split Term in Term and IndexingTerm (#2744)

* split Term in Term and IndexingTerm

* add append_json_path to JsonTermSerializer

columnar/benches/bench_first_vals.rs

@@ -89,13 +89,6 @@ fn main() {
         black_box(sum);
     });
 
-    group.register("first_block_fetch", |column| {
-        let mut block: Vec<Option<u64>> = vec![None; 64];
-        let fetch_docids = (0..64).collect::<Vec<_>>();
-        column.first_vals(&fetch_docids, &mut block);
-        black_box(block[0]);
-    });
-
     group.register("first_block_single_calls", |column| {
         let mut block: Vec<Option<u64>> = vec![None; 64];
         let fetch_docids = (0..64).collect::<Vec<_>>();

src/core/json_utils.rs

@@ -3,6 +3,7 @@ use common::json_path_writer::{JSON_END_OF_PATH, JSON_PATH_SEGMENT_SEP};
 use common::{replace_in_place, JsonPathWriter};
 use rustc_hash::FxHashMap;
 
+use crate::indexer::indexing_term::IndexingTerm;
 use crate::postings::{IndexingContext, IndexingPosition, PostingsWriter};
 use crate::schema::document::{ReferenceValue, ReferenceValueLeaf, Value};
 use crate::schema::{Type, DATE_TIME_PRECISION_INDEXED};
@@ -77,7 +78,7 @@ fn index_json_object<'a, V: Value<'a>>(
     doc: DocId,
     json_visitor: V::ObjectIter,
     text_analyzer: &mut TextAnalyzer,
-    term_buffer: &mut Term,
+    term_buffer: &mut IndexingTerm,
     json_path_writer: &mut JsonPathWriter,
     postings_writer: &mut dyn PostingsWriter,
     ctx: &mut IndexingContext,
@@ -107,17 +108,17 @@ pub(crate) fn index_json_value<'a, V: Value<'a>>(
     doc: DocId,
     json_value: V,
     text_analyzer: &mut TextAnalyzer,
-    term_buffer: &mut Term,
+    term_buffer: &mut IndexingTerm,
     json_path_writer: &mut JsonPathWriter,
     postings_writer: &mut dyn PostingsWriter,
     ctx: &mut IndexingContext,
     positions_per_path: &mut IndexingPositionsPerPath,
 ) {
-    let set_path_id = |term_buffer: &mut Term, unordered_id: u32| {
+    let set_path_id = |term_buffer: &mut IndexingTerm, unordered_id: u32| {
         term_buffer.truncate_value_bytes(0);
         term_buffer.append_bytes(&unordered_id.to_be_bytes());
     };
-    let set_type = |term_buffer: &mut Term, typ: Type| {
+    let set_type = |term_buffer: &mut IndexingTerm, typ: Type| {
         term_buffer.append_bytes(&[typ.to_code()]);
     };
 

