postgresql/contrib/tsearch2/dict_snowball.c
2003-08-04 00:43:34 +00:00

132 lines
2.5 KiB
C

/*
* 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)
ereport(ERROR,
(errcode(ERRCODE_OUT_OF_MEMORY),
errmsg("out of 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));
ereport(ERROR,
(errcode(ERRCODE_OUT_OF_MEMORY),
errmsg("out of memory")));
}
d->stem = english_stem;
PG_RETURN_POINTER(d);
}
Datum
snb_ru_init(PG_FUNCTION_ARGS)
{
DictSnowball *d = (DictSnowball *) malloc(sizeof(DictSnowball));
if (!d)
ereport(ERROR,
(errcode(ERRCODE_OUT_OF_MEMORY),
errmsg("out of 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));
ereport(ERROR,
(errcode(ERRCODE_OUT_OF_MEMORY),
errmsg("out of 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);
}