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bleve/analysis/tokenizers/unicode_word_boundary/boundary.go
Marty Schoch c526a38369 major refactor of analysis files, now wired up to registry
ultimately this is make it more convenient for us to wire up
different elements of the analysis pipeline, without having to
preload everything into memory before we need it

separately the index layer now has a mechanism for storing
internal key/value pairs.  this is expected to be used to
store the mapping, and possibly other pieces of data by the
top layer, but not exposed to the user at the top.
2014-08-13 21:14:47 -04:00

134 lines
3.6 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_word_boundary
// #cgo LDFLAGS: -licuuc -licudata
// #include <stdio.h>
// #include <stdlib.h>
// #include "unicode/utypes.h"
// #include "unicode/uchar.h"
// #include "unicode/ubrk.h"
// #include "unicode/ustring.h"
import "C"
import (
"log"
"unsafe"
"github.com/couchbaselabs/bleve/analysis"
"github.com/couchbaselabs/bleve/registry"
)
const Name = "unicode"
type UnicodeWordBoundaryTokenizer struct {
locale *C.char
}
func NewUnicodeWordBoundaryTokenizer() *UnicodeWordBoundaryTokenizer {
return &UnicodeWordBoundaryTokenizer{}
}
func NewUnicodeWordBoundaryCustomLocaleTokenizer(locale string) *UnicodeWordBoundaryTokenizer {
return &UnicodeWordBoundaryTokenizer{
locale: C.CString(locale),
}
}
func (t *UnicodeWordBoundaryTokenizer) Tokenize(input []byte) analysis.TokenStream {
rv := make(analysis.TokenStream, 0)
if len(input) < 1 {
return rv
}
// works
var myUnsafePointer = unsafe.Pointer(&(input[0]))
var myCCharPointer *C.char = (*C.char)(myUnsafePointer)
var inlen C.int32_t = C.int32_t(len(input))
var buflen C.int32_t = C.int32_t(2*len(input) + 1) // worse case each byte becomes 2
var stringToExamine []C.UChar = make([]C.UChar, buflen)
var myUnsafePointerToExamine = unsafe.Pointer(&(stringToExamine[0]))
var myUCharPointer *C.UChar = (*C.UChar)(myUnsafePointerToExamine)
C.u_uastrncpy(myUCharPointer, myCCharPointer, inlen)
var err C.UErrorCode = C.U_ZERO_ERROR
bi := C.ubrk_open(C.UBRK_WORD, t.locale, myUCharPointer, -1, &err)
if err > C.U_ZERO_ERROR {
log.Printf("error opening boundary iterator")
return rv
}
defer C.ubrk_close(bi)
position := 0
var prev C.int32_t
p := C.ubrk_first(bi)
for p != C.UBRK_DONE {
q := C.ubrk_getRuleStatus(bi)
// convert boundaries back to utf8 positions
var nilCString *C.char
var indexA C.int32_t
C.u_strToUTF8(nilCString, 0, &indexA, myUCharPointer, prev, &err)
if err > C.U_ZERO_ERROR && err != C.U_BUFFER_OVERFLOW_ERROR {
log.Printf("error converting boundary %d", err)
return rv
} else {
err = C.U_ZERO_ERROR
}
var indexB C.int32_t
C.u_strToUTF8(nilCString, 0, &indexB, myUCharPointer, p, &err)
if err > C.U_ZERO_ERROR && err != C.U_BUFFER_OVERFLOW_ERROR {
log.Printf("error converting boundary %d", err)
return rv
} else {
err = C.U_ZERO_ERROR
}
if q != 0 {
position += 1
token := analysis.Token{
Start: int(indexA),
End: int(indexB),
Term: input[indexA:indexB],
Position: position,
Type: analysis.AlphaNumeric,
}
rv = append(rv, &token)
}
prev = p
p = C.ubrk_next(bi)
}
return rv
}
func UnicodeWordBoundaryTokenizerConstructor(config map[string]interface{}, cache *registry.Cache) (analysis.Tokenizer, error) {
locale := ""
localeVal, ok := config["locale"].(string)
if ok {
locale = localeVal
}
if locale == "" {
return NewUnicodeWordBoundaryTokenizer(), nil
} else {
return NewUnicodeWordBoundaryCustomLocaleTokenizer(locale), nil
}
}
func init() {
registry.RegisterTokenizer(Name, UnicodeWordBoundaryTokenizerConstructor)
}