Bump version

Closes #731

CHANGELOG.md

@@ -1,3 +1,17 @@
+Tantivy 0.11.3
+=======================
+- Fixed DateTime as a fast field (#735)
+
+Tantivy 0.11.2
+=======================
+- The future returned by `IndexWriter::merge` does not borrow `self` mutably anymore (#732)
+- Exposing a constructor for `WatchHandle` (#731)
+
+Tantivy 0.11.1
+=====================
+- Bug fix #729
+
+
 Tantivy 0.11.0
 =====================
 
@@ -9,6 +23,7 @@ Tantivy 0.11.0
 - API change around `Box<BoxableTokenizer>`. See detail in #629
 - Avoid rebuilding Regex automaton whenever a regex query is reused. #639 (@brainlock)
 - Add footer with some metadata to index files. #605 (@fdb-hiroshima)
+- Add a method to check the compatibility of the footer in the index with the running version of tantivy (@petr-tik)
 - TopDocs collector: ensure stable sorting on equal score. #671 (@brainlock)
 - Added handling of pre-tokenized text fields (#642), which will enable users to
   load tokens created outside tantivy. See usage in examples/pre_tokenized_text. (@kkoziara)

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "tantivy"
-version = "0.11.0"
+version = "0.11.3"
 authors = ["Paul Masurel <paul.masurel@gmail.com>"]
 license = "MIT"
 categories = ["database-implementations", "data-structures"]
@@ -33,7 +33,6 @@ fs2={version="0.4", optional=true}
 itertools = "0.8"
 levenshtein_automata = {version="0.1", features=["fst_automaton"]}
 notify = {version="4", optional=true}
-bit-set = "0.5"
 uuid = { version = "0.8", features = ["v4", "serde"] }
 crossbeam = "0.7"
 futures = {version = "0.3",  features=["thread-pool"] }
@@ -41,7 +40,7 @@ owning_ref = "0.4"
 stable_deref_trait = "1.0.0"
 rust-stemmers = "1.2"
 downcast-rs = { version="1.0" }
-tantivy-query-grammar = { path="./query-grammar" }
+tantivy-query-grammar = { version="0.11", path="./query-grammar" }
 bitpacking = {version="0.8", default-features = false, features=["bitpacker4x"]}
 census = "0.4"
 fnv = "1.0.6"

query-grammar/README.md

@@ -0,0 +1,3 @@
+# Tantivy Query Grammar
+
+This crate is used by tantivy to parse queries.

src/directory/directory.rs

@@ -119,7 +119,7 @@ pub trait Directory: DirectoryClone + fmt::Debug + Send + Sync + 'static {
     /// Specifically, subsequent writes or flushes should
     /// have no effect on the returned `ReadOnlySource` object.
     ///
-    /// You should only use this to read files create with [`open_write`]
+    /// You should only use this to read files create with [Directory::open_write].
     fn open_read(&self, path: &Path) -> result::Result<ReadOnlySource, OpenReadError>;
 
     /// Removes a file
@@ -160,7 +160,7 @@ pub trait Directory: DirectoryClone + fmt::Debug + Send + Sync + 'static {
     ///
     /// This should only be used for small files.
     ///
-    /// You should only use this to read files create with [`atomic_write`]
+    /// You should only use this to read files create with [Directory::atomic_write].
     fn atomic_read(&self, path: &Path) -> Result<Vec<u8>, OpenReadError>;
 
     /// Atomically replace the content of a file with data.
@@ -197,7 +197,7 @@ pub trait Directory: DirectoryClone + fmt::Debug + Send + Sync + 'static {
     /// Registers a callback that will be called whenever a change on the `meta.json`
     /// using the `atomic_write` API is detected.
     ///
-    /// The behavior when using `.watch()` on a file using `.open_write(...)` is, on the other
+    /// The behavior when using `.watch()` on a file using [Directory::open_write] is, on the other
     /// hand, undefined.
     ///
     /// The file will be watched for the lifetime of the returned `WatchHandle`. The caller is

src/directory/error.rs

@@ -1,4 +1,4 @@
-use crate::directory::footer::Footer;
+use crate::Version;
 use std::error::Error as StdError;
 use std::fmt;
 use std::io;
@@ -157,6 +157,65 @@ impl StdError for OpenWriteError {
     }
 }
 
+/// Type of index incompatibility between the library and the index found on disk
+/// Used to catch and provide a hint to solve this incompatibility issue
+pub enum Incompatibility {
+    /// This library cannot decompress the index found on disk
+    CompressionMismatch {
+        /// Compression algorithm used by the current version of tantivy
+        library_compression_format: String,
+        /// Compression algorithm that was used to serialise the index
+        index_compression_format: String,
+    },
+    /// The index format found on disk isn't supported by this version of the library
+    IndexMismatch {
+        /// Version used by the library
+        library_version: Version,
+        /// Version the index was built with
+        index_version: Version,
+    },
+}
+
+impl fmt::Debug for Incompatibility {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
+        match self {
+            Incompatibility::CompressionMismatch {
+                library_compression_format,
+                index_compression_format,
+            } => {
+                let err = format!(
+                    "Library was compiled with {:?} compression, index was compressed with {:?}",
+                    library_compression_format, index_compression_format
+                );
+                let advice = format!(
+                    "Change the feature flag to {:?} and rebuild the library",
+                    index_compression_format
+                );
+                write!(f, "{}. {}", err, advice)?;
+            }
+            Incompatibility::IndexMismatch {
+                library_version,
+                index_version,
+            } => {
+                let err = format!(
+                    "Library version: {}, index version: {}",
+                    library_version.index_format_version, index_version.index_format_version
+                );
+                // TODO make a more useful error message
+                // include the version range that supports this index_format_version
+                let advice = format!(
+                    "Change tantivy to a version compatible with index format {} (e.g. {}.{}.x) \
+                     and rebuild your project.",
+                    index_version.index_format_version, index_version.major, index_version.minor
+                );
+                write!(f, "{}. {}", err, advice)?;
+            }
+        }
+
+        Ok(())
+    }
+}
+
 /// Error that may occur when accessing a file read
 #[derive(Debug)]
 pub enum OpenReadError {
@@ -165,8 +224,8 @@ pub enum OpenReadError {
     /// Any kind of IO error that happens when
     /// interacting with the underlying IO device.
     IOError(IOError),
-    /// The version of tantivy trying to read the index doesn't support its format
-    IncompatibleIndex(Footer),
+    /// This library doesn't support the index version found on disk
+    IncompatibleIndex(Incompatibility),
 }
 
 impl From<IOError> for OpenReadError {
@@ -193,20 +252,6 @@ impl fmt::Display for OpenReadError {
     }
 }
 
