blob: b875ce67c49eb39a8ca8ad6a688a334985db0534 [file] [log] [blame]
#ifndef HASH_H
#define HASH_H
* These are some simple generic hash table helper functions.
* Not necessarily suitable for all users, but good for things
* where you want to just keep track of a list of things, and
* have a good hash to use on them.
* It keeps the hash table at roughly 50-75% free, so the memory
* cost of the hash table itself is roughly
* 3 * 2*sizeof(void *) * nr_of_objects
* bytes.
* FIXME: on 64-bit architectures, we waste memory. It would be
* good to have just 32-bit pointers, requiring a special allocator
* for hashed entries or something.
struct hash_table_entry {
unsigned int hash;
void *ptr;
struct hash_table {
unsigned int size, nr;
struct hash_table_entry *array;
extern void *lookup_hash(unsigned int hash, const struct hash_table *table);
extern void **insert_hash(unsigned int hash, void *ptr, struct hash_table *table);
extern int for_each_hash(const struct hash_table *table, int (*fn)(void *, void *), void *data);
extern void free_hash(struct hash_table *table);
static inline void init_hash(struct hash_table *table)
table->size = 0;
table->nr = 0;
table->array = NULL;