remove searcher pool and make Searcher cloneable (#1411)

* remove searcher pool and make Searcher cloneable

closes #1410

* use SearcherInner in InnerIndexReader

CHANGELOG.md

@@ -3,7 +3,7 @@ Tantivy 0.19
 - Updated [Date Field Type](https://github.com/quickwit-oss/tantivy/pull/1396)
   The `DateTime` type has been updated to hold timestamps with microseconds precision.
   `DateOptions` and `DatePrecision` have been added to configure Date fields. The precision is used to hint on fast values compression. Otherwise, seconds precision is used everywhere else (i.e terms, indexing).
-
+- Remove Searcher pool and make `Searcher` cloneable.
 
 Tantivy 0.18
 ================================

Cargo.toml

@@ -59,6 +59,7 @@ measure_time = "0.8.2"
 pretty_assertions = "1.2.1"
 serde_cbor = { version = "0.11.2", optional = true }
 async-trait = "0.1.53"
+arc-swap = "1.5.0"
 
 [target.'cfg(windows)'.dependencies]
 winapi = "0.3.9"

examples/warmer.rs

@@ -145,11 +145,7 @@ fn main() -> tantivy::Result<()> {
     let warmers: Vec<Weak<dyn Warmer>> = vec![Arc::downgrade(
         &(price_dynamic_column.clone() as Arc<dyn Warmer>),
     )];
-    let reader: IndexReader = index
-        .reader_builder()
-        .warmers(warmers)
-        .num_searchers(1)
-        .try_into()?;
+    let reader: IndexReader = index.reader_builder().warmers(warmers).try_into()?;
     reader.reload()?;
 
     let query_parser = QueryParser::for_index(&index, vec![text]);

src/collector/tests.rs

@@ -263,7 +263,7 @@ impl SegmentCollector for BytesFastFieldSegmentCollector {
     }
 }
 
-fn make_test_searcher() -> crate::Result<crate::LeasedItem<Searcher>> {
+fn make_test_searcher() -> crate::Result<Searcher> {
     let schema = Schema::builder().build();
     let index = Index::create_in_ram(schema);
     let mut index_writer = index.writer_for_tests()?;

src/core/searcher.rs

@@ -1,4 +1,5 @@
 use std::collections::BTreeMap;
+use std::sync::Arc;
 use std::{fmt, io};
 
 use crate::collector::Collector;
@@ -62,53 +63,28 @@ impl SearcherGeneration {
 ///
 /// It guarantees that the `Segment` will not be removed before
 /// the destruction of the `Searcher`.
+#[derive(Clone)]
 pub struct Searcher {
-    schema: Schema,
-    index: Index,
-    segment_readers: Vec<SegmentReader>,
-    store_readers: Vec<StoreReader>,
-    generation: TrackedObject<SearcherGeneration>,
+    inner: Arc<SearcherInner>,
 }
 
 impl Searcher {
-    /// Creates a new `Searcher`
-    pub(crate) fn new(
-        schema: Schema,
-        index: Index,
-        segment_readers: Vec<SegmentReader>,
-        generation: TrackedObject<SearcherGeneration>,
-        doc_store_cache_size: usize,
-    ) -> io::Result<Searcher> {
-        let store_readers: Vec<StoreReader> = segment_readers
-            .iter()
-            .map(|segment_reader| segment_reader.get_store_reader(doc_store_cache_size))
-            .collect::<io::Result<Vec<_>>>()?;
-
-        Ok(Searcher {
-            schema,
-            index,
-            segment_readers,
-            store_readers,
-            generation,
-        })
-    }
-
     /// Returns the `Index` associated to the `Searcher`
     pub fn index(&self) -> &Index {
-        &self.index
+        &self.inner.index
     }
 
     /// [SearcherGeneration] which identifies the version of the snapshot held by this `Searcher`.
     pub fn generation(&self) -> &SearcherGeneration {
-        self.generation.as_ref()
+        self.inner.generation.as_ref()
     }
 
     /// Fetches a document from tantivy's store given a `DocAddress`.
     ///
     /// The searcher uses the segment ordinal to route the
     /// the request to the right `Segment`.
     pub fn doc(&self, doc_address: DocAddress) -> crate::Result<Document> {
-        let store_reader = &self.store_readers[doc_address.segment_ord as usize];
+        let store_reader = &self.inner.store_readers[doc_address.segment_ord as usize];
         store_reader.get(doc_address.doc_id)
     }
 
