use a single memory arena to store all terms

src/indexer/json_term_writer.rs

@@ -57,7 +57,7 @@ struct IndexingPositionsPerPath {
 impl IndexingPositionsPerPath {
     fn get_position(&mut self, term: &Term) -> &mut IndexingPosition {
         self.positions_per_path
-            .entry(murmurhash2(term.as_slice()))
+            .entry(murmurhash2(term.value_bytes()))
             .or_insert_with(Default::default)
     }
 }
@@ -208,7 +208,7 @@ impl<'a> JsonTermWriter<'a> {
     pub fn wrap(term_buffer: &'a mut Term) -> Self {
         term_buffer.clear_with_type(Type::Json);
         let mut path_stack = Vec::with_capacity(10);
-        path_stack.push(5);
+        path_stack.push(5); // magic number?
         Self {
             term_buffer,
             path_stack,
@@ -250,8 +250,8 @@ impl<'a> JsonTermWriter<'a> {
     /// Returns the json path of the term being currently built.
     #[cfg(test)]
     pub(crate) fn path(&self) -> &[u8] {
-        let end_of_path = self.path_stack.last().cloned().unwrap_or(6);
-        &self.term().as_slice()[5..end_of_path - 1]
+        let end_of_path = self.path_stack.last().cloned().unwrap_or(6); // TODO remove magic number
+        &self.term().value_bytes()[..end_of_path - 1]
     }
 
     pub fn set_fast_value<T: FastValue>(&mut self, val: T) {
@@ -321,10 +321,7 @@ mod tests {
         let mut json_writer = JsonTermWriter::wrap(&mut term);
         json_writer.push_path_segment("color");
         json_writer.set_str("red");
-        assert_eq!(
-            json_writer.term().as_slice(),
-            b"\x00\x00\x00\x01jcolor\x00sred"
-        )
+        assert_eq!(json_writer.term().value_bytes(), b"color\x00sred")
     }
 
     #[test]
@@ -336,8 +333,8 @@ mod tests {
         json_writer.push_path_segment("color");
         json_writer.set_fast_value(-4i64);
         assert_eq!(
-            json_writer.term().as_slice(),
-            b"\x00\x00\x00\x01jcolor\x00i\x7f\xff\xff\xff\xff\xff\xff\xfc"
+            json_writer.term().value_bytes(),
+            b"color\x00i\x7f\xff\xff\xff\xff\xff\xff\xfc"
         )
     }
 
@@ -350,8 +347,8 @@ mod tests {
         json_writer.push_path_segment("color");
         json_writer.set_fast_value(4u64);
         assert_eq!(
-            json_writer.term().as_slice(),
-            b"\x00\x00\x00\x01jcolor\x00u\x00\x00\x00\x00\x00\x00\x00\x04"
+            json_writer.term().value_bytes(),
+            b"color\x00u\x00\x00\x00\x00\x00\x00\x00\x04"
         )
     }
 
@@ -364,8 +361,8 @@ mod tests {
         json_writer.push_path_segment("color");
         json_writer.set_fast_value(4.0f64);
         assert_eq!(
-            json_writer.term().as_slice(),
-            b"\x00\x00\x00\x01jcolor\x00f\xc0\x10\x00\x00\x00\x00\x00\x00"
+            json_writer.term().value_bytes(),
+            b"color\x00f\xc0\x10\x00\x00\x00\x00\x00\x00"
         )
     }
 
@@ -380,8 +377,8 @@ mod tests {
         json_writer.push_path_segment("color");
         json_writer.set_str("red");
         assert_eq!(
-            json_writer.term().as_slice(),
-            b"\x00\x00\x00\x01jattribute\x01color\x00sred"
+            json_writer.term().value_bytes(),
+            b"attribute\x01color\x00sred"
         )
     }
 
@@ -395,10 +392,7 @@ mod tests {
         json_writer.push_path_segment("hue");
         json_writer.pop_path_segment();
         json_writer.set_str("red");
-        assert_eq!(
-            json_writer.term().as_slice(),
-            b"\x00\x00\x00\x01jcolor\x00sred"
-        )
+        assert_eq!(json_writer.term().value_bytes(), b"color\x00sred")
     }
 
     #[test]

src/indexer/segment_writer.rs

@@ -6,8 +6,7 @@ use crate::fieldnorm::{FieldNormReaders, FieldNormsWriter};
 use crate::indexer::json_term_writer::index_json_values;
 use crate::indexer::segment_serializer::SegmentSerializer;
 use crate::postings::{
-    compute_table_size, serialize_postings, IndexingContext, IndexingPosition,
-    PerFieldPostingsWriter, PostingsWriter,
+    serialize_postings, IndexingContext, IndexingPosition, PerFieldPostingsWriter, PostingsWriter,
 };
 use crate::schema::{FieldEntry, FieldType, FieldValue, Schema, Term, Value};
 use crate::store::{StoreReader, StoreWriter};
@@ -16,25 +15,6 @@ use crate::tokenizer::{
 };
 use crate::{DocId, Document, Opstamp, SegmentComponent};
 
