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Make tokenizer not rely on nul-terminated text. Instead of using

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strcspn() and a nul-terminated delimiter list, I just flagged
delimiters in an array and wrote things inline.  Submitting this for
review separately because it's pretty standalone. (CVS 3378)

FossilOrigin-Name: 2631ceaeefaca3aa837e3b439399f13c51456914
This commit is contained in:
shess 2006-09-01 00:05:17 +00:00
parent 5db455e7b5
commit c0beb14f23
3 changed files with 59 additions and 66 deletions
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109
ext/fts1/fts1_tokenizer1.c
View File

@ -29,61 +29,56 @@
#include "fts1_tokenizer.h"
/* Duplicate a string; the caller must free() the returned string.
* (We don't use strdup() since it's not part of the standard C library and
* may not be available everywhere.) */
/* TODO(shess) Copied from fulltext.c, consider util.c for such
** things. */
static char *string_dup(const char *s){
char *str = malloc(strlen(s) + 1);
strcpy(str, s);
return str;
}
typedef struct simple_tokenizer {
sqlite3_tokenizer base;
const char *zDelim; /* token delimiters */
char delim[128]; /* flag ASCII delimiters */
} simple_tokenizer;
typedef struct simple_tokenizer_cursor {
sqlite3_tokenizer_cursor base;
const char *pInput; /* input we are tokenizing */
int nBytes; /* size of the input */
const char *pCurrent; /* current position in pInput */
int iOffset; /* current position in pInput */
int iToken; /* index of next token to be returned */
char *zToken; /* storage for current token */
int nTokenBytes; /* actual size of current token */
char *pToken; /* storage for current token */
int nTokenAllocated; /* space allocated to zToken buffer */
} simple_tokenizer_cursor;
static sqlite3_tokenizer_module simpleTokenizerModule;/* forward declaration */
static int isDelim(simple_tokenizer *t, unsigned char c){
return c<0x80 && t->delim[c];
}
static int simpleCreate(
int argc, const char **argv,
sqlite3_tokenizer **ppTokenizer
){
simple_tokenizer *t;
t = (simple_tokenizer *) malloc(sizeof(simple_tokenizer));
t = (simple_tokenizer *) calloc(sizeof(simple_tokenizer), 1);
/* TODO(shess) Delimiters need to remain the same from run to run,
** else we need to reindex. One solution would be a meta-table to
** track such information in the database, then we'd only want this
** information on the initial create.
*/
if( argc>1 ){
t->zDelim = string_dup(argv[1]);
} else {
/* Build a string excluding alphanumeric ASCII characters */
char zDelim[0x80]; /* nul-terminated, so nul not a member */
int i, j;
for(i=1, j=0; i<0x80; i++){
if( !isalnum(i) ){
zDelim[j++] = i;
int i, n = strlen(argv[1]);
for(i=0; i<n; i++){
unsigned char ch = argv[1][i];
/* We explicitly don't support UTF-8 delimiters for now. */
if( ch>=0x80 ){
free(t);
return SQLITE_ERROR;
}
t->delim[ch] = 1;
}
} else {
/* Mark non-alphanumeric ASCII characters as delimiters */
int i;
for(i=1; i<0x80; i++){
t->delim[i] = !isalnum(i);
}
zDelim[j++] = '\0';
assert( j<=sizeof(zDelim) );
t->zDelim = string_dup(zDelim);
}
*ppTokenizer = &t->base;
@ -91,11 +86,7 @@ static int simpleCreate(
}
static int simpleDestroy(sqlite3_tokenizer *pTokenizer){
simple_tokenizer *t = (simple_tokenizer *) pTokenizer;
free((void *) t->zDelim);
free(t);
free(pTokenizer);
return SQLITE_OK;
}
@ -109,10 +100,9 @@ static int simpleOpen(
c = (simple_tokenizer_cursor *) malloc(sizeof(simple_tokenizer_cursor));
c->pInput = pInput;
c->nBytes = nBytes<0 ? (int) strlen(pInput) : nBytes;
c->pCurrent = c->pInput; /* start tokenizing at the beginning */
c->iOffset = 0; /* start tokenizing at the beginning */
c->iToken = 0;
c->zToken = NULL; /* no space allocated, yet. */
c->nTokenBytes = 0;
c->pToken = NULL; /* no space allocated, yet. */
c->nTokenAllocated = 0;
*ppCursor = &c->base;
@ -121,12 +111,8 @@ static int simpleOpen(
static int simpleClose(sqlite3_tokenizer_cursor *pCursor){
simple_tokenizer_cursor *c = (simple_tokenizer_cursor *) pCursor;
if( NULL!=c->zToken ){
free(c->zToken);
}
free(c->pToken);
free(c);
return SQLITE_OK;
}
@ -137,35 +123,42 @@ static int simpleNext(
){
simple_tokenizer_cursor *c = (simple_tokenizer_cursor *) pCursor;
simple_tokenizer *t = (simple_tokenizer *) pCursor->pTokenizer;
int ii;
unsigned char *p = (unsigned char *)c->pInput;
while( c->pCurrent-c->pInput<c->nBytes ){
int n = (int) strcspn(c->pCurrent, t->zDelim);
if( n>0 ){
if( n+1>c->nTokenAllocated ){
c->zToken = realloc(c->zToken, n+1);
while( c->iOffset<c->nBytes ){
int iStartOffset;
/* Scan past delimiter characters */
while( c->iOffset<c->nBytes && isDelim(t, p[c->iOffset]) ){
c->iOffset++;
}
/* Count non-delimiter characters. */
iStartOffset = c->iOffset;
while( c->iOffset<c->nBytes && !isDelim(t, p[c->iOffset]) ){
c->iOffset++;
}
if( c->iOffset>iStartOffset ){
int i, n = c->iOffset-iStartOffset;
if( n>c->nTokenAllocated ){
c->pToken = realloc(c->pToken, n);
}
for(ii=0; ii<n; ii++){
for(i=0; i<n; i++){
/* TODO(shess) This needs expansion to handle UTF-8
** case-insensitivity.
*/
char ch = c->pCurrent[ii];
c->zToken[ii] = (unsigned char)ch<0x80 ? tolower(ch) : ch;
unsigned char ch = p[iStartOffset+i];
c->pToken[i] = ch<0x80 ? tolower(ch) : ch;
}
c->zToken[n] = '\0';
*ppToken = c->zToken;
*ppToken = c->pToken;
*pnBytes = n;
*piStartOffset = (int) (c->pCurrent-c->pInput);
*piEndOffset = *piStartOffset+n;
*piStartOffset = iStartOffset;
*piEndOffset = c->iOffset;
*piPosition = c->iToken++;
c->pCurrent += n + 1;
return SQLITE_OK;
}
c->pCurrent += n + 1;
/* TODO(shess) could strspn() to skip delimiters en masse. Needs
** to happen in two places, though, which is annoying.
*/
}
return SQLITE_DONE;
}

