mirror of
https://github.com/go-gitea/gitea
synced 2024-11-09 03:34:24 +00:00
a380cfd8e0
* update bleve to master b17287a86f6cac923a5d886e10618df994eeb54b6724eac2e3b8dde89cfbe3a2 * remove unused pkg from dep file * change bleve from master to recent revision
118 lines
3.0 KiB
Go
118 lines
3.0 KiB
Go
// 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 (
|
|
"fmt"
|
|
|
|
"github.com/blevesearch/bleve/index"
|
|
"github.com/blevesearch/bleve/search"
|
|
)
|
|
|
|
var MaxFuzziness = 2
|
|
|
|
func NewFuzzySearcher(indexReader index.IndexReader, term string,
|
|
prefix, fuzziness int, field string, boost float64,
|
|
options search.SearcherOptions) (search.Searcher, error) {
|
|
|
|
if fuzziness > MaxFuzziness {
|
|
return nil, fmt.Errorf("fuzziness exceeds max (%d)", MaxFuzziness)
|
|
}
|
|
|
|
if fuzziness < 0 {
|
|
return nil, fmt.Errorf("invalid fuzziness, negative")
|
|
}
|
|
|
|
// Note: we don't byte slice the term for a prefix because of runes.
|
|
prefixTerm := ""
|
|
for i, r := range term {
|
|
if i < prefix {
|
|
prefixTerm += string(r)
|
|
} else {
|
|
break
|
|
}
|
|
}
|
|
candidateTerms, err := findFuzzyCandidateTerms(indexReader, term, fuzziness,
|
|
field, prefixTerm)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return NewMultiTermSearcher(indexReader, candidateTerms, field,
|
|
boost, options, true)
|
|
}
|
|
|
|
func findFuzzyCandidateTerms(indexReader index.IndexReader, term string,
|
|
fuzziness int, field, prefixTerm string) (rv []string, err error) {
|
|
rv = make([]string, 0)
|
|
|
|
// in case of advanced reader implementations directly call
|
|
// the levenshtein automaton based iterator to collect the
|
|
// candidate terms
|
|
if ir, ok := indexReader.(index.IndexReaderFuzzy); ok {
|
|
fieldDict, err := ir.FieldDictFuzzy(field, term, fuzziness, prefixTerm)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
defer func() {
|
|
if cerr := fieldDict.Close(); cerr != nil && err == nil {
|
|
err = cerr
|
|
}
|
|
}()
|
|
tfd, err := fieldDict.Next()
|
|
for err == nil && tfd != nil {
|
|
rv = append(rv, tfd.Term)
|
|
if tooManyClauses(len(rv)) {
|
|
return nil, tooManyClausesErr(len(rv))
|
|
}
|
|
tfd, err = fieldDict.Next()
|
|
}
|
|
return rv, err
|
|
}
|
|
|
|
var fieldDict index.FieldDict
|
|
if len(prefixTerm) > 0 {
|
|
fieldDict, err = indexReader.FieldDictPrefix(field, []byte(prefixTerm))
|
|
} else {
|
|
fieldDict, err = indexReader.FieldDict(field)
|
|
}
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
defer func() {
|
|
if cerr := fieldDict.Close(); cerr != nil && err == nil {
|
|
err = cerr
|
|
}
|
|
}()
|
|
|
|
// enumerate terms and check levenshtein distance
|
|
var reuse []int
|
|
tfd, err := fieldDict.Next()
|
|
for err == nil && tfd != nil {
|
|
var ld int
|
|
var exceeded bool
|
|
ld, exceeded, reuse = search.LevenshteinDistanceMaxReuseSlice(term, tfd.Term, fuzziness, reuse)
|
|
if !exceeded && ld <= fuzziness {
|
|
rv = append(rv, tfd.Term)
|
|
if tooManyClauses(len(rv)) {
|
|
return nil, tooManyClausesErr(len(rv))
|
|
}
|
|
}
|
|
tfd, err = fieldDict.Next()
|
|
}
|
|
|
|
return rv, err
|
|
}
|