comparison: src/ucx/avl.h
src/ucx/avl.h
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| 1 /* | |
| 2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER. | |
| 3 * | |
| 4 * Copyright 2017 Olaf Wintermann. All rights reserved. | |
| 5 * | |
| 6 * Redistribution and use in source and binary forms, with or without | |
| 7 * modification, are permitted provided that the following conditions are met: | |
| 8 * | |
| 9 * 1. Redistributions of source code must retain the above copyright | |
| 10 * notice, this list of conditions and the following disclaimer. | |
| 11 * | |
| 12 * 2. Redistributions in binary form must reproduce the above copyright | |
| 13 * notice, this list of conditions and the following disclaimer in the | |
| 14 * documentation and/or other materials provided with the distribution. | |
| 15 * | |
| 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" | |
| 17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
| 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
| 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE | |
| 20 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR | |
| 21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF | |
| 22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS | |
| 23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN | |
| 24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) | |
| 25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE | |
| 26 * POSSIBILITY OF SUCH DAMAGE. | |
| 27 */ | |
| 28 | |
| 29 | |
| 30 /** | |
| 31 * @file avl.h | |
| 32 * | |
| 33 * AVL tree implementation. | |
| 34 * | |
| 35 * This binary search tree implementation allows average O(1) insertion and | |
| 36 * removal of elements (excluding binary search time). | |
| 37 * | |
| 38 * @author Mike Becker | |
| 39 * @author Olaf Wintermann | |
| 40 */ | |
| 41 | |
| 42 #ifndef UCX_AVL_H | |
| 43 #define UCX_AVL_H | |
| 44 | |
| 45 #include <ucx/ucx.h> | |
| 46 #include <ucx/allocator.h> | |
| 47 #include <inttypes.h> | |
| 48 | |
| 49 #ifdef __cplusplus | |
| 50 extern "C" { | |
| 51 #endif | |
| 52 | |
| 53 /** | |
| 54 * UCX AVL Node type. | |
| 55 * | |
| 56 * @see UcxAVLNode | |
| 57 */ | |
| 58 typedef struct UcxAVLNode UcxAVLNode; | |
| 59 | |
| 60 /** | |
| 61 * UCX AVL Node. | |
| 62 */ | |
| 63 struct UcxAVLNode { | |
| 64 /** | |
| 65 * The key for this node. | |
| 66 */ | |
| 67 intptr_t key; | |
| 68 /** | |
| 69 * Data contained by this node. | |
| 70 */ | |
| 71 void *value; | |
| 72 /** | |
| 73 * The height of this (sub)-tree. | |
| 74 */ | |
| 75 size_t height; | |
| 76 /** | |
| 77 * Parent node. | |
| 78 */ | |
| 79 UcxAVLNode *parent; | |
| 80 /** | |
| 81 * Root node of left subtree. | |
| 82 */ | |
| 83 UcxAVLNode *left; | |
| 84 /** | |
| 85 * Root node of right subtree. | |
| 86 */ | |
| 87 UcxAVLNode *right; | |
| 88 }; | |
| 89 | |
| 90 /** | |
| 91 * UCX AVL Tree. | |
| 92 */ | |
| 93 typedef struct { | |
| 94 /** | |
| 95 * The UcxAllocator that shall be used to manage the memory for node data. | |
| 96 */ | |
| 97 UcxAllocator *allocator; | |
| 98 /** | |
| 99 * Root node of the tree. | |
| 100 */ | |
| 101 UcxAVLNode *root; | |
| 102 /** | |
| 103 * Compare function that shall be used to compare the UcxAVLNode keys. | |
| 104 * @see UcxAVLNode.key | |
| 105 */ | |
| 106 cmp_func cmpfunc; | |
| 107 /** | |
| 108 * Custom user data. | |
| 109 * This data will also be provided to the cmpfunc. | |
| 110 */ | |
| 111 void *userdata; | |
| 112 } UcxAVLTree; | |
| 113 | |
| 114 /** | |
| 115 * Initializes a new UcxAVLTree with a default allocator. | |
| 116 * | |
| 117 * @param cmpfunc the compare function that shall be used | |
| 118 * @return a new UcxAVLTree object | |
| 119 * @see ucx_avl_new_a() | |
| 120 */ | |
| 121 UcxAVLTree *ucx_avl_new(cmp_func cmpfunc); | |
| 122 | |
| 123 /** | |
| 124 * Initializes a new UcxAVLTree with the specified allocator. | |
| 125 * | |
| 126 * The cmpfunc should be capable of comparing two keys within this AVL tree. | |
