git/oidset.h

84 строки
2.0 KiB
C

#ifndef OIDSET_H
#define OIDSET_H
#include "oidmap.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 oidmap map;
};
#define OIDSET_INIT { OIDMAP_INIT }
static inline void oidset_init(struct oidset *set, size_t initial_size)
{
oidmap_init(&set->map, initial_size);
}
/**
* 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 the oid from the set.
*
* Returns 1 if the oid was present in the set, 0 otherwise.
*/
int oidset_remove(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);
struct oidset_iter {
struct oidmap_iter m_iter;
};
static inline void oidset_iter_init(struct oidset *set,
struct oidset_iter *iter)
{
oidmap_iter_init(&set->map, &iter->m_iter);
}
static inline struct object_id *oidset_iter_next(struct oidset_iter *iter)
{
struct oidmap_entry *e = oidmap_iter_next(&iter->m_iter);
return e ? &e->oid : NULL;
}
static inline struct object_id *oidset_iter_first(struct oidset *set,
struct oidset_iter *iter)
{
oidset_iter_init(set, iter);
return oidset_iter_next(iter);
}
#endif /* OIDSET_H */