a380cfd8e0
* update bleve to master b17287a86f6cac923a5d886e10618df994eeb54b6724eac2e3b8dde89cfbe3a2 * remove unused pkg from dep file * change bleve from master to recent revision
121 lines
3.4 KiB
Go
121 lines
3.4 KiB
Go
// Copyright (c) 2015 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 (
|
|
"regexp"
|
|
|
|
"github.com/blevesearch/bleve/index"
|
|
"github.com/blevesearch/bleve/search"
|
|
)
|
|
|
|
// NewRegexpStringSearcher is similar to NewRegexpSearcher, but
|
|
// additionally optimizes for index readers that handle regexp's.
|
|
func NewRegexpStringSearcher(indexReader index.IndexReader, pattern string,
|
|
field string, boost float64, options search.SearcherOptions) (
|
|
search.Searcher, error) {
|
|
ir, ok := indexReader.(index.IndexReaderRegexp)
|
|
if !ok {
|
|
r, err := regexp.Compile(pattern)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return NewRegexpSearcher(indexReader, r, field, boost, options)
|
|
}
|
|
|
|
fieldDict, err := ir.FieldDictRegexp(field, pattern)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
defer func() {
|
|
if cerr := fieldDict.Close(); cerr != nil && err == nil {
|
|
err = cerr
|
|
}
|
|
}()
|
|
|
|
var candidateTerms []string
|
|
|
|
tfd, err := fieldDict.Next()
|
|
for err == nil && tfd != nil {
|
|
candidateTerms = append(candidateTerms, tfd.Term)
|
|
tfd, err = fieldDict.Next()
|
|
}
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return NewMultiTermSearcher(indexReader, candidateTerms, field, boost,
|
|
options, true)
|
|
}
|
|
|
|
// NewRegexpSearcher creates a searcher which will match documents that
|
|
// contain terms which match the pattern regexp. The match must be EXACT
|
|
// matching the entire term. The provided regexp SHOULD NOT start with ^
|
|
// or end with $ as this can intefere with the implementation. Separately,
|
|
// matches will be checked to ensure they match the entire term.
|
|
func NewRegexpSearcher(indexReader index.IndexReader, pattern index.Regexp,
|
|
field string, boost float64, options search.SearcherOptions) (
|
|
search.Searcher, error) {
|
|
var candidateTerms []string
|
|
|
|
prefixTerm, complete := pattern.LiteralPrefix()
|
|
if complete {
|
|
// there is no pattern
|
|
candidateTerms = []string{prefixTerm}
|
|
} else {
|
|
var err error
|
|
candidateTerms, err = findRegexpCandidateTerms(indexReader, pattern, field,
|
|
prefixTerm)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
}
|
|
|
|
return NewMultiTermSearcher(indexReader, candidateTerms, field, boost,
|
|
options, true)
|
|
}
|
|
|
|
func findRegexpCandidateTerms(indexReader index.IndexReader,
|
|
pattern index.Regexp, field, prefixTerm string) (rv []string, err error) {
|
|
rv = make([]string, 0)
|
|
var fieldDict index.FieldDict
|
|
if len(prefixTerm) > 0 {
|
|
fieldDict, err = indexReader.FieldDictPrefix(field, []byte(prefixTerm))
|
|
} else {
|
|
fieldDict, err = indexReader.FieldDict(field)
|
|
}
|
|
defer func() {
|
|
if cerr := fieldDict.Close(); cerr != nil && err == nil {
|
|
err = cerr
|
|
}
|
|
}()
|
|
|
|
// enumerate the terms and check against regexp
|
|
tfd, err := fieldDict.Next()
|
|
for err == nil && tfd != nil {
|
|
matchPos := pattern.FindStringIndex(tfd.Term)
|
|
if matchPos != nil && matchPos[0] == 0 && matchPos[1] == len(tfd.Term) {
|
|
rv = append(rv, tfd.Term)
|
|
if tooManyClauses(len(rv)) {
|
|
return rv, tooManyClausesErr(len(rv))
|
|
}
|
|
}
|
|
tfd, err = fieldDict.Next()
|
|
}
|
|
|
|
return rv, err
|
|
}
|