| 1 | /* |
| 2 | * GLIB - Library of useful routines for C programming |
| 3 | * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald |
| 4 | * |
| 5 | * SPDX-License-Identifier: LGPL-2.1-or-later |
| 6 | * |
| 7 | * This library is free software; you can redistribute it and/or |
| 8 | * modify it under the terms of the GNU Lesser General Public |
| 9 | * License as published by the Free Software Foundation; either |
| 10 | * version 2.1 of the License, or (at your option) any later version. |
| 11 | * |
| 12 | * This library is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 15 | * Lesser General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU Lesser General Public |
| 18 | * License along with this library; if not, see <http://www.gnu.org/licenses/>. |
| 19 | */ |
| 20 | |
| 21 | /* |
| 22 | * Modified by the GLib Team and others 1997-2000. See the AUTHORS |
| 23 | * file for a list of people on the GLib Team. See the ChangeLog |
| 24 | * files for a list of changes. These files are distributed with |
| 25 | * GLib at ftp://ftp.gtk.org/pub/gtk/. |
| 26 | */ |
| 27 | |
| 28 | /* |
| 29 | * MT safe |
| 30 | */ |
| 31 | |
| 32 | #include "qemu/osdep.h" |
| 33 | #include "qemu/qtree.h" |
| 34 | |
| 35 | /** |
| 36 | * SECTION:trees-binary |
| 37 | * @title: Balanced Binary Trees |
| 38 | * @short_description: a sorted collection of key/value pairs optimized |
| 39 | * for searching and traversing in order |
| 40 | * |
| 41 | * The #QTree structure and its associated functions provide a sorted |
| 42 | * collection of key/value pairs optimized for searching and traversing |
| 43 | * in order. This means that most of the operations (access, search, |
| 44 | * insertion, deletion, ...) on #QTree are O(log(n)) in average and O(n) |
| 45 | * in worst case for time complexity. But, note that maintaining a |
| 46 | * balanced sorted #QTree of n elements is done in time O(n log(n)). |
| 47 | * |
| 48 | * To create a new #QTree use q_tree_new(). |
| 49 | * |
| 50 | * To insert a key/value pair into a #QTree use q_tree_insert() |
| 51 | * (O(n log(n))). |
| 52 | * |
| 53 | * To remove a key/value pair use q_tree_remove() (O(n log(n))). |
| 54 | * |
| 55 | * To look up the value corresponding to a given key, use |
| 56 | * q_tree_lookup() and q_tree_lookup_extended(). |
| 57 | * |
| 58 | * To find out the number of nodes in a #QTree, use q_tree_nnodes(). To |
| 59 | * get the height of a #QTree, use q_tree_height(). |
| 60 | * |
| 61 | * To traverse a #QTree, calling a function for each node visited in |
| 62 | * the traversal, use q_tree_foreach(). |
| 63 | * |
| 64 | * To destroy a #QTree, use q_tree_destroy(). |
| 65 | **/ |
| 66 | |
| 67 | #define MAX_GTREE_HEIGHT 40 |
| 68 | |
| 69 | /** |
| 70 | * QTree: |
| 71 | * |
| 72 | * The QTree struct is an opaque data structure representing a |
| 73 | * [balanced binary tree][glib-Balanced-Binary-Trees]. It should be |
| 74 | * accessed only by using the following functions. |
| 75 | */ |
| 76 | struct _QTree { |
| 77 | QTreeNode *root; |
| 78 | GCompareDataFunc key_compare; |
| 79 | GDestroyNotify key_destroy_func; |
| 80 | GDestroyNotify value_destroy_func; |
| 81 | gpointer key_compare_data; |
| 82 | guint nnodes; |
| 83 | gint ref_count; |
| 84 | }; |
| 85 | |
| 86 | struct _QTreeNode { |
| 87 | gpointer key; /* key for this node */ |
| 88 | gpointer value; /* value stored at this node */ |
| 89 | QTreeNode *left; /* left subtree */ |
| 90 | QTreeNode *right; /* right subtree */ |
