Adding upstream version 2.5.1.

Signed-off-by: Daniel Baumann <daniel@debian.org>

search/searcher/search_conjunction.go

@@ -0,0 +1,285 @@
+//  Copyright (c) 2014 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 searcher
+
+import (
+	"context"
+	"math"
+	"reflect"
+	"sort"
+
+	"github.com/blevesearch/bleve/v2/search"
+	"github.com/blevesearch/bleve/v2/search/scorer"
+	"github.com/blevesearch/bleve/v2/size"
+	index "github.com/blevesearch/bleve_index_api"
+)
+
+var reflectStaticSizeConjunctionSearcher int
+
+func init() {
+	var cs ConjunctionSearcher
+	reflectStaticSizeConjunctionSearcher = int(reflect.TypeOf(cs).Size())
+}
+
+type ConjunctionSearcher struct {
+	indexReader index.IndexReader
+	searchers   []search.Searcher
+	queryNorm   float64
+	currs       []*search.DocumentMatch
+	maxIDIdx    int
+	scorer      *scorer.ConjunctionQueryScorer
+	initialized bool
+	options     search.SearcherOptions
+	bytesRead   uint64
+}
+
+func NewConjunctionSearcher(ctx context.Context, indexReader index.IndexReader,
+	qsearchers []search.Searcher, options search.SearcherOptions) (
+	search.Searcher, error,
+) {
+	// build the sorted downstream searchers
+	searchers := make(OrderedSearcherList, len(qsearchers))
+	copy(searchers, qsearchers)
+	sort.Sort(searchers)
+
+	// attempt the "unadorned" conjunction optimization only when we
+	// do not need extra information like freq-norm's or term vectors
+	if len(searchers) > 1 &&
+		options.Score == "none" && !options.IncludeTermVectors {
+		rv, err := optimizeCompositeSearcher(ctx, "conjunction:unadorned",
+			indexReader, searchers, options)
+		if err != nil || rv != nil {
+			return rv, err
+		}
+	}
+
+	// build our searcher
+	rv := ConjunctionSearcher{
+		indexReader: indexReader,
+		options:     options,
+		searchers:   searchers,
+		currs:       make([]*search.DocumentMatch, len(searchers)),
+		scorer:      scorer.NewConjunctionQueryScorer(options),
+	}
+	rv.computeQueryNorm()
+
+	// attempt push-down conjunction optimization when there's >1 searchers
+	if len(searchers) > 1 {
+		rv, err := optimizeCompositeSearcher(ctx, "conjunction",
+			indexReader, searchers, options)
+		if err != nil || rv != nil {
+			return rv, err
+		}
+	}
+
+	return &rv, nil
+}
+
+func (s *ConjunctionSearcher) computeQueryNorm() {
+	// first calculate sum of squared weights
+	sumOfSquaredWeights := 0.0
+	for _, searcher := range s.searchers {
+		sumOfSquaredWeights += searcher.Weight()
+	}
+	// now compute query norm from this
+	s.queryNorm = 1.0 / math.Sqrt(sumOfSquaredWeights)
+	// finally tell all the downstream searchers the norm
+	for _, searcher := range s.searchers {
+		searcher.SetQueryNorm(s.queryNorm)
+	}
+}
+
+func (s *ConjunctionSearcher) Size() int {
+	sizeInBytes := reflectStaticSizeConjunctionSearcher + size.SizeOfPtr +
+		s.scorer.Size()
+
+	for _, entry := range s.searchers {
+		sizeInBytes += entry.Size()
+	}
+
+	for _, entry := range s.currs {
+		if entry != nil {
+			sizeInBytes += entry.Size()
+		}
+	}
+
+	return sizeInBytes
+}
+
+func (s *ConjunctionSearcher) initSearchers(ctx *search.SearchContext) error {
+	var err error
+	// get all searchers pointing at their first match
+	for i, searcher := range s.searchers {
+		if s.currs[i] != nil {
+			ctx.DocumentMatchPool.Put(s.currs[i])
+		}
+		s.currs[i], err = searcher.Next(ctx)
+		if err != nil {
+			return err
+		}
+	}
+	s.initialized = true
+	return nil
