include/irc_radixtree.h

   1 /*
   2  * charybdis: an advanced ircd.
   3  * irc_radixtree.h: Dictionary-based storage.
   4  *
   5  * Copyright (c) 2007-2016 William Pitcock <nenolod -at- dereferenced.org>
   6  * Copyright (c) 2007-2016 Jilles Tjoelker <jilles -at- stack.nl>
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions are
  10  * met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright notice,
  13  *    this list of conditions and the following disclaimer.
  14  *
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * 3. The name of the author may not be used to endorse or promote products
  20  *    derived from this software without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  24  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  25  * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
  26  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  27  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  28  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  30  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  31  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  32  * POSSIBILITY OF SUCH DAMAGE.
  33  */
  34
  35 #ifndef __irc_radixtree_H__
  36 #define __irc_radixtree_H__
  37
  38 struct irc_radixtree;/* defined in ircd/irc_radixtree.c */
  39
  40 struct irc_radixtree_leaf;      /* defined in ircd/irc_radixtree.c */
  41
  42 /*
  43  * struct irc_radixtree_iteration_state, private.
  44  */
  45 struct irc_radixtree_iteration_state
  46 {
  47         struct irc_radixtree_leaf *cur, *next;
  48         void *pspare[4];
  49         int ispare[4];
  50 };
  51
  52 /*
  53  * this is a convenience macro for inlining iteration of dictionaries.
  54  */
  55 #define IRC_RADIXTREE_FOREACH(element, state, dict) \
  56         for (irc_radixtree_foreach_start((dict), (state)); (element = irc_radixtree_foreach_cur((dict), (state))); irc_radixtree_foreach_next((dict), (state)))
  57
  58 /*
  59  * irc_radixtree_create() creates a new patricia tree of the defined resolution.
  60  * compare_cb is the canonizing function.
  61  */
  62
  63 extern struct irc_radixtree *irc_radixtree_create(const char *name, void (*canonize_cb)(char *key));
  64
  65 /*
  66  * irc_radixtree_shutdown() deallocates all heaps used in patricia trees. This is
  67  * useful on embedded devices with little memory, and/or when you know you won't need
  68  * any more patricia trees.
  69  */
  70 extern void irc_radixtree_shutdown(void);
  71
  72 /*
  73  * irc_radixtree_destroy() destroys all entries in a dtree, and also optionally calls
  74  * a defined callback function to destroy any data attached to it.
  75  */
  76 extern void irc_radixtree_destroy(struct irc_radixtree *dtree, void (*destroy_cb)(const char *key, void *data, void *privdata), void *privdata);
  77
  78 /*
  79  * irc_radixtree_foreach() iterates all entries in a dtree, and also optionally calls
  80  * a defined callback function to use any data attached to it.
  81  *
  82  * To shortcircuit iteration, return non-zero from the callback function.
  83  */
  84 extern void irc_radixtree_foreach(struct irc_radixtree *dtree, int (*foreach_cb)(const char *key, void *data, void *privdata), void *privdata);
  85
  86 /*
  87  * irc_radixtree_search() iterates all entries in a dtree, and also optionally calls
  88  * a defined callback function to use any data attached to it.
  89  *
  90  * When the object is found, a non-NULL is returned from the callback, which results
  91  * in that object being returned to the user.
  92  */
  93 extern void *irc_radixtree_search(struct irc_radixtree *dtree, void *(*foreach_cb)(const char *key, void *data, void *privdata), void *privdata);
  94
  95 /*
  96  * irc_radixtree_foreach_start() begins an iteration over all items
  97  * keeping state in the given struct. If there is only one iteration
  98  * in progress at a time, it is permitted to remove the current element
  99  * of the iteration (but not any other element).
 100  */
 101 extern void irc_radixtree_foreach_start(struct irc_radixtree *dtree, struct irc_radixtree_iteration_state *state);
 102
 103 /*
 104  * irc_radixtree_foreach_cur() returns the current element of the iteration,
 105  * or NULL if there are no more elements.
 106  */
 107 extern void *irc_radixtree_foreach_cur(struct irc_radixtree *dtree, struct irc_radixtree_iteration_state *state);
 108
 109 /*
 110  * irc_radixtree_foreach_next() moves to the next element.
 111  */
 112 extern void irc_radixtree_foreach_next(struct irc_radixtree *dtree, struct irc_radixtree_iteration_state *state);
 113
 114 /*
 115  * irc_radixtree_add() adds a key->value entry to the patricia tree.
 116  */
 117 extern int irc_radixtree_add(struct irc_radixtree *dtree, const char *key, void *data);
 118
 119 /*
 120  * irc_radixtree_find() returns data from a dtree for key 'key'.
 121  */
 122 extern void *irc_radixtree_retrieve(struct irc_radixtree *dtree, const char *key);
 123
 124 /*
 125  * irc_radixtree_delete() deletes a key->value entry from the patricia tree.
 126  */
 127 extern void *irc_radixtree_delete(struct irc_radixtree *dtree, const char *key);
 128
 129 /* Low-level functions */
 130 struct irc_radixtree_leaf *irc_radixtree_elem_add(struct irc_radixtree *dtree, const char *key, void *data);
 131 struct irc_radixtree_leaf *irc_radixtree_elem_find(struct irc_radixtree *dtree, const char *key);
 132 void irc_radixtree_elem_delete(struct irc_radixtree *dtree, struct irc_radixtree_leaf *elem);
 133 const char *irc_radixtree_elem_get_key(struct irc_radixtree_leaf *elem);
 134 void irc_radixtree_elem_set_data(struct irc_radixtree_leaf *elem, void *data);
 135 void *irc_radixtree_elem_get_data(struct irc_radixtree_leaf *elem);
 136
 137 unsigned int irc_radixtree_size(struct irc_radixtree *dict);
 138 void irc_radixtree_stats(struct irc_radixtree *dict, void (*cb)(const char *line, void *privdata), void *privdata);
 139 void irc_radixtree_stats_walk(void (*cb)(const char *line, void *privdata), void *privdata);
 140
 141 #endif