postgresql/contrib/tsearch2/stopword.c

/* 
 * stopword library
 * Teodor Sigaev <teodor@sigaev.ru>
 */
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

#include "postgres.h"
#include "common.h"
#include "dict.h"

#define STOPBUFLEN	4096

char*
lowerstr(char *str) {
	char *ptr=str;
	while(*ptr) {
		*ptr = tolower(*(unsigned char*)ptr);
		ptr++;
	}
	return str;
}

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=text2char(in);
		FILE	*hin=NULL;
		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';
			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;
}