diff options
Diffstat (limited to 'hash.h')
| -rw-r--r-- | hash.h | 50 |
1 files changed, 0 insertions, 50 deletions
@@ -1,50 +0,0 @@ -#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; -} - -static inline void preallocate_hash(struct hash_table *table, unsigned int elts) -{ - assert(table->size == 0 && table->nr == 0 && table->array == NULL); - table->size = elts * 2; - table->array = xcalloc(sizeof(struct hash_table_entry), table->size); -} - -#endif |