-/// Computes the initial size of the hash table.
-///
-/// Returns the recommended initial table size as a power of 2.
-///
-/// Note this is a very dumb way to compute log2, but it is easier to proofread that way.
-fn compute_initial_table_size(per_thread_memory_budget: usize) -> crate::Result<usize> {
-    let table_memory_upper_bound = per_thread_memory_budget / 3;
-    (10..20) // We cap it at 2^19 = 512K capacity.
-        .map(|power| 1 << power)
-        .take_while(|capacity| compute_table_size(*capacity) < table_memory_upper_bound)
-        .last()
-        .ok_or_else(|| {
-            crate::TantivyError::InvalidArgument(format!(
-                "per thread memory budget (={per_thread_memory_budget}) is too small. Raise the \
-                 memory budget or lower the number of threads."
-            ))
-        })
-}
-
 fn remap_doc_opstamps(
     opstamps: Vec<Opstamp>,
     doc_id_mapping_opt: Option<&DocIdMapping>,
@@ -78,12 +58,11 @@ impl SegmentWriter {
     /// - segment: The segment being written
     /// - schema
     pub fn for_segment(
-        memory_budget_in_bytes: usize,
+        _memory_budget_in_bytes: usize,
         segment: Segment,
         schema: Schema,
     ) -> crate::Result<SegmentWriter> {
         let tokenizer_manager = segment.index().tokenizers().clone();
-        let table_size = compute_initial_table_size(memory_budget_in_bytes)?;
         let segment_serializer = SegmentSerializer::for_segment(segment, false)?;
         let per_field_postings_writers = PerFieldPostingsWriter::for_schema(&schema);
         let per_field_text_analyzers = schema
@@ -106,7 +85,7 @@ impl SegmentWriter {
             .collect();
         Ok(SegmentWriter {
             max_doc: 0,
-            ctx: IndexingContext::new(table_size),
+            ctx: IndexingContext::new(),
             per_field_postings_writers,
             fieldnorms_writer: FieldNormsWriter::for_schema(&schema),
             segment_serializer,
@@ -149,6 +128,7 @@ impl SegmentWriter {
     pub fn mem_usage(&self) -> usize {
         self.ctx.mem_usage()
             + self.fieldnorms_writer.mem_usage()
+            + self.per_field_postings_writers.mem_usage()
             + self.fast_field_writers.mem_usage()
             + self.segment_serializer.mem_usage()
     }
@@ -223,7 +203,7 @@ impl SegmentWriter {
                     let mut indexing_position = IndexingPosition::default();
 
                     for mut token_stream in token_streams {
-                        assert_eq!(term_buffer.as_slice().len(), 5);
+                        // assert_eq!(term_buffer.as_slice().len(), 5);
                         postings_writer.index_text(
                             doc_id,
                             &mut *token_stream,
@@ -418,7 +398,6 @@ pub fn prepare_doc_for_store(doc: Document, schema: &Schema) -> Document {
 
 #[cfg(test)]
 mod tests {
-    use super::compute_initial_table_size;
     use crate::collector::Count;
     use crate::indexer::json_term_writer::JsonTermWriter;
     use crate::postings::TermInfo;
@@ -429,15 +408,6 @@ mod tests {
     use crate::tokenizer::{PreTokenizedString, Token};
     use crate::{DateTime, DocAddress, DocSet, Document, Index, Postings, Term, TERMINATED};
 
-    #[test]
-    fn test_hashmap_size() {
-        assert_eq!(compute_initial_table_size(100_000).unwrap(), 1 << 11);
-        assert_eq!(compute_initial_table_size(1_000_000).unwrap(), 1 << 14);
-        assert_eq!(compute_initial_table_size(10_000_000).unwrap(), 1 << 17);
-        assert_eq!(compute_initial_table_size(1_000_000_000).unwrap(), 1 << 19);
-        assert_eq!(compute_initial_table_size(4_000_000_000).unwrap(), 1 << 19);
-    }
-
     #[test]
     fn test_prepare_for_store() {
         let mut schema_builder = Schema::builder();

src/postings/indexing_context.rs

@@ -1,27 +1,24 @@
-use crate::postings::stacker::{MemoryArena, TermHashMap};
+use crate::postings::stacker::MemoryArena;
 
 /// IndexingContext contains all of the transient memory arenas
 /// required for building the inverted index.
 pub(crate) struct IndexingContext {
-    /// The term index is an adhoc hashmap,
-    /// itself backed by a dedicated memory arena.
-    pub term_index: TermHashMap,
     /// Arena is a memory arena that stores posting lists / term frequencies / positions.
     pub arena: MemoryArena,
+    pub arena_terms: MemoryArena,
 }
 
 impl IndexingContext {
     /// Create a new IndexingContext given the size of the term hash map.
-    pub(crate) fn new(table_size: usize) -> IndexingContext {
-        let term_index = TermHashMap::new(table_size);
+    pub(crate) fn new() -> IndexingContext {
         IndexingContext {
             arena: MemoryArena::new(),
-            term_index,
+            arena_terms: MemoryArena::new(),
         }
     }
 
     /// Returns the memory usage for the inverted index memory arenas, in bytes.
     pub(crate) fn mem_usage(&self) -> usize {
-        self.term_index.mem_usage() + self.arena.mem_usage()
+        self.arena.mem_usage() + self.arena_terms.mem_usage()
     }
 }

src/postings/json_postings_writer.rs

@@ -1,5 +1,6 @@
 use std::io;
 
+use super::stacker::TermHashMap;
 use crate::fastfield::MultiValuedFastFieldWriter;
 use crate::indexer::doc_id_mapping::DocIdMapping;
 use crate::postings::postings_writer::SpecializedPostingsWriter;
@@ -26,6 +27,14 @@ impl<Rec: Recorder> From<JsonPostingsWriter<Rec>> for Box<dyn PostingsWriter> {
 }
 
 impl<Rec: Recorder> PostingsWriter for JsonPostingsWriter<Rec> {
+    fn mem_usage(&self) -> usize {
+        self.str_posting_writer.mem_usage() + self.non_str_posting_writer.mem_usage()
+    }
+
+    fn term_map(&self) -> &TermHashMap {
+        self.str_posting_writer.term_map()
+    }
+
     fn subscribe(
         &mut self,
         doc: crate::DocId,
@@ -74,6 +83,7 @@ impl<Rec: Recorder> PostingsWriter for JsonPostingsWriter<Rec> {
                         doc_id_map,
                         &mut buffer_lender,
                         ctx,
+                        &self.str_posting_writer.term_map,
                         serializer,
                     )?;
                 } else {
@@ -83,6 +93,7 @@ impl<Rec: Recorder> PostingsWriter for JsonPostingsWriter<Rec> {
                         doc_id_map,
                         &mut buffer_lender,
                         ctx,
+                        &self.str_posting_writer.term_map,
                         serializer,
                     )?;
                 }

