Re: GLIB Hash Data

[Mark Mielke <mark mark mielke cc>]

Your example is useless. GLIB is doing exactly what you asked it to.
GLIB cannot possibly know, and would not want to know, the nature of
your data. You give it a pointer. How does it know the length of the
pointer? How does it know you are not passing it a structure, and
intend to have it copy the structure recursively?

If you need it to do strcpy(), pass the key and value through g_strdup()
before storing.

mark


On Wed, Apr 24, 2002 at 06:28:22PM -0400, Ruben I Safir wrote:
> I'm wondering how useful the hashing system can be ibn GLIB
> 
> I tried this code, and it seems that instead of copying strings, it just copies the pointer value
> resulting in making it impossible to look through input and assigning it to key values, unless I'm
> doing something worng.   This is just about useless
> 
> #include <stdio.h>
> #include <string.h>
> #include <glib.h>
> 
> GHashTable * hTable;
> 
> guint HashFunction(gpointer key){
> 	char *sKey;
> 	guint giHashValue = 0;
> 	int nIndex;
> 	
> 	sKey = key;
> 	if(key == NULL) return(0);
> 
> 	for (nIndex = 0; nIndex < strlen(sKey); nIndex++){
> 		giHashValue = (giHashValue << 4) + (giHashValue ^(guint) sKey[nIndex]);
> 	}
> 	return (giHashValue);
> }
> 
> gint HashCompare( gpointer sName1, gpointer sName2){
> 	return (!strcmp((char *)sName1, (char *) sName2));
> }
> 
> void print_hash(gpointer key, gpointer value, gpointer otherdata){
> 	g_print ("Key: %s ==> Value: %s\n", (gchar *) key, (gchar *) value);
> }
> 
> int main(int argc, char *argv[]){
> 	gchar buff_key[255];
> 	gchar buff_val[255];
> 	hTable = g_hash_table_new(HashFunction, HashCompare);
> 	while(1){
> 		if(scanf("%255s", buff_key) < 1 ) break;
> 		if(scanf("%255s", buff_val)< 1) break;
> 		g_print("%s %s\n", buff_key, buff_val);
> 	
> 		g_hash_table_insert(hTable, buff_key, buff_val);
> 	}
> 
> 
> 	g_hash_table_foreach(hTable, (GHFunc) print_hash, NULL);
> 
> exit(1);
> }
> 
> 
> ruben www2:~/gtk > ./hash
> One
> Two
> One Two
> Three
> Four
> Three Four
> Five
> Six
> Five Six
> <CTR d>
> Key: Five ==> Value: Six
> Key: Five ==> Value: Six
> Key: Five ==> Value: Six
> 
> 
> If it doesn't work like strcpy, it doesn't do much.
> 
> -- 
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-- 
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