-impl StdError for OpenReadError {
-    fn description(&self) -> &str {
-        "error occurred while opening a file for reading"
-    }
-
-    fn cause(&self) -> Option<&dyn StdError> {
-        match *self {
-            OpenReadError::FileDoesNotExist(_) => None,
-            OpenReadError::IOError(ref err) => Some(err),
-            OpenReadError::IncompatibleIndex(_) => None,
-        }
-    }
-}
-
 /// Error that may occur when trying to delete a file
 #[derive(Debug)]
 pub enum DeleteError {
@@ -223,6 +268,12 @@ impl From<IOError> for DeleteError {
     }
 }
 
+impl From<Incompatibility> for OpenReadError {
+    fn from(incompatibility: Incompatibility) -> Self {
+        OpenReadError::IncompatibleIndex(incompatibility)
+    }
+}
+
 impl fmt::Display for DeleteError {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match *self {

src/directory/footer.rs

@@ -1,4 +1,5 @@
 use crate::common::{BinarySerializable, CountingWriter, FixedSize, VInt};
+use crate::directory::error::Incompatibility;
 use crate::directory::read_only_source::ReadOnlySource;
 use crate::directory::{AntiCallToken, TerminatingWrite};
 use crate::Version;
@@ -17,11 +18,11 @@ pub struct Footer {
 }
 
 /// Serialises the footer to a byte-array
-/// - versioned_footer_len : 4bytes
+/// - versioned_footer_len : 4 bytes
 ///-  versioned_footer: variable bytes
 /// - meta_len: 4 bytes
 /// - meta: variable bytes
-/// - version_len: 4bytes
+/// - version_len: 4 bytes
 /// - version json: variable bytes
 impl BinarySerializable for Footer {
     fn serialize<W: io::Write>(&self, writer: &mut W) -> io::Result<()> {
@@ -86,16 +87,25 @@ impl Footer {
 
     /// Confirms that the index will be read correctly by this version of tantivy
     /// Has to be called after `extract_footer` to make sure it's not accessing uninitialised memory
-    pub fn is_compatible(&self) -> bool {
-        let version = &*crate::VERSION;
+    pub fn is_compatible(&self) -> Result<(), Incompatibility> {
+        let library_version = crate::version();
         match &self.versioned_footer {
             VersionedFooter::V1 {
-                crc32: _,
-                compression,
+                crc32: _crc,
+                store_compression: compression,
             } => {
-                return compression == &version.store_compression;
+                if &library_version.store_compression != compression {
+                    return Err(Incompatibility::CompressionMismatch {
+                        library_compression_format: library_version.store_compression.to_string(),
+                        index_compression_format: compression.to_string(),
+                    });
+                }
+                Ok(())
             }
-            VersionedFooter::UnknownVersion { version: _ } => false,
+            VersionedFooter::UnknownVersion => Err(Incompatibility::IndexMismatch {
+                library_version: library_version.clone(),
+                index_version: self.version.clone(),
+            }),
         }
     }
 }
@@ -103,31 +113,32 @@ impl Footer {
 /// Footer that includes a crc32 hash that enables us to checksum files in the index
 #[derive(Debug, Clone, PartialEq)]
 pub enum VersionedFooter {
-    UnknownVersion {
-        version: u32,
-    },
+    UnknownVersion,
     V1 {
         crc32: CrcHashU32,
-        compression: String,
+        store_compression: String,
     },
 }
 
 impl BinarySerializable for VersionedFooter {
     fn serialize<W: io::Write>(&self, writer: &mut W) -> io::Result<()> {
         let mut buf = Vec::new();
-        BinarySerializable::serialize(&self.version(), &mut buf)?;
         match self {
-            VersionedFooter::V1 { crc32, compression } => {
+            VersionedFooter::V1 {
+                crc32,
+                store_compression: compression,
+            } => {
                 // Serializes a valid `VersionedFooter` or panics if the version is unknown
                 // [   version    |   crc_hash  | compression_mode ]
-                // [    0..4      |     4..8    |  variable ]
+                // [    0..4      |     4..8    |     variable     ]
+                BinarySerializable::serialize(&1u32, &mut buf)?;
                 BinarySerializable::serialize(crc32, &mut buf)?;
                 BinarySerializable::serialize(compression, &mut buf)?;
             }
-            VersionedFooter::UnknownVersion { version: _ } => {
+            VersionedFooter::UnknownVersion => {
                 return Err(io::Error::new(
                     io::ErrorKind::InvalidInput,
-                    "Cannot serialize an unknown versionned footer ",
+                    "Cannot serialize an unknown versioned footer ",
                 ));
             }
         }
@@ -145,30 +156,20 @@ impl BinarySerializable for VersionedFooter {
         if version == 1 {
             let crc32 = u32::deserialize(&mut cursor)?;
             let compression = String::deserialize(&mut cursor)?;
-            Ok(VersionedFooter::V1 { crc32, compression })
+            Ok(VersionedFooter::V1 {
+                crc32,
+                store_compression: compression,
+            })
         } else {
-            Ok(VersionedFooter::UnknownVersion { version })
+            Ok(VersionedFooter::UnknownVersion)
         }
     }
 }
 
 impl VersionedFooter {
-    pub fn version(&self) -> u32 {
-        match self {
-            VersionedFooter::V1 {
-                crc32: _,
-                compression: _,
-            } => 1u32,
-            VersionedFooter::UnknownVersion { version, .. } => *version,
-        }
-    }
-
     pub fn crc(&self) -> Option<CrcHashU32> {
         match self {
-            VersionedFooter::V1 {
-                crc32,
-                compression: _,
-            } => Some(*crc32),
+            VersionedFooter::V1 { crc32, .. } => Some(*crc32),
             VersionedFooter::UnknownVersion { .. } => None,
         }
     }
@@ -207,7 +208,7 @@ impl<W: TerminatingWrite> TerminatingWrite for FooterProxy<W> {
         let crc32 = self.hasher.take().unwrap().finalize();
         let footer = Footer::new(VersionedFooter::V1 {
             crc32,
-            compression: crate::store::COMPRESSION.to_string(),
+            store_compression: crate::store::COMPRESSION.to_string(),
         });
         let mut writer = self.writer.take().unwrap();
         footer.append_footer(&mut writer)?;
@@ -227,16 +228,21 @@ mod tests {
     use regex::Regex;
 
