doc: describe git svn init --ignore-refs
[git/git-svn.git] / oidset.h
blobb7eaab5b88f3e6e287384eceb76757e6be9fe015
1 #ifndef OIDSET_H
2 #define OIDSET_H
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:
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.
12 * 2. The per-unique-oid memory footprint is slightly higher due to hash
13 * table overhead.
16 /**
17 * A single oidset; should be zero-initialized (or use OIDSET_INIT).
19 struct oidset {
20 struct hashmap map;
23 #define OIDSET_INIT { { NULL } }
25 /**
26 * Returns true iff `set` contains `oid`.
28 int oidset_contains(const struct oidset *set, const struct object_id *oid);
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.
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.
37 int oidset_insert(struct oidset *set, const struct object_id *oid);
39 /**
40 * Remove all entries from the oidset, freeing any resources associated with
41 * it.
43 void oidset_clear(struct oidset *set);
45 #endif /* OIDSET_H */