src/postings/mod.rs

@@ -26,7 +26,6 @@ pub(crate) use self::postings_writer::{serialize_postings, IndexingPosition, Pos
 pub use self::segment_postings::SegmentPostings;
 pub use self::serializer::{FieldSerializer, InvertedIndexSerializer};
 pub(crate) use self::skip::{BlockInfo, SkipReader};
-pub(crate) use self::stacker::compute_table_size;
 pub use self::term_info::TermInfo;
 
 pub(crate) type UnorderedTermId = u64;

src/postings/per_field_postings_writer.rs

@@ -10,9 +10,10 @@ pub(crate) struct PerFieldPostingsWriter {
 
 impl PerFieldPostingsWriter {
     pub fn for_schema(schema: &Schema) -> Self {
+        let num_fields = schema.num_fields();
         let per_field_postings_writers = schema
             .fields()
-            .map(|(_, field_entry)| posting_writer_from_field_entry(field_entry))
+            .map(|(_, field_entry)| posting_writer_from_field_entry(field_entry, num_fields))
             .collect();
         PerFieldPostingsWriter {
             per_field_postings_writers,
@@ -26,9 +27,19 @@ impl PerFieldPostingsWriter {
     pub(crate) fn get_for_field_mut(&mut self, field: Field) -> &mut dyn PostingsWriter {
         self.per_field_postings_writers[field.field_id() as usize].as_mut()
     }
+
+    pub(crate) fn mem_usage(&self) -> usize {
+        self.per_field_postings_writers
+            .iter()
+            .map(|postings_writer| postings_writer.mem_usage())
+            .sum()
+    }
 }
 
-fn posting_writer_from_field_entry(field_entry: &FieldEntry) -> Box<dyn PostingsWriter> {
+fn posting_writer_from_field_entry(
+    field_entry: &FieldEntry,
+    _num_fields: usize,
+) -> Box<dyn PostingsWriter> {
     match *field_entry.field_type() {
         FieldType::Str(ref text_options) => text_options
             .get_indexing_options()

src/postings/postings_writer.rs

@@ -1,11 +1,10 @@
 use std::collections::HashMap;
 use std::io;
 use std::marker::PhantomData;
-use std::ops::Range;
 
 use fnv::FnvHashMap;
 
-use super::stacker::Addr;
+use super::stacker::{Addr, TermHashMap};
 use crate::fastfield::MultiValuedFastFieldWriter;
 use crate::fieldnorm::FieldNormReaders;
 use crate::indexer::doc_id_mapping::DocIdMapping;
@@ -21,31 +20,6 @@ use crate::DocId;
 
 const POSITION_GAP: u32 = 1;
 
-fn make_field_partition(
-    term_offsets: &[(Term<&[u8]>, Addr, UnorderedTermId)],
-) -> Vec<(Field, Range<usize>)> {
-    let term_offsets_it = term_offsets
-        .iter()
-        .map(|(term, _, _)| term.field())
-        .enumerate();
-    let mut prev_field_opt = None;
-    let mut fields = vec![];
-    let mut offsets = vec![];
-    for (offset, field) in term_offsets_it {
-        if Some(field) != prev_field_opt {
-            prev_field_opt = Some(field);
-            fields.push(field);
-            offsets.push(offset);
-        }
-    }
-    offsets.push(term_offsets.len());
-    let mut field_offsets = vec![];
-    for i in 0..fields.len() {
-        field_offsets.push((fields[i], offsets[i]..offsets[i + 1]));
-    }
-    field_offsets
-}
-
 /// Serialize the inverted index.
 /// It pushes all term, one field at a time, towards the
 /// postings serializer.
@@ -57,23 +31,23 @@ pub(crate) fn serialize_postings(
     schema: &Schema,
     serializer: &mut InvertedIndexSerializer,
 ) -> crate::Result<HashMap<Field, FnvHashMap<UnorderedTermId, TermOrdinal>>> {
-    let mut term_offsets: Vec<(Term<&[u8]>, Addr, UnorderedTermId)> =
-        Vec::with_capacity(ctx.term_index.len());
-    term_offsets.extend(ctx.term_index.iter());
-    term_offsets.sort_unstable_by_key(|(k, _, _)| k.clone());
     let mut unordered_term_mappings: HashMap<Field, FnvHashMap<UnorderedTermId, TermOrdinal>> =
         HashMap::new();
 
-    let field_offsets = make_field_partition(&term_offsets);
-    for (field, byte_offsets) in field_offsets {
+    for (field, _) in schema.fields() {
+        let postings_writer = per_field_postings_writers.get_for_field(field);
+
+        let mut term_offsets: Vec<(Term<&[u8]>, Addr, UnorderedTermId)> =
+            Vec::with_capacity(postings_writer.term_map().len());
+        term_offsets.extend(postings_writer.term_map().iter(&ctx.arena_terms));
+        term_offsets.sort_unstable_by_key(|(k, _, _)| k.clone());
+
         let field_entry = schema.get_field_entry(field);
         match *field_entry.field_type() {
             FieldType::Str(_) | FieldType::Facet(_) => {
                 // populating the (unordered term ord) -> (ordered term ord) mapping
                 // for the field.
-                let unordered_term_ids = term_offsets[byte_offsets.clone()]
-                    .iter()
-                    .map(|&(_, _, bucket)| bucket);
+                let unordered_term_ids = term_offsets.iter().map(|&(_, _, bucket)| bucket);
                 let mapping: FnvHashMap<UnorderedTermId, TermOrdinal> = unordered_term_ids
                     .enumerate()
                     .map(|(term_ord, unord_term_id)| {
@@ -87,16 +61,10 @@ pub(crate) fn serialize_postings(
             FieldType::JsonObject(_) => {}
         }
 
