+            registers: RwLock::new(SegmentRegisters {
+                uncommitted: SegmentRegister::default(),
+                committed: SegmentRegister::new(segment_metas, delete_cursor),
+            }),
         }
     }
 
-    pub fn new_merge_operation(&self, opstamp: Opstamp, merge_candidate: MergeCandidate) -> MergeOperation {
-        MergeOperation::new(
-            &self.merge_operations,
-            opstamp,
-            merge_candidate.0
-
-        )
-    }
-
-    pub fn wait_merging_thread(&self) {
-        self.merge_operations.wait_until_empty()
-    }
-
     /// Returns all of the segment entries (committed or uncommitted)
     pub fn segment_entries(&self) -> Vec<SegmentEntry> {
         let registers_lock = self.read();
@@ -100,34 +94,6 @@ impl SegmentManager {
         segment_entries
     }
 
-    /// Returns the segments that are currently not in merge.
-    ///
-    /// They are split over two `Vec`. The committed segments on one hand
-    /// and the uncommitted ones on the other hand.
-    ///
-    /// This method is useful when searching for merge candidate or segments
-    /// to persists.
-    pub fn segments_not_in_merge(&self) -> (Vec<SegmentMeta>, Vec<SegmentMeta>) {
-        let in_merge_segment_ids: HashSet<SegmentId> = self.merge_operations.segment_in_merge();
-        let registers_lock = self.read();
-        (
-            registers_lock
-                .committed
-                .get_mergeable_segments(&in_merge_segment_ids),
-            registers_lock
-                .uncommitted
-                .get_mergeable_segments(&in_merge_segment_ids),
-        )
-    }
-
-    pub fn largest_segment_not_in_merge(&self) -> Option<SegmentMeta> {
-        let (committed, uncommitted) = self.segments_not_in_merge();
-        let mut segments = vec![];
-        segments.extend(committed);
-        segments.extend(uncommitted);
-        None
-    }
-
     // Lock poisoning should never happen :
     // The lock is acquired and released within this class,
     // and the operations cannot panic.

src/indexer/segment_register.rs

@@ -1,10 +1,7 @@
 use crate::core::SegmentId;
 use crate::core::SegmentMeta;
-use crate::directory::ManagedDirectory;
 use crate::indexer::delete_queue::DeleteCursor;
 use crate::indexer::segment_entry::SegmentEntry;
-use crate::schema::Schema;
-use crate::Segment;
 use std::collections::HashMap;
 use std::collections::HashSet;
 use std::fmt::{self, Debug, Formatter};
@@ -49,13 +46,6 @@ impl SegmentRegister {
             .collect()
     }
 
-    pub fn segments(&self) -> Vec<Segment> {
-        self.segment_states
-            .values()
-            .map(|segment_entry| segment_entry.segment().clone())
-            .collect()
-    }
-
     pub fn segment_entries(&self) -> Vec<SegmentEntry> {
         self.segment_states.values().cloned().collect()
     }
@@ -89,17 +79,11 @@ impl SegmentRegister {
         self.segment_states.get(segment_id).cloned()
     }
 
-    pub fn new(
-        directory: &ManagedDirectory,
-        schema: &Schema,
-        segment_metas: Vec<SegmentMeta>,
-        delete_cursor: &DeleteCursor,
-    ) -> SegmentRegister {
+    pub fn new(segment_metas: Vec<SegmentMeta>, delete_cursor: &DeleteCursor) -> SegmentRegister {
         let mut segment_states = HashMap::new();
         for segment_meta in segment_metas {
             let segment_id = segment_meta.id();
-            let segment = Segment::new_persisted(segment_meta, directory.clone(), schema.clone());
-            let segment_entry = SegmentEntry::new(segment, delete_cursor.clone(), None);
+            let segment_entry = SegmentEntry::new(segment_meta, delete_cursor.clone(), None);
             segment_states.insert(segment_id, segment_entry);
         }
         SegmentRegister { segment_states }
@@ -111,7 +95,6 @@ mod tests {
     use super::*;
     use crate::core::{SegmentId, SegmentMetaInventory};
     use crate::indexer::delete_queue::*;
-    use crate::indexer::ResourceManager;
 
     fn segment_ids(segment_register: &SegmentRegister) -> Vec<SegmentId> {
         segment_register
@@ -125,34 +108,28 @@ mod tests {
     fn test_segment_register() {
         let inventory = SegmentMetaInventory::default();
         let delete_queue = DeleteQueue::new();
-        let schema = Schema::builder().build();
 
         let mut segment_register = SegmentRegister::default();
         let segment_id_a = SegmentId::generate_random();
         let segment_id_b = SegmentId::generate_random();
         let segment_id_merged = SegmentId::generate_random();
 
-        let memory_manager = ResourceManager::default();
-
         {
-            let meta = inventory.new_segment_meta(segment_id_a, 0u32);
-            let segment = Segment::new_volatile(meta, schema.clone(), memory_manager.clone());
-            let segment_entry = SegmentEntry::new(segment, delete_queue.cursor(), None);
+            let segment_meta = inventory.new_segment_meta(segment_id_a, 0u32);
+            let segment_entry = SegmentEntry::new(segment_meta, delete_queue.cursor(), None);
             segment_register.add_segment_entry(segment_entry);
         }
         assert_eq!(segment_ids(&segment_register), vec![segment_id_a]);
         {
-            let meta = inventory.new_segment_meta(segment_id_b, 0u32);
-            let segment = Segment::new_volatile(meta, schema.clone(), memory_manager.clone());
-            let segment_entry = SegmentEntry::new(segment, delete_queue.cursor(), None);
+            let segment_meta = inventory.new_segment_meta(segment_id_b, 0u32);
+            let segment_entry = SegmentEntry::new(segment_meta, delete_queue.cursor(), None);
             segment_register.add_segment_entry(segment_entry);
         }
         segment_register.remove_segment(&segment_id_a);
         segment_register.remove_segment(&segment_id_b);
         {
             let segment_meta_merged = inventory.new_segment_meta(segment_id_merged, 0u32);
-            let segment_merged = Segment::new_volatile(segment_meta_merged, schema.clone(), memory_manager.clone());
-            let segment_entry = SegmentEntry::new(segment_merged, delete_queue.cursor(), None);
+            let segment_entry = SegmentEntry::new(segment_meta_merged, delete_queue.cursor(), None);
             segment_register.add_segment_entry(segment_entry);
         }
         assert_eq!(segment_ids(&segment_register), vec![segment_id_merged]);

src/indexer/segment_serializer.rs

@@ -3,10 +3,12 @@ use crate::core::SegmentComponent;
 use crate::fastfield::FastFieldSerializer;
 use crate::fieldnorm::FieldNormsSerializer;
 use crate::postings::InvertedIndexSerializer;
+use crate::store::StoreWriter;
 
 /// Segment serializer is in charge of laying out on disk
 /// the data accumulated and sorted by the `SegmentWriter`.
 pub struct SegmentSerializer {
+    store_writer: StoreWriter,
     fast_field_serializer: FastFieldSerializer,
     fieldnorms_serializer: FieldNormsSerializer,
     postings_serializer: InvertedIndexSerializer,
@@ -15,6 +17,8 @@ pub struct SegmentSerializer {
 impl SegmentSerializer {
     /// Creates a new `SegmentSerializer`.
     pub fn for_segment(segment: &mut Segment) -> crate::Result<SegmentSerializer> {
+        let store_write = segment.open_write(SegmentComponent::STORE)?;
+
         let fast_field_write = segment.open_write(SegmentComponent::FASTFIELDS)?;
         let fast_field_serializer = FastFieldSerializer::from_write(fast_field_write)?;
 
@@ -23,6 +27,7 @@ impl SegmentSerializer {
 
         let postings_serializer = InvertedIndexSerializer::open(segment)?;
         Ok(SegmentSerializer {
+            store_writer: StoreWriter::new(store_write),
             fast_field_serializer,
             fieldnorms_serializer,
             postings_serializer,
@@ -44,10 +49,16 @@ impl SegmentSerializer {
         &mut self.fieldnorms_serializer
     }
 
+    /// Accessor to the `StoreWriter`.
+    pub fn get_store_writer(&mut self) -> &mut StoreWriter {
+        &mut self.store_writer
+    }
+
     /// Finalize the segment serialization.
     pub fn close(self) -> crate::Result<()> {
         self.fast_field_serializer.close()?;
         self.postings_serializer.close()?;
+        self.store_writer.close()?;
         self.fieldnorms_serializer.close()?;
         Ok(())
     }

src/indexer/segment_updater.rs

@@ -1,4 +1,4 @@
-use super::segment_manager::SegmentManager;
+use super::segment_manager::{get_mergeable_segments, SegmentManager};
 use crate::core::Index;
 use crate::core::IndexMeta;
 use crate::core::Segment;
@@ -7,16 +7,18 @@ use crate::core::SegmentMeta;
 use crate::core::SerializableSegment;
 use crate::core::META_FILEPATH;
 use crate::directory::{Directory, DirectoryClone, GarbageCollectionResult};
+use crate::indexer::delete_queue::DeleteCursor;
 use crate::indexer::index_writer::advance_deletes;
+use crate::indexer::merge_operation::MergeOperationInventory;
 use crate::indexer::merger::IndexMerger;
-use crate::indexer::segment_manager::{SegmentRegisters, SegmentsStatus};
+use crate::indexer::segment_manager::SegmentsStatus;
 use crate::indexer::stamper::Stamper;
 use crate::indexer::SegmentEntry;
 use crate::indexer::SegmentSerializer;
 use crate::indexer::{DefaultMergePolicy, MergePolicy};
 use crate::indexer::{MergeCandidate, MergeOperation};
 use crate::schema::Schema;
-use crate::{Opstamp, SegmentComponent};
+use crate::Opstamp;
 use futures::channel::oneshot;
 use futures::executor::{ThreadPool, ThreadPoolBuilder};
 use futures::future::Future;
@@ -115,14 +117,15 @@ fn merge(
 
