The eleventh batch for 2.15
[git/git.git] / oidset.h
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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 */
19struct oidset {
20 struct hashmap map;
21};
22
23#define OIDSET_INIT { { NULL } }
24
25/**
26 * Returns true iff `set` contains `oid`.
27 */
28int 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 */
37int 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 */
43void oidset_clear(struct oidset *set);
44
45#endif /* OIDSET_H */