67 lines
1.8 KiB
Go
67 lines
1.8 KiB
Go
// Copyright (c) 2014 Couchbase, Inc.
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// Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file
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// except in compliance with the License. You may obtain a copy of the License at
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// http://www.apache.org/licenses/LICENSE-2.0
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// Unless required by applicable law or agreed to in writing, software distributed under the
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// License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
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// either express or implied. See the License for the specific language governing permissions
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// and limitations under the License.
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package truncate_token_filter
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import (
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"bytes"
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"unicode/utf8"
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"github.com/blevesearch/bleve/analysis"
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"github.com/blevesearch/bleve/registry"
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)
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const Name = "truncate_token"
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type TruncateTokenFilter struct {
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length int
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}
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func NewTruncateTokenFilter(length int) *TruncateTokenFilter {
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return &TruncateTokenFilter{
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length: length,
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}
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}
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func (s *TruncateTokenFilter) Filter(input analysis.TokenStream) analysis.TokenStream {
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rv := make(analysis.TokenStream, 0)
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for _, token := range input {
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wordLen := utf8.RuneCount(token.Term)
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if wordLen > s.length {
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runes := bytes.Runes(token.Term)[0:s.length]
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newterm := make([]byte, 0, s.length*4)
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for _, r := range runes {
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runeBytes := make([]byte, utf8.RuneLen(r))
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utf8.EncodeRune(runeBytes, r)
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newterm = append(newterm, runeBytes...)
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}
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token.Term = newterm
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}
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rv = append(rv, token)
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}
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return rv
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}
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func TruncateTokenFilterConstructor(config map[string]interface{}, cache *registry.Cache) (analysis.TokenFilter, error) {
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length := 25
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lenVal, ok := config["length"].(float64)
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if ok {
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length = int(lenVal)
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}
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return NewTruncateTokenFilter(length), nil
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}
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func init() {
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registry.RegisterTokenFilter(Name, TruncateTokenFilterConstructor)
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}
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