     #[test]
-    fn test_footer_version() {
+    fn test_versioned_footer() {
         let mut vec = Vec::new();
         let footer_proxy = FooterProxy::new(&mut vec);
         assert!(footer_proxy.terminate().is_ok());
         assert_eq!(vec.len(), 167);
         let footer = Footer::deserialize(&mut &vec[..]).unwrap();
-        assert_eq!(
-            footer.versioned_footer.version(),
-            crate::INDEX_FORMAT_VERSION
-        );
+        if let VersionedFooter::V1 {
+            crc32: _,
+            store_compression,
+        } = footer.versioned_footer
+        {
+            assert_eq!(store_compression, crate::store::COMPRESSION);
+        } else {
+            panic!("Versioned footer should be V1.");
+        }
         assert_eq!(&footer.version, crate::version());
     }
 
@@ -246,7 +252,7 @@ mod tests {
         let crc32 = 123456u32;
         let footer: Footer = Footer::new(VersionedFooter::V1 {
             crc32,
-            compression: "lz4".to_string(),
+            store_compression: "lz4".to_string(),
         });
         footer.serialize(&mut buffer).unwrap();
         let footer_deser = Footer::deserialize(&mut &buffer[..]).unwrap();
@@ -255,11 +261,10 @@ mod tests {
 
     #[test]
     fn footer_length() {
-        // test to make sure the ascii art in the doc-strings is correct
         let crc32 = 1111111u32;
         let versioned_footer = VersionedFooter::V1 {
             crc32,
-            compression: "lz4".to_string(),
+            store_compression: "lz4".to_string(),
         };
         let mut buf = Vec::new();
         versioned_footer.serialize(&mut buf).unwrap();
@@ -299,7 +304,7 @@ mod tests {
         let expected_crc: u32 = LittleEndian::read_u32(&v_footer_bytes[5..9]) as CrcHashU32;
         let expected_versioned_footer: VersionedFooter = VersionedFooter::V1 {
             crc32: expected_crc,
-            compression: "lz4".to_string(),
+            store_compression: "lz4".to_string(),
         };
         assert_eq!(versioned_footer, expected_versioned_footer);
         let mut buffer = Vec::new();
@@ -313,11 +318,22 @@ mod tests {
         let mut b = &v_footer_bytes[..];
         let versioned_footer = VersionedFooter::deserialize(&mut b).unwrap();
         assert!(b.is_empty());
-        let expected_versioned_footer = VersionedFooter::UnknownVersion {
-            version: 16_777_219u32,
-        };
+        let expected_versioned_footer = VersionedFooter::UnknownVersion;
         assert_eq!(versioned_footer, expected_versioned_footer);
         let mut buf = Vec::new();
         assert!(versioned_footer.serialize(&mut buf).is_err());
     }
+
+    #[test]
+    #[cfg(not(feature = "lz4"))]
+    fn compression_mismatch() {
+        let crc32 = 1111111u32;
+        let versioned_footer = VersionedFooter::V1 {
+            crc32,
+            store_compression: "lz4".to_string(),
+        };
+        let footer = Footer::new(versioned_footer);
+        let res = footer.is_compatible();
+        assert!(res.is_err());
+    }
 }

src/directory/managed_directory.rs

@@ -9,7 +9,6 @@ use crate::directory::{ReadOnlySource, WritePtr};
 use crate::directory::{WatchCallback, WatchHandle};
 use crate::error::DataCorruption;
 use crate::Directory;
-use crate::Result;
 
 use crc32fast::Hasher;
 use serde_json;
@@ -66,7 +65,7 @@ fn save_managed_paths(
 
 impl ManagedDirectory {
     /// Wraps a directory as managed directory.
-    pub fn wrap<Dir: Directory>(directory: Dir) -> Result<ManagedDirectory> {
+    pub fn wrap<Dir: Directory>(directory: Dir) -> crate::Result<ManagedDirectory> {
         match directory.atomic_read(&MANAGED_FILEPATH) {
             Ok(data) => {
                 let managed_files_json = String::from_utf8_lossy(&data);
@@ -89,8 +88,10 @@ impl ManagedDirectory {
                 meta_informations: Arc::default(),
             }),
             Err(OpenReadError::IOError(e)) => Err(From::from(e)),
-            Err(OpenReadError::IncompatibleIndex(footer)) => {
-                Err(crate::Error::IncompatibleIndex(format!("{:?}", footer)))
+            Err(OpenReadError::IncompatibleIndex(incompatibility)) => {
+                // For the moment, this should never happen  `meta.json`
+                // do not have any footer and cannot detect incompatibility.
+                Err(crate::TantivyError::IncompatibleIndex(incompatibility))
             }
         }
     }
@@ -267,9 +268,7 @@ impl Directory for ManagedDirectory {
         let read_only_source = self.directory.open_read(path)?;
         let (footer, reader) = Footer::extract_footer(read_only_source)
             .map_err(|err| IOError::with_path(path.to_path_buf(), err))?;
-        if !footer.is_compatible() {
-            return Err(OpenReadError::IncompatibleIndex(footer));
-        }
+        footer.is_compatible()?;
         Ok(reader)
     }
 

src/directory/mod.rs

@@ -23,11 +23,9 @@ 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::watch_event_router::WatchCallbackList;
-pub use self::watch_event_router::{WatchCallback, WatchHandle};
+pub use self::watch_event_router::{WatchCallback, WatchCallbackList, WatchHandle};
 use std::io::{self, BufWriter, Write};
 use std::path::PathBuf;
-
 /// Outcome of the Garbage collection
 pub struct GarbageCollectionResult {
     /// List of files that were deleted in this cycle
@@ -48,6 +46,9 @@ pub use self::mmap_directory::MmapDirectory;
 pub use self::managed_directory::ManagedDirectory;
 
 /// Struct used to prevent from calling [`terminate_ref`](trait.TerminatingWrite#method.terminate_ref) directly
+///
+/// The point is that while the type is public, it cannot be built by anyone
+/// outside of this module.
 pub struct AntiCallToken(());
 
 /// Trait used to indicate when no more write need to be done on a writer

src/directory/watch_event_router.rs

@@ -24,13 +24,20 @@ pub struct WatchCallbackList {
 #[derive(Clone)]
 pub struct WatchHandle(Arc<WatchCallback>);
 
+impl WatchHandle {
+    /// Create a WatchHandle handle.
+    pub fn new(watch_callback: Arc<WatchCallback>) -> WatchHandle {
+        WatchHandle(watch_callback)
+    }
+}
+
 impl WatchCallbackList {
     /// Suscribes a new callback and returns a handle that controls the lifetime of the callback.
     pub fn subscribe(&self, watch_callback: WatchCallback) -> WatchHandle {
         let watch_callback_arc = Arc::new(watch_callback);
         let watch_callback_weak = Arc::downgrade(&watch_callback_arc);
         self.router.write().unwrap().push(watch_callback_weak);
-        WatchHandle(watch_callback_arc)
+        WatchHandle::new(watch_callback_arc)
     }
 
     fn list_callback(&self) -> Vec<Arc<WatchCallback>> {

src/error.rs

@@ -2,8 +2,8 @@
 
 use std::io;
 
