[thirdparty/git.git] / oidset.h

#ifndef OIDSET_H
#define OIDSET_H

/**
 * This API is similar to sha1-array, in that it maintains a set of object ids
 * in a memory-efficient way. The major differences are:
 *
 *   1. It uses a hash, so we can do online duplicate removal, rather than
 *      sort-and-uniq at the end. This can reduce memory footprint if you have
 *      a large list of oids with many duplicates.
 *
 *   2. The per-unique-oid memory footprint is slightly higher due to hash
 *      table overhead.
 */

/**
 * A single oidset; should be zero-initialized (or use OIDSET_INIT).
 */
struct oidset {
	struct hashmap map;
};

#define OIDSET_INIT { { NULL } }

/**
 * Returns true iff `set` contains `oid`.
 */
int oidset_contains(const struct oidset *set, const struct object_id *oid);

/**
 * Insert the oid into the set; a copy is made, so "oid" does not need
 * to persist after this function is called.
 *
 * Returns 1 if the oid was already in the set, 0 otherwise. This can be used
 * to perform an efficient check-and-add.
 */
int oidset_insert(struct oidset *set, const struct object_id *oid);

/**
 * Remove all entries from the oidset, freeing any resources associated with
 * it.
 */
void oidset_clear(struct oidset *set);

#endif /* OIDSET_H */
Commit	Line	Data
29c2bd5f JK	1	#ifndef OIDSET_H
	2	#define OIDSET_H
	3
	4	/**
	5	* This API is similar to sha1-array, in that it maintains a set of object ids
	6	* in a memory-efficient way. The major differences are:
	7	*
	8	* 1. It uses a hash, so we can do online duplicate removal, rather than
	9	* sort-and-uniq at the end. This can reduce memory footprint if you have
	10	* a large list of oids with many duplicates.
	11	*
	12	* 2. The per-unique-oid memory footprint is slightly higher due to hash
	13	* table overhead.
	14	*/
	15
	16	/**
	17	* A single oidset; should be zero-initialized (or use OIDSET_INIT).
	18	*/
	19	struct oidset {
	20	struct hashmap map;
	21	};
	22
	23	#define OIDSET_INIT { { NULL } }
	24
	25	/**
	26	* Returns true iff `set` contains `oid`.
	27	*/
	28	int oidset_contains(const struct oidset set, const struct object_id oid);
	29
	30	/**
	31	* Insert the oid into the set; a copy is made, so "oid" does not need
	32	* to persist after this function is called.
	33	*
	34	* Returns 1 if the oid was already in the set, 0 otherwise. This can be used
	35	* to perform an efficient check-and-add.
	36	*/
	37	int oidset_insert(struct oidset set, const struct object_id oid);
	38
	39	/**
	40	* Remove all entries from the oidset, freeing any resources associated with
	41	* it.
	42	*/
	43	void oidset_clear(struct oidset *set);
	44
	45	#endif /* OIDSET_H */