     // First we apply all of the delet to the merged segment, up to the target opstamp.
     for segment_entry in &mut segment_entries {
-        advance_deletes(segment_entry, target_opstamp)?;
+        let segment = index.segment(segment_entry.meta().clone());
+        advance_deletes(segment, segment_entry, target_opstamp)?;
     }
 
-    let delete_cursor = segment_entries[0].delete_cursor();
+    let delete_cursor = segment_entries[0].delete_cursor().clone();
 
     let segments: Vec<Segment> = segment_entries
         .iter()
-        .map(|segment_entry| segment_entry.segment().clone())
+        .map(|segment_entry| index.segment(segment_entry.meta().clone()))
         .collect();
 
     // An IndexMerger is like a "view" of our merged segments.
@@ -131,16 +134,11 @@ fn merge(
     // ... we just serialize this index merger in our new segment to merge the two segments.
     let segment_serializer = SegmentSerializer::for_segment(&mut merged_segment)?;
 
-    let store_wrt = merged_segment.open_write(SegmentComponent::STORE)?;
-    merger.write_storable_fields(store_wrt)?;
+    let num_docs = merger.write(segment_serializer)?;
 
-    let max_doc = merger.write(segment_serializer)?;
+    let segment_meta = index.new_segment_meta(merged_segment.id(), num_docs);
 
-    Ok(SegmentEntry::new(
-        merged_segment.with_max_doc(max_doc),
-        delete_cursor,
-        None,
-    ))
+    Ok(SegmentEntry::new(segment_meta, delete_cursor, None))
 }
 
 pub(crate) struct InnerSegmentUpdater {
@@ -159,15 +157,17 @@ pub(crate) struct InnerSegmentUpdater {
     merge_policy: RwLock<Arc<Box<dyn MergePolicy>>>,
     killed: AtomicBool,
     stamper: Stamper,
+    merge_operations: MergeOperationInventory,
 }
 
 impl SegmentUpdater {
     pub fn create(
-        segment_registers: Arc<RwLock<SegmentRegisters>>,
         index: Index,
         stamper: Stamper,
+        delete_cursor: &DeleteCursor,
     ) -> crate::Result<SegmentUpdater> {
-        let segment_manager = SegmentManager::new(segment_registers);
+        let segments = index.searchable_segment_metas()?;
+        let segment_manager = SegmentManager::from_segments(segments, delete_cursor);
         let pool = ThreadPoolBuilder::new()
             .name_prefix("segment_updater")
             .pool_size(1)
@@ -196,6 +196,7 @@ impl SegmentUpdater {
             merge_policy: RwLock::new(Arc::new(Box::new(DefaultMergePolicy::default()))),
             killed: AtomicBool::new(false),
             stamper,
+            merge_operations: Default::default(),
         })))
     }
 
@@ -261,7 +262,8 @@ impl SegmentUpdater {
     fn purge_deletes(&self, target_opstamp: Opstamp) -> crate::Result<Vec<SegmentEntry>> {
         let mut segment_entries = self.segment_manager.segment_entries();
         for segment_entry in &mut segment_entries {
-            advance_deletes(segment_entry, target_opstamp)?;
+            let segment = self.index.segment(segment_entry.meta().clone());
+            advance_deletes(segment, segment_entry, target_opstamp)?;
         }
         Ok(segment_entries)
     }
@@ -329,21 +331,12 @@ impl SegmentUpdater {
         &self,
         opstamp: Opstamp,
         payload: Option<String>,
-        soft_commit: bool,
     ) -> impl Future<Output = crate::Result<()>> {
         let segment_updater: SegmentUpdater = self.clone();
-        let directory = self.index.directory().clone();
         self.schedule_future(async move {
-            let mut segment_entries = segment_updater.purge_deletes(opstamp)?;
-            if !soft_commit {
-                for segment_entry in &mut segment_entries {
-                    segment_entry.persist(directory.clone())?;
-                }
-            }
+            let segment_entries = segment_updater.purge_deletes(opstamp)?;
             segment_updater.segment_manager.commit(segment_entries);
-            if !soft_commit {
-                segment_updater.save_metas(opstamp, payload)?;
-            }
+            segment_updater.save_metas(opstamp, payload)?;
             let _ = garbage_collect_files(segment_updater.clone()).await;
             segment_updater.consider_merge_options().await;
             Ok(())
@@ -360,7 +353,7 @@ impl SegmentUpdater {
 
     pub(crate) fn make_merge_operation(&self, segment_ids: &[SegmentId]) -> MergeOperation {
         let commit_opstamp = self.load_metas().opstamp;
-        self.segment_manager.new_merge_operation(commit_opstamp, MergeCandidate(segment_ids.to_vec()))
+        MergeOperation::new(&self.merge_operations, commit_opstamp, segment_ids.to_vec())
     }
 
     // Starts a merge operation. This function will block until the merge operation is effectively
@@ -434,8 +427,9 @@ impl SegmentUpdater {
     }
 
     async fn consider_merge_options(&self) {
+        let merge_segment_ids: HashSet<SegmentId> = self.merge_operations.segment_in_merge();
         let (committed_segments, uncommitted_segments) =
-            self.segment_manager.segments_not_in_merge();
+            get_mergeable_segments(&merge_segment_ids, &self.segment_manager);
 
         // Committed segments cannot be merged with uncommitted_segments.
         // We therefore consider merges using these two sets of segments independently.
@@ -446,7 +440,7 @@ impl SegmentUpdater {
             .compute_merge_candidates(&uncommitted_segments)
             .into_iter()
             .map(|merge_candidate| {
-                self.segment_manager.new_merge_operation(current_opstamp, merge_candidate)
+                MergeOperation::new(&self.merge_operations, current_opstamp, merge_candidate.0)
             })
             .collect();
 
@@ -455,7 +449,7 @@ impl SegmentUpdater {
             .compute_merge_candidates(&committed_segments)
             .into_iter()
             .map(|merge_candidate: MergeCandidate| {
-                self.segment_manager.new_merge_operation(commit_opstamp, merge_candidate)
+                MergeOperation::new(&self.merge_operations, commit_opstamp, merge_candidate.0)
             })
             .collect::<Vec<_>>();
         merge_candidates.extend(committed_merge_candidates.into_iter());
@@ -480,13 +474,17 @@ impl SegmentUpdater {
         let end_merge_future = self.schedule_future(async move {
             info!("End merge {:?}", after_merge_segment_entry.meta());
             {
-                let mut delete_cursor = after_merge_segment_entry.delete_cursor();
+                let mut delete_cursor = after_merge_segment_entry.delete_cursor().clone();
                 if let Some(delete_operation) = delete_cursor.get() {
                     let committed_opstamp = segment_updater.load_metas().opstamp;
                     if delete_operation.opstamp < committed_opstamp {
-                        if let Err(e) =
-                            advance_deletes(&mut after_merge_segment_entry, committed_opstamp)
-                        {
+                        let index = &segment_updater.index;
+                        let segment = index.segment(after_merge_segment_entry.meta().clone());
+                        if let Err(e) = advance_deletes(
+                            segment,
+                            &mut after_merge_segment_entry,
+                            committed_opstamp,
+                        ) {
                             error!(
                                 "Merge of {:?} was cancelled (advancing deletes failed): {:?}",
                                 merge_operation.segment_ids(),
@@ -535,8 +533,9 @@ impl SegmentUpdater {
     ///
     /// Obsolete files will eventually be cleaned up
     /// by the directory garbage collector.
-    pub fn wait_merging_thread(&self) {
-        self.segment_manager.wait_merging_thread()
+    pub fn wait_merging_thread(&self) -> crate::Result<()> {
+        self.merge_operations.wait_until_empty();
+        Ok(())
     }
 }
 
@@ -545,8 +544,7 @@ mod tests {
 
     use crate::indexer::merge_policy::tests::MergeWheneverPossible;
     use crate::schema::*;
-    use crate::{Index, SegmentId};
-    use futures::executor::block_on;
+    use crate::Index;
 
     #[test]
     fn test_delete_during_merge() {
@@ -697,27 +695,4 @@ mod tests {
             .segment_entries();
         assert!(seg_vec.is_empty());
     }
-
-    #[test]
-    fn test_merge_over_soft_commit() {
-        let mut schema_builder = Schema::builder();
-        let text_field = schema_builder.add_text_field("text", TEXT);
-        let schema = schema_builder.build();
-        let index = Index::create_in_ram(schema);
-        // writing the segment
-        let mut index_writer = index.writer_with_num_threads(1, 3_000_000).unwrap();
-        index_writer.add_document(doc!(text_field=>"a"));
-        assert!(index_writer.soft_commit().is_ok());
-        index_writer.add_document(doc!(text_field=>"a"));
-        assert!(index_writer.soft_commit().is_ok());
-
-        let reader = index_writer.reader(1).unwrap();
-        let segment_ids: Vec<SegmentId> = reader
-            .searcher()
-            .segment_readers()
-            .iter()
-            .map(|reader| reader.segment_id())
-            .collect();
-        assert!(block_on(index_writer.merge(&segment_ids)).is_ok());
-    }
 }

src/indexer/segment_writer.rs

@@ -1,11 +1,9 @@
 use super::operation::AddOperation;
 use crate::core::Segment;
 use crate::core::SerializableSegment;
-use crate::directory::{SpillingResult, SpillingWriter, TerminatingWrite};
 use crate::fastfield::FastFieldsWriter;
 use crate::fieldnorm::FieldNormsWriter;
 use crate::indexer::segment_serializer::SegmentSerializer;
-use crate::indexer::IndexWriterConfig;
 use crate::postings::compute_table_size;
 use crate::postings::MultiFieldPostingsWriter;
 use crate::schema::FieldType;
@@ -13,24 +11,21 @@ use crate::schema::Schema;
 use crate::schema::Term;
 use crate::schema::Value;
 use crate::schema::{Field, FieldEntry};
-use crate::store::StoreWriter;
 use crate::tokenizer::{BoxTokenStream, PreTokenizedStream};
-use crate::tokenizer::{FacetTokenizer, TextAnalyzer, TokenizerManager};
+use crate::tokenizer::{FacetTokenizer, TextAnalyzer};
 use crate::tokenizer::{TokenStreamChain, Tokenizer};
+use crate::DocId;
 use crate::Opstamp;
-use crate::{DocId, SegmentComponent};
 use std::io;
-use std::io::Write;
 use std::str;
-use crate::indexer::resource_manager::ResourceManager;
 