-use crate::directory::error::LockError;
 use crate::directory::error::{IOError, OpenDirectoryError, OpenReadError, OpenWriteError};
+use crate::directory::error::{Incompatibility, LockError};
 use crate::fastfield::FastFieldNotAvailableError;
 use crate::query;
 use crate::schema;
@@ -81,11 +81,8 @@ pub enum TantivyError {
     #[fail(display = "System error.'{}'", _0)]
     SystemError(String),
     /// Index incompatible with current version of tantivy
-    #[fail(
-        display = "Current version of tantivy is incompatible with index version: '{}'",
-        _0
-    )]
-    IncompatibleIndex(String),
+    #[fail(display = "{:?}", _0)]
+    IncompatibleIndex(Incompatibility),
 }
 
 impl From<DataCorruption> for TantivyError {
@@ -135,8 +132,8 @@ impl From<OpenReadError> for TantivyError {
         match error {
             OpenReadError::FileDoesNotExist(filepath) => TantivyError::PathDoesNotExist(filepath),
             OpenReadError::IOError(io_error) => TantivyError::IOError(io_error),
-            OpenReadError::IncompatibleIndex(tantivy_err) => {
-                TantivyError::IncompatibleIndex(format!("{:?}", tantivy_err))
+            OpenReadError::IncompatibleIndex(incompatibility) => {
+                TantivyError::IncompatibleIndex(incompatibility)
             }
         }
     }

src/fastfield/delete.rs

@@ -1,9 +1,8 @@
-use crate::common::HasLen;
+use crate::common::{BitSet, HasLen};
 use crate::directory::ReadOnlySource;
 use crate::directory::WritePtr;
 use crate::space_usage::ByteCount;
 use crate::DocId;
-use bit_set::BitSet;
 use std::io;
 use std::io::Write;
 
@@ -17,7 +16,7 @@ pub fn write_delete_bitset(
 ) -> io::Result<()> {
     let mut byte = 0u8;
     let mut shift = 0u8;
-    for doc in 0..(max_doc as usize) {
+    for doc in 0..max_doc {
         if delete_bitset.contains(doc) {
             byte |= 1 << shift;
         }
@@ -32,7 +31,7 @@ pub fn write_delete_bitset(
     if max_doc % 8 > 0 {
         writer.write_all(&[byte])?;
     }
-    writer.flush()
+    Ok(())
 }
 
 /// Set of deleted `DocId`s.
@@ -86,7 +85,6 @@ impl HasLen for DeleteBitSet {
 mod tests {
     use super::*;
     use crate::directory::*;
-    use bit_set::BitSet;
     use std::path::PathBuf;
 
     fn test_delete_bitset_helper(bitset: &BitSet, max_doc: u32) {
@@ -95,27 +93,26 @@ mod tests {
         {
             let mut writer = directory.open_write(&*test_path).unwrap();
             write_delete_bitset(bitset, max_doc, &mut writer).unwrap();
+            writer.terminate().unwrap();
         }
-        {
-            let source = directory.open_read(&test_path).unwrap();
-            let delete_bitset = DeleteBitSet::open(source);
-            for doc in 0..max_doc as usize {
-                assert_eq!(bitset.contains(doc), delete_bitset.is_deleted(doc as DocId));
-            }
-            assert_eq!(delete_bitset.len(), bitset.len());
+        let source = directory.open_read(&test_path).unwrap();
+        let delete_bitset = DeleteBitSet::open(source);
+        for doc in 0..max_doc {
+            assert_eq!(bitset.contains(doc), delete_bitset.is_deleted(doc as DocId));
         }
+        assert_eq!(delete_bitset.len(), bitset.len());
     }
 
     #[test]
     fn test_delete_bitset() {
         {
-            let mut bitset = BitSet::with_capacity(10);
+            let mut bitset = BitSet::with_max_value(10);
             bitset.insert(1);
             bitset.insert(9);
             test_delete_bitset_helper(&bitset, 10);
         }
         {
-            let mut bitset = BitSet::with_capacity(8);
+            let mut bitset = BitSet::with_max_value(8);
             bitset.insert(1);
             bitset.insert(2);
             bitset.insert(3);

src/fastfield/mod.rs

@@ -33,6 +33,7 @@ pub use self::reader::FastFieldReader;
 pub use self::readers::FastFieldReaders;
 pub use self::serializer::FastFieldSerializer;
 pub use self::writer::{FastFieldsWriter, IntFastFieldWriter};
+use crate::chrono::{NaiveDateTime, Utc};
 use crate::common;
 use crate::schema::Cardinality;
 use crate::schema::FieldType;
@@ -49,7 +50,7 @@ mod serializer;
 mod writer;
 
 /// Trait for types that are allowed for fast fields: (u64, i64 and f64).
-pub trait FastValue: Default + Clone + Copy + Send + Sync + PartialOrd {
+pub trait FastValue: Clone + Copy + Send + Sync + PartialOrd {
     /// Converts a value from u64
     ///
     /// Internally all fast field values are encoded as u64.
@@ -69,6 +70,12 @@ pub trait FastValue: Default + Clone + Copy + Send + Sync + PartialOrd {
     /// Cast value to `u64`.
     /// The value is just reinterpreted in memory.
     fn as_u64(&self) -> u64;
+
+    /// Build a default value. This default value is never used, so the value does not
+    /// really matter.
+    fn make_zero() -> Self {
+        Self::from_u64(0i64.to_u64())
+    }
 }
 
 impl FastValue for u64 {
@@ -135,11 +142,34 @@ impl FastValue for f64 {
     }
 }
 
