mirror of
https://github.com/git/git.git
synced 2024-05-20 11:06:07 +02:00
d1f128b050
This is in an effort to make the source index of 'unpack_trees()' as being const, and thus making the compiler help us verify that we only access it for reading. The constification also extended to some of the hashing helpers that get called indirectly. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
44 lines
1.1 KiB
C
44 lines
1.1 KiB
C
#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 *));
|
|
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;
|
|
}
|
|
|
|
#endif
|