132 lines
3 KiB
Go
132 lines
3 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 unicode
|
||
|
|
|
||
|
|
import (
|
||
|
|
"github.com/blevesearch/segment"
|
||
|
|
|
||
|
|
"github.com/blevesearch/bleve/analysis"
|
||
|
|
"github.com/blevesearch/bleve/registry"
|
||
|
|
)
|
||
|
|
|
||
|
|
const Name = "unicode"
|
||
|
|
|
||
|
|
type UnicodeTokenizer struct {
|
||
|
|
}
|
||
|
|
|
||
|
|
func NewUnicodeTokenizer() *UnicodeTokenizer {
|
||
|
|
return &UnicodeTokenizer{}
|
||
|
|
}
|
||
|
|
|
||
|
|
func (rt *UnicodeTokenizer) Tokenize(input []byte) analysis.TokenStream {
|
||
|
|
rvx := make([]analysis.TokenStream, 0, 10) // When rv gets full, append to rvx.
|
||
|
|
rv := make(analysis.TokenStream, 0, 1)
|
||
|
|
|
||
|
|
ta := []analysis.Token(nil)
|
||
|
|
taNext := 0
|
||
|
|
|
||
|
|
segmenter := segment.NewWordSegmenterDirect(input)
|
||
|
|
start := 0
|
||
|
|
pos := 1
|
||
|
|
|
||
|
|
guessRemaining := func(end int) int {
|
||
|
|
avgSegmentLen := end / (len(rv) + 1)
|
||
|
|
if avgSegmentLen < 1 {
|
||
|
|
avgSegmentLen = 1
|
||
|
|
}
|
||
|
|
|
||
|
|
remainingLen := len(input) - end
|
||
|
|
|
||
|
|
return remainingLen / avgSegmentLen
|
||
|
|
}
|
||
|
|
|
||
|
|
for segmenter.Segment() {
|
||
|
|
segmentBytes := segmenter.Bytes()
|
||
|
|
end := start + len(segmentBytes)
|
||
|
|
if segmenter.Type() != segment.None {
|
||
|
|
if taNext >= len(ta) {
|
||
|
|
remainingSegments := guessRemaining(end)
|
||
|
|
if remainingSegments > 1000 {
|
||
|
|
remainingSegments = 1000
|
||
|
|
}
|
||
|
|
if remainingSegments < 1 {
|
||
|
|
remainingSegments = 1
|
||
|
|
}
|
||
|
|
|
||
|
|
ta = make([]analysis.Token, remainingSegments)
|
||
|
|
taNext = 0
|
||
|
|
}
|
||
|
|
|
||
|
|
token := &ta[taNext]
|
||
|
|
taNext++
|
||
|
|
|
||
|
|
token.Term = segmentBytes
|
||
|
|
token.Start = start
|
||
|
|
token.End = end
|
||
|
|
token.Position = pos
|
||
|
|
token.Type = convertType(segmenter.Type())
|
||
|
|
|
||
|
|
if len(rv) >= cap(rv) { // When rv is full, save it into rvx.
|
||
|
|
rvx = append(rvx, rv)
|
||
|
|
|
||
|
|
rvCap := cap(rv) * 2
|
||
|
|
if rvCap > 256 {
|
||
|
|
rvCap = 256
|
||
|
|
}
|
||
|
|
|
||
|
|
rv = make(analysis.TokenStream, 0, rvCap) // Next rv cap is bigger.
|
||
|
|
}
|
||
|
|
|
||
|
|
rv = append(rv, token)
|
||
|
|
pos++
|
||
|
|
}
|
||
|
|
start = end
|
||
|
|
}
|
||
|
|
|
||
|
|
if len(rvx) > 0 {
|
||
|
|
n := len(rv)
|
||
|
|
for _, r := range rvx {
|
||
|
|
n += len(r)
|
||
|
|
}
|
||
|
|
rall := make(analysis.TokenStream, 0, n)
|
||
|
|
for _, r := range rvx {
|
||
|
|
rall = append(rall, r...)
|
||
|
|
}
|
||
|
|
return append(rall, rv...)
|
||
|
|
}
|
||
|
|
|
||
|
|
return rv
|
||
|
|
}
|
||
|
|
|
||
|
|
func UnicodeTokenizerConstructor(config map[string]interface{}, cache *registry.Cache) (analysis.Tokenizer, error) {
|
||
|
|
return NewUnicodeTokenizer(), nil
|
||
|
|
}
|
||
|
|
|
||
|
|
func init() {
|
||
|
|
registry.RegisterTokenizer(Name, UnicodeTokenizerConstructor)
|
||
|
|
}
|
||
|
|
|
||
|
|
func convertType(segmentWordType int) analysis.TokenType {
|
||
|
|
switch segmentWordType {
|
||
|
|
case segment.Ideo:
|
||
|
|
return analysis.Ideographic
|
||
|
|
case segment.Kana:
|
||
|
|
return analysis.Ideographic
|
||
|
|
case segment.Number:
|
||
|
|
return analysis.Numeric
|
||
|
|
}
|
||
|
|
return analysis.AlphaNumeric
|
||
|
|
}
|