-        let postings_writer = per_field_postings_writers.get_for_field(field);
         let fieldnorm_reader = fieldnorm_readers.get_field(field)?;
         let mut field_serializer =
             serializer.new_field(field, postings_writer.total_num_tokens(), fieldnorm_reader)?;
-        postings_writer.serialize(
-            &term_offsets[byte_offsets],
-            doc_id_map,
-            &ctx,
-            &mut field_serializer,
-        )?;
+        postings_writer.serialize(&term_offsets, doc_id_map, &ctx, &mut field_serializer)?;
         field_serializer.close()?;
     }
     Ok(unordered_term_mappings)
@@ -128,6 +96,10 @@ pub(crate) trait PostingsWriter {
         ctx: &mut IndexingContext,
     ) -> UnorderedTermId;
 
+    fn mem_usage(&self) -> usize;
+
+    fn term_map(&self) -> &TermHashMap;
+
     /// Serializes the postings on disk.
     /// The actual serialization format is handled by the `PostingsSerializer`.
     fn serialize(
@@ -148,7 +120,7 @@ pub(crate) trait PostingsWriter {
         indexing_position: &mut IndexingPosition,
         mut term_id_fast_field_writer_opt: Option<&mut MultiValuedFastFieldWriter>,
     ) {
-        let end_of_path_idx = term_buffer.as_slice().len();
+        let end_of_path_idx = term_buffer.value_bytes().len();
         let mut num_tokens = 0;
         let mut end_position = 0;
         token_stream.process(&mut |token: &Token| {
@@ -188,6 +160,7 @@ pub(crate) trait PostingsWriter {
 pub(crate) struct SpecializedPostingsWriter<Rec: Recorder> {
     total_num_tokens: u64,
     _recorder_type: PhantomData<Rec>,
+    pub(crate) term_map: TermHashMap,
 }
 
 impl<Rec: Recorder> From<SpecializedPostingsWriter<Rec>> for Box<dyn PostingsWriter> {
@@ -206,9 +179,10 @@ impl<Rec: Recorder> SpecializedPostingsWriter<Rec> {
         doc_id_map: Option<&DocIdMapping>,
         buffer_lender: &mut BufferLender,
         ctx: &IndexingContext,
+        term_index: &TermHashMap,
         serializer: &mut FieldSerializer,
     ) -> io::Result<()> {
-        let recorder: Rec = ctx.term_index.read(addr);
+        let recorder: Rec = term_index.read(addr, &ctx.arena_terms);
         let term_doc_freq = recorder.term_doc_freq().unwrap_or(0u32);
         serializer.new_term(term.value_bytes(), term_doc_freq)?;
         recorder.serialize(&ctx.arena, doc_id_map, serializer, buffer_lender);
@@ -218,6 +192,14 @@ impl<Rec: Recorder> SpecializedPostingsWriter<Rec> {
 }
 
 impl<Rec: Recorder> PostingsWriter for SpecializedPostingsWriter<Rec> {
+    fn mem_usage(&self) -> usize {
+        self.term_map.mem_usage()
+    }
+
+    fn term_map(&self) -> &TermHashMap {
+        &self.term_map
+    }
+
     fn subscribe(
         &mut self,
         doc: DocId,
@@ -225,25 +207,30 @@ impl<Rec: Recorder> PostingsWriter for SpecializedPostingsWriter<Rec> {
         term: &Term,
         ctx: &mut IndexingContext,
     ) -> UnorderedTermId {
-        debug_assert!(term.as_slice().len() >= 4);
+        //debug_assert!(term.value_bytes().len() >= 1);
         self.total_num_tokens += 1;
-        let (term_index, arena) = (&mut ctx.term_index, &mut ctx.arena);
-        term_index.mutate_or_create(term.as_slice(), |opt_recorder: Option<Rec>| {
-            if let Some(mut recorder) = opt_recorder {
-                let current_doc = recorder.current_doc();
-                if current_doc != doc {
-                    recorder.close_doc(arena);
+        let arena = &mut ctx.arena;
+        let arena_terms = &mut ctx.arena_terms;
+        self.term_map.mutate_or_create(
+            term.value_bytes(),
+            arena_terms,
+            |opt_recorder: Option<Rec>| {
+                if let Some(mut recorder) = opt_recorder {
+                    let current_doc = recorder.current_doc();
+                    if current_doc != doc {
+                        recorder.close_doc(arena);
+                        recorder.new_doc(doc, arena);
+                    }
+                    recorder.record_position(position, arena);
+                    recorder
+                } else {
+                    let mut recorder = Rec::default();
                     recorder.new_doc(doc, arena);
+                    recorder.record_position(position, arena);
+                    recorder
                 }
-                recorder.record_position(position, arena);
-                recorder
-            } else {
-                let mut recorder = Rec::default();
-                recorder.new_doc(doc, arena);
-                recorder.record_position(position, arena);
-                recorder
-            }
-        }) as UnorderedTermId
+            },
+        ) as UnorderedTermId
     }
 
     fn serialize(
@@ -255,7 +242,15 @@ impl<Rec: Recorder> PostingsWriter for SpecializedPostingsWriter<Rec> {
     ) -> io::Result<()> {
         let mut buffer_lender = BufferLender::default();
         for (term, addr, _) in term_addrs {
-            Self::serialize_one_term(term, *addr, doc_id_map, &mut buffer_lender, ctx, serializer)?;
+            Self::serialize_one_term(
+                term,
+                *addr,
+                doc_id_map,
+                &mut buffer_lender,
+                ctx,
+                &self.term_map,
+                serializer,
+            )?;
         }
         Ok(())
     }

src/postings/stacker/memory_arena.rs

@@ -46,6 +46,7 @@ impl Addr {
     }
 
     /// Returns the `Addr` object for `addr + offset`
+    #[inline]
     pub fn offset(self, offset: u32) -> Addr {
         Addr(self.0.wrapping_add(offset))
     }
@@ -54,20 +55,24 @@ impl Addr {
         Addr((page_id << NUM_BITS_PAGE_ADDR | local_addr) as u32)
     }
 
