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783abceccd11e1786c7d6b54b2848f3eeb6d4983
   1#ifndef OIDSET_H
   2#define OIDSET_H
   3
   4#include "oidmap.h"
   5
   6/**
   7 * This API is similar to sha1-array, in that it maintains a set of object ids
   8 * in a memory-efficient way. The major differences are:
   9 *
  10 *   1. It uses a hash, so we can do online duplicate removal, rather than
  11 *      sort-and-uniq at the end. This can reduce memory footprint if you have
  12 *      a large list of oids with many duplicates.
  13 *
  14 *   2. The per-unique-oid memory footprint is slightly higher due to hash
  15 *      table overhead.
  16 */
  17
  18/**
  19 * A single oidset; should be zero-initialized (or use OIDSET_INIT).
  20 */
  21struct oidset {
  22        struct oidmap map;
  23};
  24
  25#define OIDSET_INIT { OIDMAP_INIT }
  26
  27
  28static inline void oidset_init(struct oidset *set, size_t initial_size)
  29{
  30        return oidmap_init(&set->map, initial_size);
  31}
  32
  33/**
  34 * Returns true iff `set` contains `oid`.
  35 */
  36int oidset_contains(const struct oidset *set, const struct object_id *oid);
  37
  38/**
  39 * Insert the oid into the set; a copy is made, so "oid" does not need
  40 * to persist after this function is called.
  41 *
  42 * Returns 1 if the oid was already in the set, 0 otherwise. This can be used
  43 * to perform an efficient check-and-add.
  44 */
  45int oidset_insert(struct oidset *set, const struct object_id *oid);
  46
  47/**
  48 * Remove the oid from the set.
  49 *
  50 * Returns 1 if the oid was present in the set, 0 otherwise.
  51 */
  52int oidset_remove(struct oidset *set, const struct object_id *oid);
  53
  54/**
  55 * Remove all entries from the oidset, freeing any resources associated with
  56 * it.
  57 */
  58void oidset_clear(struct oidset *set);
  59
  60struct oidset_iter {
  61        struct oidmap_iter m_iter;
  62};
  63
  64static inline void oidset_iter_init(struct oidset *set,
  65                                    struct oidset_iter *iter)
  66{
  67        oidmap_iter_init(&set->map, &iter->m_iter);
  68}
  69
  70static inline struct object_id *oidset_iter_next(struct oidset_iter *iter)
  71{
  72        struct oidmap_entry *e = oidmap_iter_next(&iter->m_iter);
  73        return e ? &e->oid : NULL;
  74}
  75
  76static inline struct object_id *oidset_iter_first(struct oidset *set,
  77                                                  struct oidset_iter *iter)
  78{
  79        oidset_iter_init(set, iter);
  80        return oidset_iter_next(iter);
  81}
  82
  83#endif /* OIDSET_H */