| 91 | gint8 balance; /* height (right) - height (left) */ |
| 92 | guint8 left_child; |
| 93 | guint8 right_child; |
| 94 | }; |
| 95 | |
| 96 | |
| 97 | static QTreeNode *q_tree_node_new(gpointer key, |
| 98 | gpointer value); |
| 99 | static QTreeNode *q_tree_insert_internal(QTree *tree, |
| 100 | gpointer key, |
| 101 | gpointer value, |
| 102 | gboolean replace); |
| 103 | static gboolean q_tree_remove_internal(QTree *tree, |
| 104 | gconstpointer key, |
| 105 | gboolean steal); |
| 106 | static QTreeNode *q_tree_node_balance(QTreeNode *node); |
| 107 | static QTreeNode *q_tree_find_node(QTree *tree, |
| 108 | gconstpointer key); |
| 109 | static QTreeNode *q_tree_node_search(QTreeNode *node, |
| 110 | GCompareFunc search_func, |
| 111 | gconstpointer data); |
| 112 | static QTreeNode *q_tree_node_rotate_left(QTreeNode *node); |
| 113 | static QTreeNode *q_tree_node_rotate_right(QTreeNode *node); |
| 114 | #ifdef Q_TREE_DEBUG |
| 115 | static void q_tree_node_check(QTreeNode *node); |
| 116 | #endif |
| 117 | |
| 118 | static QTreeNode* |
| 119 | q_tree_node_new(gpointer key, |
| 120 | gpointer value) |
| 121 | { |
| 122 | QTreeNode *node = g_new(QTreeNode, 1); |
| 123 | |
| 124 | node->balance = 0; |
| 125 | node->left = NULL; |
| 126 | node->right = NULL; |
| 127 | node->left_child = FALSE; |
| 128 | node->right_child = FALSE; |
| 129 | node->key = key; |
| 130 | node->value = value; |
| 131 | |
| 132 | return node; |
| 133 | } |
| 134 | |
| 135 | /** |
| 136 | * q_tree_new: |
| 137 | * @key_compare_func: the function used to order the nodes in the #QTree. |
| 138 | * It should return values similar to the standard strcmp() function - |
| 139 | * 0 if the two arguments are equal, a negative value if the first argument |
| 140 | * comes before the second, or a positive value if the first argument comes |
| 141 | * after the second. |
| 142 | * |
| 143 | * Creates a new #QTree. |
| 144 | * |
| 145 | * Returns: a newly allocated #QTree |
| 146 | */ |
| 147 | QTree * |
| 148 | q_tree_new(GCompareFunc key_compare_func) |
| 149 | { |
| 150 | g_return_val_if_fail(key_compare_func != NULL, NULL); |
| 151 | |
| 152 | return q_tree_new_full((GCompareDataFunc) key_compare_func, NULL, |
| 153 | NULL, NULL); |
| 154 | } |
| 155 | |
| 156 | /** |
| 157 | * q_tree_new_with_data: |
| 158 | * @key_compare_func: qsort()-style comparison function |
| 159 | * @key_compare_data: data to pass to comparison function |
| 160 | * |
| 161 | * Creates a new #QTree with a comparison function that accepts user data. |
| 162 | * See q_tree_new() for more details. |
| 163 | * |
| 164 | * Returns: a newly allocated #QTree |
| 165 | */ |
| 166 | QTree * |
| 167 | q_tree_new_with_data(GCompareDataFunc key_compare_func, |
| 168 | gpointer key_compare_data) |
| 169 | { |
| 170 | g_return_val_if_fail(key_compare_func != NULL, NULL); |
| 171 | |
| 172 | return q_tree_new_full(key_compare_func, key_compare_data, |
| 173 | NULL, NULL); |
| 174 | } |
| 175 | |
| 176 | /** |
| 177 | * q_tree_new_full: |
| 178 | * @key_compare_func: qsort()-style comparison function |
| 179 | * @key_compare_data: data to pass to comparison function |
| 180 | * @key_destroy_func: a function to free the memory allocated for the key |
| 181 | * used when removing the entry from the #QTree or %NULL if you don't |
| 182 | * want to supply such a function |
| 183 | * @value_destroy_func: a function to free the memory allocated for the |
| 184 | * value used when removing the entry from the #QTree or %NULL if you |