src/indexer/indexing_term.rs

@@ -0,0 +1,184 @@
+use std::net::Ipv6Addr;
+
+use columnar::MonotonicallyMappableToU128;
+
+use crate::fastfield::FastValue;
+use crate::schema::{Field, Type};
+
+/// Term represents the value that the token can take.
+/// It's a serialized representation over different types.
+///
+/// It actually wraps a `Vec<u8>`. The first 5 bytes are metadata.
+/// 4 bytes are the field id, and the last byte is the type.
+///
+/// The serialized value `ValueBytes` is considered everything after the 4 first bytes (term id).
+#[derive(Clone)]
+pub(crate) struct IndexingTerm<B = Vec<u8>>(B)
+where B: AsRef<[u8]>;
+
+/// The number of bytes used as metadata by `Term`.
+const TERM_METADATA_LENGTH: usize = 5;
+
+impl IndexingTerm {
+    /// Create a new Term with a buffer with a given capacity.
+    pub fn with_capacity(capacity: usize) -> IndexingTerm {
+        let mut data = Vec::with_capacity(TERM_METADATA_LENGTH + capacity);
+        data.resize(TERM_METADATA_LENGTH, 0u8);
+        IndexingTerm(data)
+    }
+
+    /// Panics when the term is not empty... ie: some value is set.
+    /// Use `clear_with_field_and_type` in that case.
+    ///
+    /// Sets field and the type.
+    pub(crate) fn set_field_and_type(&mut self, field: Field, typ: Type) {
+        assert!(self.is_empty());
+        self.0[0..4].clone_from_slice(field.field_id().to_be_bytes().as_ref());
+        self.0[4] = typ.to_code();
+    }
+
+    /// Is empty if there are no value bytes.
+    pub fn is_empty(&self) -> bool {
+        self.0.len() == TERM_METADATA_LENGTH
+    }
+
+    /// Removes the value_bytes and set the field and type code.
+    pub(crate) fn clear_with_field_and_type(&mut self, typ: Type, field: Field) {
+        self.truncate_value_bytes(0);
+        self.set_field_and_type(field, typ);
+    }
+
+    /// Sets a u64 value in the term.
+    ///
+    /// U64 are serialized using (8-byte) BigEndian
+    /// representation.
+    /// The use of BigEndian has the benefit of preserving
+    /// the natural order of the values.
+    pub fn set_u64(&mut self, val: u64) {
+        self.set_fast_value(val);
+    }
+
+    /// Sets a `i64` value in the term.
+    pub fn set_i64(&mut self, val: i64) {
+        self.set_fast_value(val);
+    }
+
+    /// Sets a `f64` value in the term.
+    pub fn set_f64(&mut self, val: f64) {
+        self.set_fast_value(val);
+    }
+
+    /// Sets a `bool` value in the term.
+    pub fn set_bool(&mut self, val: bool) {
+        self.set_fast_value(val);
+    }
+
+    fn set_fast_value<T: FastValue>(&mut self, val: T) {
+        self.set_bytes(val.to_u64().to_be_bytes().as_ref());
+    }
+
+    /// Append a type marker + fast value to a term.
+    /// This is used in JSON type to append a fast value after the path.
+    ///
+    /// It will not clear existing bytes.
+    pub fn append_type_and_fast_value<T: FastValue>(&mut self, val: T) {
+        self.0.push(T::to_type().to_code());
+        let value = val.to_u64();
+        self.0.extend(value.to_be_bytes().as_ref());
+    }
+
+    /// Sets a `Ipv6Addr` value in the term.
+    pub fn set_ip_addr(&mut self, val: Ipv6Addr) {
+        self.set_bytes(val.to_u128().to_be_bytes().as_ref());
+    }
+
+    /// Sets the value of a `Bytes` field.
+    pub fn set_bytes(&mut self, bytes: &[u8]) {
+        self.truncate_value_bytes(0);
+        self.0.extend(bytes);
+    }
+
+    /// Truncates the value bytes of the term. Value and field type stays the same.
+    pub fn truncate_value_bytes(&mut self, len: usize) {
+        self.0.truncate(len + TERM_METADATA_LENGTH);
+    }
+
+    /// The length of the bytes.
+    pub fn len_bytes(&self) -> usize {
+        self.0.len() - TERM_METADATA_LENGTH
+    }
+
+    /// Appends value bytes to the Term.
+    ///
+    /// This function returns the segment that has just been added.
+    #[inline]
+    pub fn append_bytes(&mut self, bytes: &[u8]) -> &mut [u8] {
+        let len_before = self.0.len();
+        self.0.extend_from_slice(bytes);
+        &mut self.0[len_before..]
+    }
+}
+
+impl<B> IndexingTerm<B>
+where B: AsRef<[u8]>
+{
+    /// Returns the serialized representation of Term.
+    /// This includes field_id, value type and value.
+    ///
+    /// Do NOT rely on this byte representation in the index.
+    /// This value is likely to change in the future.
+    #[inline]
+    pub fn serialized_term(&self) -> &[u8] {
+        self.0.as_ref()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+
+    use crate::schema::*;
+
+    #[test]
+    pub fn test_term_str() {
+        let mut schema_builder = Schema::builder();
+        schema_builder.add_text_field("text", STRING);
+        let title_field = schema_builder.add_text_field("title", STRING);
+        let term = Term::from_field_text(title_field, "test");
+        assert_eq!(term.field(), title_field);
+        assert_eq!(term.typ(), Type::Str);
+        assert_eq!(term.value().as_str(), Some("test"))
+    }
+
+    /// Size (in bytes) of the buffer of a fast value (u64, i64, f64, or date) term.
+    /// <field> + <type byte> + <value len>
+    ///
+    /// - <field> is a big endian encoded u32 field id
+    /// - <type_byte>'s most significant bit expresses whether the term is a json term or not The
+    ///   remaining 7 bits are used to encode the type of the value. If this is a JSON term, the
+    ///   type is the type of the leaf of the json.
+    /// - <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 prepended with the path that leads to this leaf value.
+    const FAST_VALUE_TERM_LEN: usize = 4 + 1 + 8;
+
+    #[test]
+    pub fn test_term_u64() {
+        let mut schema_builder = Schema::builder();
+        let count_field = schema_builder.add_u64_field("count", INDEXED);
+        let term = Term::from_field_u64(count_field, 983u64);
+        assert_eq!(term.field(), count_field);
+        assert_eq!(term.typ(), Type::U64);
+        assert_eq!(term.serialized_term().len(), FAST_VALUE_TERM_LEN);
+        assert_eq!(term.value().as_u64(), Some(983u64))
+    }
+
+    #[test]
+    pub fn test_term_bool() {
+        let mut schema_builder = Schema::builder();
+        let bool_field = schema_builder.add_bool_field("bool", INDEXED);
+        let term = Term::from_field_bool(bool_field, true);
+        assert_eq!(term.field(), bool_field);
+        assert_eq!(term.typ(), Type::Bool);
+        assert_eq!(term.serialized_term().len(), FAST_VALUE_TERM_LEN);
+        assert_eq!(term.value().as_bool(), Some(true))
+    }
+}

