mirror of
https://github.com/tursodatabase/libsql.git
synced 2024-11-23 15:36:17 +00:00
398 lines
12 KiB
C
398 lines
12 KiB
C
/*
|
|
** 2012 May 24
|
|
**
|
|
** The author disclaims copyright to this source code. In place of
|
|
** a legal notice, here is a blessing:
|
|
**
|
|
** May you do good and not evil.
|
|
** May you find forgiveness for yourself and forgive others.
|
|
** May you share freely, never taking more than you give.
|
|
**
|
|
******************************************************************************
|
|
**
|
|
** Implementation of the "unicode" full-text-search tokenizer.
|
|
*/
|
|
|
|
#ifndef SQLITE_DISABLE_FTS3_UNICODE
|
|
|
|
#include "fts3Int.h"
|
|
#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)
|
|
|
|
#include <assert.h>
|
|
#include <stdlib.h>
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
|
|
#include "fts3_tokenizer.h"
|
|
|
|
/*
|
|
** The following two macros - READ_UTF8 and WRITE_UTF8 - have been copied
|
|
** from the sqlite3 source file utf.c. If this file is compiled as part
|
|
** of the amalgamation, they are not required.
|
|
*/
|
|
#ifndef SQLITE_AMALGAMATION
|
|
|
|
static const unsigned char sqlite3Utf8Trans1[] = {
|
|
0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
|
|
0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
|
|
0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
|
|
0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
|
|
0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
|
|
0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
|
|
0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
|
|
0x00, 0x01, 0x02, 0x03, 0x00, 0x01, 0x00, 0x00,
|
|
};
|
|
|
|
#define READ_UTF8(zIn, zTerm, c) \
|
|
c = *(zIn++); \
|
|
if( c>=0xc0 ){ \
|
|
c = sqlite3Utf8Trans1[c-0xc0]; \
|
|
while( zIn!=zTerm && (*zIn & 0xc0)==0x80 ){ \
|
|
c = (c<<6) + (0x3f & *(zIn++)); \
|
|
} \
|
|
if( c<0x80 \
|
|
|| (c&0xFFFFF800)==0xD800 \
|
|
|| (c&0xFFFFFFFE)==0xFFFE ){ c = 0xFFFD; } \
|
|
}
|
|
|
|
#define WRITE_UTF8(zOut, c) { \
|
|
if( c<0x00080 ){ \
|
|
*zOut++ = (u8)(c&0xFF); \
|
|
} \
|
|
else if( c<0x00800 ){ \
|
|
*zOut++ = 0xC0 + (u8)((c>>6)&0x1F); \
|
|
*zOut++ = 0x80 + (u8)(c & 0x3F); \
|
|
} \
|
|
else if( c<0x10000 ){ \
|
|
*zOut++ = 0xE0 + (u8)((c>>12)&0x0F); \
|
|
*zOut++ = 0x80 + (u8)((c>>6) & 0x3F); \
|
|
*zOut++ = 0x80 + (u8)(c & 0x3F); \
|
|
}else{ \
|
|
*zOut++ = 0xF0 + (u8)((c>>18) & 0x07); \
|
|
*zOut++ = 0x80 + (u8)((c>>12) & 0x3F); \
|
|
*zOut++ = 0x80 + (u8)((c>>6) & 0x3F); \
|
|
*zOut++ = 0x80 + (u8)(c & 0x3F); \
|
|
} \
|
|
}
|
|
|
|
#endif /* ifndef SQLITE_AMALGAMATION */
|
|
|
|
typedef struct unicode_tokenizer unicode_tokenizer;
|
|
typedef struct unicode_cursor unicode_cursor;
|
|
|
|
struct unicode_tokenizer {
|
|
sqlite3_tokenizer base;
|
|
int eRemoveDiacritic;
|
|
int nException;
|
|
int *aiException;
|
|
};
|
|
|
|
struct unicode_cursor {
|
|
sqlite3_tokenizer_cursor base;
|
|
const unsigned char *aInput; /* Input text being tokenized */
|
|
int nInput; /* Size of aInput[] in bytes */
|
|
int iOff; /* Current offset within aInput[] */
|
|
int iToken; /* Index of next token to be returned */
|
|
char *zToken; /* storage for current token */
|
|
int nAlloc; /* space allocated at zToken */
|
|
};