@@ -117,6 +93,7 @@ impl Searcher {
     /// Aggregates the sum for each segment store reader.
     pub fn doc_store_cache_stats(&self) -> CacheStats {
         let cache_stats: CacheStats = self
+            .inner
             .store_readers
             .iter()
             .map(|reader| reader.cache_stats())
@@ -127,18 +104,19 @@ impl Searcher {
     /// Fetches a document in an asynchronous manner.
     #[cfg(feature = "quickwit")]
     pub async fn doc_async(&self, doc_address: DocAddress) -> crate::Result<Document> {
-        let store_reader = &self.store_readers[doc_address.segment_ord as usize];
+        let store_reader = &self.inner.store_readers[doc_address.segment_ord as usize];
         store_reader.get_async(doc_address.doc_id).await
     }
 
     /// Access the schema associated to the index of this searcher.
     pub fn schema(&self) -> &Schema {
-        &self.schema
+        &self.inner.schema
     }
 
     /// Returns the overall number of documents in the index.
     pub fn num_docs(&self) -> u64 {
-        self.segment_readers
+        self.inner
+            .segment_readers
             .iter()
             .map(|segment_reader| u64::from(segment_reader.num_docs()))
             .sum::<u64>()
@@ -148,7 +126,7 @@ impl Searcher {
     /// the given term.
     pub fn doc_freq(&self, term: &Term) -> crate::Result<u64> {
         let mut total_doc_freq = 0;
-        for segment_reader in &self.segment_readers {
+        for segment_reader in &self.inner.segment_readers {
             let inverted_index = segment_reader.inverted_index(term.field())?;
             let doc_freq = inverted_index.doc_freq(term)?;
             total_doc_freq += u64::from(doc_freq);
@@ -158,12 +136,12 @@ impl Searcher {
 
     /// Return the list of segment readers
     pub fn segment_readers(&self) -> &[SegmentReader] {
-        &self.segment_readers
+        &self.inner.segment_readers
     }
 
     /// Returns the segment_reader associated with the given segment_ord
     pub fn segment_reader(&self, segment_ord: u32) -> &SegmentReader {
-        &self.segment_readers[segment_ord as usize]
+        &self.inner.segment_readers[segment_ord as usize]
     }
 
     /// Runs a query on the segment readers wrapped by the searcher.
@@ -185,7 +163,7 @@ impl Searcher {
         query: &dyn Query,
         collector: &C,
     ) -> crate::Result<C::Fruit> {
-        let executor = self.index.search_executor();
+        let executor = self.inner.index.search_executor();
         self.search_with_executor(query, collector, executor)
     }
 
@@ -222,17 +200,59 @@ impl Searcher {
     /// Summarize total space usage of this searcher.
     pub fn space_usage(&self) -> io::Result<SearcherSpaceUsage> {
         let mut space_usage = SearcherSpaceUsage::new();
-        for segment_reader in &self.segment_readers {
+        for segment_reader in self.segment_readers() {
             space_usage.add_segment(segment_reader.space_usage()?);
         }
         Ok(space_usage)
     }
 }
 
+impl From<Arc<SearcherInner>> for Searcher {
+    fn from(inner: Arc<SearcherInner>) -> Self {
+        Searcher { inner }
+    }
+}
+
+/// Holds a list of `SegmentReader`s ready for search.
+///
+/// It guarantees that the `Segment` will not be removed before
+/// the destruction of the `Searcher`.
+pub(crate) struct SearcherInner {
+    schema: Schema,
+    index: Index,
+    segment_readers: Vec<SegmentReader>,
+    store_readers: Vec<StoreReader>,
+    generation: TrackedObject<SearcherGeneration>,
+}
+
+impl SearcherInner {
+    /// Creates a new `Searcher`
+    pub(crate) fn new(
+        schema: Schema,
+        index: Index,
+        segment_readers: Vec<SegmentReader>,
+        generation: TrackedObject<SearcherGeneration>,
+        doc_store_cache_size: usize,
+    ) -> io::Result<SearcherInner> {
+        let store_readers: Vec<StoreReader> = segment_readers
+            .iter()
+            .map(|segment_reader| segment_reader.get_store_reader(doc_store_cache_size))
+            .collect::<io::Result<Vec<_>>>()?;
+
+        Ok(SearcherInner {
+            schema,
+            index,
+            segment_readers,
+            store_readers,
+            generation,
+        })
+    }
+}
+
 impl fmt::Debug for Searcher {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         let segment_ids = self
-            .segment_readers
+            .segment_readers()
             .iter()
             .map(SegmentReader::segment_id)
             .collect::<Vec<_>>();

src/fastfield/bytes/mod.rs

@@ -6,8 +6,6 @@ pub use self::writer::BytesFastFieldWriter;
 
