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bleve/search/searchers/search_regexp.go
2015-03-11 16:57:22 -04:00

109 lines
2.8 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 searchers
import (
"regexp"
"github.com/blevesearch/bleve/index"
"github.com/blevesearch/bleve/search"
)
type RegexpSearcher struct {
indexReader index.IndexReader
pattern *regexp.Regexp
field string
explain bool
searcher *DisjunctionSearcher
}
func NewRegexpSearcher(indexReader index.IndexReader, pattern *regexp.Regexp, field string, boost float64, explain bool) (*RegexpSearcher, error) {
prefixTerm, complete := pattern.LiteralPrefix()
candidateTerms := make([]string, 0)
if complete {
// there is no pattern
candidateTerms = append(candidateTerms, prefixTerm)
} else {
var fieldDict index.FieldDict
var err error
if len(prefixTerm) > 0 {
fieldDict, err = indexReader.FieldDictPrefix(field, []byte(prefixTerm))
} else {
fieldDict, err = indexReader.FieldDict(field)
}
// enumerate the terms and check against regexp
tfd, err := fieldDict.Next()
for err == nil && tfd != nil {
if pattern.MatchString(tfd.Term) {
candidateTerms = append(candidateTerms, tfd.Term)
}
tfd, err = fieldDict.Next()
}
if err != nil {
return nil, err
}
}
// enumerate all the terms in the range
qsearchers := make([]search.Searcher, 0, 25)
for _, cterm := range candidateTerms {
qsearcher, err := NewTermSearcher(indexReader, cterm, field, 1.0, explain)
if err != nil {
return nil, err
}
qsearchers = append(qsearchers, qsearcher)
}
// build disjunction searcher of these ranges
searcher, err := NewDisjunctionSearcher(indexReader, qsearchers, 0, explain)
if err != nil {
return nil, err
}
return &RegexpSearcher{
indexReader: indexReader,
pattern: pattern,
field: field,
explain: explain,
searcher: searcher,
}, nil
}
func (s *RegexpSearcher) Count() uint64 {
return s.searcher.Count()
}
func (s *RegexpSearcher) Weight() float64 {
return s.searcher.Weight()
}
func (s *RegexpSearcher) SetQueryNorm(qnorm float64) {
s.searcher.SetQueryNorm(qnorm)
}
func (s *RegexpSearcher) Next() (*search.DocumentMatch, error) {
return s.searcher.Next()
}
func (s *RegexpSearcher) Advance(ID string) (*search.DocumentMatch, error) {
return s.searcher.Next()
}
func (s *RegexpSearcher) Close() error {
return s.searcher.Close()
}
func (s *RegexpSearcher) Min() int {
return 0
}