f8fdfebb6c
- TermSearcher has alternate constructor if term is []byte, this can avoid copying in some cases. TermScorer updated to accept []byte term. Also removed a few struct fields which were not being used. - New MultiTermSearcher searches for documents containing any of a list of terms. Current implementation simply uses DisjunctionSearcher. - Several other searcher constructors now simply build a list of terms and then delegate to the MultiTermSearcher - NewPrefixSearcher - NewRegexpSearcher - NewFuzzySearcher - NewNumericRangeSearcher - NewGeoBoundingBoxSearcher and NewGeoPointDistanceSearcher make use of the MultiTermSearcher internally, and follow the pattern of returning an existing search.Searcher, as opposed to their own wrapping struct. - Callback filter functions used in NewGeoBoundingBoxSearcher and NewGeoPointDistanceSearcher have been extracted into separate functions which makes the code much easier to read.
75 lines
2.1 KiB
Go
75 lines
2.1 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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"github.com/blevesearch/bleve/index"
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"github.com/blevesearch/bleve/search"
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)
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func NewFuzzySearcher(indexReader index.IndexReader, term string,
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prefix, fuzziness int, field string, boost float64,
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options search.SearcherOptions) (search.Searcher, error) {
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// Note: we don't byte slice the term for a prefix because of runes.
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prefixTerm := ""
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for i, r := range term {
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if i < prefix {
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prefixTerm += string(r)
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} else {
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break
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}
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}
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candidateTerms, err := findFuzzyCandidateTerms(indexReader, term, fuzziness,
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field, prefixTerm)
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if err != nil {
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return nil, err
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}
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return NewMultiTermSearcher(indexReader, candidateTerms, field,
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boost, options)
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}
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func findFuzzyCandidateTerms(indexReader index.IndexReader, term string,
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fuzziness int, field, prefixTerm string) (rv []string, err error) {
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rv = make([]string, 0)
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var fieldDict index.FieldDict
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if len(prefixTerm) > 0 {
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fieldDict, err = indexReader.FieldDictPrefix(field, []byte(prefixTerm))
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} else {
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fieldDict, err = indexReader.FieldDict(field)
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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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// enumerate terms and check levenshtein distance
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tfd, err := fieldDict.Next()
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for err == nil && tfd != nil {
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ld, exceeded := search.LevenshteinDistanceMax(term, tfd.Term, fuzziness)
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if !exceeded && ld <= fuzziness {
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rv = append(rv, tfd.Term)
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if tooManyClauses(len(rv)) {
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return rv, tooManyClausesErr()
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}
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}
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tfd, err = fieldDict.Next()
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}
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return rv, err
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}
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