|
|
|
|
|
|
/*
|
|
** Destroy a tokenizer allocated by unicodeCreate().
|
|
*/
|
|
static int unicodeDestroy(sqlite3_tokenizer *pTokenizer){
|
|
if( pTokenizer ){
|
|
unicode_tokenizer *p = (unicode_tokenizer *)pTokenizer;
|
|
sqlite3_free(p->aiException);
|
|
sqlite3_free(p);
|
|
}
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** As part of a tokenchars= or separators= option, the CREATE VIRTUAL TABLE
|
|
** statement has specified that the tokenizer for this table shall consider
|
|
** all characters in string zIn/nIn to be separators (if bAlnum==0) or
|
|
** token characters (if bAlnum==1).
|
|
**
|
|
** For each codepoint in the zIn/nIn string, this function checks if the
|
|
** sqlite3FtsUnicodeIsalnum() function already returns the desired result.
|
|
** If so, no action is taken. Otherwise, the codepoint is added to the
|
|
** unicode_tokenizer.aiException[] array. For the purposes of tokenization,
|
|
** the return value of sqlite3FtsUnicodeIsalnum() is inverted for all
|
|
** codepoints in the aiException[] array.
|
|
**
|
|
** If a standalone diacritic mark (one that sqlite3FtsUnicodeIsdiacritic()
|
|
** identifies as a diacritic) occurs in the zIn/nIn string it is ignored.
|
|
** It is not possible to change the behavior of the tokenizer with respect
|
|
** to these codepoints.
|
|
*/
|
|
static int unicodeAddExceptions(
|
|
unicode_tokenizer *p, /* Tokenizer to add exceptions to */
|
|
int bAlnum, /* Replace Isalnum() return value with this */
|
|
const char *zIn, /* Array of characters to make exceptions */
|
|
int nIn /* Length of z in bytes */
|
|
){
|
|
const unsigned char *z = (const unsigned char *)zIn;
|
|
const unsigned char *zTerm = &z[nIn];
|
|
unsigned int iCode;
|
|
int nEntry = 0;
|
|
|
|
assert( bAlnum==0 || bAlnum==1 );
|
|
|
|
while( z<zTerm ){
|
|
READ_UTF8(z, zTerm, iCode);
|
|
assert( (sqlite3FtsUnicodeIsalnum((int)iCode) & 0xFFFFFFFE)==0 );
|
|
if( sqlite3FtsUnicodeIsalnum((int)iCode)!=bAlnum
|
|
&& sqlite3FtsUnicodeIsdiacritic((int)iCode)==0
|
|
){
|
|
nEntry++;
|
|
}
|
|
}
|
|
|
|
if( nEntry ){
|
|
int *aNew; /* New aiException[] array */
|
|
int nNew; /* Number of valid entries in array aNew[] */
|
|
|
|
aNew = sqlite3_realloc64(p->aiException,(p->nException+nEntry)*sizeof(int));
|
|
if( aNew==0 ) return SQLITE_NOMEM;
|
|
nNew = p->nException;
|
|
|
|
z = (const unsigned char *)zIn;
|
|
while( z<zTerm ){
|
|
READ_UTF8(z, zTerm, iCode);
|
|
if( sqlite3FtsUnicodeIsalnum((int)iCode)!=bAlnum
|
|
&& sqlite3FtsUnicodeIsdiacritic((int)iCode)==0
|
|
){
|
|
int i, j;
|
|
for(i=0; i<nNew && aNew[i]<(int)iCode; i++);
|
|
for(j=nNew; j>i; j--) aNew[j] = aNew[j-1];
|
|
aNew[i] = (int)iCode;
|
|
nNew++;
|
|
}
|
|
}
|
|
p->aiException = aNew;
|
|
p->nException = nNew;
|
|
}
|
|
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** Return true if the p->aiException[] array contains the value iCode.