+impl FastValue for crate::DateTime {
+    fn from_u64(timestamp_u64: u64) -> Self {
+        let timestamp_i64 = i64::from_u64(timestamp_u64);
+        crate::DateTime::from_utc(NaiveDateTime::from_timestamp(timestamp_i64, 0), Utc)
+    }
+
+    fn to_u64(&self) -> u64 {
+        self.timestamp().to_u64()
+    }
+
+    fn fast_field_cardinality(field_type: &FieldType) -> Option<Cardinality> {
+        match *field_type {
+            FieldType::Date(ref integer_options) => integer_options.get_fastfield_cardinality(),
+            _ => None,
+        }
+    }
+
+    fn as_u64(&self) -> u64 {
+        self.timestamp().as_u64()
+    }
+}
+
 fn value_to_u64(value: &Value) -> u64 {
     match *value {
         Value::U64(ref val) => *val,
         Value::I64(ref val) => common::i64_to_u64(*val),
         Value::F64(ref val) => common::f64_to_u64(*val),
+        Value::Date(ref datetime) => common::i64_to_u64(datetime.timestamp()),
         _ => panic!("Expected a u64/i64/f64 field, got {:?} ", value),
     }
 }
@@ -151,10 +181,12 @@ mod tests {
     use crate::common::CompositeFile;
     use crate::directory::{Directory, RAMDirectory, WritePtr};
     use crate::fastfield::FastFieldReader;
-    use crate::schema::Document;
+    use crate::merge_policy::NoMergePolicy;
     use crate::schema::Field;
     use crate::schema::Schema;
     use crate::schema::FAST;
+    use crate::schema::{Document, IntOptions};
+    use crate::{Index, SegmentId, SegmentReader};
     use once_cell::sync::Lazy;
     use rand::prelude::SliceRandom;
     use rand::rngs::StdRng;
@@ -178,6 +210,12 @@ mod tests {
         assert_eq!(test_fastfield.get(2), 300);
     }
 
+    #[test]
+    pub fn test_fastfield_i64_u64() {
+        let datetime = crate::DateTime::from_utc(NaiveDateTime::from_timestamp(0i64, 0), Utc);
+        assert_eq!(i64::from_u64(datetime.to_u64()), 0i64);
+    }
+
     #[test]
     fn test_intfastfield_small() {
         let path = Path::new("test");
@@ -429,6 +467,93 @@ mod tests {
             }
         }
     }
+
+    #[test]
+    fn test_merge_missing_date_fast_field() {
+        let mut schema_builder = Schema::builder();
+        let date_field = schema_builder.add_date_field("date", FAST);
+        let schema = schema_builder.build();
+        let index = Index::create_in_ram(schema);
+        let mut index_writer = index.writer_with_num_threads(1, 3_000_000).unwrap();
+        index_writer.set_merge_policy(Box::new(NoMergePolicy));
+        index_writer.add_document(doc!(date_field =>crate::chrono::prelude::Utc::now()));
+        index_writer.commit().unwrap();
+        index_writer.add_document(doc!());
+        index_writer.commit().unwrap();
+        let reader = index.reader().unwrap();
+        let segment_ids: Vec<SegmentId> = reader
+            .searcher()
+            .segment_readers()
+            .iter()
+            .map(SegmentReader::segment_id)
+            .collect();
+        assert_eq!(segment_ids.len(), 2);
+        let merge_future = index_writer.merge(&segment_ids[..]);
+        let merge_res = futures::executor::block_on(merge_future);
+        assert!(merge_res.is_ok());
+        assert!(reader.reload().is_ok());
+        assert_eq!(reader.searcher().segment_readers().len(), 1);
+    }
+
+    #[test]
+    fn test_default_datetime() {
+        assert_eq!(crate::DateTime::make_zero().timestamp(), 0i64);
+    }
+
+    #[test]
+    fn test_datefastfield() {
+        use crate::fastfield::FastValue;
+        let mut schema_builder = Schema::builder();
+        let date_field = schema_builder.add_date_field("date", FAST);
+        let multi_date_field = schema_builder.add_date_field(
+            "multi_date",
+            IntOptions::default().set_fast(Cardinality::MultiValues),
+        );
+        let schema = schema_builder.build();
+        let index = Index::create_in_ram(schema);
+        let mut index_writer = index.writer_with_num_threads(1, 3_000_000).unwrap();
+        index_writer.set_merge_policy(Box::new(NoMergePolicy));
+        index_writer.add_document(doc!(
+            date_field => crate::DateTime::from_u64(1i64.to_u64()),
+            multi_date_field => crate::DateTime::from_u64(2i64.to_u64()),
+            multi_date_field => crate::DateTime::from_u64(3i64.to_u64())
+        ));
+        index_writer.add_document(doc!(
+            date_field => crate::DateTime::from_u64(4i64.to_u64())
+        ));
+        index_writer.add_document(doc!(
+            multi_date_field => crate::DateTime::from_u64(5i64.to_u64()),
+            multi_date_field => crate::DateTime::from_u64(6i64.to_u64())
+        ));
+        index_writer.commit().unwrap();
+        let reader = index.reader().unwrap();
+        let searcher = reader.searcher();
+        assert_eq!(searcher.segment_readers().len(), 1);
+        let segment_reader = searcher.segment_reader(0);
+        let fast_fields = segment_reader.fast_fields();
+        let date_fast_field = fast_fields.date(date_field).unwrap();
+        let dates_fast_field = fast_fields.dates(multi_date_field).unwrap();
+        let mut dates = vec![];
+        {
+            assert_eq!(date_fast_field.get(0u32).timestamp(), 1i64);
+            dates_fast_field.get_vals(0u32, &mut dates);
+            assert_eq!(dates.len(), 2);
+            assert_eq!(dates[0].timestamp(), 2i64);
+            assert_eq!(dates[1].timestamp(), 3i64);
+        }
+        {
+            assert_eq!(date_fast_field.get(1u32).timestamp(), 4i64);
+            dates_fast_field.get_vals(1u32, &mut dates);
+            assert!(dates.is_empty());
+        }
+        {
+            assert_eq!(date_fast_field.get(2u32).timestamp(), 0i64);
+            dates_fast_field.get_vals(2u32, &mut dates);
+            assert_eq!(dates.len(), 2);
+            assert_eq!(dates[0].timestamp(), 5i64);
+            assert_eq!(dates[1].timestamp(), 6i64);
+        }
+    }
 }
 
