Adding upstream version 2.5.1.

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

document/field_synonym.go

@@ -0,0 +1,149 @@
+//  Copyright (c) 2024 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 document
+
+import (
+	"reflect"
+
+	"github.com/blevesearch/bleve/v2/analysis"
+	"github.com/blevesearch/bleve/v2/size"
+	index "github.com/blevesearch/bleve_index_api"
+)
+
+var reflectStaticSizeSynonymField int
+
+func init() {
+	var f SynonymField
+	reflectStaticSizeSynonymField = int(reflect.TypeOf(f).Size())
+}
+
+const DefaultSynonymIndexingOptions = index.IndexField
+
+type SynonymField struct {
+	name              string
+	analyzer          analysis.Analyzer
+	options           index.FieldIndexingOptions
+	input             []string
+	synonyms          []string
+	numPlainTextBytes uint64
+
+	// populated during analysis
+	synonymMap map[string][]string
+}
+
+func (s *SynonymField) Size() int {
+	return reflectStaticSizeSynonymField + size.SizeOfPtr +
+		len(s.name)
+}
+
+func (s *SynonymField) Name() string {
+	return s.name
+}
+
+func (s *SynonymField) ArrayPositions() []uint64 {
+	return nil
+}
+
+func (s *SynonymField) Options() index.FieldIndexingOptions {
+	return s.options
+}
+
+func (s *SynonymField) NumPlainTextBytes() uint64 {
+	return s.numPlainTextBytes
+}
+
+func (s *SynonymField) AnalyzedLength() int {
+	return 0
+}
+
+func (s *SynonymField) EncodedFieldType() byte {
+	return 'y'
+}
+
+func (s *SynonymField) AnalyzedTokenFrequencies() index.TokenFrequencies {
+	return nil
+}
+
+func (s *SynonymField) Analyze() {
+	var analyzedInput []string
+	if len(s.input) > 0 {
+		analyzedInput = make([]string, 0, len(s.input))
+		for _, term := range s.input {
+			analyzedTerm := analyzeSynonymTerm(term, s.analyzer)
+			if analyzedTerm != "" {
+				analyzedInput = append(analyzedInput, analyzedTerm)
+			}
+		}
+	}
+	analyzedSynonyms := make([]string, 0, len(s.synonyms))
+	for _, syn := range s.synonyms {
+		analyzedTerm := analyzeSynonymTerm(syn, s.analyzer)
+		if analyzedTerm != "" {
+			analyzedSynonyms = append(analyzedSynonyms, analyzedTerm)
+		}
+	}
+	s.synonymMap = processSynonymData(analyzedInput, analyzedSynonyms)
+}
+
+func (s *SynonymField) Value() []byte {
+	return nil
+}
+
+func (s *SynonymField) IterateSynonyms(visitor func(term string, synonyms []string)) {
+	for term, synonyms := range s.synonymMap {
+		visitor(term, synonyms)
+	}
+}
+
+func NewSynonymField(name string, analyzer analysis.Analyzer, input []string, synonyms []string) *SynonymField {
+	return &SynonymField{
+		name:     name,
+		analyzer: analyzer,
+		options:  DefaultSynonymIndexingOptions,
+		input:    input,
+		synonyms: synonyms,
+	}
+}
+
+func processSynonymData(input []string, synonyms []string) map[string][]string {
+	var synonymMap map[string][]string
+	if len(input) > 0 {
+		// Map each term to the same list of synonyms.
+		synonymMap = make(map[string][]string, len(input))
+		for _, term := range input {
+			synonymMap[term] = synonyms
+		}
+	} else {
+		synonymMap = make(map[string][]string, len(synonyms))
+		// Precompute a map where each synonym points to all other synonyms.
+		for i, elem := range synonyms {
+			synonymMap[elem] = make([]string, 0, len(synonyms)-1)
+			for j, otherElem := range synonyms {
+				if i != j {
+					synonymMap[elem] = append(synonymMap[elem], otherElem)
+				}
+			}
+		}
+	}
+	return synonymMap
+}
+
+func analyzeSynonymTerm(term string, analyzer analysis.Analyzer) string {
+	tokenStream := analyzer.Analyze([]byte(term))
+	if len(tokenStream) == 1 {
+		return string(tokenStream[0].Term)
+	}
+	return ""
+}