oidset.h

   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  */
  21 struct oidset {
  22         struct oidmap map;
  23 };
  24
  25 #define OIDSET_INIT { OIDMAP_INIT }
  26
  27 /**
  28  * Returns true iff `set` contains `oid`.
  29  */
  30 int oidset_contains(const struct oidset *set, const struct object_id *oid);
  31
  32 /**
  33  * Insert the oid into the set; a copy is made, so "oid" does not need
  34  * to persist after this function is called.
  35  *
  36  * Returns 1 if the oid was already in the set, 0 otherwise. This can be used
  37  * to perform an efficient check-and-add.
  38  */
  39 int oidset_insert(struct oidset *set, const struct object_id *oid);
  40
  41 /**
  42  * Remove all entries from the oidset, freeing any resources associated with
  43  * it.
  44  */
  45 void oidset_clear(struct oidset *set);
  46
  47 #endif /* OIDSET_H */