const void * HashSet::add( const void * item )
{
unsigned int hash = hashfn( item );
unsigned index = hash % bucketCount;
HashSetEntry *entry;
/* search the item in the set*/
for ( entry = buckets[index]; entry; entry = entry->next )
if ( entry->hash == hash && comparefn ( entry->item, item ) == 0 )
return item;
/* if count exceeds threshold, rehash all the items */
if ( count >= threshold )
{
this->rehash();
index = hash % this->bucketCount;
}
/* save the new item */
entry = ( HashSetEntry * )malloc( sizeof( HashSetEntry ) );
entry->hash = hash;
entry->item = (void *) item;
entry->next = buckets[index];
this->buckets[index] = entry;
++this->count;
return NULL;
}
int exists_in_list(list_t *list, void *data,
int (*comparefn)(const void *, const void *))
{
while (list) {
if (!comparefn((void *) car(list), data))
return 1;
list = cdr(list);
}
return 0;
}
const void * HashSet::get( void * item )
{
unsigned int hash = this->hashfn( item );
unsigned int index = hash % this->bucketCount;
HashSetEntry * entry;
for ( entry = buckets[index]; entry; entry = entry->next )
{
if ( entry->hash == hash && comparefn( entry->item, item ) == 0)
return ( entry->item );
}
return (NULL);
}
const void * HashSet::remove( const void * item )
{
unsigned int hash = hashfn( item );
unsigned int indx = hash % bucketCount;
HashSetEntry *entry, *prev;
for ( entry = this->buckets[indx], prev = NULL; entry; prev = entry, entry = entry->next )
{
if ( entry->hash == hash && comparefn( entry->item, item )==0 )
{
item = entry->item;
if ( prev )
prev->next = entry->next;
else
this->buckets[indx] = entry->next;
free( entry );
--this->count;
return ( item );
}
}
return (NULL);
}