src/indexer/mod.rs

@@ -12,6 +12,7 @@ mod doc_opstamp_mapping;
 mod flat_map_with_buffer;
 pub(crate) mod index_writer;
 pub(crate) mod index_writer_status;
+pub(crate) mod indexing_term;
 mod log_merge_policy;
 mod merge_index_test;
 mod merge_operation;

src/indexer/segment_writer.rs

@@ -7,6 +7,7 @@ use super::operation::AddOperation;
 use crate::fastfield::FastFieldsWriter;
 use crate::fieldnorm::{FieldNormReaders, FieldNormsWriter};
 use crate::index::{Segment, SegmentComponent};
+use crate::indexer::indexing_term::IndexingTerm;
 use crate::indexer::segment_serializer::SegmentSerializer;
 use crate::json_utils::{index_json_value, IndexingPositionsPerPath};
 use crate::postings::{
@@ -14,7 +15,7 @@ use crate::postings::{
     PerFieldPostingsWriter, PostingsWriter,
 };
 use crate::schema::document::{Document, Value};
-use crate::schema::{FieldEntry, FieldType, Schema, Term, DATE_TIME_PRECISION_INDEXED};
+use crate::schema::{FieldEntry, FieldType, Schema, DATE_TIME_PRECISION_INDEXED};
 use crate::tokenizer::{FacetTokenizer, PreTokenizedStream, TextAnalyzer, Tokenizer};
 use crate::{DocId, Opstamp, TantivyError};
 
@@ -55,7 +56,7 @@ pub struct SegmentWriter {
     pub(crate) json_positions_per_path: IndexingPositionsPerPath,
     pub(crate) doc_opstamps: Vec<Opstamp>,
     per_field_text_analyzers: Vec<TextAnalyzer>,
-    term_buffer: Term,
+    term_buffer: IndexingTerm,
     schema: Schema,
 }
 
