Merge branch 'tb/banned-vsprintf-namefix'
[git/git.git] / oidset.h
1 #ifndef OIDSET_H
2 #define OIDSET_H
3
4 #include "hashmap.h"
5 #include "khash.h"
6
7 /**
8 * This API is similar to sha1-array, in that it maintains a set of object ids
9 * in a memory-efficient way. The major differences are:
10 *
11 * 1. It uses a hash, so we can do online duplicate removal, rather than
12 * sort-and-uniq at the end. This can reduce memory footprint if you have
13 * a large list of oids with many duplicates.
14 *
15 * 2. The per-unique-oid memory footprint is slightly higher due to hash
16 * table overhead.
17 */
18
19 /**
20 * A single oidset; should be zero-initialized (or use OIDSET_INIT).
21 */
22 struct oidset {
23 kh_oid_set_t set;
24 };
25
26 #define OIDSET_INIT { { 0 } }
27
28
29 /**
30 * Initialize the oidset structure `set`.
31 *
32 * If `initial_size` is bigger than 0 then preallocate to allow inserting
33 * the specified number of elements without further allocations.
34 */
35 void oidset_init(struct oidset *set, size_t initial_size);
36
37 /**
38 * Returns true iff `set` contains `oid`.
39 */
40 int oidset_contains(const struct oidset *set, const struct object_id *oid);
41
42 /**
43 * Insert the oid into the set; a copy is made, so "oid" does not need
44 * to persist after this function is called.
45 *
46 * Returns 1 if the oid was already in the set, 0 otherwise. This can be used
47 * to perform an efficient check-and-add.
48 */
49 int oidset_insert(struct oidset *set, const struct object_id *oid);
50
51 /**
52 * Remove the oid from the set.
53 *
54 * Returns 1 if the oid was present in the set, 0 otherwise.
55 */
56 int oidset_remove(struct oidset *set, const struct object_id *oid);
57
58 /**
59 * Remove all entries from the oidset, freeing any resources associated with
60 * it.
61 */
62 void oidset_clear(struct oidset *set);
63
64 /**
65 * Add the contents of the file 'path' to an initialized oidset. Each line is
66 * an unabbreviated object name. Comments begin with '#', and trailing comments
67 * are allowed. Leading whitespace and empty or white-space only lines are
68 * ignored.
69 */
70 void oidset_parse_file(struct oidset *set, const char *path);
71
72 struct oidset_iter {
73 kh_oid_set_t *set;
74 khiter_t iter;
75 };
76
77 static inline void oidset_iter_init(struct oidset *set,
78 struct oidset_iter *iter)
79 {
80 iter->set = &set->set;
81 iter->iter = kh_begin(iter->set);
82 }
83
84 static inline struct object_id *oidset_iter_next(struct oidset_iter *iter)
85 {
86 for (; iter->iter != kh_end(iter->set); iter->iter++) {
87 if (kh_exist(iter->set, iter->iter))
88 return &kh_key(iter->set, iter->iter++);
89 }
90 return NULL;
91 }
92
93 static inline struct object_id *oidset_iter_first(struct oidset *set,
94 struct oidset_iter *iter)
95 {
96 oidset_iter_init(set, iter);
97 return oidset_iter_next(iter);
98 }
99
100 #endif /* OIDSET_H */