src/hashmap.h

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 #ifndef foohashmaphfoo
   4 #define foohashmaphfoo
   5
   6 /***
   7   This file is part of systemd.
   8
   9   Copyright 2010 Lennart Poettering
  10
  11   systemd is free software; you can redistribute it and/or modify it
  12   under the terms of the GNU General Public License as published by
  13   the Free Software Foundation; either version 2 of the License, or
  14   (at your option) any later version.
  15
  16   systemd is distributed in the hope that it will be useful, but
  17   WITHOUT ANY WARRANTY; without even the implied warranty of
  18   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  19   General Public License for more details.
  20
  21   You should have received a copy of the GNU General Public License
  22   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  23 ***/
  24
  25 #include <stdbool.h>
  26
  27 /* Pretty straightforward hash table implementation. As a minor
  28  * optimization a NULL hashmap object will be treated as empty hashmap
  29  * for all read operations. That way it is not necessary to
  30  * instantiate an object for each Hashmap use. */
  31
  32 typedef struct Hashmap Hashmap;
  33 typedef struct _IteratorStruct _IteratorStruct;
  34 typedef _IteratorStruct* Iterator;
  35
  36 #define ITERATOR_FIRST ((Iterator) 0)
  37 #define ITERATOR_LAST ((Iterator) -1)
  38
  39 typedef unsigned (*hash_func_t)(const void *p);
  40 typedef int (*compare_func_t)(const void *a, const void *b);
  41
  42 unsigned string_hash_func(const void *p);
  43 int string_compare_func(const void *a, const void *b);
  44
  45 unsigned trivial_hash_func(const void *p);
  46 int trivial_compare_func(const void *a, const void *b);
  47
  48 Hashmap *hashmap_new(hash_func_t hash_func, compare_func_t compare_func);
  49 void hashmap_free(Hashmap *h);
  50 void hashmap_free_free(Hashmap *h);
  51 Hashmap *hashmap_copy(Hashmap *h);
  52 int hashmap_ensure_allocated(Hashmap **h, hash_func_t hash_func, compare_func_t compare_func);
  53
  54 int hashmap_put(Hashmap *h, const void *key, void *value);
  55 int hashmap_replace(Hashmap *h, const void *key, void *value);
  56 void* hashmap_get(Hashmap *h, const void *key);
  57 void* hashmap_remove(Hashmap *h, const void *key);
  58 void* hashmap_remove_value(Hashmap *h, const void *key, void *value);
  59 int hashmap_remove_and_put(Hashmap *h, const void *old_key, const void *new_key, void *value);
  60 int hashmap_remove_and_replace(Hashmap *h, const void *old_key, const void *new_key, void *value);
  61
  62 int hashmap_merge(Hashmap *h, Hashmap *other);
  63 void hashmap_move(Hashmap *h, Hashmap *other);
  64 int hashmap_move_one(Hashmap *h, Hashmap *other, const void *key);
  65
  66 unsigned hashmap_size(Hashmap *h);
  67 bool hashmap_isempty(Hashmap *h);
  68
  69 void *hashmap_iterate(Hashmap *h, Iterator *i, const void **key);
  70 void *hashmap_iterate_backwards(Hashmap *h, Iterator *i, const void **key);
  71 void *hashmap_iterate_skip(Hashmap *h, const void *key, Iterator *i);
  72
  73 void hashmap_clear(Hashmap *h);
  74 void *hashmap_steal_first(Hashmap *h);
  75 void *hashmap_steal_first_key(Hashmap *h);
  76 void* hashmap_first(Hashmap *h);
  77 void* hashmap_last(Hashmap *h);
  78
  79 #define HASHMAP_FOREACH(e, h, i) \
  80         for ((i) = ITERATOR_FIRST, (e) = hashmap_iterate((h), &(i), NULL); (e); (e) = hashmap_iterate((h), &(i), NULL))
  81
  82 #define HASHMAP_FOREACH_KEY(e, k, h, i) \
  83         for ((i) = ITERATOR_FIRST, (e) = hashmap_iterate((h), &(i), (const void**) &(k)); (e); (e) = hashmap_iterate((h), &(i), (const void**) &(k)))
  84
  85 #define HASHMAP_FOREACH_BACKWARDS(e, h, i) \
  86         for ((i) = ITERATOR_LAST, (e) = hashmap_iterate_backwards((h), &(i), NULL); (e); (e) = hashmap_iterate_backwards((h), &(i), NULL))
  87
  88 #endif