 /// Computes the initial size of the hash table.
 ///
 /// Returns a number of bit `b`, such that the recommended initial table size is 2^b.
-fn initial_table_size(per_thread_memory_budget: u64) -> crate::Result<usize> {
-    let table_memory_upper_bound = per_thread_memory_budget / 3u64;
+fn initial_table_size(per_thread_memory_budget: usize) -> crate::Result<usize> {
+    let table_memory_upper_bound = per_thread_memory_budget / 3;
     if let Some(limit) = (10..)
-        .take_while(|num_bits| compute_table_size(*num_bits) < table_memory_upper_bound)
+        .take_while(|num_bits: &usize| compute_table_size(*num_bits) < table_memory_upper_bound)
         .last()
     {
         Ok(limit.min(19)) // we cap it at 2^19 = 512K.
@@ -48,13 +43,11 @@ fn initial_table_size(per_thread_memory_budget: u64) -> crate::Result<usize> {
 pub struct SegmentWriter {
     max_doc: DocId,
     multifield_postings: MultiFieldPostingsWriter,
-    segment: Segment,
+    segment_serializer: SegmentSerializer,
     fast_field_writers: FastFieldsWriter,
     fieldnorms_writer: FieldNormsWriter,
     doc_opstamps: Vec<Opstamp>,
     tokenizers: Vec<Option<TextAnalyzer>>,
-    store_writer: StoreWriter<SpillingWriter>,
-    memory_manager: ResourceManager,
 }
 
 impl SegmentWriter {
@@ -68,13 +61,12 @@ impl SegmentWriter {
     /// - segment: The segment being written
     /// - schema
     pub fn for_segment(
-        config: &IndexWriterConfig,
-        segment: Segment,
+        memory_budget: usize,
+        mut segment: Segment,
         schema: &Schema,
-        tokenizer_manager: &TokenizerManager,
-        memory_manager: ResourceManager
     ) -> crate::Result<SegmentWriter> {
-        let table_num_bits = initial_table_size(config.heap_size_in_byte_per_thread())?;
+        let table_num_bits = initial_table_size(memory_budget)?;
+        let segment_serializer = SegmentSerializer::for_segment(&mut segment)?;
         let multifield_postings = MultiFieldPostingsWriter::new(schema, table_num_bits);
         let tokenizers = schema
             .fields()
@@ -84,32 +76,20 @@ impl SegmentWriter {
                         .get_indexing_options()
                         .and_then(|text_index_option| {
                             let tokenizer_name = &text_index_option.tokenizer();
-                            tokenizer_manager.get(tokenizer_name)
+                            segment.index().tokenizers().get(tokenizer_name)
                         }),
                     _ => None,
                 },
             )
             .collect();
-        let mut segment_clone = segment.clone();
-        let spilling_wrt = SpillingWriter::new(
-            50_000_000,
-            Box::new(move || {
-                segment_clone
-                    .open_write(SegmentComponent::STORE)
-                    .map_err(|err| io::Error::new(io::ErrorKind::Other, err))
-            }),
-        );
-        let store_writer = StoreWriter::new(spilling_wrt);
         Ok(SegmentWriter {
             max_doc: 0,
             multifield_postings,
             fieldnorms_writer: FieldNormsWriter::for_schema(schema),
-            segment,
+            segment_serializer,
             fast_field_writers: FastFieldsWriter::from_schema(schema),
             doc_opstamps: Vec::with_capacity(1_000),
             tokenizers,
-            store_writer,
-            memory_manager
         })
     }
 
@@ -117,33 +97,18 @@ impl SegmentWriter {
     ///
     /// Finalize consumes the `SegmentWriter`, so that it cannot
     /// be used afterwards.
-    pub fn finalize(mut self) -> crate::Result<(Segment, Vec<u64>)> {
+    pub fn finalize(mut self) -> crate::Result<Vec<u64>> {
         self.fieldnorms_writer.fill_up_to_max_doc(self.max_doc);
-        let spilling_wrt = self.store_writer.close()?;
-        let mut segment: Segment;
-        match spilling_wrt.finalize()? {
-            SpillingResult::Spilled => {
-                segment = self.segment.clone();
-            }
-            SpillingResult::Buffer(buf) => {
-                segment = self.segment.into_volatile(self.memory_manager.clone());
-                let mut store_wrt = segment.open_write(SegmentComponent::STORE)?;
-                store_wrt.write_all(&buf[..])?;
-                store_wrt.terminate()?;
-            }
-        }
-        let segment_serializer = SegmentSerializer::for_segment(&mut segment)?;
-        segment = segment.with_max_doc(self.max_doc);
         write(
             &self.multifield_postings,
             &self.fast_field_writers,
             &self.fieldnorms_writer,
-            segment_serializer,
+            self.segment_serializer,
         )?;
-        Ok((segment, self.doc_opstamps))
+        Ok(self.doc_opstamps)
     }
 
-    pub fn mem_usage(&self) -> u64 {
+    pub fn mem_usage(&self) -> usize {
         self.multifield_postings.mem_usage()
     }
 
@@ -281,7 +246,8 @@ impl SegmentWriter {
         }
         doc.filter_fields(|field| schema.get_field_entry(field).is_stored());
         doc.prepare_for_store();
-        self.store_writer.store(&doc)?;
+        let doc_writer = self.segment_serializer.get_store_writer();
+        doc_writer.store(&doc)?;
         self.max_doc += 1;
         Ok(())
     }

src/lib.rs

@@ -163,7 +163,7 @@ pub use crate::core::{Index, IndexMeta, Searcher, Segment, SegmentId, SegmentMet
 pub use crate::core::{InvertedIndexReader, SegmentReader};
 pub use crate::directory::Directory;
 pub use crate::indexer::operation::UserOperation;
-pub use crate::indexer::{IndexWriter, IndexWriterConfig};
+pub use crate::indexer::IndexWriter;
 pub use crate::postings::Postings;
 pub use crate::reader::LeasedItem;
 pub use crate::schema::{Document, Term};
@@ -269,6 +269,144 @@ impl DocAddress {
     }
 }
 
+
+
+mod sse2 {
+    use crate::postings::compression::{AlignedBuffer, COMPRESSION_BLOCK_SIZE};
+    use std::arch::x86_64::__m128i as DataType;
+    use std::arch::x86_64::_mm_add_epi32 as op_add;
+    use std::arch::x86_64::_mm_cmplt_epi32 as op_lt;
+    use std::arch::x86_64::_mm_load_si128 as op_load;
+    // requires 128-bits alignment
+    use std::arch::x86_64::_mm_set1_epi32 as set1;
+    use std::arch::x86_64::_mm_setzero_si128 as set0;
+    use std::arch::x86_64::_mm_sub_epi32 as op_sub;
+    use std::arch::x86_64::{_mm_cvtsi128_si32, _mm_shuffle_epi32};
+
+    const MASK1: i32 = 78;
+    const MASK2: i32 = 177;
+
+    /// Performs an exhaustive linear search over the
+    ///
+    /// There is no early exit here. We simply count the
+    /// number of elements that are `< target`.
+    pub unsafe fn linear_search_sse2_128(arr: &AlignedBuffer, target: u32) -> usize {
+        let ptr = arr as *const AlignedBuffer as *const DataType;
+        let vkey = set1(target as i32);
+        let mut cnt = set0();
+        // We work over 4 `__m128i` at a time.
+        // A single `__m128i` actual contains 4 `u32`.
+        for i in 0..(COMPRESSION_BLOCK_SIZE as isize) / (4 * 4) {
+            let cmp1 = op_lt(op_load(ptr.offset(i * 4)), vkey);
+            let cmp2 = op_lt(op_load(ptr.offset(i * 4 + 1)), vkey);
+            let cmp3 = op_lt(op_load(ptr.offset(i * 4 + 2)), vkey);
+            let cmp4 = op_lt(op_load(ptr.offset(i * 4 + 3)), vkey);
+            let sum = op_add(op_add(cmp1, cmp2), op_add(cmp3, cmp4));
+            cnt = op_sub(cnt, sum);
+        }
+        cnt = op_add(cnt, _mm_shuffle_epi32(cnt, MASK1));
+        cnt = op_add(cnt, _mm_shuffle_epi32(cnt, MASK2));
+        _mm_cvtsi128_si32(cnt) as usize
+    }
+}
+
+
+const MAX_DOC: u32 = 2_000_000_000u32;
+
+use sse2::linear_search_sse2_128;
+use crate::postings::BlockSegmentPostings;
+use crate::schema::IndexRecordOption;
+
+struct DocCursor {
+    block_segment_postings: BlockSegmentPostings,
+    cursor: usize,
+}
+
+impl DocCursor {
+    fn new(mut block_segment_postings: BlockSegmentPostings) -> DocCursor {
+        block_segment_postings.advance();
+        DocCursor {
+            block_segment_postings,
+            cursor: 0,
+        }
+    }
+    fn doc(&self,) -> DocId {
+        self.block_segment_postings.doc(self.cursor)
+    }
+
+    fn len(&self,) -> usize {
+        self.block_segment_postings.doc_freq()
+    }
+
+    fn advance(&mut self) {
+        if self.cursor == 127 {
+            self.block_segment_postings.advance();
+            self.cursor = 0;
+        } else {
+            self.cursor += 1;
+        }
+    }
+
+    fn skip_to(&mut self, target: DocId) {
+        if self.block_segment_postings.skip_reader.doc() >= target {
+            unsafe {
+                let mut ptr = self.block_segment_postings.docs_aligned_b().0.get_unchecked(self.cursor) as *const u32;
+                while *ptr < target {
+                    self.cursor += 1;
+                    ptr = ptr.offset(1);
+                }
+            }
+            return;
+        }
+        self.block_segment_postings.skip_to_b(target);
+        let block= self.block_segment_postings.docs_aligned_b();
+        self.cursor = unsafe { linear_search_sse2_128(&block, target) };
+
+    }
+}
+
+pub fn intersection(idx: &InvertedIndexReader, terms: &[Term]) -> crate::Result<u32> {
+    let mut posting_lists: Vec<DocCursor> = Vec::with_capacity(terms.len());
+    for term in terms {
+        if let Some(mut block_postings) = idx.read_block_postings(term, IndexRecordOption::Basic) {
+            posting_lists.push(DocCursor::new(block_postings ));
+        } else {
+            return Ok(0);
+        }
+    }
+    posting_lists.sort_by_key(|posting_list| posting_list.len());
+    Ok({ intersection_idx(&mut posting_lists[..]) })
+}
+
+fn intersection_idx(posting_lists: &mut [DocCursor]) -> DocId {
+    let mut candidate = posting_lists[0].doc();
+    let mut i = 1;
+
+    let mut count = 0u32;
+
+    let num_posting_lists = posting_lists.len();
+    loop {
+        while i < num_posting_lists {
+            posting_lists[i].skip_to(candidate);
+            if posting_lists[i].doc() != candidate {
+                candidate = posting_lists[i].doc();
+                i = 0;
+                continue;
+            }
+            i += 1;
+        }
+        count += 1;
+        if candidate == MAX_DOC {
+            break;
+        }
+        posting_lists[0].advance();
+        candidate = posting_lists[0].doc();
+        i = 1;
+    }
+    count - 1u32
+}
+
+
 /// `DocAddress` contains all the necessary information
 /// to identify a document given a `Searcher` object.
 ///