+    #[inline]
     fn page_id(self) -> usize {
         (self.0 as usize) >> NUM_BITS_PAGE_ADDR
     }
 
+    #[inline]
     fn page_local_addr(self) -> usize {
         (self.0 as usize) & (PAGE_SIZE - 1)
     }
 
     /// Returns true if and only if the `Addr` is null.
+    #[inline]
     pub fn is_null(self) -> bool {
         self.0 == u32::max_value()
     }
 }
 
+#[inline]
 pub fn store<Item: Copy + 'static>(dest: &mut [u8], val: Item) {
     assert_eq!(dest.len(), std::mem::size_of::<Item>());
     unsafe {
@@ -75,6 +80,7 @@ pub fn store<Item: Copy + 'static>(dest: &mut [u8], val: Item) {
     }
 }
 
+#[inline]
 pub fn load<Item: Copy + 'static>(data: &[u8]) -> Item {
     assert_eq!(data.len(), std::mem::size_of::<Item>());
     unsafe { ptr::read_unaligned(data.as_ptr() as *const Item) }
@@ -110,6 +116,7 @@ impl MemoryArena {
         self.pages.len() * PAGE_SIZE
     }
 
+    #[inline]
     pub fn write_at<Item: Copy + 'static>(&mut self, addr: Addr, val: Item) {
         let dest = self.slice_mut(addr, std::mem::size_of::<Item>());
         store(dest, val);
@@ -120,6 +127,7 @@ impl MemoryArena {
     /// # Panics
     ///
     /// If the address is erroneous
+    #[inline]
     pub fn read<Item: Copy + 'static>(&self, addr: Addr) -> Item {
         load(self.slice(addr, mem::size_of::<Item>()))
     }
@@ -128,6 +136,7 @@ impl MemoryArena {
         self.pages[addr.page_id()].slice(addr.page_local_addr(), len)
     }
 
+    #[inline]
     pub fn slice_from(&self, addr: Addr) -> &[u8] {
         self.pages[addr.page_id()].slice_from(addr.page_local_addr())
     }

src/postings/stacker/mod.rs

@@ -4,4 +4,4 @@ mod term_hashmap;
 
 pub(crate) use self::expull::ExpUnrolledLinkedList;
 pub(crate) use self::memory_arena::{Addr, MemoryArena};
-pub(crate) use self::term_hashmap::{compute_table_size, TermHashMap};
+pub(crate) use self::term_hashmap::TermHashMap;

src/postings/stacker/term_hashmap.rs

@@ -1,6 +1,6 @@
+use std::convert::TryInto;
 use std::{iter, mem, slice};
 
-use byteorder::{ByteOrder, NativeEndian};
 use murmurhash32::murmurhash2;
 
 use super::{Addr, MemoryArena};
@@ -8,13 +8,6 @@ use crate::postings::stacker::memory_arena::store;
 use crate::postings::UnorderedTermId;
 use crate::Term;
 
-/// Returns the actual memory size in bytes
-/// required to create a table with a given capacity.
-/// required to create a table of size
-pub(crate) fn compute_table_size(capacity: usize) -> usize {
-    capacity * mem::size_of::<KeyValue>()
-}
-
 /// `KeyValue` is the item stored in the hash table.
 /// The key is actually a `BytesRef` object stored in an external memory arena.
 /// The `value_addr` also points to an address in the memory arena.
@@ -36,6 +29,7 @@ impl Default for KeyValue {
 }
 
 impl KeyValue {
+    #[inline]
     fn is_empty(self) -> bool {
         self.key_value_addr.is_null()
     }
@@ -51,12 +45,17 @@ impl KeyValue {
 /// or copying the key as long as there is no insert.
 pub struct TermHashMap {
     table: Box<[KeyValue]>,
-    memory_arena: MemoryArena,
     mask: usize,
     occupied: Vec<usize>,
     len: usize,
 }
 
+impl Default for TermHashMap {
+    fn default() -> Self {
+        Self::new(1 << 10)
+    }
+}
+
 struct QuadraticProbing {
     hash: usize,
     i: usize,
@@ -75,18 +74,21 @@ impl QuadraticProbing {
     }
 }
 
-pub struct Iter<'a> {
+pub struct Iter<'a, 'm> {
     hashmap: &'a TermHashMap,
+    memory_arena: &'m MemoryArena,
     inner: slice::Iter<'a, usize>,
 }
 
-impl<'a> Iterator for Iter<'a> {
-    type Item = (Term<&'a [u8]>, Addr, UnorderedTermId);
+impl<'a, 'm> Iterator for Iter<'a, 'm> {
+    type Item = (Term<&'m [u8]>, Addr, UnorderedTermId);
 
     fn next(&mut self) -> Option<Self::Item> {
         self.inner.next().cloned().map(move |bucket: usize| {
             let kv = self.hashmap.table[bucket];
-            let (key, offset): (&'a [u8], Addr) = self.hashmap.get_key_value(kv.key_value_addr);
+            let (key, offset): (&'m [u8], Addr) = self
+                .hashmap
+                .get_key_value(kv.key_value_addr, self.memory_arena);
             (Term::wrap(key), offset, kv.unordered_term_id)
         })
     }
@@ -106,21 +108,19 @@ impl TermHashMap {
     pub(crate) fn new(table_size: usize) -> TermHashMap {
         assert!(table_size > 0);
         let table_size_power_of_2 = compute_previous_power_of_two(table_size);
-        let memory_arena = MemoryArena::new();
         let table: Vec<KeyValue> = iter::repeat(KeyValue::default())
             .take(table_size_power_of_2)
             .collect();
         TermHashMap {
             table: table.into_boxed_slice(),
-            memory_arena,
             mask: table_size_power_of_2 - 1,
             occupied: Vec::with_capacity(table_size_power_of_2 / 2),
             len: 0,
         }
     }
 
