githaven-fork/vendor/github.com/blevesearch/bleve/search/query/phrase.go
2017-01-25 10:43:02 +08:00

98 lines
2.7 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 query
import (
"encoding/json"
"fmt"
"github.com/blevesearch/bleve/index"
"github.com/blevesearch/bleve/mapping"
"github.com/blevesearch/bleve/search"
"github.com/blevesearch/bleve/search/searcher"
)
type PhraseQuery struct {
Terms []string `json:"terms"`
Field string `json:"field,omitempty"`
BoostVal *Boost `json:"boost,omitempty"`
termQueries []Query
}
// NewPhraseQuery creates a new Query for finding
// exact term phrases in the index.
// The provided terms must exist in the correct
// order, at the correct index offsets, in the
// specified field. Queried field must have been indexed with
// IncludeTermVectors set to true.
func NewPhraseQuery(terms []string, field string) *PhraseQuery {
termQueries := make([]Query, 0)
for _, term := range terms {
if term != "" {
tq := NewTermQuery(term)
tq.SetField(field)
termQueries = append(termQueries, tq)
}
}
return &PhraseQuery{
Terms: terms,
Field: field,
termQueries: termQueries,
}
}
func (q *PhraseQuery) SetBoost(b float64) {
boost := Boost(b)
q.BoostVal = &boost
}
func (q *PhraseQuery) Boost() float64{
return q.BoostVal.Value()
}
func (q *PhraseQuery) Searcher(i index.IndexReader, m mapping.IndexMapping, explain bool) (search.Searcher, error) {
conjunctionQuery := NewConjunctionQuery(q.termQueries)
conjunctionSearcher, err := conjunctionQuery.Searcher(i, m, explain)
if err != nil {
return nil, err
}
return searcher.NewPhraseSearcher(i, conjunctionSearcher.(*searcher.ConjunctionSearcher), q.Terms)
}
func (q *PhraseQuery) Validate() error {
if len(q.termQueries) < 1 {
return fmt.Errorf("phrase query must contain at least one term")
}
return nil
}
func (q *PhraseQuery) UnmarshalJSON(data []byte) error {
type _phraseQuery PhraseQuery
tmp := _phraseQuery{}
err := json.Unmarshal(data, &tmp)
if err != nil {
return err
}
q.Terms = tmp.Terms
q.Field = tmp.Field
q.BoostVal = tmp.BoostVal
q.termQueries = make([]Query, len(q.Terms))
for i, term := range q.Terms {
q.termQueries[i] = &TermQuery{Term: term, FieldVal: q.Field, BoostVal: q.BoostVal}
}
return nil
}