14
manifest
View File

@ -1,5 +1,5 @@
C Refactor\sthe\sFTS1\smodule\sso\sthat\sits\sname\sis\s"fts1"\sinstead\sof\s"fulltext",\nso\sthat\sall\ssymbols\swith\sexternal\slinkage\sbegin\swith\s"sqlite3Fts1",\sand\nso\sthat\sall\sfilenames\sbegin\swith\s"fts1".\s(CVS\s3377)
D 2006-08-31T15:07:14
C Make\stokenizer\snot\srely\son\snul-terminated\stext.\s\sInstead\sof\susing\nstrcspn()\sand\sa\snul-terminated\sdelimiter\slist,\sI\sjust\sflagged\ndelimiters\sin\san\sarray\sand\swrote\sthings\sinline.\s\sSubmitting\sthis\sfor\nreview\sseparately\sbecause\sit's\spretty\sstandalone.\s(CVS\s3378)
D 2006-09-01T00:05:17
F Makefile.in 8e7f9ecebab2c6e0f3db20ff129a8f9405ab64f8
F Makefile.linux-gcc 2d8574d1ba75f129aba2019f0b959db380a90935
F README 9c4e2d6706bdcc3efdd773ce752a8cdab4f90028
@ -26,7 +26,7 @@ F ext/fts1/fts1.h fe8e8f38dd6d2d2645b9b0d6972e80985249575f
F ext/fts1/fts1_hash.c 3196cee866edbebb1c0521e21672e6d599965114
F ext/fts1/fts1_hash.h 957d378355ed29f672cd5add012ce8b088a5e089
F ext/fts1/fts1_tokenizer.h 887580709d32e44ca4ee3c7107c06ee444eb44c2
F ext/fts1/fts1_tokenizer1.c 13789776e1afc4a4db04f2700eba24f9c5e77a90
F ext/fts1/fts1_tokenizer1.c 03a9af15f252cf0ee3d518be8c2f48b3eb1d31a1
F ext/fts1/fulltext.c d935e600d87bc86b7d64f55c7520ea41d6034c5c
F ext/fts1/fulltext.h 08525a47852d1d62a0be81d3fc3fe2d23b094efd
F ext/fts1/simple_tokenizer.c 1844d72f7194c3fd3d7e4173053911bf0661b70d
@ -395,7 +395,7 @@ F www/tclsqlite.tcl bb0d1357328a42b1993d78573e587c6dcbc964b9
F www/vdbe.tcl 87a31ace769f20d3627a64fa1fade7fed47b90d0
F www/version3.tcl 890248cf7b70e60c383b0e84d77d5132b3ead42b
F www/whentouse.tcl 97e2b5cd296f7d8057e11f44427dea8a4c2db513
P 6c77c2d5e15e9d3efed3e274bc93cd5a4868f574
R 3fbd41e2a6fe983095c0be06e9b96477
U drh
Z 4687716ffdce69db90a5a92c651e7fec
P e1891f0dc58e5498a8845d8b9b5b092d7f9c7003
R acb5259f7be3fb128befffe51d68519d
U shess
Z 5622cbcf68194bca1ea9e4f2a7e4d027

2
manifest.uuid
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@ -1 +1 @@
e1891f0dc58e5498a8845d8b9b5b092d7f9c7003
2631ceaeefaca3aa837e3b439399f13c51456914