 #[cfg(all(test, feature = "unstable"))]

src/fastfield/multivalued/reader.rs

@@ -45,7 +45,7 @@ impl<Item: FastValue> MultiValueIntFastFieldReader<Item> {
     pub fn get_vals(&self, doc: DocId, vals: &mut Vec<Item>) {
         let (start, stop) = self.range(doc);
         let len = (stop - start) as usize;
-        vals.resize(len, Item::default());
+        vals.resize(len, Item::make_zero());
         self.vals_reader.get_range_u64(start, &mut vals[..]);
     }
 

src/fastfield/readers.rs

@@ -15,9 +15,11 @@ pub struct FastFieldReaders {
     fast_field_i64: HashMap<Field, FastFieldReader<i64>>,
     fast_field_u64: HashMap<Field, FastFieldReader<u64>>,
     fast_field_f64: HashMap<Field, FastFieldReader<f64>>,
+    fast_field_date: HashMap<Field, FastFieldReader<crate::DateTime>>,
     fast_field_i64s: HashMap<Field, MultiValueIntFastFieldReader<i64>>,
     fast_field_u64s: HashMap<Field, MultiValueIntFastFieldReader<u64>>,
     fast_field_f64s: HashMap<Field, MultiValueIntFastFieldReader<f64>>,
+    fast_field_dates: HashMap<Field, MultiValueIntFastFieldReader<crate::DateTime>>,
     fast_bytes: HashMap<Field, BytesFastFieldReader>,
     fast_fields_composite: CompositeFile,
 }
@@ -26,6 +28,7 @@ enum FastType {
     I64,
     U64,
     F64,
+    Date,
 }
 
 fn type_and_cardinality(field_type: &FieldType) -> Option<(FastType, Cardinality)> {
@@ -39,6 +42,9 @@ fn type_and_cardinality(field_type: &FieldType) -> Option<(FastType, Cardinality
         FieldType::F64(options) => options
             .get_fastfield_cardinality()
             .map(|cardinality| (FastType::F64, cardinality)),
+        FieldType::Date(options) => options
+            .get_fastfield_cardinality()
+            .map(|cardinality| (FastType::Date, cardinality)),
         FieldType::HierarchicalFacet => Some((FastType::U64, Cardinality::MultiValues)),
         _ => None,
     }
@@ -53,9 +59,11 @@ impl FastFieldReaders {
             fast_field_i64: Default::default(),
             fast_field_u64: Default::default(),
             fast_field_f64: Default::default(),
+            fast_field_date: Default::default(),
             fast_field_i64s: Default::default(),
             fast_field_u64s: Default::default(),
             fast_field_f64s: Default::default(),
+            fast_field_dates: Default::default(),
             fast_bytes: Default::default(),
             fast_fields_composite: fast_fields_composite.clone(),
         };
@@ -95,6 +103,12 @@ impl FastFieldReaders {
                                         FastFieldReader::open(fast_field_data.clone()),
                                     );
                                 }
+                                FastType::Date => {
+                                    fast_field_readers.fast_field_date.insert(
+                                        field,
+                                        FastFieldReader::open(fast_field_data.clone()),
+                                    );
+                                }
                             }
                         } else {
                             return Err(From::from(FastFieldNotAvailableError::new(field_entry)));
@@ -130,6 +144,14 @@ impl FastFieldReaders {
                                         .fast_field_f64s
                                         .insert(field, multivalued_int_fast_field);
                                 }
+                                FastType::Date => {
+                                    let vals_reader = FastFieldReader::open(fast_field_data);
+                                    let multivalued_int_fast_field =
+                                        MultiValueIntFastFieldReader::open(idx_reader, vals_reader);
+                                    fast_field_readers
+                                        .fast_field_dates
+                                        .insert(field, multivalued_int_fast_field);
+                                }
                             }
                         } else {
                             return Err(From::from(FastFieldNotAvailableError::new(field_entry)));
@@ -156,8 +178,6 @@ impl FastFieldReaders {
     /// If the field is a i64-fast field, return the associated u64 reader. Values are
     /// mapped from i64 to u64 using a (well the, it is unique) monotonic mapping.    ///
     ///
-    ///TODO should it also be lenient with f64?
-    ///
     /// This method is useful when merging segment reader.
     pub(crate) fn u64_lenient(&self, field: Field) -> Option<FastFieldReader<u64>> {
         if let Some(u64_ff_reader) = self.u64(field) {
@@ -166,6 +186,12 @@ impl FastFieldReaders {
         if let Some(i64_ff_reader) = self.i64(field) {
             return Some(i64_ff_reader.into_u64_reader());
         }
+        if let Some(f64_ff_reader) = self.f64(field) {
+            return Some(f64_ff_reader.into_u64_reader());
+        }
+        if let Some(date_ff_reader) = self.date(field) {
+            return Some(date_ff_reader.into_u64_reader());
+        }
         None
     }
 
@@ -176,6 +202,13 @@ impl FastFieldReaders {
         self.fast_field_i64.get(&field).cloned()
     }
 
+    /// Returns the `i64` fast field reader reader associated to `field`.
+    ///
+    /// If `field` is not a i64 fast field, this method returns `None`.
+    pub fn date(&self, field: Field) -> Option<FastFieldReader<crate::DateTime>> {
+        self.fast_field_date.get(&field).cloned()
+    }
+
     /// Returns the `f64` fast field reader reader associated to `field`.
     ///
     /// If `field` is not a f64 fast field, this method returns `None`.
@@ -202,6 +235,9 @@ impl FastFieldReaders {
         if let Some(i64s_ff_reader) = self.i64s(field) {
             return Some(i64s_ff_reader.into_u64s_reader());
         }
+        if let Some(f64s_ff_reader) = self.f64s(field) {
+            return Some(f64s_ff_reader.into_u64s_reader());
+        }
         None
     }
 
@@ -219,6 +255,13 @@ impl FastFieldReaders {
         self.fast_field_f64s.get(&field).cloned()
     }
 
+    /// Returns a `crate::DateTime` multi-valued fast field reader reader associated to `field`.
+    ///
+    /// If `field` is not a `crate::DateTime` multi-valued fast field, this method returns `None`.
+    pub fn dates(&self, field: Field) -> Option<MultiValueIntFastFieldReader<crate::DateTime>> {
+        self.fast_field_dates.get(&field).cloned()
+    }
+
     /// Returns the `bytes` fast field reader associated to `field`.
     ///
     /// If `field` is not a bytes fast field, returns `None`.

src/fastfield/writer.rs

@@ -4,7 +4,7 @@ use crate::common::BinarySerializable;
 use crate::common::VInt;
 use crate::fastfield::{BytesFastFieldWriter, FastFieldSerializer};
 use crate::postings::UnorderedTermId;
-use crate::schema::{Cardinality, Document, Field, FieldType, Schema};
+use crate::schema::{Cardinality, Document, Field, FieldEntry, FieldType, Schema};
 use crate::termdict::TermOrdinal;
 use fnv::FnvHashMap;
 use std::collections::HashMap;
@@ -17,6 +17,14 @@ pub struct FastFieldsWriter {
     bytes_value_writers: Vec<BytesFastFieldWriter>,
 }
 
