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