| 185 | * don't want to supply such a function |
| 186 | * |
| 187 | * Creates a new #QTree like q_tree_new() and allows to specify functions |
| 188 | * to free the memory allocated for the key and value that get called when |
| 189 | * removing the entry from the #QTree. |
| 190 | * |
| 191 | * Returns: a newly allocated #QTree |
| 192 | */ |
| 193 | QTree * |
| 194 | q_tree_new_full(GCompareDataFunc key_compare_func, |
| 195 | gpointer key_compare_data, |
| 196 | GDestroyNotify key_destroy_func, |
| 197 | GDestroyNotify value_destroy_func) |
| 198 | { |
| 199 | QTree *tree; |
| 200 | |
| 201 | g_return_val_if_fail(key_compare_func != NULL, NULL); |
| 202 | |
| 203 | tree = g_new(QTree, 1); |
| 204 | tree->root = NULL; |
| 205 | tree->key_compare = key_compare_func; |
| 206 | tree->key_destroy_func = key_destroy_func; |
| 207 | tree->value_destroy_func = value_destroy_func; |
| 208 | tree->key_compare_data = key_compare_data; |
| 209 | tree->nnodes = 0; |
| 210 | tree->ref_count = 1; |
| 211 | |
| 212 | return tree; |
| 213 | } |
| 214 | |
| 215 | /** |
| 216 | * q_tree_node_first: |
| 217 | * @tree: a #QTree |
| 218 | * |
| 219 | * Returns the first in-order node of the tree, or %NULL |
| 220 | * for an empty tree. |
| 221 | * |
| 222 | * Returns: (nullable) (transfer none): the first node in the tree |
| 223 | * |
| 224 | * Since: 2.68 in GLib. Internal in Qtree, i.e. not in the public API. |
| 225 | */ |
| 226 | static QTreeNode * |
| 227 | q_tree_node_first(QTree *tree) |
| 228 | { |
| 229 | QTreeNode *tmp; |
| 230 | |
| 231 | g_return_val_if_fail(tree != NULL, NULL); |
| 232 | |
| 233 | if (!tree->root) { |
| 234 | return NULL; |
| 235 | } |
| 236 | |
| 237 | tmp = tree->root; |
| 238 | |
| 239 | while (tmp->left_child) { |
| 240 | tmp = tmp->left; |
| 241 | } |
| 242 | |
| 243 | return tmp; |
| 244 | } |
| 245 | |
| 246 | /** |
| 247 | * q_tree_node_previous |
| 248 | * @node: a #QTree node |
| 249 | * |
| 250 | * Returns the previous in-order node of the tree, or %NULL |
| 251 | * if the passed node was already the first one. |
| 252 | * |
| 253 | * Returns: (nullable) (transfer none): the previous node in the tree |
| 254 | * |
| 255 | * Since: 2.68 in GLib. Internal in Qtree, i.e. not in the public API. |
| 256 | */ |
| 257 | static QTreeNode * |
| 258 | q_tree_node_previous(QTreeNode *node) |
| 259 | { |
| 260 | QTreeNode *tmp; |
| 261 | |
| 262 | g_return_val_if_fail(node != NULL, NULL); |
| 263 | |
| 264 | tmp = node->left; |
| 265 | |
| 266 | if (node->left_child) { |
| 267 | while (tmp->right_child) { |
| 268 | tmp = tmp->right; |
| 269 | } |
| 270 | } |
| 271 | |
| 272 | return tmp; |
| 273 | } |
| 274 | |
| 275 | /** |
| 276 | * q_tree_node_next |
| 277 | * @node: a #QTree node |
| 278 | * |
| 279 | * Returns the next in-order node of the tree, or %NULL |
| 280 | * if the passed node was already the last one. |
| 281 | * |
| 282 | * Returns: (nullable) (transfer none): the next node in the tree |
| 283 | * |
| 284 | * Since: 2.68 in GLib. Internal in Qtree, i.e. not in the public API. |
| 285 | */ |
| 286 | static QTreeNode * |
| 287 | q_tree_node_next(QTreeNode *node) |
| 288 | { |
| 289 | QTreeNode *tmp; |
| 290 | |
| 291 | g_return_val_if_fail(node != NULL, NULL); |
| 292 | |
| 293 | tmp = node->right; |
| 294 | |
| 295 | if (node->right_child) { |
| 296 | while (tmp->left_child) { |
| 297 | tmp = tmp->left; |
| 298 | } |
| 299 | } |
| 300 | |
| 301 | return tmp; |
| 302 | } |
| 303 | |
| 304 | /** |