-    pub fn read<Item: Copy + 'static>(&self, addr: Addr) -> Item {
-        self.memory_arena.read(addr)
+    pub fn read<Item: Copy + 'static>(&self, addr: Addr, memory_arena: &MemoryArena) -> Item {
+        memory_arena.read(addr)
     }
 
     fn probe(&self, hash: u32) -> QuadraticProbing {
@@ -129,6 +129,8 @@ impl TermHashMap {
 
     pub fn mem_usage(&self) -> usize {
         self.table.len() * mem::size_of::<KeyValue>()
+            + self.occupied.len()
+                * std::mem::size_of_val(&self.occupied.get(0).cloned().unwrap_or_default())
     }
 
     fn is_saturated(&self) -> bool {
@@ -136,16 +138,22 @@ impl TermHashMap {
     }
 
     #[inline]
-    fn get_key_value(&self, addr: Addr) -> (&[u8], Addr) {
-        let data = self.memory_arena.slice_from(addr);
-        let key_bytes_len = NativeEndian::read_u16(data) as usize;
-        let key_bytes: &[u8] = &data[2..][..key_bytes_len];
+    fn get_key_value<'m>(&self, addr: Addr, memory_arena: &'m MemoryArena) -> (&'m [u8], Addr) {
+        let data = memory_arena.slice_from(addr);
+        let (key_bytes_len_enc, data) = data.split_at(2);
+        let key_bytes_len: u16 = u16::from_ne_bytes(key_bytes_len_enc.try_into().unwrap());
+        let key_bytes: &[u8] = &data[..key_bytes_len as usize];
         (key_bytes, addr.offset(2u32 + key_bytes_len as u32))
     }
 
     #[inline]
-    fn get_value_addr_if_key_match(&self, target_key: &[u8], addr: Addr) -> Option<Addr> {
-        let (stored_key, value_addr) = self.get_key_value(addr);
+    fn get_value_addr_if_key_match(
+        &self,
+        target_key: &[u8],
+        addr: Addr,
+        memory_arena: &mut MemoryArena,
+    ) -> Option<Addr> {
+        let (stored_key, value_addr) = self.get_key_value(addr, memory_arena);
         if stored_key == target_key {
             Some(value_addr)
         } else {
@@ -169,10 +177,11 @@ impl TermHashMap {
         self.len
     }
 
-    pub fn iter(&self) -> Iter<'_> {
+    pub fn iter<'a, 'm>(&'a self, memory_arena: &'m MemoryArena) -> Iter<'a, 'm> {
         Iter {
             inner: self.occupied.iter(),
             hashmap: self,
+            memory_arena,
         }
     }
 
@@ -209,6 +218,7 @@ impl TermHashMap {
     pub fn mutate_or_create<V, TMutator>(
         &mut self,
         key: &[u8],
+        memory_arena: &mut MemoryArena,
         mut updater: TMutator,
     ) -> UnorderedTermId
     where
@@ -219,28 +229,33 @@ impl TermHashMap {
             self.resize();
         }
         let hash = murmurhash2(key);
+
         let mut probe = self.probe(hash);
         loop {
             let bucket = probe.next_probe();
             let kv: KeyValue = self.table[bucket];
+
             if kv.is_empty() {
                 // The key does not exists yet.
                 let val = updater(None);
                 let num_bytes = std::mem::size_of::<u16>() + key.len() + std::mem::size_of::<V>();
-                let key_addr = self.memory_arena.allocate_space(num_bytes);
+                let key_addr = memory_arena.allocate_space(num_bytes);
                 {
-                    let data = self.memory_arena.slice_mut(key_addr, num_bytes);
-                    NativeEndian::write_u16(data, key.len() as u16);
-                    let stop = 2 + key.len();
-                    data[2..stop].copy_from_slice(key);
+                    let data = memory_arena.slice_mut(key_addr, num_bytes);
+                    let (key_len, data) = data.split_at_mut(2);
+                    key_len.copy_from_slice(&(key.len() as u16).to_le_bytes());
+                    let stop = key.len();
+                    data[..key.len()].copy_from_slice(key);
                     store(&mut data[stop..], val);
                 }
                 return self.set_bucket(hash, key_addr, bucket);
             } else if kv.hash == hash {
-                if let Some(val_addr) = self.get_value_addr_if_key_match(key, kv.key_value_addr) {
-                    let v = self.memory_arena.read(val_addr);
+                if let Some(val_addr) =
+                    self.get_value_addr_if_key_match(key, kv.key_value_addr, memory_arena)
+                {
+                    let v = memory_arena.read(val_addr);
                     let new_v = updater(Some(v));
-                    self.memory_arena.write_at(val_addr, new_v);
+                    memory_arena.write_at(val_addr, new_v);
                     return kv.unordered_term_id;
                 }
             }
@@ -254,26 +269,28 @@ mod tests {
     use std::collections::HashMap;
 
     use super::{compute_previous_power_of_two, TermHashMap};
+    use crate::postings::stacker::MemoryArena;
 
