void hash_table_free(HashTable *hash_table)
{
HashTableEntry *rover;
HashTableEntry *next;
unsigned long long int i;
/* Free all entries in all chains */
for (i=0; i<hash_table->table_size; ++i) {
rover = hash_table->table[i];
while (rover != NULL) {
next = rover->next;
hash_table_free_entry(hash_table, rover);
rover = next;
}
}
/* Free the table */
free(hash_table->table);
/* Free the hash table structure */
free(hash_table);
}
int hash_table_remove(HashTable *hash_table, HashTableKey key)
{
HashTableEntry **rover;
HashTableEntry *entry;
unsigned int index;
int result;
/* Generate the hash of the key and hence the index into the table */
index = hash_table->hash_func(key) % hash_table->table_size;
/* Rover points at the pointer which points at the current entry
* in the chain being inspected. ie. the entry in the table, or
* the "next" pointer of the previous entry in the chain. This
* allows us to unlink the entry when we find it. */
result = 0;
rover = &hash_table->table[index];
while (*rover != NULL) {
if (hash_table->equal_func(key, (*rover)->key) != 0) {
/* This is the entry to remove */
entry = *rover;
/* Unlink from the list */
*rover = entry->next;
/* Destroy the entry structure */
hash_table_free_entry(hash_table, entry);
/* Track count of entries */
--hash_table->entries;
result = 1;
break;
}
/* Advance to the next entry */
rover = &((*rover)->next);
}
return result;
}
int hash_table_remove(HashTable *hash_table, HashTableKey key, bool resize)
{
HashTableEntry **rover;
HashTableEntry *entry;
unsigned long long int index;
unsigned long long int result;
/* If there are too few items in the table with respect to the table
* size, the table is taking up too much space.
* Shrink table to improve space efficiency. */
if (resize && (hash_table->entries * 8) / hash_table->table_size <= 0) {
/* Table is less than 1/8 full */
if (!hash_table_resize(hash_table)) {
/* Failed to enlarge the table */
return 0;
}
}
/* Generate the hash of the key and hence the index into the table */
index = hash_table->hash_func(key) % hash_table->table_size;
/* Rover points at the pointer which points at the current entry
* in the chain being inspected. ie. the entry in the table, or
* the "next" pointer of the previous entry in the chain. This
* allows us to unlink the entry when we find it. */
result = 0;
rover = &hash_table->table[index];
while (*rover != NULL) {
if (hash_table->equal_func(key, (*rover)->key) != 0) {
/* This is the entry to remove */
entry = *rover;
/* Unlink from the list */
*rover = entry->next;
/* Destroy the entry structure */
hash_table_free_entry(hash_table, entry);
/* Track count of entries */
--hash_table->entries;
result = 1;
break;
}
/* Advance to the next entry */
rover = &((*rover)->next);
}
return result;
}