src/postings/block_search.rs

@@ -25,7 +25,7 @@ mod sse2 {
     ///
     /// There is no early exit here. We simply count the
     /// number of elements that are `< target`.
-    pub(crate) fn linear_search_sse2_128(arr: &AlignedBuffer, target: u32) -> usize {
+    pub fn linear_search_sse2_128(arr: &AlignedBuffer, target: u32) -> usize {
         unsafe {
             let ptr = arr as *const AlignedBuffer as *const DataType;
             let vkey = set1(target as i32);
@@ -63,6 +63,8 @@ mod sse2 {
     }
 }
 
+pub use self::sse2::linear_search_sse2_128;
+
 /// This `linear search` browser exhaustively through the array.
 /// but the early exit is very difficult to predict.
 ///

src/postings/compression/mod.rs

@@ -46,7 +46,7 @@ impl BlockEncoder {
 /// We ensure that the OutputBuffer is align on 128 bits
 /// in order to run SSE2 linear search on it.
 #[repr(align(128))]
-pub(crate) struct AlignedBuffer(pub [u32; COMPRESSION_BLOCK_SIZE]);
+pub struct AlignedBuffer(pub [u32; COMPRESSION_BLOCK_SIZE]);
 
 pub struct BlockDecoder {
     bitpacker: BitPacker4x,
@@ -67,6 +67,18 @@ impl BlockDecoder {
         }
     }
 
+    pub fn uncompress_vint_sorted_b<'a>(
+        &mut self,
+        compressed_data: &'a [u8],
+        offset: u32,
+        num_els: usize,
+    ) {
+        if num_els > 0 {
+            vint::uncompress_sorted(compressed_data, &mut self.output.0[..num_els], offset);
+        }
+        self.output.0[num_els..].iter_mut().for_each(|val| *val = 2_000_000_000u32);
+    }
+
     pub fn uncompress_block_sorted(
         &mut self,
         compressed_data: &[u8],
@@ -94,6 +106,11 @@ impl BlockDecoder {
         (&self.output, self.output_len)
     }
 
+    #[inline]
+    pub(crate) fn output_aligned_2(&self) -> &AlignedBuffer {
+        &self.output
+    }
+
     #[inline]
     pub fn output(&self, idx: usize) -> u32 {
         self.output.0[idx]

src/postings/mod.rs

@@ -3,7 +3,7 @@ Postings module (also called inverted index)
 */
 
 mod block_search;
-pub(crate) mod compression;
+pub mod compression;
 /// Postings module
 ///
 /// Postings, also called inverted lists, is the key datastructure
@@ -54,7 +54,7 @@ pub mod tests {
     use crate::docset::{DocSet, SkipResult};
     use crate::fieldnorm::FieldNormReader;
     use crate::indexer::operation::AddOperation;
-    use crate::indexer::{IndexWriterConfig, SegmentWriter, ResourceManager};
+    use crate::indexer::SegmentWriter;
     use crate::merge_policy::NoMergePolicy;
     use crate::query::Scorer;
     use crate::schema::{Document, Schema, Term, INDEXED, STRING, TEXT};
@@ -216,17 +216,11 @@ pub mod tests {
         let text_field = schema_builder.add_text_field("text", TEXT);
         let schema = schema_builder.build();
         let index = Index::create_in_ram(schema.clone());
+        let segment = index.new_segment();
 
-        let resource_manager = ResourceManager::default();
-        let segment = {
-            let mut segment_writer = SegmentWriter::for_segment(
-                &IndexWriterConfig::for_test(),
-                index.new_segment(),
-                &schema,
-                index.tokenizers(),
-                resource_manager
-            )
-            .unwrap();
+        {
+            let mut segment_writer =
+                SegmentWriter::for_segment(3_000_000, segment.clone(), &schema).unwrap();
             {
                 let mut doc = Document::default();
                 // checking that position works if the field has two values
@@ -258,9 +252,8 @@ pub mod tests {
                 };
                 segment_writer.add_document(op, &schema).unwrap();
             }
-            let (segment, _) = segment_writer.finalize().unwrap();
-            segment
-        };
+            segment_writer.finalize().unwrap();
+        }
         {
             let segment_reader = SegmentReader::open(&segment).unwrap();
             {

src/postings/postings_writer.rs

@@ -95,7 +95,7 @@ impl MultiFieldPostingsWriter {
         }
     }
 
-    pub fn mem_usage(&self) -> u64 {
+    pub fn mem_usage(&self) -> usize {
         self.term_index.mem_usage() + self.heap.mem_usage()
     }
 

src/postings/segment_postings.rs

@@ -317,7 +317,7 @@ pub struct BlockSegmentPostings {
     num_vint_docs: usize,
 
     remaining_data: OwnedRead,
-    skip_reader: SkipReader,
+    pub skip_reader: SkipReader,
 }
 
 fn split_into_skips_and_postings(
@@ -414,7 +414,12 @@ impl BlockSegmentPostings {
         self.doc_decoder.output_array()
     }
 
-    pub(crate) fn docs_aligned(&self) -> (&AlignedBuffer, usize) {
+    #[inline(always)]
+    pub fn docs_aligned_b(&self) -> &AlignedBuffer {
+        self.doc_decoder.output_aligned_2()
+    }
+
+    pub fn docs_aligned(&self) -> (&AlignedBuffer, usize) {
         self.doc_decoder.output_aligned()
     }
 
@@ -486,6 +491,7 @@ impl BlockSegmentPostings {
                     }
                 }
                 self.doc_offset = self.skip_reader.doc();
+                unsafe { core::arch::x86_64::_mm_prefetch(self.remaining_data.as_ref() as *mut i8, _MM_HINT_T1) };
                 return BlockSegmentPostingsSkipResult::Success(skip_freqs);
             } else {
                 skip_freqs += self.skip_reader.tf_sum();
@@ -526,6 +532,41 @@ impl BlockSegmentPostings {
         BlockSegmentPostingsSkipResult::Terminated
     }
 
+    /// Ensure we are located on the right block.
+    #[inline(never)]
+    pub fn skip_to_b(&mut self, target_doc: DocId) {
+       while self.skip_reader.advance() {
+            if self.skip_reader.doc() >= target_doc {
+                // the last document of the current block is larger
+                // than the target.
+                //
+                // We found our block!
+                let num_bits = self.skip_reader.doc_num_bits();
+                let num_consumed_bytes = self.doc_decoder.uncompress_block_sorted(
+                    self.remaining_data.as_ref(),
+                    self.doc_offset,
+                    num_bits,
+                );
+                let tf_num_bits = self.skip_reader.tf_num_bits();
+                let num_bytes_to_skip = compressed_block_size(tf_num_bits);
+                self.remaining_data.advance(num_consumed_bytes + num_bytes_to_skip);
+                self.doc_offset = self.skip_reader.doc();
+                return;
+            } else {
+                let advance_len = self.skip_reader.total_block_len();
+                self.doc_offset = self.skip_reader.doc();
+                self.remaining_data.advance(advance_len);
+            }
+        }
+
+        // we are now on the last, incomplete, variable encoded block.
+        self.doc_decoder.uncompress_vint_sorted_b(
+           self.remaining_data.as_ref(),
+           self.doc_offset,
+          self.num_vint_docs
+        );
+    }
+
     /// Advance to the next block.
     ///
     /// Returns false iff there was no remaining blocks.