@@ -112,7 +113,7 @@ impl SegmentWriter {
             )?,
             doc_opstamps: Vec::with_capacity(1_000),
             per_field_text_analyzers,
-            term_buffer: Term::with_capacity(16),
+            term_buffer: IndexingTerm::with_capacity(16),
             schema,
         })
     }

src/postings/json_postings_writer.rs

@@ -3,13 +3,14 @@ use std::io;
 use common::json_path_writer::JSON_END_OF_PATH;
 use stacker::Addr;
 
+use crate::indexer::indexing_term::IndexingTerm;
 use crate::indexer::path_to_unordered_id::OrderedPathId;
 use crate::postings::postings_writer::SpecializedPostingsWriter;
 use crate::postings::recorder::{BufferLender, DocIdRecorder, Recorder};
 use crate::postings::{FieldSerializer, IndexingContext, IndexingPosition, PostingsWriter};
-use crate::schema::{Field, Type};
+use crate::schema::{Field, Type, ValueBytes};
 use crate::tokenizer::TokenStream;
-use crate::{DocId, Term};
+use crate::DocId;
 
 /// The `JsonPostingsWriter` is odd in that it relies on a hidden contract:
 ///
@@ -33,7 +34,7 @@ impl<Rec: Recorder> PostingsWriter for JsonPostingsWriter<Rec> {
         &mut self,
         doc: crate::DocId,
         pos: u32,
-        term: &crate::Term,
+        term: &IndexingTerm,
         ctx: &mut IndexingContext,
     ) {
         self.non_str_posting_writer.subscribe(doc, pos, term, ctx);
@@ -43,7 +44,7 @@ impl<Rec: Recorder> PostingsWriter for JsonPostingsWriter<Rec> {
         &mut self,
         doc_id: DocId,
         token_stream: &mut dyn TokenStream,
-        term_buffer: &mut Term,
+        term_buffer: &mut IndexingTerm,
         ctx: &mut IndexingContext,
         indexing_position: &mut IndexingPosition,
     ) {
@@ -64,26 +65,25 @@ impl<Rec: Recorder> PostingsWriter for JsonPostingsWriter<Rec> {
         ctx: &IndexingContext,
         serializer: &mut FieldSerializer,
     ) -> io::Result<()> {
-        let mut term_buffer = Term::with_capacity(48);
+        let mut term_buffer = JsonTermSerializer(Vec::with_capacity(48));
         let mut buffer_lender = BufferLender::default();
-        term_buffer.clear_with_field_and_type(Type::Json, Field::from_field_id(0));
         let mut prev_term_id = u32::MAX;
         let mut term_path_len = 0; // this will be set in the first iteration
         for (_field, path_id, term, addr) in ordered_term_addrs {
             if prev_term_id != path_id.path_id() {
-                term_buffer.truncate_value_bytes(0);
-                term_buffer.append_path(ordered_id_to_path[path_id.path_id() as usize].as_bytes());
-                term_buffer.append_bytes(&[JSON_END_OF_PATH]);
-                term_path_len = term_buffer.len_bytes();
+                term_buffer.clear();
+                term_buffer.append_json_path(ordered_id_to_path[path_id.path_id() as usize]);
+                term_path_len = term_buffer.len();
                 prev_term_id = path_id.path_id();
             }
-            term_buffer.truncate_value_bytes(term_path_len);
+            term_buffer.truncate(term_path_len);
             term_buffer.append_bytes(term);
-            if let Some(json_value) = term_buffer.value().as_json_value_bytes() {
+
+            let json_value = ValueBytes::wrap(term);
             let typ = json_value.typ();
             if typ == Type::Str {
                 SpecializedPostingsWriter::<Rec>::serialize_one_term(
-                        term_buffer.serialized_value_bytes(),
+                    term_buffer.as_bytes(),
                     *addr,
                     &mut buffer_lender,
                     ctx,
@@ -91,7 +91,7 @@ impl<Rec: Recorder> PostingsWriter for JsonPostingsWriter<Rec> {
                 )?;
             } else {
                 SpecializedPostingsWriter::<DocIdRecorder>::serialize_one_term(
-                        term_buffer.serialized_value_bytes(),
+                    term_buffer.as_bytes(),
                     *addr,
                     &mut buffer_lender,
                     ctx,
@@ -99,7 +99,6 @@ impl<Rec: Recorder> PostingsWriter for JsonPostingsWriter<Rec> {
                 )?;
             }
         }
-        }
         Ok(())
     }
 