|
|
*/
|
|
static int unicodeIsException(unicode_tokenizer *p, int iCode){
|
|
if( p->nException>0 ){
|
|
int *a = p->aiException;
|
|
int iLo = 0;
|
|
int iHi = p->nException-1;
|
|
|
|
while( iHi>=iLo ){
|
|
int iTest = (iHi + iLo) / 2;
|
|
if( iCode==a[iTest] ){
|
|
return 1;
|
|
}else if( iCode>a[iTest] ){
|
|
iLo = iTest+1;
|
|
}else{
|
|
iHi = iTest-1;
|
|
}
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
** Return true if, for the purposes of tokenization, codepoint iCode is
|
|
** considered a token character (not a separator).
|
|
*/
|
|
static int unicodeIsAlnum(unicode_tokenizer *p, int iCode){
|
|
assert( (sqlite3FtsUnicodeIsalnum(iCode) & 0xFFFFFFFE)==0 );
|
|
return sqlite3FtsUnicodeIsalnum(iCode) ^ unicodeIsException(p, iCode);
|
|
}
|
|
|
|
/*
|
|
** Create a new tokenizer instance.
|
|
*/
|
|
static int unicodeCreate(
|
|
int nArg, /* Size of array argv[] */
|
|
const char * const *azArg, /* Tokenizer creation arguments */
|
|
sqlite3_tokenizer **pp /* OUT: New tokenizer handle */
|
|
){
|
|
unicode_tokenizer *pNew; /* New tokenizer object */
|
|
int i;
|
|
int rc = SQLITE_OK;
|
|
|
|
pNew = (unicode_tokenizer *) sqlite3_malloc(sizeof(unicode_tokenizer));
|
|
if( pNew==NULL ) return SQLITE_NOMEM;
|
|
memset(pNew, 0, sizeof(unicode_tokenizer));
|
|
pNew->eRemoveDiacritic = 1;
|
|
|
|
for(i=0; rc==SQLITE_OK && i<nArg; i++){
|
|
const char *z = azArg[i];
|
|
int n = (int)strlen(z);
|
|
|
|
if( n==19 && memcmp("remove_diacritics=1", z, 19)==0 ){
|
|
pNew->eRemoveDiacritic = 1;
|
|
}
|
|
else if( n==19 && memcmp("remove_diacritics=0", z, 19)==0 ){
|
|
pNew->eRemoveDiacritic = 0;
|
|
}
|
|
else if( n==19 && memcmp("remove_diacritics=2", z, 19)==0 ){
|
|
pNew->eRemoveDiacritic = 2;
|
|
}
|
|
else if( n>=11 && memcmp("tokenchars=", z, 11)==0 ){
|
|
rc = unicodeAddExceptions(pNew, 1, &z[11], n-11);
|
|
}
|
|
else if( n>=11 && memcmp("separators=", z, 11)==0 ){
|
|
rc = unicodeAddExceptions(pNew, 0, &z[11], n-11);
|
|
}
|
|
else{
|
|
/* Unrecognized argument */
|
|
rc = SQLITE_ERROR;
|
|
}
|
|
}
|
|
|
|
if( rc!=SQLITE_OK ){
|
|
unicodeDestroy((sqlite3_tokenizer *)pNew);
|
|
pNew = 0;
|
|
}
|
|
*pp = (sqlite3_tokenizer *)pNew;
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Prepare to begin tokenizing a particular string. The input
|
|
** string to be tokenized is pInput[0..nBytes-1]. A cursor
|
|
** used to incrementally tokenize this string is returned in
|
|
** *ppCursor.
|
|
*/
|
|
static int unicodeOpen(
|
|
sqlite3_tokenizer *p, /* The tokenizer */
|
|
const char *aInput, /* Input string */
|
|
int nInput, /* Size of string aInput in bytes */
|
|
sqlite3_tokenizer_cursor **pp /* OUT: New cursor object */
|
|
){
|
|
unicode_cursor *pCsr;
|
|
|
|
pCsr = (unicode_cursor *)sqlite3_malloc(sizeof(unicode_cursor));
|
|
if( pCsr==0 ){
|
|
return SQLITE_NOMEM;
|
|
}
|
|
memset(pCsr, 0, sizeof(unicode_cursor));
|
|
|
|
pCsr->aInput = (const unsigned char *)aInput;
|
|
if( aInput==0 ){
|
|
pCsr->nInput = 0;
|
|
pCsr->aInput = (const unsigned char*)"";
|
|
}else if( nInput<0 ){
|
|
pCsr->nInput = (int)strlen(aInput);
|
|
}else{
|
|
pCsr->nInput = nInput;
|
|
}
|
|
|
|
*pp = &pCsr->base;
|
|
UNUSED_PARAMETER(p);
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** Close a tokenization cursor previously opened by a call to