| 305 | * q_tree_remove_all: |
| 306 | * @tree: a #QTree |
| 307 | * |
| 308 | * Removes all nodes from a #QTree and destroys their keys and values, |
| 309 | * then resets the #QTree’s root to %NULL. |
| 310 | * |
| 311 | * Since: 2.70 in GLib. Internal in Qtree, i.e. not in the public API. |
| 312 | */ |
| 313 | static void QEMU_DISABLE_CFI |
| 314 | q_tree_remove_all(QTree *tree) |
| 315 | { |
| 316 | QTreeNode *node; |
| 317 | QTreeNode *next; |
| 318 | |
| 319 | g_return_if_fail(tree != NULL); |
| 320 | |
| 321 | node = q_tree_node_first(tree); |
| 322 | |
| 323 | while (node) { |
| 324 | next = q_tree_node_next(node); |
| 325 | |
| 326 | if (tree->key_destroy_func) { |
| 327 | tree->key_destroy_func(node->key); |
| 328 | } |
| 329 | if (tree->value_destroy_func) { |
| 330 | tree->value_destroy_func(node->value); |
| 331 | } |
| 332 | g_free(node); |
| 333 | |
| 334 | #ifdef Q_TREE_DEBUG |
| 335 | g_assert(tree->nnodes > 0); |
| 336 | tree->nnodes--; |
| 337 | #endif |
| 338 | |
| 339 | node = next; |
| 340 | } |
| 341 | |
| 342 | #ifdef Q_TREE_DEBUG |
| 343 | g_assert(tree->nnodes == 0); |
| 344 | #endif |
| 345 | |
| 346 | tree->root = NULL; |
| 347 | #ifndef Q_TREE_DEBUG |
| 348 | tree->nnodes = 0; |
| 349 | #endif |
| 350 | } |
| 351 | |
| 352 | /** |
| 353 | * q_tree_ref: |
| 354 | * @tree: a #QTree |
| 355 | * |
| 356 | * Increments the reference count of @tree by one. |
| 357 | * |
| 358 | * It is safe to call this function from any thread. |
| 359 | * |
| 360 | * Returns: the passed in #QTree |
| 361 | * |
| 362 | * Since: 2.22 |
| 363 | */ |
| 364 | QTree * |
| 365 | q_tree_ref(QTree *tree) |
| 366 | { |
| 367 | g_return_val_if_fail(tree != NULL, NULL); |
| 368 | |
| 369 | g_atomic_int_inc(&tree->ref_count); |
| 370 | |
| 371 | return tree; |
| 372 | } |
| 373 | |
| 374 | /** |
| 375 | * q_tree_unref: |
| 376 | * @tree: a #QTree |
| 377 | * |
| 378 | * Decrements the reference count of @tree by one. |
| 379 | * If the reference count drops to 0, all keys and values will |
| 380 | * be destroyed (if destroy functions were specified) and all |
| 381 | * memory allocated by @tree will be released. |
| 382 | * |
| 383 | * It is safe to call this function from any thread. |
| 384 | * |
| 385 | * Since: 2.22 |
| 386 | */ |
| 387 | void |
| 388 | q_tree_unref(QTree *tree) |
| 389 | { |
| 390 | g_return_if_fail(tree != NULL); |
| 391 | |
| 392 | if (g_atomic_int_dec_and_test(&tree->ref_count)) { |
| 393 | q_tree_remove_all(tree); |
| 394 | g_free(tree); |
| 395 | } |
| 396 | } |
| 397 | |
| 398 | /** |
| 399 | * q_tree_destroy: |
| 400 | * @tree: a #QTree |
| 401 | * |
| 402 | * Removes all keys and values from the #QTree and decreases its |
| 403 | * reference count by one. If keys and/or values are dynamically |
| 404 | * allocated, you should either free them first or create the #QTree |
| 405 | * using q_tree_new_full(). In the latter case the destroy functions |
| 406 | * you supplied will be called on all keys and values before destroying |
| 407 | * the #QTree. |
| 408 | */ |
| 409 | void |
| 410 | q_tree_destroy(QTree *tree) |
| 411 | { |
| 412 | g_return_if_fail(tree != NULL); |
| 413 | |
| 414 | q_tree_remove_all(tree); |
| 415 | q_tree_unref(tree); |
| 416 | } |
| 417 | |
| 418 | /** |
| 419 | * q_tree_insert_node: |
| 420 | * @tree: a #QTree |
| 421 | * @key: the key to insert |
| 422 | * @value: the value corresponding to the key |
| 423 | * |
| 424 | * Inserts a key/value pair into a #QTree. |
| 425 | * |
