postgresql/contrib/tsearch2/dict_snowball.c

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2003-07-21 18:27:44 +08:00
/*
* example of Snowball dictionary
* http://snowball.tartarus.org/
* Teodor Sigaev <teodor@sigaev.ru>
*/
#include <stdlib.h>
#include <string.h>
#include "postgres.h"
#include "dict.h"
#include "common.h"
#include "snowball/header.h"
#include "snowball/english_stem.h"
#include "snowball/russian_stem.h"
typedef struct {
struct SN_env *z;
StopList stoplist;
int (*stem)(struct SN_env * z);
} DictSnowball;
PG_FUNCTION_INFO_V1(snb_en_init);
Datum snb_en_init(PG_FUNCTION_ARGS);
PG_FUNCTION_INFO_V1(snb_ru_init);
Datum snb_ru_init(PG_FUNCTION_ARGS);
PG_FUNCTION_INFO_V1(snb_lexize);
Datum snb_lexize(PG_FUNCTION_ARGS);
Datum
snb_en_init(PG_FUNCTION_ARGS) {
DictSnowball *d = (DictSnowball*)malloc( sizeof(DictSnowball) );
if ( !d )
elog(ERROR, "No memory");
memset(d,0,sizeof(DictSnowball));
d->stoplist.wordop=lowerstr;
if ( !PG_ARGISNULL(0) && PG_GETARG_POINTER(0)!=NULL ) {
text *in = PG_GETARG_TEXT_P(0);
readstoplist(in, &(d->stoplist));
sortstoplist(&(d->stoplist));
PG_FREE_IF_COPY(in, 0);
}
d->z = english_create_env();
if (!d->z) {
freestoplist(&(d->stoplist));
elog(ERROR,"No memory");
}
d->stem=english_stem;
PG_RETURN_POINTER(d);
}
Datum
snb_ru_init(PG_FUNCTION_ARGS) {
DictSnowball *d = (DictSnowball*)malloc( sizeof(DictSnowball) );
if ( !d )
elog(ERROR, "No memory");
memset(d,0,sizeof(DictSnowball));
d->stoplist.wordop=lowerstr;
if ( !PG_ARGISNULL(0) && PG_GETARG_POINTER(0)!=NULL ) {
text *in = PG_GETARG_TEXT_P(0);
readstoplist(in, &(d->stoplist));
sortstoplist(&(d->stoplist));
PG_FREE_IF_COPY(in, 0);
}
d->z = russian_create_env();
if (!d->z) {
freestoplist(&(d->stoplist));
elog(ERROR,"No memory");
}
d->stem=russian_stem;
PG_RETURN_POINTER(d);
}
Datum
snb_lexize(PG_FUNCTION_ARGS) {
DictSnowball *d = (DictSnowball*)PG_GETARG_POINTER(0);
char *in = (char*)PG_GETARG_POINTER(1);
char *txt = pnstrdup(in, PG_GETARG_INT32(2));
char **res=palloc(sizeof(char*)*2);
if ( *txt=='\0' || searchstoplist(&(d->stoplist),txt) ) {
pfree(txt);
res[0]=NULL;
} else {
SN_set_current(d->z, strlen(txt), txt);
(d->stem)(d->z);
if ( d->z->p && d->z->l ) {
txt=repalloc(txt, d->z->l+1);
memcpy( txt, d->z->p, d->z->l);
txt[d->z->l]='\0';
}
res[0]=txt;
}
res[1]=NULL;
PG_RETURN_POINTER(res);
}