src/postings/skip.rs

@@ -49,7 +49,7 @@ impl SkipSerializer {
     }
 }
 
-pub(crate) struct SkipReader {
+pub struct SkipReader {
     doc: DocId,
     owned_read: OwnedRead,
     doc_num_bits: u8,

src/postings/stacker/memory_arena.rs

@@ -106,8 +106,8 @@ impl MemoryArena {
     ///
     /// Internally, it counts a number of `1MB` pages
     /// and therefore delivers an upperbound.
-    pub fn mem_usage(&self) -> u64 {
-        (self.pages.len() as u64) * (PAGE_SIZE as u64)
+    pub fn mem_usage(&self) -> usize {
+        self.pages.len() * PAGE_SIZE
     }
 
     pub fn write_at<Item: Copy + 'static>(&mut self, addr: Addr, val: Item) {

src/postings/stacker/term_hashmap.rs

@@ -12,8 +12,8 @@ use std::slice;
 
 /// Returns the actual memory size in bytes
 /// required to create a table of size $2^num_bits$.
-pub fn compute_table_size(num_bits: usize) -> u64 {
-    (1u64 << num_bits as u64) * mem::size_of::<KeyValue>() as u64
+pub fn compute_table_size(num_bits: usize) -> usize {
+    (1 << num_bits) * mem::size_of::<KeyValue>()
 }
 
 /// `KeyValue` is the item stored in the hash table.
@@ -116,8 +116,8 @@ impl TermHashMap {
         QuadraticProbing::compute(hash as usize, self.mask)
     }
 
-    pub fn mem_usage(&self) -> u64 {
-        self.table.len() as u64 * mem::size_of::<KeyValue>() as u64
+    pub fn mem_usage(&self) -> usize {
+        self.table.len() * mem::size_of::<KeyValue>()
     }
 
     fn is_saturated(&self) -> bool {

src/query/boolean_query/mod.rs

@@ -31,24 +31,11 @@ mod tests {
             // writing the segment
             let mut index_writer = index.writer_with_num_threads(1, 3_000_000).unwrap();
             {
-                let doc = doc!(text_field => "a b c");
-                index_writer.add_document(doc);
-            }
-            {
-                let doc = doc!(text_field => "a c");
-                index_writer.add_document(doc);
-            }
-            {
-                let doc = doc!(text_field => "b c");
-                index_writer.add_document(doc);
-            }
-            {
-                let doc = doc!(text_field => "a b c d");
-                index_writer.add_document(doc);
-            }
-            {
-                let doc = doc!(text_field => "d");
-                index_writer.add_document(doc);
+                index_writer.add_document(doc!(text_field => "a b c"));
+                index_writer.add_document(doc!(text_field => "a c"));
+                index_writer.add_document(doc!(text_field => "b c"));
+                index_writer.add_document(doc!(text_field => "a b c d"));
+                index_writer.add_document(doc!(text_field => "d"));
             }
             assert!(index_writer.commit().is_ok());
         }

src/query/fuzzy_query.rs

@@ -2,10 +2,36 @@ use crate::query::{AutomatonWeight, Query, Weight};
 use crate::schema::Term;
 use crate::Searcher;
 use crate::TantivyError::InvalidArgument;
-use levenshtein_automata::{LevenshteinAutomatonBuilder, DFA};
+use levenshtein_automata::{Distance, LevenshteinAutomatonBuilder, DFA};
 use once_cell::sync::Lazy;
 use std::collections::HashMap;
 use std::ops::Range;
+use tantivy_fst::Automaton;
+
+pub(crate) struct DFAWrapper(pub DFA);
+
+impl Automaton for DFAWrapper {
+    type State = u32;
+
+    fn start(&self) -> Self::State {
+        self.0.initial_state()
+    }
+
+    fn is_match(&self, state: &Self::State) -> bool {
+        match self.0.distance(*state) {
+            Distance::Exact(_) => true,
+            Distance::AtLeast(_) => false,
+        }
+    }
+
+    fn can_match(&self, state: &u32) -> bool {
+        *state != levenshtein_automata::SINK_STATE
+    }
+
+    fn accept(&self, state: &Self::State, byte: u8) -> Self::State {
+        self.0.transition(*state, byte)
+    }
+}
 
 /// A range of Levenshtein distances that we will build DFAs for our terms
 /// The computation is exponential, so best keep it to low single digits
@@ -101,13 +127,20 @@ impl FuzzyTermQuery {
         }
     }
 
-    fn specialized_weight(&self) -> crate::Result<AutomatonWeight<DFA>> {
+    fn specialized_weight(&self) -> crate::Result<AutomatonWeight<DFAWrapper>> {
         // LEV_BUILDER is a HashMap, whose `get` method returns an Option
         match LEV_BUILDER.get(&(self.distance, false)) {
             // Unwrap the option and build the Ok(AutomatonWeight)
             Some(automaton_builder) => {
-                let automaton = automaton_builder.build_dfa(self.term.text());
-                Ok(AutomatonWeight::new(self.term.field(), automaton))
+                let automaton = if self.prefix {
+                    automaton_builder.build_prefix_dfa(self.term.text())
+                } else {
+                    automaton_builder.build_dfa(self.term.text())
+                };
+                Ok(AutomatonWeight::new(
+                    self.term.field(),
+                    DFAWrapper(automaton),
+                ))
             }
             None => Err(InvalidArgument(format!(
                 "Levenshtein distance of {} is not allowed. Choose a value in the {:?} range",
@@ -166,5 +199,17 @@ mod test {
             let (score, _) = top_docs[0];
             assert_nearly_equals(1f32, score);
         }
+
+        {
+            let term = Term::from_field_text(country_field, "jap");
+
+            let fuzzy_query = FuzzyTermQuery::new_prefix(term, 1, true);
+            let top_docs = searcher
+                .search(&fuzzy_query, &TopDocs::with_limit(2))
+                .unwrap();
+            assert_eq!(top_docs.len(), 1, "Expected only 1 document");
+            let (score, _) = top_docs[0];
+            assert_nearly_equals(1f32, score);
+        }
     }
 }

src/query/mod.rs

@@ -24,6 +24,7 @@ mod term_query;
 mod union;
 mod weight;
 
+
 #[cfg(test)]
 mod vec_docset;
 
@@ -43,6 +44,7 @@ pub use self::empty_query::{EmptyQuery, EmptyScorer, EmptyWeight};
 pub use self::exclude::Exclude;
 pub use self::explanation::Explanation;
 pub use self::fuzzy_query::FuzzyTermQuery;
+pub(crate) use self::fuzzy_query::DFAWrapper;
 pub use self::intersection::intersect_scorers;
 pub use self::phrase_query::PhraseQuery;
 pub use self::query::Query;

src/query/phrase_query/mod.rs

@@ -12,7 +12,6 @@ pub mod tests {
     use super::*;
     use crate::collector::tests::{TEST_COLLECTOR_WITHOUT_SCORE, TEST_COLLECTOR_WITH_SCORE};
     use crate::core::Index;
-    use crate::error::TantivyError;
     use crate::schema::{Schema, Term, TEXT};
     use crate::tests::assert_nearly_equals;
     use crate::DocAddress;
@@ -127,21 +126,16 @@ pub mod tests {
             Term::from_field_text(text_field, "a"),
             Term::from_field_text(text_field, "b"),
         ]);
-        match searcher
+
+        let search_result = searcher
             .search(&phrase_query, &TEST_COLLECTOR_WITH_SCORE)
-            .map(|_| ())
-            .unwrap_err()
-        {
-            TantivyError::SchemaError(ref msg) => {
-                assert_eq!(
-                    "Applied phrase query on field \"text\", which does not have positions indexed",
-                    msg.as_str()
-                );
-            }
-            _ => {
-                panic!("Should have returned an error");
-            }
-        }
+            .map(|_| ());
+        assert!(matches!(
+            search_result,
+            Err(crate::TantivyError::SchemaError(msg))
+            if msg == "Applied phrase query on field \"text\", which does not have positions \
+            indexed"
+        ));
     }
 
     #[test]

src/query/query.rs

@@ -1,11 +1,17 @@
 use super::Weight;
 use crate::core::searcher::Searcher;
 use crate::query::Explanation;
-use crate::DocAddress;
+use crate::{DocAddress, Score};
 use crate::Term;
 use downcast_rs::impl_downcast;
 use std::collections::BTreeSet;
 use std::fmt;
+use crate::collector::{TopDocs, Collector, SegmentCollector, Count};
+
+pub struct TopKResult {
+    pub count: u64,
+    docs: Vec<(Score, DocAddress)>
+}
 
 /// The `Query` trait defines a set of documents and a scoring method
 /// for those documents.
@@ -56,6 +62,27 @@ pub trait Query: QueryClone + downcast_rs::Downcast + fmt::Debug {
         weight.explain(reader, doc_address.doc())
     }
 
+    fn top_k(&self, searcher: &Searcher, num_hits: usize) -> crate::Result<TopKResult> {
+        let top_docs = TopDocs::with_limit(num_hits);
+        let collector = (Count, top_docs);
+        let weight = self.weight(searcher, false)?;
+        let mut count = 0u64;
+        let mut result = 0;
+        let mut child_fruits = Vec::with_capacity(searcher.segment_readers().len());
+        for (segment_ord, reader) in searcher.segment_readers().iter().enumerate() {
+            let mut child_top_k = collector.for_segment(segment_ord as u32, reader)?;
+            let mut scorer = weight.scorer(reader, 1.0f32)?;
+            // handle deletes
+            scorer.top_k(&mut child_top_k);
+            child_fruits.push(child_top_k.harvest());
+        }
+        let (count, docs) = collector.merge_fruits(child_fruits)?;
+        Ok(TopKResult {
+            count: count as u64,
+            docs
+        })
+    }
+
     /// Returns the number of documents matching the query.
     fn count(&self, searcher: &Searcher) -> crate::Result<usize> {
         let weight = self.weight(searcher, false)?;

src/query/query_parser/query_parser.rs

@@ -174,6 +174,16 @@ pub struct QueryParser {
     boost: HashMap<Field, f32>,
 }
 
