oidmap: add oidmap iterator methods
[git/git.git] / oidmap.h
1 #ifndef OIDMAP_H
2 #define OIDMAP_H
3
4 #include "hashmap.h"
5
6 /*
7 * struct oidmap_entry is a structure representing an entry in the hash table,
8 * which must be used as first member of user data structures.
9 *
10 * Users should set the oid field. oidmap_put() will populate the
11 * internal_entry field.
12 */
13 struct oidmap_entry {
14 /* For internal use only */
15 struct hashmap_entry internal_entry;
16
17 struct object_id oid;
18 };
19
20 struct oidmap {
21 struct hashmap map;
22 };
23
24 #define OIDMAP_INIT { { NULL } }
25
26 /*
27 * Initializes an oidmap structure.
28 *
29 * `map` is the oidmap to initialize.
30 *
31 * If the total number of entries is known in advance, the `initial_size`
32 * parameter may be used to preallocate a sufficiently large table and thus
33 * prevent expensive resizing. If 0, the table is dynamically resized.
34 */
35 extern void oidmap_init(struct oidmap *map, size_t initial_size);
36
37 /*
38 * Frees an oidmap structure and allocated memory.
39 *
40 * If `free_entries` is true, each oidmap_entry in the map is freed as well
41 * using stdlibs free().
42 */
43 extern void oidmap_free(struct oidmap *map, int free_entries);
44
45 /*
46 * Returns the oidmap entry for the specified oid, or NULL if not found.
47 */
48 extern void *oidmap_get(const struct oidmap *map,
49 const struct object_id *key);
50
51 /*
52 * Adds or replaces an oidmap entry.
53 *
54 * ((struct oidmap_entry *) entry)->internal_entry will be populated by this
55 * function.
56 *
57 * Returns the replaced entry, or NULL if not found (i.e. the entry was added).
58 */
59 extern void *oidmap_put(struct oidmap *map, void *entry);
60
61 /*
62 * Removes an oidmap entry matching the specified oid.
63 *
64 * Returns the removed entry, or NULL if not found.
65 */
66 extern void *oidmap_remove(struct oidmap *map, const struct object_id *key);
67
68
69 struct oidmap_iter {
70 struct hashmap_iter h_iter;
71 };
72
73 static inline void oidmap_iter_init(struct oidmap *map, struct oidmap_iter *iter)
74 {
75 hashmap_iter_init(&map->map, &iter->h_iter);
76 }
77
78 static inline void *oidmap_iter_next(struct oidmap_iter *iter)
79 {
80 return hashmap_iter_next(&iter->h_iter);
81 }
82
83 static inline void *oidmap_iter_first(struct oidmap *map,
84 struct oidmap_iter *iter)
85 {
86 oidmap_iter_init(map, iter);
87 return oidmap_iter_next(iter);
88 }
89
90 #endif