|
|
** simpleOpen() above.
|
|
*/
|
|
static int unicodeClose(sqlite3_tokenizer_cursor *pCursor){
|
|
unicode_cursor *pCsr = (unicode_cursor *) pCursor;
|
|
sqlite3_free(pCsr->zToken);
|
|
sqlite3_free(pCsr);
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** Extract the next token from a tokenization cursor. The cursor must
|
|
** have been opened by a prior call to simpleOpen().
|
|
*/
|
|
static int unicodeNext(
|
|
sqlite3_tokenizer_cursor *pC, /* Cursor returned by simpleOpen */
|
|
const char **paToken, /* OUT: Token text */
|
|
int *pnToken, /* OUT: Number of bytes at *paToken */
|
|
int *piStart, /* OUT: Starting offset of token */
|
|
int *piEnd, /* OUT: Ending offset of token */
|
|
int *piPos /* OUT: Position integer of token */
|
|
){
|
|
unicode_cursor *pCsr = (unicode_cursor *)pC;
|
|
unicode_tokenizer *p = ((unicode_tokenizer *)pCsr->base.pTokenizer);
|
|
unsigned int iCode = 0;
|
|
char *zOut;
|
|
const unsigned char *z = &pCsr->aInput[pCsr->iOff];
|
|
const unsigned char *zStart = z;
|
|
const unsigned char *zEnd;
|
|
const unsigned char *zTerm = &pCsr->aInput[pCsr->nInput];
|
|
|
|
/* Scan past any delimiter characters before the start of the next token.
|
|
** Return SQLITE_DONE early if this takes us all the way to the end of
|
|
** the input. */
|
|
while( z<zTerm ){
|
|
READ_UTF8(z, zTerm, iCode);
|
|
if( unicodeIsAlnum(p, (int)iCode) ) break;
|
|
zStart = z;
|
|
}
|
|
if( zStart>=zTerm ) return SQLITE_DONE;
|
|
|
|
zOut = pCsr->zToken;
|
|
do {
|
|
int iOut;
|
|
|
|
/* Grow the output buffer if required. */
|
|
if( (zOut-pCsr->zToken)>=(pCsr->nAlloc-4) ){
|
|
char *zNew = sqlite3_realloc64(pCsr->zToken, pCsr->nAlloc+64);
|
|
if( !zNew ) return SQLITE_NOMEM;
|
|
zOut = &zNew[zOut - pCsr->zToken];
|
|
pCsr->zToken = zNew;
|
|
pCsr->nAlloc += 64;
|
|
}
|
|
|
|
/* Write the folded case of the last character read to the output */
|
|
zEnd = z;
|
|
iOut = sqlite3FtsUnicodeFold((int)iCode, p->eRemoveDiacritic);
|
|
if( iOut ){
|
|
WRITE_UTF8(zOut, iOut);
|
|
}
|
|
|
|
/* If the cursor is not at EOF, read the next character */
|
|
if( z>=zTerm ) break;
|
|
READ_UTF8(z, zTerm, iCode);
|
|
}while( unicodeIsAlnum(p, (int)iCode)
|
|
|| sqlite3FtsUnicodeIsdiacritic((int)iCode)
|
|
);
|
|
|
|
/* Set the output variables and return. */
|
|
pCsr->iOff = (int)(z - pCsr->aInput);
|
|
*paToken = pCsr->zToken;
|
|
*pnToken = (int)(zOut - pCsr->zToken);
|
|
*piStart = (int)(zStart - pCsr->aInput);
|
|
*piEnd = (int)(zEnd - pCsr->aInput);
|
|
*piPos = pCsr->iToken++;
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** Set *ppModule to a pointer to the sqlite3_tokenizer_module
|
|
** structure for the unicode tokenizer.
|
|
*/
|
|
void sqlite3Fts3UnicodeTokenizer(sqlite3_tokenizer_module const **ppModule){
|
|
static const sqlite3_tokenizer_module module = {
|
|
0,
|
|
unicodeCreate,
|
|
unicodeDestroy,
|
|
unicodeOpen,
|
|
unicodeClose,
|
|
unicodeNext,
|
|
0,
|
|
};
|
|
*ppModule = &module;
|
|
}
|
|
|
|
#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */
|
|
#endif /* ifndef SQLITE_DISABLE_FTS3_UNICODE */
|