| 426 | * If the given key already exists in the #QTree its corresponding value |
| 427 | * is set to the new value. If you supplied a @value_destroy_func when |
| 428 | * creating the #QTree, the old value is freed using that function. If |
| 429 | * you supplied a @key_destroy_func when creating the #QTree, the passed |
| 430 | * key is freed using that function. |
| 431 | * |
| 432 | * The tree is automatically 'balanced' as new key/value pairs are added, |
| 433 | * so that the distance from the root to every leaf is as small as possible. |
| 434 | * The cost of maintaining a balanced tree while inserting new key/value |
| 435 | * result in a O(n log(n)) operation where most of the other operations |
| 436 | * are O(log(n)). |
| 437 | * |
| 438 | * Returns: (transfer none): the inserted (or set) node. |
| 439 | * |
| 440 | * Since: 2.68 in GLib. Internal in Qtree, i.e. not in the public API. |
| 441 | */ |
| 442 | static QTreeNode * |
| 443 | q_tree_insert_node(QTree *tree, |
| 444 | gpointer key, |
| 445 | gpointer value) |
| 446 | { |
| 447 | QTreeNode *node; |
| 448 | |
| 449 | g_return_val_if_fail(tree != NULL, NULL); |
| 450 | |
| 451 | node = q_tree_insert_internal(tree, key, value, FALSE); |
| 452 | |
| 453 | #ifdef Q_TREE_DEBUG |
| 454 | q_tree_node_check(tree->root); |
| 455 | #endif |
| 456 | |
| 457 | return node; |
| 458 | } |
| 459 | |
| 460 | /** |
| 461 | * q_tree_insert: |
| 462 | * @tree: a #QTree |
| 463 | * @key: the key to insert |
| 464 | * @value: the value corresponding to the key |
| 465 | * |
| 466 | * Inserts a key/value pair into a #QTree. |
| 467 | * |
| 468 | * Inserts a new key and value into a #QTree as q_tree_insert_node() does, |
| 469 | * only this function does not return the inserted or set node. |
| 470 | */ |
| 471 | void |
| 472 | q_tree_insert(QTree *tree, |
| 473 | gpointer key, |
| 474 | gpointer value) |
| 475 | { |
| 476 | q_tree_insert_node(tree, key, value); |
| 477 | } |
| 478 | |
| 479 | /** |
| 480 | * q_tree_replace_node: |
| 481 | * @tree: a #QTree |
| 482 | * @key: the key to insert |
| 483 | * @value: the value corresponding to the key |
| 484 | * |
| 485 | * Inserts a new key and value into a #QTree similar to q_tree_insert_node(). |
| 486 | * The difference is that if the key already exists in the #QTree, it gets |
| 487 | * replaced by the new key. If you supplied a @value_destroy_func when |
| 488 | * creating the #QTree, the old value is freed using that function. If you |
| 489 | * supplied a @key_destroy_func when creating the #QTree, the old key is |
| 490 | * freed using that function. |
| 491 | * |
| 492 | * The tree is automatically 'balanced' as new key/value pairs are added, |
| 493 | * so that the distance from the root to every leaf is as small as possible. |
| 494 | * |
| 495 | * Returns: (transfer none): the inserted (or set) node. |
| 496 | * |
| 497 | * Since: 2.68 in GLib. Internal in Qtree, i.e. not in the public API. |
| 498 | */ |
| 499 | static QTreeNode * |
| 500 | q_tree_replace_node(QTree *tree, |
| 501 | gpointer key, |
| 502 | gpointer value) |
| 503 | { |
| 504 | QTreeNode *node; |
| 505 | |
| 506 | g_return_val_if_fail(tree != NULL, NULL); |
| 507 | |
| 508 | node = q_tree_insert_internal(tree, key, value, TRUE); |
| 509 | |
| 510 | #ifdef Q_TREE_DEBUG |
| 511 | q_tree_node_check(tree->root); |
| 512 | #endif |
| 513 | |
| 514 | return node; |
| 515 | } |
| 516 | |
| 517 | /** |
| 518 | * q_tree_replace: |
| 519 | * @tree: a #QTree |
| 520 | * @key: the key to insert |
