dispatch/vendor/github.com/blevesearch/bleve/query_phrase.go

109 lines
2.8 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 bleve
import (
"encoding/json"
"fmt"
"github.com/blevesearch/bleve/index"
"github.com/blevesearch/bleve/search"
"github.com/blevesearch/bleve/search/searchers"
)
type phraseQuery struct {
TermQueries []Query `json:"terms"`
BoostVal float64 `json:"boost,omitempty"`
terms []string
}
// 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.
func NewPhraseQuery(terms []string, field string) *phraseQuery {
termQueries := make([]Query, 0)
for _, term := range terms {
if term != "" {
termQueries = append(termQueries, NewTermQuery(term).SetField(field))
}
}
return &phraseQuery{
TermQueries: termQueries,
BoostVal: 1.0,
terms: terms,
}
}
func (q *phraseQuery) Boost() float64 {
return q.BoostVal
}
func (q *phraseQuery) SetBoost(b float64) Query {
q.BoostVal = b
return q
}
func (q *phraseQuery) Searcher(i index.IndexReader, m *IndexMapping, explain bool) (search.Searcher, error) {
conjunctionQuery := NewConjunctionQuery(q.TermQueries)
conjunctionSearcher, err := conjunctionQuery.Searcher(i, m, explain)
if err != nil {
return nil, err
}
return searchers.NewPhraseSearcher(i, conjunctionSearcher.(*searchers.ConjunctionSearcher), q.terms)
}
func (q *phraseQuery) Validate() error {
if len(q.TermQueries) < 1 {
return ErrorPhraseQueryNoTerms
}
return nil
}
func (q *phraseQuery) UnmarshalJSON(data []byte) error {
tmp := struct {
Terms []json.RawMessage `json:"terms"`
BoostVal float64 `json:"boost,omitempty"`
}{}
err := json.Unmarshal(data, &tmp)
if err != nil {
return err
}
q.TermQueries = make([]Query, len(tmp.Terms))
q.terms = make([]string, 0)
for i, term := range tmp.Terms {
query, err := ParseQuery(term)
if err != nil {
return err
}
q.TermQueries[i] = query
tq, isTermQuery := query.(*termQuery)
if !isTermQuery {
return fmt.Errorf("phrase query can only contain term queries")
}
q.terms = append(q.terms, tq.Term)
}
q.BoostVal = tmp.BoostVal
if q.BoostVal == 0 {
q.BoostVal = 1
}
return nil
}
func (q *phraseQuery) Field() string {
return ""
}
func (q *phraseQuery) SetField(f string) Query {
return q
}