postgresql/contrib/tsearch2/snmap.c

/* 
 * simple but fast map from str to Oid
 * Teodor Sigaev <teodor@sigaev.ru>
 */
#include <errno.h>
#include <stdlib.h>
#include <string.h>

#include "postgres.h"
#include "snmap.h"
#include "common.h"

static int
compareSNMapEntry(const void *a, const void *b) {
	return strcmp( ((SNMapEntry*)a)->key, ((SNMapEntry*)b)->key );
}

void 
addSNMap( SNMap *map, char *key, Oid value ) {
	if (map->len>=map->reallen) {
		SNMapEntry *tmp;
		int len = (map->reallen) ? 2*map->reallen : 16;
		tmp=(SNMapEntry*)realloc(map->list, sizeof(SNMapEntry) * len);
		if ( !tmp )
			ereport(ERROR,
					(errcode(ERRCODE_OUT_OF_MEMORY),
					 errmsg("out of memory")));
		map->reallen=len;
		map->list=tmp;
	}
	map->list[ map->len ].key = strdup(key);
	if ( ! map->list[ map->len ].key )
		ereport(ERROR,
				(errcode(ERRCODE_OUT_OF_MEMORY),
				 errmsg("out of memory")));
	map->list[ map->len ].value=value;
	map->len++;
	if ( map->len>1 ) qsort(map->list, map->len, sizeof(SNMapEntry), compareSNMapEntry);
}

void 
addSNMap_t( SNMap *map, text *key, Oid value ) {
	char *k=text2char( key );
	addSNMap(map, k, value);
	pfree(k);
}

Oid 
findSNMap( SNMap *map, char *key ) {
	SNMapEntry *ptr;
	SNMapEntry ks = {key, 0};
	if ( map->len==0 || !map->list )
		return 0;	
	ptr = (SNMapEntry*) bsearch(&ks, map->list, map->len, sizeof(SNMapEntry), compareSNMapEntry);
	return (ptr) ? ptr->value : 0;
}

Oid  
findSNMap_t( SNMap *map, text *key ) {
	char *k=text2char(key);
	int res;
	res= findSNMap(map, k);
	pfree(k);
	return res;
}

void freeSNMap( SNMap *map ) {
	SNMapEntry *entry=map->list;
	if ( map->list ) {
		while( map->len ) {
			if ( entry->key ) free(entry->key);
			entry++; map->len--;
		}
		free( map->list );
	}
	memset(map,0,sizeof(SNMap));
}