oidset.h

   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 */