+}
+
+func (s *ConjunctionSearcher) Weight() float64 {
+	var rv float64
+	for _, searcher := range s.searchers {
+		rv += searcher.Weight()
+	}
+	return rv
+}
+
+func (s *ConjunctionSearcher) SetQueryNorm(qnorm float64) {
+	for _, searcher := range s.searchers {
+		searcher.SetQueryNorm(qnorm)
+	}
+}
+
+func (s *ConjunctionSearcher) Next(ctx *search.SearchContext) (*search.DocumentMatch, error) {
+	if !s.initialized {
+		err := s.initSearchers(ctx)
+		if err != nil {
+			return nil, err
+		}
+	}
+	var rv *search.DocumentMatch
+	var err error
+OUTER:
+	for s.maxIDIdx < len(s.currs) && s.currs[s.maxIDIdx] != nil {
+		maxID := s.currs[s.maxIDIdx].IndexInternalID
+
+		i := 0
+		for i < len(s.currs) {
+			if s.currs[i] == nil {
+				return nil, nil
+			}
+
+			if i == s.maxIDIdx {
+				i++
+				continue
+			}
+
+			cmp := maxID.Compare(s.currs[i].IndexInternalID)
+			if cmp == 0 {
+				i++
+				continue
+			}
+
+			if cmp < 0 {
+				// maxID < currs[i], so we found a new maxIDIdx
+				s.maxIDIdx = i
+
+				// advance the positions where [0 <= x < i], since we
+				// know they were equal to the former max entry
+				maxID = s.currs[s.maxIDIdx].IndexInternalID
+				for x := 0; x < i; x++ {
+					err = s.advanceChild(ctx, x, maxID)
+					if err != nil {
+						return nil, err
+					}
+				}
+
+				continue OUTER
+			}
+
+			// maxID > currs[i], so need to advance searchers[i]
+			err = s.advanceChild(ctx, i, maxID)
+			if err != nil {
+				return nil, err
+			}
+
+			// don't bump i, so that we'll examine the just-advanced
+			// currs[i] again
+		}
+
+		// if we get here, a doc matched all readers, so score and add it
+		rv = s.scorer.Score(ctx, s.currs)
+
+		// we know all the searchers are pointing at the same thing
+		// so they all need to be bumped
+		for i, searcher := range s.searchers {
+			if s.currs[i] != rv {
+				ctx.DocumentMatchPool.Put(s.currs[i])
+			}
+			s.currs[i], err = searcher.Next(ctx)
+			if err != nil {
+				return nil, err
+			}
+		}
+
+		// don't continue now, wait for the next call to Next()
+		break
+	}
+	return rv, nil
+}
+
+func (s *ConjunctionSearcher) Advance(ctx *search.SearchContext, ID index.IndexInternalID) (*search.DocumentMatch, error) {
+	if !s.initialized {
+		err := s.initSearchers(ctx)
+		if err != nil {
+			return nil, err
+		}
+	}
+	for i := range s.searchers {
+		if s.currs[i] != nil && s.currs[i].IndexInternalID.Compare(ID) >= 0 {
+			continue
+		}
+		err := s.advanceChild(ctx, i, ID)
+		if err != nil {
+			return nil, err
+		}
+	}
+	return s.Next(ctx)
+}
+
+func (s *ConjunctionSearcher) advanceChild(ctx *search.SearchContext, i int, ID index.IndexInternalID) (err error) {
+	if s.currs[i] != nil {
+		ctx.DocumentMatchPool.Put(s.currs[i])
+	}
+	s.currs[i], err = s.searchers[i].Advance(ctx, ID)
+	return err
+}
+
+func (s *ConjunctionSearcher) Count() uint64 {
+	// for now return a worst case
+	var sum uint64
+	for _, searcher := range s.searchers {
+		sum += searcher.Count()
+	}
+	return sum
+}
+
+func (s *ConjunctionSearcher) Close() (rv error) {
+	for _, searcher := range s.searchers {
+		err := searcher.Close()
+		if err != nil && rv == nil {
+			rv = err
+		}
+	}
+	return rv
+}
+
+func (s *ConjunctionSearcher) Min() int {
+	return 0
+}
+
+func (s *ConjunctionSearcher) DocumentMatchPoolSize() int {
+	rv := len(s.currs)
+	for _, s := range s.searchers {
+		rv += s.DocumentMatchPoolSize()
+	}
+	return rv
+}