| 521 | * @value: the value corresponding to the key |
| 522 | * |
| 523 | * Inserts a new key and value into a #QTree as q_tree_replace_node() does, |
| 524 | * only this function does not return the inserted or set node. |
| 525 | */ |
| 526 | void |
| 527 | q_tree_replace(QTree *tree, |
| 528 | gpointer key, |
| 529 | gpointer value) |
| 530 | { |
| 531 | q_tree_replace_node(tree, key, value); |
| 532 | } |
| 533 | |
| 534 | /* internal insert routine */ |
| 535 | static QTreeNode * QEMU_DISABLE_CFI |
| 536 | q_tree_insert_internal(QTree *tree, |
| 537 | gpointer key, |
| 538 | gpointer value, |
| 539 | gboolean replace) |
| 540 | { |
| 541 | QTreeNode *node, *retnode; |
| 542 | QTreeNode *path[MAX_GTREE_HEIGHT]; |
| 543 | int idx; |
| 544 | |
| 545 | g_return_val_if_fail(tree != NULL, NULL); |
| 546 | |
| 547 | if (!tree->root) { |
| 548 | tree->root = q_tree_node_new(key, value); |
| 549 | tree->nnodes++; |
| 550 | return tree->root; |
| 551 | } |
| 552 | |
| 553 | idx = 0; |
| 554 | path[idx++] = NULL; |
| 555 | node = tree->root; |
| 556 | |
| 557 | while (1) { |
| 558 | int cmp = tree->key_compare(key, node->key, tree->key_compare_data); |
| 559 | |
| 560 | if (cmp == 0) { |
| 561 | if (tree->value_destroy_func) { |
| 562 | tree->value_destroy_func(node->value); |
| 563 | } |
| 564 | |
| 565 | node->value = value; |
| 566 | |
| 567 | if (replace) { |
| 568 | if (tree->key_destroy_func) { |
| 569 | tree->key_destroy_func(node->key); |
| 570 | } |
| 571 | |
| 572 | node->key = key; |
| 573 | } else { |
| 574 | /* free the passed key */ |
| 575 | if (tree->key_destroy_func) { |
| 576 | tree->key_destroy_func(key); |
| 577 | } |
| 578 | } |
| 579 | |
| 580 | return node; |
| 581 | } else if (cmp < 0) { |
| 582 | if (node->left_child) { |
| 583 | path[idx++] = node; |
| 584 | node = node->left; |
| 585 | } else { |
| 586 | QTreeNode *child = q_tree_node_new(key, value); |
| 587 | |
| 588 | child->left = node->left; |
| 589 | child->right = node; |
| 590 | node->left = child; |
| 591 | node->left_child = TRUE; |
| 592 | node->balance -= 1; |
| 593 | |
| 594 | tree->nnodes++; |
| 595 | |
| 596 | retnode = child; |
| 597 | break; |
| 598 | } |
| 599 | } else { |
| 600 | if (node->right_child) { |
| 601 | path[idx++] = node; |
| 602 | node = node->right; |
| 603 | } else { |
| 604 | QTreeNode *child = q_tree_node_new(key, value); |
| 605 | |
| 606 | child->right = node->right; |
| 607 | child->left = node; |
| 608 | node->right = child; |
| 609 | node->right_child = TRUE; |
| 610 | node->balance += 1; |
| 611 | |
| 612 | tree->nnodes++; |
| 613 | |
| 614 | retnode = child; |
| 615 | break; |
| 616 | } |
| 617 | } |
| 618 | } |
| 619 | |
| 620 | /* |
| 621 | * Restore balance. This is the goodness of a non-recursive |
| 622 | * implementation, when we are done with balancing we 'break' |
| 623 | * the loop and we are done. |
| 624 | */ |
| 625 | while (1) { |
| 626 | QTreeNode *bparent = path[--idx]; |
| 627 | gboolean left_node = (bparent && node == bparent->left); |
| 628 | g_assert(!bparent || bparent->left == node || bparent->right == node); |
| 629 | |
| 630 | if (node->balance < -1 || node->balance > 1) { |
| 631 | node = q_tree_node_balance(node); |
| 632 | if (bparent == NULL) { |
| 633 | tree->root = node; |
| 634 | } else if (left_node) { |
| 635 | bparent->left = node; |
| 636 | } else { |
| 637 | bparent->right = node; |
| 638 | } |
| 639 | } |
| 640 | |
| 641 | if (node->balance == 0 || bparent == NULL) { |
| 642 | break; |
| 643 | } |
