86 lines
2.4 KiB
Go
86 lines
2.4 KiB
Go
// Copyright (c) 2014 Couchbase, Inc.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package searcher
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import (
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"context"
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"strings"
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"github.com/blevesearch/bleve/v2/search"
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index "github.com/blevesearch/bleve_index_api"
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)
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func NewTermPrefixSearcher(ctx context.Context, indexReader index.IndexReader, prefix string,
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field string, boost float64, options search.SearcherOptions) (
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search.Searcher, error) {
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// find the terms with this prefix
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fieldDict, err := indexReader.FieldDictPrefix(field, []byte(prefix))
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if err != nil {
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return nil, err
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}
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defer func() {
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if cerr := fieldDict.Close(); cerr != nil && err == nil {
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err = cerr
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}
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}()
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var terms []string
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var termSet = make(map[string]struct{})
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tfd, err := fieldDict.Next()
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for err == nil && tfd != nil {
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if _, exists := termSet[tfd.Term]; !exists {
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termSet[tfd.Term] = struct{}{}
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terms = append(terms, tfd.Term)
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if tooManyClauses(len(terms)) {
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return nil, tooManyClausesErr(field, len(terms))
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}
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tfd, err = fieldDict.Next()
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}
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}
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if err != nil {
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return nil, err
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}
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if ctx != nil {
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reportIOStats(ctx, fieldDict.BytesRead())
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search.RecordSearchCost(ctx, search.AddM, fieldDict.BytesRead())
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}
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if ctx != nil {
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if fts, ok := ctx.Value(search.FieldTermSynonymMapKey).(search.FieldTermSynonymMap); ok {
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if ts, exists := fts[field]; exists {
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for term := range ts {
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if _, exists := termSet[term]; exists {
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continue
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}
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if strings.HasPrefix(term, prefix) {
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termSet[term] = struct{}{}
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terms = append(terms, term)
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if tooManyClauses(len(terms)) {
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return nil, tooManyClausesErr(field, len(terms))
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}
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}
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}
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}
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}
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}
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// check if the terms are empty or have one term which is the prefix itself
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if len(terms) == 0 || (len(terms) == 1 && terms[0] == prefix) {
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return NewTermSearcher(ctx, indexReader, prefix, field, boost, options)
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}
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return NewMultiTermSearcher(ctx, indexReader, terms, field, boost, options, true)
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}
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