     #[test]
     fn test_hash_map() {
+        let mut arena = MemoryArena::new();
         let mut hash_map: TermHashMap = TermHashMap::new(1 << 18);
-        hash_map.mutate_or_create(b"abc", |opt_val: Option<u32>| {
+        hash_map.mutate_or_create(b"abc", &mut arena, |opt_val: Option<u32>| {
             assert_eq!(opt_val, None);
             3u32
         });
-        hash_map.mutate_or_create(b"abcd", |opt_val: Option<u32>| {
+        hash_map.mutate_or_create(b"abcd", &mut arena, |opt_val: Option<u32>| {
             assert_eq!(opt_val, None);
             4u32
         });
-        hash_map.mutate_or_create(b"abc", |opt_val: Option<u32>| {
+        hash_map.mutate_or_create(b"abc", &mut arena, |opt_val: Option<u32>| {
             assert_eq!(opt_val, Some(3u32));
             5u32
         });
         let mut vanilla_hash_map = HashMap::new();
-        let iter_values = hash_map.iter();
+        let iter_values = hash_map.iter(&arena);
         for (key, addr, _) in iter_values {
-            let val: u32 = hash_map.memory_arena.read(addr);
+            let val: u32 = arena.read(addr);
             vanilla_hash_map.insert(key.to_owned(), val);
         }
         assert_eq!(vanilla_hash_map.len(), 2);

src/query/query_parser/query_parser.rs

@@ -718,7 +718,7 @@ fn generate_literals_for_json_object(
     }
     json_term_writer.close_path_and_set_type(Type::Str);
     drop(json_term_writer);
-    let term_num_bytes = term.as_slice().len();
+    let term_num_bytes = term.value_bytes().len();
     let mut token_stream = text_analyzer.token_stream(phrase);
     let mut terms: Vec<(usize, Term)> = Vec::new();
     token_stream.process(&mut |token| {

src/schema/term.rs

@@ -17,7 +17,7 @@ use crate::DateTime;
 ///
 /// - <value> is,  if this is not the json term, a binary representation specific to the type.
 /// If it is a JSON Term, then it is preprended with the path that leads to this leaf value.
-const FAST_VALUE_TERM_LEN: usize = 4 + 1 + 8;
+const FAST_VALUE_TERM_LEN: usize = 8;
 
 /// Separates the different segments of
 /// the json path.
@@ -33,22 +33,33 @@ pub const JSON_END_OF_PATH: u8 = 0u8;
 ///
 /// It actually wraps a `Vec<u8>`.
 #[derive(Clone)]
-pub struct Term<B = Vec<u8>>(B)
-where B: AsRef<[u8]>;
+pub struct Term<B = Vec<u8>> {
+    data: B,
+    field: Field,
+    field_type: Type,
+}
 
 impl AsMut<Vec<u8>> for Term {
     fn as_mut(&mut self) -> &mut Vec<u8> {
-        &mut self.0
+        &mut self.data
     }
 }
 
 impl Term {
     pub(crate) fn new() -> Term {
-        Term(Vec::with_capacity(100))
+        Self::with_capacity(32)
+    }
+
+    pub(crate) fn with_capacity(cap: usize) -> Term {
+        Term {
+            data: Vec::with_capacity(cap),
+            field: Field::from_field_id(0),
+            field_type: Type::Str,
+        }
     }
 
     fn from_fast_value<T: FastValue>(field: Field, val: &T) -> Term {
-        let mut term = Term(vec![0u8; FAST_VALUE_TERM_LEN]);
+        let mut term = Term::with_capacity(FAST_VALUE_TERM_LEN);
         term.set_field(T::to_type(), field);
         term.set_u64(val.to_u64());
         term
@@ -86,9 +97,9 @@ impl Term {
     }
 
     fn create_bytes_term(typ: Type, field: Field, bytes: &[u8]) -> Term {
-        let mut term = Term(vec![0u8; 5 + bytes.len()]);
+        let mut term = Term::with_capacity(bytes.len());
         term.set_field(typ, field);
-        term.0.extend_from_slice(bytes);
+        term.data.extend_from_slice(bytes);
         term
     }
 
@@ -98,10 +109,9 @@ impl Term {
     }
 
     pub(crate) fn set_field(&mut self, typ: Type, field: Field) {
-        self.0.clear();
-        self.0
-            .extend_from_slice(field.field_id().to_be_bytes().as_ref());
-        self.0.push(typ.to_code());
+        self.field = field;
+        self.field_type = typ;
+        self.data.clear();
     }
 
     /// Sets a u64 value in the term.
@@ -112,11 +122,9 @@ impl Term {
     /// the natural order of the values.
     pub fn set_u64(&mut self, val: u64) {
         self.set_fast_value(val);
-        self.set_bytes(val.to_be_bytes().as_ref());
     }
 
     fn set_fast_value<T: FastValue>(&mut self, val: T) {
-        self.0.resize(FAST_VALUE_TERM_LEN, 0u8);
         self.set_bytes(val.to_u64().to_be_bytes().as_ref());
     }
 
@@ -137,8 +145,8 @@ impl Term {
 
     /// Sets the value of a `Bytes` field.
     pub fn set_bytes(&mut self, bytes: &[u8]) {
-        self.0.resize(5, 0u8);
-        self.0.extend(bytes);
+        self.data.clear();
+        self.data.extend(bytes);
     }
 
     /// Set the texts only, keeping the field untouched.
@@ -148,18 +156,18 @@ impl Term {
 
     /// Removes the value_bytes and set the type code.
     pub fn clear_with_type(&mut self, typ: Type) {
-        self.truncate(5);
-        self.0[4] = typ.to_code();
+        self.data.clear();
+        self.field_type = typ;
     }
 
     /// Truncate the term right after the field and the type code.
     pub fn truncate(&mut self, len: usize) {
-        self.0.truncate(len);
+        self.data.truncate(len);
     }
 
     /// Truncate the term right after the field and the type code.
     pub fn append_bytes(&mut self, bytes: &[u8]) {
-        self.0.extend_from_slice(bytes);
+        self.data.extend_from_slice(bytes);
     }
 }
 