| 644 | |
| 645 | if (left_node) { |
| 646 | bparent->balance -= 1; |
| 647 | } else { |
| 648 | bparent->balance += 1; |
| 649 | } |
| 650 | |
| 651 | node = bparent; |
| 652 | } |
| 653 | |
| 654 | return retnode; |
| 655 | } |
| 656 | |
| 657 | /** |
| 658 | * q_tree_remove: |
| 659 | * @tree: a #QTree |
| 660 | * @key: the key to remove |
| 661 | * |
| 662 | * Removes a key/value pair from a #QTree. |
| 663 | * |
| 664 | * If the #QTree was created using q_tree_new_full(), the key and value |
| 665 | * are freed using the supplied destroy functions, otherwise you have to |
| 666 | * make sure that any dynamically allocated values are freed yourself. |
| 667 | * If the key does not exist in the #QTree, the function does nothing. |
| 668 | * |
| 669 | * The cost of maintaining a balanced tree while removing a key/value |
| 670 | * result in a O(n log(n)) operation where most of the other operations |
| 671 | * are O(log(n)). |
| 672 | * |
| 673 | * Returns: %TRUE if the key was found (prior to 2.8, this function |
| 674 | * returned nothing) |
| 675 | */ |
| 676 | gboolean |
| 677 | q_tree_remove(QTree *tree, |
| 678 | gconstpointer key) |
| 679 | { |
| 680 | gboolean removed; |
| 681 | |
| 682 | g_return_val_if_fail(tree != NULL, FALSE); |
| 683 | |
| 684 | removed = q_tree_remove_internal(tree, key, FALSE); |
| 685 | |
| 686 | #ifdef Q_TREE_DEBUG |
| 687 | q_tree_node_check(tree->root); |
| 688 | #endif |
| 689 | |
| 690 | return removed; |
| 691 | } |
| 692 | |
| 693 | /** |
| 694 | * q_tree_steal: |
| 695 | * @tree: a #QTree |
| 696 | * @key: the key to remove |
| 697 | * |
| 698 | * Removes a key and its associated value from a #QTree without calling |
| 699 | * the key and value destroy functions. |
| 700 | * |
| 701 | * If the key does not exist in the #QTree, the function does nothing. |
| 702 | * |
| 703 | * Returns: %TRUE if the key was found (prior to 2.8, this function |
| 704 | * returned nothing) |
| 705 | */ |
| 706 | gboolean |
| 707 | q_tree_steal(QTree *tree, |
| 708 | gconstpointer key) |
| 709 | { |
| 710 | gboolean removed; |
| 711 | |
| 712 | g_return_val_if_fail(tree != NULL, FALSE); |
| 713 | |
| 714 | removed = q_tree_remove_internal(tree, key, TRUE); |
| 715 | |
| 716 | #ifdef Q_TREE_DEBUG |
| 717 | q_tree_node_check(tree->root); |
| 718 | #endif |
| 719 | |
| 720 | return removed; |
| 721 | } |
| 722 | |
| 723 | /* internal remove routine */ |
| 724 | static gboolean QEMU_DISABLE_CFI |
| 725 | q_tree_remove_internal(QTree *tree, |
| 726 | gconstpointer key, |
| 727 | gboolean steal) |
| 728 | { |
| 729 | QTreeNode *node, *parent, *balance; |
| 730 | QTreeNode *path[MAX_GTREE_HEIGHT]; |
| 731 | int idx; |
| 732 | gboolean left_node; |
| 733 | |
| 734 | g_return_val_if_fail(tree != NULL, FALSE); |
| 735 | |
| 736 | if (!tree->root) { |
| 737 | return FALSE; |
| 738 | } |
| 739 | |
| 740 | idx = 0; |
| 741 | path[idx++] = NULL; |
| 742 | node = tree->root; |
| 743 | |
| 744 | while (1) { |
| 745 | int cmp = tree->key_compare(key, node->key, tree->key_compare_data); |
| 746 | |
| 747 | if (cmp == 0) { |
| 748 | break; |
| 749 | } else if (cmp < 0) { |
| 750 | if (!node->left_child) { |
| 751 | return FALSE; |
| 752 | } |
| 753 | |
| 754 | path[idx++] = node; |
| 755 | node = node->left; |
| 756 | } else { |
| 757 | if (!node->right_child) { |
| 758 | return FALSE; |
| 759 | } |
| 760 | |
| 761 | path[idx++] = node; |
| 762 | node = node->right; |
| 763 | } |
| 764 | } |
| 765 | |
| 766 | /* |