@@ -107,3 +106,48 @@ impl<Rec: Recorder> PostingsWriter for JsonPostingsWriter<Rec> {
         self.str_posting_writer.total_num_tokens() + self.non_str_posting_writer.total_num_tokens()
     }
 }
+
+struct JsonTermSerializer(Vec<u8>);
+impl JsonTermSerializer {
+    /// Appends a JSON path to the Term.
+    /// The path is terminated by a special end-of-path 0 byte.
+    #[inline]
+    pub fn append_json_path(&mut self, path: &str) {
+        let bytes = path.as_bytes();
+        // Replace any occurrence of the end-of-path byte with Ascii '0' byte.
+        if bytes.contains(&JSON_END_OF_PATH) {
+            self.0.extend(
+                bytes
+                    .iter()
+                    .map(|&b| if b == JSON_END_OF_PATH { b'0' } else { b }),
+            );
+        } else {
+            self.0.extend_from_slice(bytes);
+        }
+        self.0.push(JSON_END_OF_PATH);
+    }
+
+    /// Appends value bytes to the Term.
+    ///
+    /// This function returns the segment that has just been added.
+    #[inline]
+    pub fn append_bytes(&mut self, bytes: &[u8]) -> &mut [u8] {
+        let len_before = self.0.len();
+        self.0.extend_from_slice(bytes);
+        &mut self.0[len_before..]
+    }
+
+    fn clear(&mut self) {
+        self.0.clear();
+    }
+    fn truncate(&mut self, len: usize) {
+        self.0.truncate(len);
+    }
+    fn len(&self) -> usize {
+        self.0.len()
+    }
+
+    fn as_bytes(&self) -> &[u8] {
+        &self.0
+    }
+}

src/postings/postings_writer.rs

@@ -5,6 +5,7 @@ use std::ops::Range;
 use stacker::Addr;
 
 use crate::fieldnorm::FieldNormReaders;
+use crate::indexer::indexing_term::IndexingTerm;
 use crate::indexer::path_to_unordered_id::OrderedPathId;
 use crate::postings::recorder::{BufferLender, Recorder};
 use crate::postings::{
@@ -111,7 +112,7 @@ pub(crate) trait PostingsWriter: Send + Sync {
     /// * term - the term
     /// * ctx - Contains a term hashmap and a memory arena to store all necessary posting list
     ///   information.
-    fn subscribe(&mut self, doc: DocId, pos: u32, term: &Term, ctx: &mut IndexingContext);
+    fn subscribe(&mut self, doc: DocId, pos: u32, term: &IndexingTerm, ctx: &mut IndexingContext);
 
     /// Serializes the postings on disk.
     /// The actual serialization format is handled by the `PostingsSerializer`.
@@ -128,7 +129,7 @@ pub(crate) trait PostingsWriter: Send + Sync {
         &mut self,
         doc_id: DocId,
         token_stream: &mut dyn TokenStream,
-        term_buffer: &mut Term,
+        term_buffer: &mut IndexingTerm,
         ctx: &mut IndexingContext,
         indexing_position: &mut IndexingPosition,
     ) {
@@ -198,7 +199,13 @@ impl<Rec: Recorder> SpecializedPostingsWriter<Rec> {
 
 impl<Rec: Recorder> PostingsWriter for SpecializedPostingsWriter<Rec> {
     #[inline]
-    fn subscribe(&mut self, doc: DocId, position: u32, term: &Term, ctx: &mut IndexingContext) {
+    fn subscribe(
+        &mut self,
+        doc: DocId,
+        position: u32,
+        term: &IndexingTerm,
+        ctx: &mut IndexingContext,
+    ) {
         debug_assert!(term.serialized_term().len() >= 4);
         self.total_num_tokens += 1;
         let (term_index, arena) = (&mut ctx.term_index, &mut ctx.arena);

src/schema/term.rs

@@ -95,7 +95,7 @@ impl Term {
 
     pub(crate) fn from_fast_value<T: FastValue>(field: Field, val: &T) -> Term {
         let mut term = Self::with_type_and_field(T::to_type(), field);
-        term.set_u64(val.to_u64());
+        term.set_bytes(val.to_u64().to_be_bytes().as_ref());
         term
     }
 
