postgresql/contrib/tsearch2/stopword.c
Teodor Sigaev 22505f4703 Add thesaurus dictionary which can replace N>0 lexemes by M>0 lexemes.
It required some changes in lexize algorithm, but interface with
dictionaries stays compatible with old dictionaries.

Funded by Georgia Public Library Service and LibLime, Inc.
2006-05-31 14:05:31 +00:00

113 lines
2.0 KiB
C

/*
* stopword library
* Teodor Sigaev <teodor@sigaev.ru>
*/
#include "postgres.h"
#include "common.h"
#include "dict.h"
#include "ts_locale.h"
#define STOPBUFLEN 4096
void
freestoplist(StopList * s)
{
char **ptr = s->stop;
if (ptr)
while (*ptr && s->len > 0)
{
free(*ptr);
ptr++;
s->len--;
free(s->stop);
}
memset(s, 0, sizeof(StopList));
}
void
readstoplist(text *in, StopList * s)
{
char **stop = NULL;
s->len = 0;
if (in && VARSIZE(in) - VARHDRSZ > 0)
{
char *filename = to_absfilename(text2char(in));
FILE *hin;
char buf[STOPBUFLEN];
int reallen = 0;
if ((hin = fopen(filename, "r")) == NULL)
ereport(ERROR,
(errcode(ERRCODE_CONFIG_FILE_ERROR),
errmsg("could not open file \"%s\": %m",
filename)));
while (fgets(buf, STOPBUFLEN, hin))
{
buf[strlen(buf) - 1] = '\0';
pg_verifymbstr( buf, strlen(buf), false );
lowerstr(buf);
if (*buf == '\0')
continue;
if (s->len >= reallen)
{
char **tmp;
reallen = (reallen) ? reallen * 2 : 16;
tmp = (char **) realloc((void *) stop, sizeof(char *) * reallen);
if (!tmp)
{
freestoplist(s);
fclose(hin);
ereport(ERROR,
(errcode(ERRCODE_OUT_OF_MEMORY),
errmsg("out of memory")));
}
stop = tmp;
}
stop[s->len] = strdup(buf);
if (!stop[s->len])
{
freestoplist(s);
fclose(hin);
ereport(ERROR,
(errcode(ERRCODE_OUT_OF_MEMORY),
errmsg("out of memory")));
}
if (s->wordop)
stop[s->len] = (s->wordop) (stop[s->len]);
(s->len)++;
}
fclose(hin);
pfree(filename);
}
s->stop = stop;
}
static int
comparestr(const void *a, const void *b)
{
return strcmp(*(char **) a, *(char **) b);
}
void
sortstoplist(StopList * s)
{
if (s->stop && s->len > 0)
qsort(s->stop, s->len, sizeof(char *), comparestr);
}
bool
searchstoplist(StopList * s, char *key)
{
if (s->wordop)
key = (*(s->wordop)) (key);
return (s->stop && s->len > 0 && bsearch(&key, s->stop, s->len, sizeof(char *), comparestr)) ? true : false;
}