src/gallium/auxiliary/cso_cache/cso_hash.h

   1 /**************************************************************************
   2  *
   3  * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  21  * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
  22  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  23  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27
  28 /**
  29  * @file
  30  * Hash table implementation.
  31  *
  32  * This file provides a hash implementation that is capable of dealing
  33  * with collisions. It stores colliding entries in linked list. All
  34  * functions operating on the hash return an iterator. The iterator
  35  * itself points to the collision list. If there wasn't any collision
  36  * the list will have just one entry, otherwise client code should
  37  * iterate over the entries to find the exact entry among ones that
  38  * had the same key (e.g. memcmp could be used on the data to check
  39  * that)
  40  *
  41  * @author Zack Rusin <zack@tungstengraphics.com>
  42  */
  43
  44 #ifndef CSO_HASH_H
  45 #define CSO_HASH_H
  46
  47
  48 #ifdef  __cplusplus
  49 extern "C" {
  50 #endif
  51
  52
  53 struct cso_hash;
  54 struct cso_node;
  55
  56
  57 struct cso_hash_iter {
  58    struct cso_hash *hash;
  59    struct cso_node  *node;
  60 };
  61
  62
  63 struct cso_hash *cso_hash_create(void);
  64 void             cso_hash_delete(struct cso_hash *hash);
  65
  66
  67 int              cso_hash_size(struct cso_hash *hash);
  68
  69
  70 /**
  71  * Adds a data with the given key to the hash. If entry with the given
  72  * key is already in the hash, this current entry is instered before it
  73  * in the collision list.
  74  * Function returns iterator pointing to the inserted item in the hash.
  75  */
  76 struct cso_hash_iter cso_hash_insert(struct cso_hash *hash, unsigned key,
  77                                      void *data);
  78 /**
  79  * Removes the item pointed to by the current iterator from the hash.
  80  * Note that the data itself is not erased and if it was a malloc'ed pointer
  81  * it will have to be freed after calling this function by the callee.
  82  * Function returns iterator pointing to the item after the removed one in
  83  * the hash.
  84  */
  85 struct cso_hash_iter cso_hash_erase(struct cso_hash *hash, struct cso_hash_iter iter);
  86
  87 void  *cso_hash_take(struct cso_hash *hash, unsigned key);
  88
  89
  90
  91 struct cso_hash_iter cso_hash_first_node(struct cso_hash *hash);
  92
  93 /**
  94  * Return an iterator pointing to the first entry in the collision list.
  95  */
  96 struct cso_hash_iter cso_hash_find(struct cso_hash *hash, unsigned key);
  97
  98
  99 int       cso_hash_iter_is_null(struct cso_hash_iter iter);
 100 unsigned  cso_hash_iter_key(struct cso_hash_iter iter);
 101 void     *cso_hash_iter_data(struct cso_hash_iter iter);
 102
 103
 104 struct cso_hash_iter cso_hash_iter_next(struct cso_hash_iter iter);
 105 struct cso_hash_iter cso_hash_iter_prev(struct cso_hash_iter iter);
 106
 107
 108 /**
 109  * Convenience routine to iterate over the collision list while doing a memory
 110  * comparison to see which entry in the list is a direct copy of our template
 111  * and returns that entry.
 112  */
 113 void *cso_hash_find_data_from_template( struct cso_hash *hash,
 114                                         unsigned hash_key,
 115                                         void *templ,
 116                                         int size );
 117
 118
 119 #ifdef  __cplusplus
 120 }
 121 #endif
 122
 123 #endif