+fn all_negative(ast: &LogicalAST) -> bool {
+    match ast {
+        LogicalAST::Leaf(_) => false,
+        LogicalAST::Boost(ref child_ast, _) => all_negative(&*child_ast),
+        LogicalAST::Clause(children) => children
+            .iter()
+            .all(|(ref occur, child)| (*occur == Occur::MustNot) || all_negative(child)),
+    }
+}
+
 impl QueryParser {
     /// Creates a `QueryParser`, given
     /// * schema - index Schema
@@ -253,8 +263,13 @@ impl QueryParser {
         &self,
         user_input_ast: UserInputAST,
     ) -> Result<LogicalAST, QueryParserError> {
-        let (occur, ast) = self.compute_logical_ast_with_occur(user_input_ast)?;
-        if occur == Occur::MustNot {
+        let ast = self.compute_logical_ast_with_occur(user_input_ast)?;
+        if let LogicalAST::Clause(children) = &ast {
+            if children.is_empty() {
+                return Ok(ast);
+            }
+        }
+        if all_negative(&ast) {
             return Err(QueryParserError::AllButQueryForbidden);
         }
         Ok(ast)
@@ -410,31 +425,23 @@ impl QueryParser {
     fn compute_logical_ast_with_occur(
         &self,
         user_input_ast: UserInputAST,
-    ) -> Result<(Occur, LogicalAST), QueryParserError> {
+    ) -> Result<LogicalAST, QueryParserError> {
         match user_input_ast {
             UserInputAST::Clause(sub_queries) => {
                 let default_occur = self.default_occur();
                 let mut logical_sub_queries: Vec<(Occur, LogicalAST)> = Vec::new();
-                for sub_query in sub_queries {
-                    let (occur, sub_ast) = self.compute_logical_ast_with_occur(sub_query)?;
-                    let new_occur = Occur::compose(default_occur, occur);
-                    logical_sub_queries.push((new_occur, sub_ast));
+                for (occur_opt, sub_ast) in sub_queries {
+                    let sub_ast = self.compute_logical_ast_with_occur(sub_ast)?;
+                    let occur = occur_opt.unwrap_or(default_occur);
+                    logical_sub_queries.push((occur, sub_ast));
                 }
-                Ok((Occur::Should, LogicalAST::Clause(logical_sub_queries)))
-            }
-            UserInputAST::Unary(left_occur, subquery) => {
-                let (right_occur, logical_sub_queries) =
-                    self.compute_logical_ast_with_occur(*subquery)?;
-                Ok((Occur::compose(left_occur, right_occur), logical_sub_queries))
+                Ok(LogicalAST::Clause(logical_sub_queries))
             }
             UserInputAST::Boost(ast, boost) => {
-                let (occur, ast_without_occur) = self.compute_logical_ast_with_occur(*ast)?;
-                Ok((occur, ast_without_occur.boost(boost)))
-            }
-            UserInputAST::Leaf(leaf) => {
-                let result_ast = self.compute_logical_ast_from_leaf(*leaf)?;
-                Ok((Occur::Should, result_ast))
+                let ast = self.compute_logical_ast_with_occur(*ast)?;
+                Ok(ast.boost(boost))
             }
+            UserInputAST::Leaf(leaf) => self.compute_logical_ast_from_leaf(*leaf),
         }
     }
 
@@ -782,6 +789,20 @@ mod test {
         );
     }
 
+    #[test]
+    fn test_parse_query_to_ast_ab_c() {
+        test_parse_query_to_logical_ast_helper(
+            "(+title:a +title:b) title:c",
+            "((+Term(field=0,bytes=[97]) +Term(field=0,bytes=[98])) Term(field=0,bytes=[99]))",
+            false,
+        );
+        test_parse_query_to_logical_ast_helper(
+            "(+title:a +title:b) title:c",
+            "(+(+Term(field=0,bytes=[97]) +Term(field=0,bytes=[98])) +Term(field=0,bytes=[99]))",
+            true,
+        );
+    }
+
     #[test]
     pub fn test_parse_query_to_ast_single_term() {
         test_parse_query_to_logical_ast_helper(
@@ -801,11 +822,13 @@ mod test {
              Term(field=1,bytes=[116, 105, 116, 105])))",
             false,
         );
-        assert_eq!(
-            parse_query_to_logical_ast("-title:toto", false)
-                .err()
-                .unwrap(),
-            QueryParserError::AllButQueryForbidden
+    }
+
+    #[test]
+    fn test_single_negative_term() {
+        assert_matches!(
+            parse_query_to_logical_ast("-title:toto", false),
+            Err(QueryParserError::AllButQueryForbidden)
         );
     }
 
@@ -965,6 +988,18 @@ mod test {
         assert!(query_parser.parse_query("with_stop_words:the").is_ok());
     }
 
+    #[test]
+    pub fn test_parse_query_single_negative_term_through_error() {
+        assert_matches!(
+            parse_query_to_logical_ast("-title:toto", true),
+            Err(QueryParserError::AllButQueryForbidden)
+        );
+        assert_matches!(
+            parse_query_to_logical_ast("-title:toto", false),
+            Err(QueryParserError::AllButQueryForbidden)
+        );
+    }
+
     #[test]
     pub fn test_parse_query_to_ast_conjunction() {
         test_parse_query_to_logical_ast_helper(
@@ -984,12 +1019,6 @@ mod test {
              Term(field=1,bytes=[116, 105, 116, 105])))",
             true,
         );
-        assert_eq!(
-            parse_query_to_logical_ast("-title:toto", true)
-                .err()
-                .unwrap(),
-            QueryParserError::AllButQueryForbidden
-        );
         test_parse_query_to_logical_ast_helper(
             "title:a b",
             "(+Term(field=0,bytes=[97]) \
@@ -1013,4 +1042,26 @@ mod test {
             false
         );
     }
+
+    #[test]
+    fn test_and_default_regardless_of_default_conjunctive() {
+        for &default_conjunction in &[false, true] {
+            test_parse_query_to_logical_ast_helper(
+                "title:a AND title:b",
+                "(+Term(field=0,bytes=[97]) +Term(field=0,bytes=[98]))",
+                default_conjunction,
+            );
+        }
+    }
+
+    #[test]
+    fn test_or_default_conjunctive() {
+        for &default_conjunction in &[false, true] {
+            test_parse_query_to_logical_ast_helper(
+                "title:a OR title:b",
+                "(Term(field=0,bytes=[97]) Term(field=0,bytes=[98]))",
+                default_conjunction,
+            );
+        }
+    }
 }

src/query/scorer.rs

@@ -4,6 +4,8 @@ use crate::DocId;
 use crate::Score;
 use downcast_rs::impl_downcast;
 use std::ops::DerefMut;
+use crate::collector::{SegmentCollector, Collector, TopDocs, Count};
+
 
 /// Scored set of documents matching a query within a specific segment.
 ///
@@ -21,6 +23,12 @@ pub trait Scorer: downcast_rs::Downcast + DocSet + 'static {
             callback(self.doc(), self.score());
         }
     }
+
+    fn top_k(&mut self, collector: &mut <(Count, TopDocs) as Collector>::Child) {
+        while self.advance() {
+            collector.collect(self.doc(), self.score());
+        }
+    }
 }
 
 impl_downcast!(Scorer);

src/reader/index_writer_reader.rs

@@ -1,84 +0,0 @@
-use crate::directory::{WatchCallbackList, WatchHandle};
-use crate::indexer::SegmentRegisters;
-use crate::reader::pool::Pool;
-use crate::{Index, LeasedItem, Searcher, Segment, SegmentReader};
-use std::iter::repeat_with;
-use std::sync::{Arc, RwLock, Weak};
-
-struct InnerNRTReader {
-    num_searchers: usize,
-    index: Index,
-    searcher_pool: Pool<Searcher>,
-    segment_registers: Arc<RwLock<SegmentRegisters>>,
-}
-
-impl InnerNRTReader {
-    fn load_segment_readers(&self) -> crate::Result<Vec<SegmentReader>> {
-        let segments: Vec<Segment> = self
-            .segment_registers
-            .read()
-            .expect("lock should never be polluted. Please report.")
-            .committed_segment();
-        segments
-            .iter()
-            .map(SegmentReader::open)
-            .collect::<crate::Result<Vec<SegmentReader>>>()
-    }
-
-    pub fn reload(&self) -> crate::Result<()> {
-        let segment_readers: Vec<SegmentReader> = self.load_segment_readers()?;
-        let schema = self.index.schema();
-        let searchers = repeat_with(|| {
-            Searcher::new(schema.clone(), self.index.clone(), segment_readers.clone())
-        })
-        .take(self.num_searchers)
-        .collect();
-        self.searcher_pool.publish_new_generation(searchers);
-        Ok(())
-    }
-
-    pub fn searcher(&self) -> LeasedItem<Searcher> {
-        self.searcher_pool.acquire()
-    }
-}
-
-#[derive(Clone)]
-pub struct NRTReader {
-    inner: Arc<InnerNRTReader>,
-    watch_handle: WatchHandle,
-}
-
-impl NRTReader {
-    pub fn reload(&self) -> crate::Result<()> {
-        self.inner.reload()
-    }
-
-    pub fn searcher(&self) -> LeasedItem<Searcher> {
-        self.inner.searcher()
-    }
-
-    pub(crate) fn create(
-        num_searchers: usize,
-        index: Index,
-        segment_registers: Arc<RwLock<SegmentRegisters>>,
-        watch_callback_list: &WatchCallbackList,
-    ) -> crate::Result<Self> {
-        let inner_reader: Arc<InnerNRTReader> = Arc::new(InnerNRTReader {
-            num_searchers,
-            index,
-            searcher_pool: Pool::new(),
-            segment_registers,
-        });
-        let inner_reader_weak: Weak<InnerNRTReader> = Arc::downgrade(&inner_reader);
-        let watch_handle = watch_callback_list.subscribe(Box::new(move || {
-            if let Some(nrt_reader_arc) = inner_reader_weak.upgrade() {
-                let _ = nrt_reader_arc.reload();
-            }
-        }));
-        inner_reader.reload()?;
-        Ok(NRTReader {
-            inner: inner_reader,
-            watch_handle,
-        })
-    }
-}