| 127 * So if you want to use null terminated strings as keys, you could use the | |
| 128 * ucx_strcmp() function here. | |
| 129 * | |
| 130 * @param cmpfunc the compare function that shall be used | |
| 131 * @param allocator the UcxAllocator that shall be used | |
| 132 * @return a new UcxAVLTree object | |
| 133 */ | |
| 134 UcxAVLTree *ucx_avl_new_a(cmp_func cmpfunc, UcxAllocator *allocator); | |
| 135 | |
| 136 /** | |
| 137 * Destroys a UcxAVLTree. | |
| 138 * @param tree the tree to destroy | |
| 139 */ | |
| 140 void ucx_avl_free(UcxAVLTree *tree); | |
| 141 | |
| 142 /** | |
| 143 * Macro for initializing a new UcxAVLTree with the default allocator and a | |
| 144 * ucx_ptrcmp() compare function. | |
| 145 * | |
| 146 * @return a new default UcxAVLTree object | |
| 147 */ | |
| 148 #define ucx_avl_default_new() ucx_avl_new_a(ucx_ptrcmp, ucx_default_allocator()) | |
| 149 | |
| 150 /** | |
| 151 * Gets the node from the tree, that is associated with the specified key. | |
| 152 * @param tree the UcxAVLTree | |
| 153 * @param key the key | |
| 154 * @return the node (or <code>NULL</code>, if the key is not present) | |
| 155 */ | |
| 156 UcxAVLNode *ucx_avl_get_node(UcxAVLTree *tree, intptr_t key); | |
| 157 | |
| 158 /** | |
| 159 * Gets the value from the tree, that is associated with the specified key. | |
| 160 * @param tree the UcxAVLTree | |
| 161 * @param key the key | |
| 162 * @return the value (or <code>NULL</code>, if the key is not present) | |
| 163 */ | |
| 164 void *ucx_avl_get(UcxAVLTree *tree, intptr_t key); | |
| 165 | |
| 166 /** | |
| 167 * A mode for #ucx_avl_find_node() with the same behavior as | |
| 168 * #ucx_avl_get_node(). | |
| 169 */ | |
| 170 #define UCX_AVL_FIND_EXACT 0 | |
| 171 /** | |
| 172 * A mode for #ucx_avl_find_node() finding the node whose key is at least | |
| 173 * as large as the specified key. | |
| 174 */ | |
| 175 #define UCX_AVL_FIND_LOWER_BOUNDED 1 | |
| 176 /** | |
| 177 * A mode for #ucx_avl_find_node() finding the node whose key is at most | |
| 178 * as large as the specified key. | |
| 179 */ | |
| 180 #define UCX_AVL_FIND_UPPER_BOUNDED 2 | |
| 181 /** | |
| 182 * A mode for #ucx_avl_find_node() finding the node with a key that is as close | |
| 183 * to the specified key as possible. If the key is present, the behavior is | |
| 184 * like #ucx_avl_get_node(). This mode only returns <code>NULL</code> on | |
| 185 * empty trees. | |
| 186 */ | |
| 187 #define UCX_AVL_FIND_CLOSEST 3 | |
| 188 | |
| 189 /** | |
| 190 * Finds a node within the tree. The following modes are supported: | |
| 191 * <ul> | |
| 192 * <li>#UCX_AVL_FIND_EXACT: the same behavior as #ucx_avl_get_node()</li> | |
| 193 * <li>#UCX_AVL_FIND_LOWER_BOUNDED: finds the node whose key is at least | |
| 194 * as large as the specified key</li> | |
| 195 * <li>#UCX_AVL_FIND_UPPER_BOUNDED: finds the node whose key is at most | |
| 196 * as large as the specified key</li> | |
| 197 * <li>#UCX_AVL_FIND_CLOSEST: finds the node with a key that is as close to | |
| 198 * the specified key as possible. If the key is present, the behavior is | |
| 199 * like #ucx_avl_get_node(). This mode only returns <code>NULL</code> on | |
| 200 * empty trees.</li> | |
| 201 * </ul> | |
| 202 * | |
| 203 * The distance function provided MUST agree with the compare function of | |
| 204 * the AVL tree. | |
| 205 * | |
| 206 * @param tree the UcxAVLTree | |
| 207 * @param key the key | |
| 208 * @param dfnc the distance function | |
| 209 * @param mode the find mode | |
| 210 * @return the node (or <code>NULL</code>, if no node can be found) | |
| 211 */ | |
| 212 UcxAVLNode *ucx_avl_find_node(UcxAVLTree *tree, intptr_t key, | |
| 213 distance_func dfnc, int mode); | |
| 214 | |
| 215 /** | |
| 216 * Finds a value within the tree. | |
| 217 * See #ucx_avl_find_node() for details. | |
| 218 * | |
| 219 * @param tree the UcxAVLTree | |
| 220 * @param key the key | |
| 221 * @param dfnc the distance function | |
| 222 * @param mode the find mode | |
| 223 * @return the value (or <code>NULL</code>, if no value can be found) | |