@@ -167,7 +175,7 @@ impl<B> Ord for Term<B>
 where B: AsRef<[u8]>
 {
     fn cmp(&self, other: &Self) -> std::cmp::Ordering {
-        self.as_slice().cmp(other.as_slice())
+        self.value_bytes().cmp(other.value_bytes())
     }
 }
 
@@ -183,7 +191,7 @@ impl<B> PartialEq for Term<B>
 where B: AsRef<[u8]>
 {
     fn eq(&self, other: &Self) -> bool {
-        self.as_slice() == other.as_slice()
+        self.value_bytes() == other.value_bytes()
     }
 }
 
@@ -193,7 +201,7 @@ impl<B> Hash for Term<B>
 where B: AsRef<[u8]>
 {
     fn hash<H: Hasher>(&self, state: &mut H) {
-        self.0.as_ref().hash(state)
+        self.data.as_ref().hash(state)
     }
 }
 
@@ -202,14 +210,15 @@ where B: AsRef<[u8]>
 {
     /// Wraps a object holding bytes
     pub fn wrap(data: B) -> Term<B> {
-        Term(data)
+        Term {
+            data,
+            field: Field::from_field_id(0),
+            field_type: Type::Str,
+        }
     }
 
     fn typ_code(&self) -> u8 {
-        *self
-            .as_slice()
-            .get(4)
-            .expect("the byte representation is too short")
+        self.field_type as u8
     }
 
     /// Return the type of the term.
@@ -219,55 +228,7 @@ where B: AsRef<[u8]>
 
     /// Returns the field.
     pub fn field(&self) -> Field {
-        let mut field_id_bytes = [0u8; 4];
-        field_id_bytes.copy_from_slice(&self.0.as_ref()[..4]);
-        Field::from_field_id(u32::from_be_bytes(field_id_bytes))
-    }
-
-    /// Returns the `u64` value stored in a term.
-    ///
-    /// Returns None if the term is not of the u64 type, or if the term byte representation
-    /// is invalid.
-    pub fn as_u64(&self) -> Option<u64> {
-        self.get_fast_type::<u64>()
-    }
-
-    fn get_fast_type<T: FastValue>(&self) -> Option<T> {
-        if self.typ() != T::to_type() {
-            return None;
-        }
-        let mut value_bytes = [0u8; 8];
-        let bytes = self.value_bytes();
-        if bytes.len() != 8 {
-            return None;
-        }
-        value_bytes.copy_from_slice(self.value_bytes());
-        let value_u64 = u64::from_be_bytes(value_bytes);
-        Some(FastValue::from_u64(value_u64))
-    }
-
-    /// Returns the `i64` value stored in a term.
-    ///
-    /// Returns None if the term is not of the i64 type, or if the term byte representation
-    /// is invalid.
-    pub fn as_i64(&self) -> Option<i64> {
-        self.get_fast_type::<i64>()
-    }
-
-    /// Returns the `f64` value stored in a term.
-    ///
-    /// Returns None if the term is not of the f64 type, or if the term byte representation
-    /// is invalid.
-    pub fn as_f64(&self) -> Option<f64> {
-        self.get_fast_type::<f64>()
-    }
-
-    /// Returns the `Date` value stored in a term.
-    ///
-    /// Returns None if the term is not of the Date type, or if the term byte representation
-    /// is invalid.
-    pub fn as_date(&self) -> Option<DateTime> {
-        self.get_fast_type::<DateTime>()
+        self.field
     }
 
     /// Returns the text associated with the term.
@@ -275,43 +236,12 @@ where B: AsRef<[u8]>
     /// Returns None if the field is not of string type
     /// or if the bytes are not valid utf-8.
     pub fn as_str(&self) -> Option<&str> {
-        if self.as_slice().len() < 5 {
-            return None;
-        }
         if self.typ() != Type::Str {
             return None;
         }
         str::from_utf8(self.value_bytes()).ok()
     }
 
-    /// Returns the facet associated with the term.
-    ///
-    /// Returns None if the field is not of facet type
-    /// or if the bytes are not valid utf-8.
-    pub fn as_facet(&self) -> Option<Facet> {
-        if self.as_slice().len() < 5 {
-            return None;
-        }
-        if self.typ() != Type::Facet {
-            return None;
-        }
-        let facet_encode_str = str::from_utf8(self.value_bytes()).ok()?;
-        Some(Facet::from_encoded_string(facet_encode_str.to_string()))
-    }
-
-    /// Returns the bytes associated with the term.
-    ///
-    /// Returns None if the field is not of bytes type.
-    pub fn as_bytes(&self) -> Option<&[u8]> {
-        if self.as_slice().len() < 5 {
-            return None;
-        }
-        if self.typ() != Type::Bytes {
-            return None;
-        }
-        Some(self.value_bytes())
-    }
-
     /// Returns the serialized value of the term.
     /// (this does not include the field.)
     ///
@@ -319,15 +249,7 @@ where B: AsRef<[u8]>
     /// If the term is a u64, its value is encoded according
     /// to `byteorder::LittleEndian`.
     pub fn value_bytes(&self) -> &[u8] {
-        &self.0.as_ref()[5..]
-    }
-
-    /// Returns the underlying `&[u8]`.
-    ///
-    /// Do NOT rely on this byte representation in the index.
-    /// This value is likely to change in the future.
-    pub(crate) fn as_slice(&self) -> &[u8] {
-        self.0.as_ref()
+        &self.data.as_ref()
     }
 }
 
@@ -434,7 +356,6 @@ mod tests {
         let term = Term::from_field_u64(count_field, 983u64);
         assert_eq!(term.field(), count_field);
         assert_eq!(term.typ(), Type::U64);
-        assert_eq!(term.as_slice().len(), super::FAST_VALUE_TERM_LEN);
-        assert_eq!(term.as_u64(), Some(983u64))
+        assert_eq!(term.value_bytes().len(), super::FAST_VALUE_TERM_LEN);
     }
 }