src/reader/meta_file_reader.rs

@@ -1,177 +0,0 @@
-use super::pool::Pool;
-use crate::core::Segment;
-use crate::directory::Directory;
-use crate::directory::WatchHandle;
-use crate::directory::META_LOCK;
-use crate::Searcher;
-use crate::SegmentReader;
-use crate::{Index, LeasedItem};
-use crate::{IndexReader, Result};
-use std::iter::repeat_with;
-use std::sync::Arc;
-
-/// Defines when a new version of the index should be reloaded.
-///
-/// Regardless of whether you search and index in the same process, tantivy does not necessarily
-/// reflects the change that are commited to your index. `ReloadPolicy` precisely helps you define
-/// when you want your index to be reloaded.
-#[derive(Clone, Copy)]
-pub enum ReloadPolicy {
-    /// The index is entirely reloaded manually.
-    /// All updates of the index should be manual.
-    ///
-    /// No change is reflected automatically. You are required to call `.load_seacher()` manually.
-    Manual,
-    /// The index is reloaded within milliseconds after a new commit is available.
-    /// This is made possible by watching changes in the `meta.json` file.
-    OnCommit, // TODO add NEAR_REAL_TIME(target_ms)
-}
-
-/// `IndexReader` builder
-///
-/// It makes it possible to set the following values.
-///
-/// - `num_searchers` (by default, the number of detected CPU threads):
-///
-///   When `num_searchers` queries are requested at the same time, the `num_searchers` will block
-///   until the one of the searcher in-use gets released.
-/// - `reload_policy` (by default `ReloadPolicy::OnCommit`):
-///
-///   See [`ReloadPolicy`](./enum.ReloadPolicy.html) for more details.
-#[derive(Clone)]
-pub struct IndexReaderBuilder {
-    num_searchers: usize,
-    reload_policy: ReloadPolicy,
-    index: Index,
-}
-
-impl IndexReaderBuilder {
-    pub(crate) fn new(index: Index) -> IndexReaderBuilder {
-        IndexReaderBuilder {
-            num_searchers: num_cpus::get(),
-            reload_policy: ReloadPolicy::Manual,
-            index,
-        }
-    }
-
-    /// Sets the reload_policy.
-    ///
-    /// See [`ReloadPolicy`](./enum.ReloadPolicy.html) for more details.
-    pub fn reload_policy(mut self, reload_policy: ReloadPolicy) -> IndexReaderBuilder {
-        self.reload_policy = reload_policy;
-        self
-    }
-
-    /// Sets the number of `Searcher` in the searcher pool.
-    pub fn num_searchers(mut self, num_searchers: usize) -> IndexReaderBuilder {
-        self.num_searchers = num_searchers;
-        self
-    }
-
-    /// Building the reader is a non-trivial operation that requires
-    /// to open different segment readers. It may take hundreds of milliseconds
-    /// of time and it may return an error.
-    pub fn try_into(self) -> crate::Result<IndexReader> {
-        let inner_reader = MetaFileIndexReaderInner {
-            index: self.index,
-            num_searchers: self.num_searchers,
-            searcher_pool: Pool::new(),
-        };
-        inner_reader.reload()?;
-        let inner_reader_arc = Arc::new(inner_reader);
-        let watch_handle_opt: Option<WatchHandle>;
-        match self.reload_policy {
-            ReloadPolicy::Manual => {
-                // No need to set anything...
-                watch_handle_opt = None;
-            }
-            ReloadPolicy::OnCommit => {
-                let inner_reader_arc_clone = inner_reader_arc.clone();
-                let callback = move || {
-                    if let Err(err) = inner_reader_arc_clone.reload() {
-                        error!(
-                            "Error while loading searcher after commit was detected. {:?}",
-                            err
-                        );
-                    }
-                };
-                let watch_handle = inner_reader_arc
-                    .index
-                    .directory()
-                    .watch(Box::new(callback))?;
-                watch_handle_opt = Some(watch_handle);
-            }
-        }
-        Ok(IndexReader::from(MetaFileIndexReader {
-            inner: inner_reader_arc,
-            watch_handle_opt,
-        }))
-    }
-}
-
-struct MetaFileIndexReaderInner {
-    num_searchers: usize,
-    searcher_pool: Pool<Searcher>,
-    index: Index,
-}
-
-impl MetaFileIndexReaderInner {
-    fn load_segment_readers(&self) -> crate::Result<Vec<SegmentReader>> {
-        // We keep the lock until we have effectively finished opening the
-        // the `SegmentReader` because it prevents a diffferent process
-        // to garbage collect these file while we open them.
-        //
-        // Once opened, on linux & mac, the mmap will remain valid after
-        // the file has been deleted
-        // On windows, the file deletion will fail.
-        let _meta_lock = self.index.directory().acquire_lock(&META_LOCK)?;
-        let searchable_segments = self.searchable_segments()?;
-        searchable_segments
-            .iter()
-            .map(SegmentReader::open)
-            .collect::<Result<_>>()
-    }
-
-    fn reload(&self) -> crate::Result<()> {
-        let segment_readers: Vec<SegmentReader> = self.load_segment_readers()?;
-        let schema = self.index.schema();
-        let searchers = repeat_with(|| {
-            Searcher::new(schema.clone(), self.index.clone(), segment_readers.clone())
-        })
-        .take(self.num_searchers)
-        .collect();
-        self.searcher_pool.publish_new_generation(searchers);
-        Ok(())
-    }
-
-    /// Returns the list of segments that are searchable
-    fn searchable_segments(&self) -> crate::Result<Vec<Segment>> {
-        self.index.searchable_segments()
-    }
-
-    fn searcher(&self) -> LeasedItem<Searcher> {
-        self.searcher_pool.acquire()
-    }
-}
-
-/// `IndexReader` is your entry point to read and search the index.
-///
-/// It controls when a new version of the index should be loaded and lends
-/// you instances of `Searcher` for the last loaded version.
-///
-/// `Clone` does not clone the different pool of searcher. `IndexReader`
-/// just wraps and `Arc`.
-#[derive(Clone)]
-pub struct MetaFileIndexReader {
-    inner: Arc<MetaFileIndexReaderInner>,
-    watch_handle_opt: Option<WatchHandle>,
-}
-
-impl MetaFileIndexReader {
-    pub fn reload(&self) -> crate::Result<()> {
-        self.inner.reload()
-    }
-    pub fn searcher(&self) -> LeasedItem<Searcher> {
-        self.inner.searcher()
-    }
-}

src/reader/mod.rs

@@ -1,14 +1,151 @@
-mod index_writer_reader;
-mod meta_file_reader;
 mod pool;
 