@@ -117,7 +117,7 @@ impl Term {
     /// Builds a term given a field, and a `Ipv6Addr`-value
     pub fn from_field_ip_addr(field: Field, ip_addr: Ipv6Addr) -> Term {
         let mut term = Self::with_type_and_field(Type::IpAddr, field);
-        term.set_ip_addr(ip_addr);
+        term.set_bytes(ip_addr.to_u128().to_be_bytes().as_ref());
         term
     }
 
@@ -174,52 +174,12 @@ impl Term {
         Term::with_bytes_and_field_and_payload(Type::Bytes, field, bytes)
     }
 
-    /// Removes the value_bytes and set the field and type code.
-    pub(crate) fn clear_with_field_and_type(&mut self, typ: Type, field: Field) {
-        self.truncate_value_bytes(0);
-        self.set_field_and_type(field, typ);
-    }
-
     /// Removes the value_bytes and set the type code.
     pub fn clear_with_type(&mut self, typ: Type) {
         self.truncate_value_bytes(0);
         self.0[4] = typ.to_code();
     }
 
-    /// Sets a u64 value in the term.
-    ///
-    /// U64 are serialized using (8-byte) BigEndian
-    /// representation.
-    /// The use of BigEndian has the benefit of preserving
-    /// the natural order of the values.
-    pub fn set_u64(&mut self, val: u64) {
-        self.set_fast_value(val);
-    }
-
-    /// Sets a `i64` value in the term.
-    pub fn set_i64(&mut self, val: i64) {
-        self.set_fast_value(val);
-    }
-
-    /// Sets a `DateTime` value in the term.
-    pub fn set_date(&mut self, date: DateTime) {
-        self.set_fast_value(date);
-    }
-
-    /// Sets a `f64` value in the term.
-    pub fn set_f64(&mut self, val: f64) {
-        self.set_fast_value(val);
-    }
-
-    /// Sets a `bool` value in the term.
-    pub fn set_bool(&mut self, val: bool) {
-        self.set_fast_value(val);
-    }
-
-    fn set_fast_value<T: FastValue>(&mut self, val: T) {
-        self.set_bytes(val.to_u64().to_be_bytes().as_ref());
-    }
-
     /// Append a type marker + fast value to a term.
     /// This is used in JSON type to append a fast value after the path.
     ///
@@ -239,11 +199,6 @@ impl Term {
         self.0.extend(val.as_bytes().as_ref());
     }
 
-    /// Sets a `Ipv6Addr` value in the term.
-    pub fn set_ip_addr(&mut self, val: Ipv6Addr) {
-        self.set_bytes(val.to_u128().to_be_bytes().as_ref());
-    }
-
     /// Sets the value of a `Bytes` field.
     pub fn set_bytes(&mut self, bytes: &[u8]) {
         self.truncate_value_bytes(0);
@@ -269,19 +224,6 @@ impl Term {
         self.0.extend_from_slice(bytes);
         &mut self.0[len_before..]
     }
-
-    /// Appends json path bytes to the Term.
-    /// If the path contains 0 bytes, they are replaced by a "0" string.
-    /// The 0 byte is used to mark the end of the path.
-    ///
-    /// This function returns the segment that has just been added.
-    #[inline]
-    pub fn append_path(&mut self, bytes: &[u8]) -> &mut [u8] {
-        let len_before = self.0.len();
-        assert!(!bytes.contains(&JSON_END_OF_PATH));
-        self.0.extend_from_slice(bytes);
-        &mut self.0[len_before..]
-    }
 }
 
 impl<B> Term<B>