 #[cfg(test)]
 mod tests {
-    use std::ops::Deref;
-
     use crate::query::TermQuery;
     use crate::schema::{BytesOptions, IndexRecordOption, Schema, Value, FAST, INDEXED, STORED};
     use crate::{DocAddress, DocSet, Index, Searcher, Term};
@@ -37,9 +35,7 @@ mod tests {
         Ok(())
     }
 
-    fn create_index_for_test<T: Into<BytesOptions>>(
-        byte_options: T,
-    ) -> crate::Result<impl Deref<Target = Searcher>> {
+    fn create_index_for_test<T: Into<BytesOptions>>(byte_options: T) -> crate::Result<Searcher> {
         let mut schema_builder = Schema::builder();
         let field = schema_builder.add_bytes_field("string_bytes", byte_options.into());
         let schema = schema_builder.build();
@@ -86,7 +82,7 @@ mod tests {
         let field = searcher.schema().get_field("string_bytes").unwrap();
         let term = Term::from_field_bytes(field, b"lucene".as_ref());
         let term_query = TermQuery::new(term, IndexRecordOption::Basic);
-        let term_weight = term_query.specialized_weight(&*searcher, true)?;
+        let term_weight = term_query.specialized_weight(&searcher, true)?;
         let term_scorer = term_weight.specialized_scorer(searcher.segment_reader(0), 1.0)?;
         assert_eq!(term_scorer.doc(), 0u32);
         Ok(())
@@ -99,7 +95,7 @@ mod tests {
         let field = searcher.schema().get_field("string_bytes").unwrap();
         let term = Term::from_field_bytes(field, b"lucene".as_ref());
         let term_query = TermQuery::new(term, IndexRecordOption::Basic);
-        let term_weight_err = term_query.specialized_weight(&*searcher, false);
+        let term_weight_err = term_query.specialized_weight(&searcher, false);
         assert!(matches!(
             term_weight_err,
             Err(crate::TantivyError::SchemaError(_))

src/fieldnorm/mod.rs

@@ -112,7 +112,7 @@ mod tests {
             Term::from_field_text(text, "hello"),
             IndexRecordOption::WithFreqs,
         );
-        let weight = query.weight(&*searcher, true)?;
+        let weight = query.weight(&searcher, true)?;
         let mut scorer = weight.scorer(searcher.segment_reader(0), 1.0f32)?;
         assert_eq!(scorer.doc(), 0);
         assert!((scorer.score() - 0.22920431).abs() < 0.001f32);
@@ -141,7 +141,7 @@ mod tests {
             Term::from_field_text(text, "hello"),
             IndexRecordOption::WithFreqs,
         );
-        let weight = query.weight(&*searcher, true)?;
+        let weight = query.weight(&searcher, true)?;
         let mut scorer = weight.scorer(searcher.segment_reader(0), 1.0f32)?;
         assert_eq!(scorer.doc(), 0);
         assert!((scorer.score() - 0.22920431).abs() < 0.001f32);

src/lib.rs

@@ -307,7 +307,6 @@ pub use crate::indexer::demuxer::*;
 pub use crate::indexer::operation::UserOperation;
 pub use crate::indexer::{merge_filtered_segments, merge_indices, IndexWriter, PreparedCommit};
 pub use crate::postings::Postings;
-pub use crate::reader::LeasedItem;
 pub use crate::schema::{DateOptions, DatePrecision, Document, Term};
 
 /// Index format version.

src/query/phrase_query/mod.rs

@@ -359,7 +359,7 @@ pub mod tests {
         let matching_docs = |query: &str| {
             let query_parser = QueryParser::for_index(&index, vec![json_field]);
             let phrase_query = query_parser.parse_query(query).unwrap();
-            let phrase_weight = phrase_query.weight(&*searcher, false).unwrap();
+            let phrase_weight = phrase_query.weight(&searcher, false).unwrap();
             let mut phrase_scorer = phrase_weight
                 .scorer(searcher.segment_reader(0), 1.0f32)
                 .unwrap();

src/query/term_query/mod.rs

@@ -141,7 +141,7 @@ mod tests {
         let term_a = Term::from_field_text(text_field, "a");
         let term_query = TermQuery::new(term_a, IndexRecordOption::Basic);
         let reader = index.reader()?;
-        assert_eq!(term_query.count(&*reader.searcher())?, 1);
+        assert_eq!(term_query.count(&reader.searcher())?, 1);
         Ok(())
     }