-use self::meta_file_reader::MetaFileIndexReader;
-pub use self::meta_file_reader::{IndexReaderBuilder, ReloadPolicy};
 pub use self::pool::LeasedItem;
-
-pub(crate) use crate::reader::index_writer_reader::NRTReader;
-
+use self::pool::Pool;
+use crate::core::Segment;
+use crate::directory::Directory;
+use crate::directory::WatchHandle;
+use crate::directory::META_LOCK;
+use crate::Index;
 use crate::Searcher;
+use crate::SegmentReader;
+use std::sync::Arc;
+
+/// Defines when a new version of the index should be reloaded.
+///
+/// Regardless of whether you search and index in the same process, tantivy does not necessarily
+/// reflects the change that are commited to your index. `ReloadPolicy` precisely helps you define
+/// when you want your index to be reloaded.
+#[derive(Clone, Copy)]
+pub enum ReloadPolicy {
+    /// The index is entirely reloaded manually.
+    /// All updates of the index should be manual.
+    ///
+    /// No change is reflected automatically. You are required to call `.load_seacher()` manually.
+    Manual,
+    /// The index is reloaded within milliseconds after a new commit is available.
+    /// This is made possible by watching changes in the `meta.json` file.
+    OnCommit, // TODO add NEAR_REAL_TIME(target_ms)
+}
+
+/// `IndexReader` builder
+///
+/// It makes it possible to set the following values.
+///
+/// - `num_searchers` (by default, the number of detected CPU threads):
+///
+///   When `num_searchers` queries are requested at the same time, the `num_searchers` will block
+///   until the one of the searcher in-use gets released.
+/// - `reload_policy` (by default `ReloadPolicy::OnCommit`):
+///
+///   See [`ReloadPolicy`](./enum.ReloadPolicy.html) for more details.
+#[derive(Clone)]
+pub struct IndexReaderBuilder {
+    num_searchers: usize,
+    reload_policy: ReloadPolicy,
+    index: Index,
+}
+
+impl IndexReaderBuilder {
+    pub(crate) fn new(index: Index) -> IndexReaderBuilder {
+        IndexReaderBuilder {
+            num_searchers: num_cpus::get(),
+            reload_policy: ReloadPolicy::OnCommit,
+            index,
+        }
+    }
+
+    /// Builds the reader.
+    ///
+    /// Building the reader is a non-trivial operation that requires
+    /// to open different segment readers. It may take hundreds of milliseconds
+    /// of time and it may return an error.
+    /// TODO(pmasurel) Use the `TryInto` trait once it is available in stable.
+    pub fn try_into(self) -> crate::Result<IndexReader> {
+        let inner_reader = InnerIndexReader {
+            index: self.index,
+            num_searchers: self.num_searchers,
+            searcher_pool: Pool::new(),
+        };
+        inner_reader.reload()?;
+        let inner_reader_arc = Arc::new(inner_reader);
+        let watch_handle_opt: Option<WatchHandle>;
+        match self.reload_policy {
+            ReloadPolicy::Manual => {
+                // No need to set anything...
+                watch_handle_opt = None;
+            }
+            ReloadPolicy::OnCommit => {
+                let inner_reader_arc_clone = inner_reader_arc.clone();
+                let callback = move || {
+                    if let Err(err) = inner_reader_arc_clone.reload() {
+                        error!(
+                            "Error while loading searcher after commit was detected. {:?}",
+                            err
+                        );
+                    }
+                };
+                let watch_handle = inner_reader_arc
+                    .index
+                    .directory()
+                    .watch(Box::new(callback))?;
+                watch_handle_opt = Some(watch_handle);
+            }
+        }
+        Ok(IndexReader {
+            inner: inner_reader_arc,
+            watch_handle_opt,
+        })
+    }
+
+    /// Sets the reload_policy.
+    ///
+    /// See [`ReloadPolicy`](./enum.ReloadPolicy.html) for more details.
+    pub fn reload_policy(mut self, reload_policy: ReloadPolicy) -> IndexReaderBuilder {
+        self.reload_policy = reload_policy;
+        self
+    }
+
+    /// Sets the number of `Searcher` in the searcher pool.
+    pub fn num_searchers(mut self, num_searchers: usize) -> IndexReaderBuilder {
+        self.num_searchers = num_searchers;
+        self
+    }
+}
+
+struct InnerIndexReader {
+    num_searchers: usize,
+    searcher_pool: Pool<Searcher>,
+    index: Index,
+}
+
+impl InnerIndexReader {
+    fn reload(&self) -> crate::Result<()> {
+        let segment_readers: Vec<SegmentReader> = {
+            let _meta_lock = self.index.directory().acquire_lock(&META_LOCK)?;
+            let searchable_segments = self.searchable_segments()?;
+            searchable_segments
+                .iter()
+                .map(SegmentReader::open)
+                .collect::<crate::Result<_>>()?
+        };
+        let schema = self.index.schema();
+        let searchers = (0..self.num_searchers)
+            .map(|_| Searcher::new(schema.clone(), self.index.clone(), segment_readers.clone()))
+            .collect();
+        self.searcher_pool.publish_new_generation(searchers);
+        Ok(())
+    }
+
+    /// Returns the list of segments that are searchable
+    fn searchable_segments(&self) -> crate::Result<Vec<Segment>> {
+        self.index.searchable_segments()
+    }
+
+    fn searcher(&self) -> LeasedItem<Searcher> {
+        self.searcher_pool.acquire()
+    }
+}
 
 /// `IndexReader` is your entry point to read and search the index.
 ///
@@ -18,12 +155,17 @@ use crate::Searcher;
 /// `Clone` does not clone the different pool of searcher. `IndexReader`
 /// just wraps and `Arc`.
 #[derive(Clone)]
-pub enum IndexReader {
-    FromMetaFile(MetaFileIndexReader),
-    NRT(NRTReader),
+pub struct IndexReader {
+    inner: Arc<InnerIndexReader>,
+    watch_handle_opt: Option<WatchHandle>,
 }
 
 impl IndexReader {
+    #[cfg(test)]
+    pub(crate) fn index(&self) -> Index {
+        self.inner.index.clone()
+    }
+
     /// Update searchers so that they reflect the state of the last
     /// `.commit()`.
     ///
@@ -34,10 +176,7 @@ impl IndexReader {
     /// This automatic reload can take 10s of milliseconds to kick in however, and in unit tests
     /// it can be nice to deterministically force the reload of searchers.
     pub fn reload(&self) -> crate::Result<()> {
-        match self {
-            IndexReader::FromMetaFile(meta_file_reader) => meta_file_reader.reload(),
-            IndexReader::NRT(nrt_reader) => nrt_reader.reload(),
-        }
+        self.inner.reload()
     }
 
     /// Returns a searcher
@@ -51,21 +190,6 @@ impl IndexReader {
     /// The same searcher must be used for a given query, as it ensures
     /// the use of a consistent segment set.
     pub fn searcher(&self) -> LeasedItem<Searcher> {
-        match self {
-            IndexReader::FromMetaFile(meta_file_reader) => meta_file_reader.searcher(),
-            IndexReader::NRT(nrt_reader) => nrt_reader.searcher(),
-        }
-    }
-}
-
-impl From<MetaFileIndexReader> for IndexReader {
-    fn from(meta_file_reader: MetaFileIndexReader) -> Self {
-        IndexReader::FromMetaFile(meta_file_reader)
-    }
-}
-
-impl From<NRTReader> for IndexReader {
-    fn from(nrt_reader: NRTReader) -> Self {
-        IndexReader::NRT(nrt_reader)
+        self.inner.searcher()
     }
 }

src/schema/text_options.rs

@@ -156,30 +156,17 @@ mod tests {
 
     #[test]
     fn test_field_options() {
-        {
-            let field_options = STORED | TEXT;
-            assert!(field_options.is_stored());
-            assert!(field_options.get_indexing_options().is_some());
-        }
-        {
-            let mut schema_builder = Schema::builder();
-            schema_builder.add_text_field("body", TEXT);
-            let schema = schema_builder.build();
-            let field = schema.get_field("body").unwrap();
-            let field_entry = schema.get_field_entry(field);
-            match field_entry.field_type() {
-                &FieldType::Str(ref text_options) => {
-                    assert!(text_options.get_indexing_options().is_some());
-                    assert_eq!(
-                        text_options.get_indexing_options().unwrap().tokenizer(),
-                        "default"
-                    );
-                }
-                _ => {
-                    panic!("");
-                }
-            }
-        }
+        let field_options = STORED | TEXT;
+        assert!(field_options.is_stored());
+        assert!(field_options.get_indexing_options().is_some());
+        let mut schema_builder = Schema::builder();
+        schema_builder.add_text_field("body", TEXT);
+        let schema = schema_builder.build();
+        let field = schema.get_field("body").unwrap();
+        let field_entry = schema.get_field_entry(field);
+        assert!(matches!(field_entry.field_type(),
+                &FieldType::Str(ref text_options)
+                if text_options.get_indexing_options().unwrap().tokenizer() == "default"));
     }
 
     #[test]

src/store/writer.rs

@@ -3,6 +3,8 @@ use super::skiplist::SkipListBuilder;
 use super::StoreReader;
 use crate::common::CountingWriter;
 use crate::common::{BinarySerializable, VInt};
+use crate::directory::TerminatingWrite;
+use crate::directory::WritePtr;
 use crate::schema::Document;
 use crate::DocId;
 use std::io::{self, Write};
@@ -17,20 +19,20 @@ const BLOCK_SIZE: usize = 16_384;
 ///
 /// The skip list index on the other hand, is built in memory.
 ///
-pub struct StoreWriter<W: io::Write> {
+pub struct StoreWriter {
     doc: DocId,
     offset_index_writer: SkipListBuilder<u64>,
-    writer: CountingWriter<W>,
+    writer: CountingWriter<WritePtr>,
     intermediary_buffer: Vec<u8>,
     current_block: Vec<u8>,
 }
 
-impl<W: io::Write> StoreWriter<W> {
+impl StoreWriter {
     /// Create a store writer.
     ///
     /// The store writer will writes blocks on disc as
     /// document are added.
-    pub fn new(writer: W) -> StoreWriter<W> {
+    pub fn new(writer: WritePtr) -> StoreWriter {
         StoreWriter {
             doc: 0,
             offset_index_writer: SkipListBuilder::new(4),
@@ -100,9 +102,7 @@ impl<W: io::Write> StoreWriter<W> {
     ///
     /// Compress the last unfinished block if any,
     /// and serializes the skip list index on disc.
-    ///
-    /// The returned writer is not flushed.
-    pub fn close(mut self) -> io::Result<W> {
+    pub fn close(mut self) -> io::Result<()> {
         if !self.current_block.is_empty() {
             self.write_and_compress_block()?;
         }
@@ -110,7 +110,6 @@ impl<W: io::Write> StoreWriter<W> {
         self.offset_index_writer.write(&mut self.writer)?;
         header_offset.serialize(&mut self.writer)?;
         self.doc.serialize(&mut self.writer)?;
-        let (wrt, _) = self.writer.finish()?;
-        Ok(wrt)
+        self.writer.terminate()
     }
 }

src/termdict/mod.rs

@@ -435,6 +435,7 @@ mod tests {
     #[test]
     fn test_automaton_search() {
         use levenshtein_automata::LevenshteinAutomatonBuilder;
+        use crate::query::DFAWrapper;
 
         const COUNTRIES: [&'static str; 7] = [
             "San Marino",
@@ -463,7 +464,7 @@ mod tests {
 
         // We can now build an entire dfa.
         let lev_automaton_builder = LevenshteinAutomatonBuilder::new(2, true);
-        let automaton = lev_automaton_builder.build_dfa("Spaen");
+        let automaton = DFAWrapper(lev_automaton_builder.build_dfa("Spaen"));
 
         let mut range = term_dict.search(automaton).into_stream();