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bleve/search/searchers/search_docid.go
Marty Schoch 24a2b57e29 refactor search package to reuse DocumentMatch and ID []byte's
the motivation for this commit is long and detailed and has been
documented externally here:

https://gist.github.com/mschoch/5cc5c9cf4669a5fe8512cb7770d3c1a2

the core of the changes are:

1.  recognize that collector/searcher need only a fixed number
of DocumentMatch instances, and this number can be determined
from the structure of the query, not the size of the data

2.  knowing this, instances can be allocated in bulk, up front
and they can be reused without locking (since all search
operations take place in a single goroutine

3.  combined with previous commits which enabled reuse of
the IndexInternalID []byte, this allows for no allocation/copy
of these bytes as well (by using DocumentMatch Reset() method
when returning entries to the pool
2016-08-08 22:21:47 -04:00

89 lines
2.2 KiB
Go

// Copyright (c) 2015 Couchbase, Inc.
// Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file
// except in compliance with the License. You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
// Unless required by applicable law or agreed to in writing, software distributed under the
// License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
// either express or implied. See the License for the specific language governing permissions
// and limitations under the License.
package searchers
import (
"github.com/blevesearch/bleve/index"
"github.com/blevesearch/bleve/search"
"github.com/blevesearch/bleve/search/scorers"
)
// DocIDSearcher returns documents matching a predefined set of identifiers.
type DocIDSearcher struct {
reader index.DocIDReader
scorer *scorers.ConstantScorer
count int
}
func NewDocIDSearcher(indexReader index.IndexReader, ids []string, boost float64,
explain bool) (searcher *DocIDSearcher, err error) {
reader, err := indexReader.DocIDReaderOnly(ids)
if err != nil {
return nil, err
}
scorer := scorers.NewConstantScorer(1.0, boost, explain)
return &DocIDSearcher{
scorer: scorer,
reader: reader,
count: len(ids),
}, nil
}
func (s *DocIDSearcher) Count() uint64 {
return uint64(s.count)
}
func (s *DocIDSearcher) Weight() float64 {
return s.scorer.Weight()
}
func (s *DocIDSearcher) SetQueryNorm(qnorm float64) {
s.scorer.SetQueryNorm(qnorm)
}
func (s *DocIDSearcher) Next(ctx *search.SearchContext) (*search.DocumentMatch, error) {
docidMatch, err := s.reader.Next()
if err != nil {
return nil, err
}
if docidMatch == nil {
return nil, nil
}
docMatch := s.scorer.Score(ctx, docidMatch)
return docMatch, nil
}
func (s *DocIDSearcher) Advance(ctx *search.SearchContext, ID index.IndexInternalID) (*search.DocumentMatch, error) {
docidMatch, err := s.reader.Advance(ID)
if err != nil {
return nil, err
}
if docidMatch == nil {
return nil, nil
}
docMatch := s.scorer.Score(ctx, docidMatch)
return docMatch, nil
}
func (s *DocIDSearcher) Close() error {
return nil
}
func (s *DocIDSearcher) Min() int {
return 0
}
func (s *DocIDSearcher) DocumentMatchPoolSize() int {
return 1
}