include/irc_dictionary.h

   1 /*
   2  * charybdis: an advanced ircd.
   3  * irc_dictionary.h: Dictionary-based storage.
   4  *
   5  * Copyright (c) 2007 William Pitcock <nenolod -at- sacredspiral.co.uk>
   6  * Copyright (c) 2007 Jilles Tjoelker <jilles -at- stack.nl>
   7  *
   8  * Permission to use, copy, modify, and/or distribute this software for any
   9  * purpose with or without fee is hereby granted, provided that the above
  10  * copyright notice and this permission notice is present in all copies.
  11  *
  12  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  13  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  14  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  15  * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
  16  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  17  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  18  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  19  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  20  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  21  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  22  * POSSIBILITY OF SUCH DAMAGE.
  23  */
  24
  25 #ifndef __IRC_DICTIONARY_H__
  26 #define __IRC_DICTIONARY_H__
  27
  28 struct Dictionary; /* defined in src/dictionary.c */
  29
  30 typedef int (*DCF)(/* const void *a, const void *b */);
  31
  32 struct DictionaryElement
  33 {
  34         struct DictionaryElement *left, *right, *prev, *next;
  35         void *data;
  36         const void *key;
  37         int position;
  38 };
  39
  40 struct DictionaryIter
  41 {
  42         struct DictionaryElement *cur, *next;
  43 };
  44
  45 /*
  46  * this is a convenience macro for inlining iteration of dictionaries.
  47  */
  48 #define DICTIONARY_FOREACH(element, state, dict) for (irc_dictionary_foreach_start((dict), (state)); (element = irc_dictionary_foreach_cur((dict), (state))); irc_dictionary_foreach_next((dict), (state)))
  49
  50 /*
  51  * irc_dictionary_create_named() creates a new dictionary tree which has a name.
  52  * name is the name, compare_cb is the comparator.
  53  */
  54 extern struct Dictionary *irc_dictionary_create(const char *name, DCF compare_cb);
  55
  56 /*
  57  * irc_dictionary_set_comparator_func() resets the comparator used for lookups and
  58  * insertions in the DTree structure.
  59  */
  60 extern void irc_dictionary_set_comparator_func(struct Dictionary *dict,
  61         DCF compare_cb);
  62
  63 /*
  64  * irc_dictionary_get_comparator_func() returns the comparator used for lookups and
  65  * insertions in the DTree structure.
  66  */
  67 extern DCF irc_dictionary_get_comparator_func(struct Dictionary *dict);
  68
  69 /*
  70  * irc_dictionary_get_linear_index() returns the linear index of an object in the
  71  * DTree structure.
  72  */
  73 extern int irc_dictionary_get_linear_index(struct Dictionary *dict, const void *key);
  74
  75 /*
  76  * irc_dictionary_destroy() destroys all entries in a dtree, and also optionally calls
  77  * a defined callback function to destroy any data attached to it.
  78  */
  79 extern void irc_dictionary_destroy(struct Dictionary *dtree,
  80         void (*destroy_cb)(struct DictionaryElement *delem, void *privdata),
  81         void *privdata);
  82
  83 /*
  84  * irc_dictionary_foreach() iterates all entries in a dtree, and also optionally calls
  85  * a defined callback function to use any data attached to it.
  86  *
  87  * To shortcircuit iteration, return non-zero from the callback function.
  88  */
  89 extern void irc_dictionary_foreach(struct Dictionary *dtree,
  90         int (*foreach_cb)(struct DictionaryElement *delem, void *privdata),
  91         void *privdata);
  92
  93 /*
  94  * irc_dictionary_search() iterates all entries in a dtree, and also optionally calls
  95  * a defined callback function to use any data attached to it.
  96  *
  97  * When the object is found, a non-NULL is returned from the callback, which results
  98  * in that object being returned to the user.
  99  */
 100 extern void *irc_dictionary_search(struct Dictionary *dtree,
 101         void *(*foreach_cb)(struct DictionaryElement *delem, void *privdata),
 102         void *privdata);
 103
 104 /*
 105  * irc_dictionary_foreach_start() begins an iteration over all items
 106  * keeping state in the given struct. If there is only one iteration
 107  * in progress at a time, it is permitted to remove the current element
 108  * of the iteration (but not any other element).
 109  */
 110 extern void irc_dictionary_foreach_start(struct Dictionary *dtree,
 111         struct DictionaryIter *state);
 112
 113 /*
 114  * irc_dictionary_foreach_cur() returns the current element of the iteration,
 115  * or NULL if there are no more elements.
 116  */
 117 extern void *irc_dictionary_foreach_cur(struct Dictionary *dtree,
 118         struct DictionaryIter *state);
 119
 120 /*
 121  * irc_dictionary_foreach_next() moves to the next element.
 122  */
 123 extern void irc_dictionary_foreach_next(struct Dictionary *dtree,
 124         struct DictionaryIter *state);
 125
 126 /*
 127  * irc_dictionary_add() adds a key->value entry to the dictionary tree.
 128  */
 129 extern struct DictionaryElement *irc_dictionary_add(struct Dictionary *dtree, const void *key, void *data);
 130
 131 /*
 132  * irc_dictionary_find() returns a struct DictionaryElement container from a dtree for key 'key'.
 133  */
 134 extern struct DictionaryElement *irc_dictionary_find(struct Dictionary *dtree, const void *key);
 135
 136 /*
 137  * irc_dictionary_find() returns data from a dtree for key 'key'.
 138  */
 139 extern void *irc_dictionary_retrieve(struct Dictionary *dtree, const void *key);
 140
 141 /*
 142  * irc_dictionary_delete() deletes a key->value entry from the dictionary tree.
 143  */
 144 extern void *irc_dictionary_delete(struct Dictionary *dtree, const void *key);
 145
 146 /*
 147  * irc_dictionary_size() returns the number of elements in a dictionary tree.
 148  */
 149 extern unsigned int irc_dictionary_size(struct Dictionary *dtree);
 150
 151 void irc_dictionary_stats(struct Dictionary *dict, void (*cb)(const char *line, void *privdata), void *privdata);
 152 void irc_dictionary_stats_walk(void (*cb)(const char *line, void *privdata), void *privdata);
 153
 154 #define IRC_POINTER_TO_INT(x)           ((int32_t) (long) (x))
 155 #define IRC_INT_TO_POINTER(x)           ((void *) (long) (int32_t) (x))
 156
 157 #define IRC_POINTER_TO_UINT(x)          ((uint32_t) (unsigned long) (x))
 158 #define IRC_UINT_TO_POINTER(x)          ((void *) (unsigned long) (uint32_t) (x))
 159
 160 static inline int irc_int32cmp(const void *a, const void *b)
 161 {
 162         return IRC_POINTER_TO_INT(b) - IRC_POINTER_TO_INT(a);
 163 }
 164
 165 static inline int irc_uint32cmp(const void *a, const void *b)
 166 {
 167         return IRC_POINTER_TO_UINT(b) - IRC_POINTER_TO_UINT(a);
 168 }
 169
 170 #endif