| 224 */ | |
| 225 void *ucx_avl_find(UcxAVLTree *tree, intptr_t key, | |
| 226 distance_func dfnc, int mode); | |
| 227 | |
| 228 /** | |
| 229 * Puts a key/value pair into the tree. | |
| 230 * | |
| 231 * Attention: use this function only, if a possible old value does not need | |
| 232 * to be preserved. | |
| 233 * | |
| 234 * @param tree the UcxAVLTree | |
| 235 * @param key the key | |
| 236 * @param value the new value | |
| 237 * @return zero, if and only if the operation succeeded | |
| 238 */ | |
| 239 int ucx_avl_put(UcxAVLTree *tree, intptr_t key, void *value); | |
| 240 | |
| 241 /** | |
| 242 * Puts a key/value pair into the tree. | |
| 243 * | |
| 244 * This is a secure function which saves the old value to the variable pointed | |
| 245 * at by oldvalue. | |
| 246 * | |
| 247 * @param tree the UcxAVLTree | |
| 248 * @param key the key | |
| 249 * @param value the new value | |
| 250 * @param oldvalue optional: a pointer to the location where a possible old | |
| 251 * value shall be stored | |
| 252 * @return zero, if and only if the operation succeeded | |
| 253 */ | |
| 254 int ucx_avl_put_s(UcxAVLTree *tree, intptr_t key, void *value, void **oldvalue); | |
| 255 | |
| 256 /** | |
| 257 * Removes a node from the AVL tree. | |
| 258 * | |
| 259 * Note: the specified node is logically removed. The tree implementation | |
| 260 * decides which memory area is freed. In most cases the here provided node | |
| 261 * is freed, so its further use is generally undefined. | |
| 262 * | |
| 263 * @param tree the UcxAVLTree | |
| 264 * @param node the node to remove | |
| 265 * @return zero, if and only if an element has been removed | |
| 266 */ | |
| 267 int ucx_avl_remove_node(UcxAVLTree *tree, UcxAVLNode *node); | |
| 268 | |
| 269 /** | |
| 270 * Removes an element from the AVL tree. | |
| 271 * | |
| 272 * @param tree the UcxAVLTree | |
| 273 * @param key the key | |
| 274 * @return zero, if and only if an element has been removed | |
| 275 */ | |
| 276 int ucx_avl_remove(UcxAVLTree *tree, intptr_t key); | |
| 277 | |
| 278 /** | |
| 279 * Removes an element from the AVL tree. | |
| 280 * | |
| 281 * This is a secure function which saves the old key and value data from node | |
| 282 * to the variables at the location of oldkey and oldvalue (if specified), so | |
| 283 * they can be freed afterwards (if necessary). | |
| 284 * | |
| 285 * Note: the returned key in oldkey is possibly not the same as the provided | |
| 286 * key for the lookup (in terms of memory location). | |
| 287 * | |
| 288 * @param tree the UcxAVLTree | |
| 289 * @param key the key of the element to remove | |
| 290 * @param oldkey optional: a pointer to the location where the old key shall be | |
| 291 * stored | |
| 292 * @param oldvalue optional: a pointer to the location where the old value | |
| 293 * shall be stored | |
| 294 * @return zero, if and only if an element has been removed | |
| 295 */ | |
| 296 int ucx_avl_remove_s(UcxAVLTree *tree, intptr_t key, | |
| 297 intptr_t *oldkey, void **oldvalue); | |
| 298 | |
| 299 /** | |
| 300 * Counts the nodes in the specified UcxAVLTree. | |
| 301 * @param tree the AVL tree | |
| 302 * @return the node count | |
| 303 */ | |
| 304 size_t ucx_avl_count(UcxAVLTree *tree); | |
| 305 | |
| 306 /** | |
| 307 * Finds the in-order predecessor of the given node. | |
| 308 * @param node an AVL node | |
| 309 * @return the in-order predecessor of the given node, or <code>NULL</code> if | |
| 310 * the given node is the in-order minimum | |
| 311 */ | |
| 312 UcxAVLNode* ucx_avl_pred(UcxAVLNode* node); | |
| 313 | |
| 314 /** | |
| 315 * Finds the in-order successor of the given node. | |
| 316 * @param node an AVL node | |
| 317 * @return the in-order successor of the given node, or <code>NULL</code> if | |
| 318 * the given node is the in-order maximum | |
| 319 */ | |
| 320 UcxAVLNode* ucx_avl_succ(UcxAVLNode* node); | |
| 321 | |
| 322 #ifdef __cplusplus | |
| 323 } | |
| 324 #endif | |
| 325 | |
| 326 #endif /* UCX_AVL_H */ | |
| 327 |
