grafana/pkg/services/searchV2/substring_query.go
Artur Wierzbicki 1353177e15
Search: Add substring matcher (#54813)
* search: bring back substring search

* lint fix

* search: bring back ngram

* search: bring back ngram

* search: more tests
2022-09-08 12:10:30 +02:00

103 lines
2.4 KiB
Go

// based on https://github.com/blugelabs/bluge/blob/57414197005148539c5dc5db8ab581594969df79/query.go#L1407-L1482, license:
// Copyright (c) 2020 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 searchV2
import (
"strings"
"github.com/blugelabs/bluge/search"
"github.com/blugelabs/bluge/search/searcher"
"github.com/blugelabs/bluge/search/similarity"
)
type boost float64
func (b *boost) Value() float64 {
if b == nil {
return 1
}
return float64(*b)
}
type SubstringQuery struct {
substring string
field string
boost *boost
scorer search.Scorer
}
func NewSubstringQuery(wildcard string) *SubstringQuery {
return &SubstringQuery{
substring: wildcard,
}
}
// Wildcard returns the substring being queried
func (q *SubstringQuery) Wildcard() string {
return q.substring
}
func (q *SubstringQuery) SetBoost(b float64) *SubstringQuery {
boostVal := boost(b)
q.boost = &boostVal
return q
}
func (q *SubstringQuery) Boost() float64 {
return q.boost.Value()
}
func (q *SubstringQuery) SetField(f string) *SubstringQuery {
q.field = f
return q
}
func (q *SubstringQuery) Field() string {
return q.field
}
var regexpEscaper = strings.NewReplacer(
// characters in the substring that must
// be escaped in the regexp
"+", `\+`,
"*", `\*`,
"(", `\(`,
")", `\)`,
"^", `\^`,
"$", `\$`,
".", `\.`,
"{", `\{`,
"}", `\}`,
"[", `\[`,
"]", `\]`,
`|`, `\|`,
`\`, `\\`)
func (q *SubstringQuery) Searcher(i search.Reader, options search.SearcherOptions) (search.Searcher, error) {
field := q.field
if q.field == "" {
field = options.DefaultSearchField
}
regexpString := ".*" + regexpEscaper.Replace(q.substring) + ".*"
return searcher.NewRegexpStringSearcher(i, regexpString, field,
q.boost.Value(), q.scorer, similarity.NewCompositeSumScorer(), options)
}
func (q *SubstringQuery) Validate() error {
return nil // real validation delayed until searcher constructor
}