oidmap.h

   1 #ifndef OIDMAP_H
   2 #define OIDMAP_H
   3
   4 #include "hash.h"
   5 #include "hashmap.h"
   6
   7 /*
   8  * struct oidmap_entry is a structure representing an entry in the hash table,
   9  * which must be used as first member of user data structures.
  10  *
  11  * Users should set the oid field. oidmap_put() will populate the
  12  * internal_entry field.
  13  */
  14 struct oidmap_entry {
  15         /* For internal use only */
  16         struct hashmap_entry internal_entry;
  17
  18         struct object_id oid;
  19 };
  20
  21 struct oidmap {
  22         struct hashmap map;
  23 };
  24
  25 #define OIDMAP_INIT { { NULL } }
  26
  27 /*
  28  * Initializes an oidmap structure.
  29  *
  30  * `map` is the oidmap to initialize.
  31  *
  32  * If the total number of entries is known in advance, the `initial_size`
  33  * parameter may be used to preallocate a sufficiently large table and thus
  34  * prevent expensive resizing. If 0, the table is dynamically resized.
  35  */
  36 void oidmap_init(struct oidmap *map, size_t initial_size);
  37
  38 /*
  39  * Clear an oidmap, freeing any allocated memory. The map is empty and
  40  * can be reused without another explicit init.
  41  *
  42  * If `free_entries` is true, each oidmap_entry in the map is freed as well
  43  * using stdlibs free().
  44  */
  45 void oidmap_clear(struct oidmap *map, int free_entries);
  46
  47 /*
  48  * Returns the oidmap entry for the specified oid, or NULL if not found.
  49  */
  50 void *oidmap_get(const struct oidmap *map,
  51                  const struct object_id *key);
  52
  53 /*
  54  * Adds or replaces an oidmap entry.
  55  *
  56  * ((struct oidmap_entry *) entry)->internal_entry will be populated by this
  57  * function.
  58  *
  59  * Returns the replaced entry, or NULL if not found (i.e. the entry was added).
  60  */
  61 void *oidmap_put(struct oidmap *map, void *entry);
  62
  63 /*
  64  * Removes an oidmap entry matching the specified oid.
  65  *
  66  * Returns the removed entry, or NULL if not found.
  67  */
  68 void *oidmap_remove(struct oidmap *map, const struct object_id *key);
  69
  70 static inline unsigned int oidmap_get_size(struct oidmap *map)
  71 {
  72         return hashmap_get_size(&map->map);
  73 }
  74
  75 struct oidmap_iter {
  76         struct hashmap_iter h_iter;
  77 };
  78
  79 static inline void oidmap_iter_init(struct oidmap *map, struct oidmap_iter *iter)
  80 {
  81         hashmap_iter_init(&map->map, &iter->h_iter);
  82 }
  83
  84 static inline void *oidmap_iter_next(struct oidmap_iter *iter)
  85 {
  86         /* TODO: this API could be reworked to do compile-time type checks */
  87         return (void *)hashmap_iter_next(&iter->h_iter);
  88 }
  89
  90 static inline void *oidmap_iter_first(struct oidmap *map,
  91                                       struct oidmap_iter *iter)
  92 {
  93         oidmap_iter_init(map, iter);
  94         /* TODO: this API could be reworked to do compile-time type checks */
  95         return (void *)oidmap_iter_next(iter);
  96 }
  97
  98 #endif