+fn fast_field_default_value(field_entry: &FieldEntry) -> u64 {
+    match *field_entry.field_type() {
+        FieldType::I64(_) | FieldType::Date(_) => common::i64_to_u64(0i64),
+        FieldType::F64(_) => common::f64_to_u64(0.0f64),
+        _ => 0u64,
+    }
+}
+
 impl FastFieldsWriter {
     /// Create all `FastFieldWriter` required by the schema.
     pub fn from_schema(schema: &Schema) -> FastFieldsWriter {
@@ -25,18 +33,15 @@ impl FastFieldsWriter {
         let mut bytes_value_writers = Vec::new();
 
         for (field, field_entry) in schema.fields() {
-            let default_value = match *field_entry.field_type() {
-                FieldType::I64(_) => common::i64_to_u64(0i64),
-                FieldType::F64(_) => common::f64_to_u64(0.0f64),
-                _ => 0u64,
-            };
             match *field_entry.field_type() {
                 FieldType::I64(ref int_options)
                 | FieldType::U64(ref int_options)
-                | FieldType::F64(ref int_options) => {
+                | FieldType::F64(ref int_options)
+                | FieldType::Date(ref int_options) => {
                     match int_options.get_fastfield_cardinality() {
                         Some(Cardinality::SingleValue) => {
                             let mut fast_field_writer = IntFastFieldWriter::new(field);
+                            let default_value = fast_field_default_value(field_entry);
                             fast_field_writer.set_val_if_missing(default_value);
                             single_value_writers.push(fast_field_writer);
                         }

src/indexer/index_writer.rs

@@ -1,6 +1,7 @@
 use super::operation::{AddOperation, UserOperation};
 use super::segment_updater::SegmentUpdater;
 use super::PreparedCommit;
+use crate::common::BitSet;
 use crate::core::Index;
 use crate::core::Segment;
 use crate::core::SegmentComponent;
@@ -23,7 +24,6 @@ use crate::schema::Document;
 use crate::schema::IndexRecordOption;
 use crate::schema::Term;
 use crate::Opstamp;
-use bit_set::BitSet;
 use crossbeam::channel;
 use futures::executor::block_on;
 use futures::future::Future;
@@ -115,7 +115,7 @@ fn compute_deleted_bitset(
             while docset.advance() {
                 let deleted_doc = docset.doc();
                 if deleted_doc < limit_doc {
-                    delete_bitset.insert(deleted_doc as usize);
+                    delete_bitset.insert(deleted_doc);
                     might_have_changed = true;
                 }
             }
@@ -126,51 +126,60 @@ fn compute_deleted_bitset(
     Ok(might_have_changed)
 }
 
-/// Advance delete for the given segment up
-/// to the target opstamp.
+/// Advance delete for the given segment up to the target opstamp.
+///
+/// Note that there are no guarantee that the resulting `segment_entry` delete_opstamp
+/// is `==` target_opstamp.
+/// 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<()> {
-    {
-        if segment_entry.meta().delete_opstamp() == Some(target_opstamp) {
-            // We are already up-to-date here.
-            return Ok(());
-        }
+    if segment_entry.meta().delete_opstamp() == Some(target_opstamp) {
+        // We are already up-to-date here.
+        return Ok(());
+    }
 
-        let segment_reader = SegmentReader::open(&segment)?;
+    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(());
+    }
 
-        let max_doc = segment_reader.max_doc();
-        let mut delete_bitset: BitSet = match segment_entry.delete_bitset() {
-            Some(previous_delete_bitset) => (*previous_delete_bitset).clone(),
-            None => BitSet::with_capacity(max_doc as usize),
-        };
+    let segment_reader = SegmentReader::open(&segment)?;
 
-        let delete_cursor = segment_entry.delete_cursor();
-        compute_deleted_bitset(
-            &mut delete_bitset,
-            &segment_reader,
-            delete_cursor,
-            &DocToOpstampMapping::None,
-            target_opstamp,
-        )?;
+    let max_doc = segment_reader.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),
+    };
 
-        // TODO optimize
+    compute_deleted_bitset(
+        &mut delete_bitset,
+        &segment_reader,
+        segment_entry.delete_cursor(),
+        &DocToOpstampMapping::None,
+        target_opstamp,
+    )?;
+
+    // TODO optimize
+    if let Some(seg_delete_bitset) = segment_reader.delete_bitset() {
         for doc in 0u32..max_doc {
-            if segment_reader.is_deleted(doc) {
-                delete_bitset.insert(doc as usize);
+            if seg_delete_bitset.is_deleted(doc) {
+                delete_bitset.insert(doc);
             }
         }
-
-        let num_deleted_docs = delete_bitset.len();
-        if num_deleted_docs > 0 {
-            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()?;
-        }
     }
+
+    let num_deleted_docs = delete_bitset.len();
+    if num_deleted_docs > 0 {
+        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.set_meta(segment.meta().clone());
     Ok(())
 }
@@ -236,7 +245,7 @@ fn apply_deletes(
     mut delete_cursor: &mut DeleteCursor,
     doc_opstamps: &[Opstamp],
     last_docstamp: Opstamp,
-) -> crate::Result<Option<BitSet<u32>>> {
+) -> crate::Result<Option<BitSet>> {
     if delete_cursor.get().is_none() {
         // if there are no delete operation in the queue, no need
         // to even open the segment.
@@ -246,7 +255,7 @@ fn apply_deletes(
     let doc_to_opstamps = DocToOpstampMapping::from(doc_opstamps);
 
     let max_doc = segment.meta().max_doc();
-    let mut deleted_bitset = BitSet::with_capacity(max_doc as usize);
+    let mut deleted_bitset = BitSet::with_max_value(max_doc);
     let may_have_deletes = compute_deleted_bitset(
         &mut deleted_bitset,
         &segment_reader,
@@ -505,9 +514,13 @@ impl IndexWriter {
     /// Merges a given list of segments
     ///
     /// `segment_ids` is required to be non-empty.
-    pub async fn merge(&mut self, segment_ids: &[SegmentId]) -> crate::Result<SegmentMeta> {
+    pub fn merge(
+        &mut self,
+        segment_ids: &[SegmentId],
+    ) -> impl Future<Output = crate::Result<SegmentMeta>> {
         let merge_operation = self.segment_updater.make_merge_operation(segment_ids);
-        self.segment_updater.start_merge(merge_operation)?.await
+        let segment_updater = self.segment_updater.clone();
+        async move { segment_updater.start_merge(merge_operation)?.await }
     }
 
     /// Closes the current document channel send.

src/indexer/merger.rs

@@ -1492,4 +1492,46 @@ mod tests {
             assert_eq!(&vals, &[20]);
         }
     }
+
+    #[test]
+    fn merges_f64_fast_fields_correctly() -> crate::Result<()> {
+        let mut builder = schema::SchemaBuilder::new();
+
+        let fast_multi = IntOptions::default().set_fast(Cardinality::MultiValues);
+
+        let field = builder.add_f64_field("f64", schema::FAST);
+        let multi_field = builder.add_f64_field("f64s", fast_multi);
+
+        let index = Index::create_in_ram(builder.build());
+
+        let mut writer = index.writer_with_num_threads(1, 3_000_000)?;
+
+        // Make sure we'll attempt to merge every created segment
+        let mut policy = crate::indexer::LogMergePolicy::default();
+        policy.set_min_merge_size(2);
+        writer.set_merge_policy(Box::new(policy));
+
+        for i in 0..100 {
+            let mut doc = Document::new();
+            doc.add_f64(field, 42.0);
+
+            doc.add_f64(multi_field, 0.24);
+            doc.add_f64(multi_field, 0.27);
+
+            writer.add_document(doc);
+
+            if i % 5 == 0 {
+                writer.commit()?;
+            }
+        }
+
+        writer.commit()?;
+        writer.wait_merging_threads()?;
+
+        // If a merging thread fails, we should end up with more
+        // than one segment here
+        assert_eq!(1, index.searchable_segments()?.len());
+
+        Ok(())
+    }
 }

src/indexer/mod.rs

@@ -33,6 +33,7 @@ pub type DefaultMergePolicy = LogMergePolicy;
 mod tests {
     use crate::schema::{self, Schema};
     use crate::{Index, Term};
+
     #[test]
     fn test_advance_delete_bug() {
         let mut schema_builder = Schema::builder();

src/indexer/segment_entry.rs

@@ -1,7 +1,7 @@
+use crate::common::BitSet;
 use crate::core::SegmentId;
 use crate::core::SegmentMeta;
 use crate::indexer::delete_queue::DeleteCursor;
-use bit_set::BitSet;
 use std::fmt;
 
 /// A segment entry describes the state of

src/indexer/segment_updater.rs

@@ -214,6 +214,10 @@ impl SegmentUpdater {
             self.pool.spawn_ok(async move {
                 let _ = sender.send(f.await);
             });
+        } else {
+            let _ = sender.send(Err(crate::TantivyError::SystemError(
+                "Segment updater killed".to_string(),
+            )));
         }
         receiver.unwrap_or_else(|_| {
             let err_msg =
@@ -326,13 +330,11 @@ impl SegmentUpdater {
     ) -> impl Future<Output = crate::Result<()>> {
         let segment_updater: SegmentUpdater = self.clone();
         self.schedule_future(async move {
-            if segment_updater.is_alive() {
-                let segment_entries = segment_updater.purge_deletes(opstamp)?;
-                segment_updater.segment_manager.commit(segment_entries);
-                segment_updater.save_metas(opstamp, payload)?;
-                let _ = garbage_collect_files(segment_updater.clone()).await;
-                segment_updater.consider_merge_options().await;
-            }
+            let segment_entries = segment_updater.purge_deletes(opstamp)?;
+            segment_updater.segment_manager.commit(segment_entries);
+            segment_updater.save_metas(opstamp, payload)?;
+            let _ = garbage_collect_files(segment_updater.clone()).await;
+            segment_updater.consider_merge_options().await;
             Ok(())
         })
     }

src/lib.rs

@@ -173,6 +173,7 @@ use std::fmt;
 
 use once_cell::sync::Lazy;
 
+/// Index format version.
 const INDEX_FORMAT_VERSION: u32 = 1;
 
 /// Structure version for the index.
@@ -939,4 +940,73 @@ mod tests {
             assert_eq!(fast_field_reader.get(0), 4f64)
         }
     }
+
+    // motivated by #729
+    #[test]
+    fn test_update_via_delete_insert() {
+        use crate::collector::Count;
+        use crate::indexer::NoMergePolicy;
+        use crate::query::AllQuery;
+        use crate::SegmentId;
+        use futures::executor::block_on;
+
+        const DOC_COUNT: u64 = 2u64;
+
+        let mut schema_builder = SchemaBuilder::default();
+        let id = schema_builder.add_u64_field("id", INDEXED);
+        let schema = schema_builder.build();
+
+        let index = Index::create_in_ram(schema.clone());
+        let index_reader = index.reader().unwrap();
+
+        let mut index_writer = index.writer(3_000_000).unwrap();
+        index_writer.set_merge_policy(Box::new(NoMergePolicy));
+
+        for doc_id in 0u64..DOC_COUNT {
+            index_writer.add_document(doc!(id => doc_id));
+        }
+        index_writer.commit().unwrap();
+
+        index_reader.reload().unwrap();
+        let searcher = index_reader.searcher();
+
+        assert_eq!(
+            searcher.search(&AllQuery, &Count).unwrap(),
+            DOC_COUNT as usize
+        );
+
+        // update the 10 elements by deleting and re-adding
+        for doc_id in 0u64..DOC_COUNT {
+            index_writer.delete_term(Term::from_field_u64(id, doc_id));
+            index_writer.commit().unwrap();
+            index_reader.reload().unwrap();
+            let doc = doc!(id =>  doc_id);
+            index_writer.add_document(doc);
+            index_writer.commit().unwrap();
+            index_reader.reload().unwrap();
+            let searcher = index_reader.searcher();
+            // The number of document should be stable.
+            assert_eq!(
+                searcher.search(&AllQuery, &Count).unwrap(),
+                DOC_COUNT as usize
+            );
+        }
+
+        index_reader.reload().unwrap();
+        let searcher = index_reader.searcher();
+        let segment_ids: Vec<SegmentId> = searcher
+            .segment_readers()
+            .into_iter()
+            .map(|reader| reader.segment_id())
+            .collect();
+        block_on(index_writer.merge(&segment_ids)).unwrap();
+
+        index_reader.reload().unwrap();
+        let searcher = index_reader.searcher();
+
+        assert_eq!(
+            searcher.search(&AllQuery, &Count).unwrap(),
+            DOC_COUNT as usize
+        );
+    }
 }

src/schema/value.rs

@@ -209,8 +209,8 @@ impl From<f64> for Value {
     }
 }
 
-impl From<DateTime> for Value {
-    fn from(date_time: DateTime) -> Value {
+impl From<crate::DateTime> for Value {
+    fn from(date_time: crate::DateTime) -> Value {
         Value::Date(date_time)
     }
 }

src/store/compression_snap.rs

@@ -5,7 +5,7 @@ use std::io::{self, Read, Write};
 /// Name of the compression scheme used in the doc store.
 ///
 /// This name is appended to the version string of tantivy.
-pub const COMPRESSION: &'static str = "snappy";
+pub const COMPRESSION: &str = "snappy";
 
 pub fn compress(uncompressed: &[u8], compressed: &mut Vec<u8>) -> io::Result<()> {
     compressed.clear();