| 767 | * The following code is almost equal to q_tree_remove_node, |
| 768 | * except that we do not have to call q_tree_node_parent. |
| 769 | */ |
| 770 | balance = parent = path[--idx]; |
| 771 | g_assert(!parent || parent->left == node || parent->right == node); |
| 772 | left_node = (parent && node == parent->left); |
| 773 | |
| 774 | if (!node->left_child) { |
| 775 | if (!node->right_child) { |
| 776 | if (!parent) { |
| 777 | tree->root = NULL; |
| 778 | } else if (left_node) { |
| 779 | parent->left_child = FALSE; |
| 780 | parent->left = node->left; |
| 781 | parent->balance += 1; |
| 782 | } else { |
| 783 | parent->right_child = FALSE; |
| 784 | parent->right = node->right; |
| 785 | parent->balance -= 1; |
| 786 | } |
| 787 | } else { |
| 788 | /* node has a right child */ |
| 789 | QTreeNode *tmp = q_tree_node_next(node); |
| 790 | tmp->left = node->left; |
| 791 | |
| 792 | if (!parent) { |
| 793 | tree->root = node->right; |
| 794 | } else if (left_node) { |
| 795 | parent->left = node->right; |
| 796 | parent->balance += 1; |
| 797 | } else { |
| 798 | parent->right = node->right; |
| 799 | parent->balance -= 1; |
| 800 | } |
| 801 | } |
| 802 | } else { |
| 803 | /* node has a left child */ |
| 804 | if (!node->right_child) { |
| 805 | QTreeNode *tmp = q_tree_node_previous(node); |
| 806 | tmp->right = node->right; |
| 807 | |
| 808 | if (parent == NULL) { |
| 809 | tree->root = node->left; |
| 810 | } else if (left_node) { |
| 811 | parent->left = node->left; |
| 812 | parent->balance += 1; |
| 813 | } else { |
| 814 | parent->right = node->left; |
| 815 | parent->balance -= 1; |
| 816 | } |
| 817 | } else { |
| 818 | /* node has a both children (pant, pant!) */ |
| 819 | QTreeNode *prev = node->left; |
| 820 | QTreeNode *next = node->right; |
| 821 | QTreeNode *nextp = node; |
| 822 | int old_idx = idx + 1; |
| 823 | idx++; |
| 824 | |
| 825 | /* path[idx] == parent */ |
| 826 | /* find the immediately next node (and its parent) */ |
| 827 | while (next->left_child) { |
| 828 | path[++idx] = nextp = next; |
| 829 | next = next->left; |
| 830 | } |
| 831 | |
| 832 | path[old_idx] = next; |
| 833 | balance = path[idx]; |
| 834 | |
| 835 | /* remove 'next' from the tree */ |
| 836 | if (nextp != node) { |
| 837 | if (next->right_child) { |
| 838 | nextp->left = next->right; |
| 839 | } else { |
| 840 | nextp->left_child = FALSE; |
| 841 | } |
| 842 | nextp->balance += 1; |
| 843 | |
| 844 | next->right_child = TRUE; |
| 845 | next->right = node->right; |
| 846 | } else { |
| 847 | node->balance -= 1; |
| 848 | } |
| 849 | |
| 850 | /* set the prev to point to the right place */ |
| 851 | while (prev->right_child) { |
| 852 | prev = prev->right; |
| 853 | } |
| 854 | prev->right = next; |
| 855 | |
| 856 | /* prepare 'next' to replace 'node' */ |
| 857 | next->left_child = TRUE; |
| 858 | next->left = node->left; |
| 859 | next->balance = node->balance; |
| 860 | |
| 861 | if (!parent) { |
| 862 | tree->root = next; |
| 863 | } else if (left_node) { |
| 864 | parent->left = next; |
| 865 | } else { |
| 866 | parent->right = next; |
| 867 | } |
| 868 | } |
| 869 | } |
| 870 | |
| 871 | /* restore balance */ |
| 872 | if (balance) { |
| 873 | while (1) { |
| 874 | QTreeNode *bparent = path[--idx]; |
| 875 | g_assert(!bparent || |
| 876 | bparent->left == balance || |
| 877 | bparent->right == balance); |
| 878 | left_node = (bparent && balance == bparent->left); |
| 879 | |
| 880 | if (balance->balance < -1 || balance->balance > 1) { |
| 881 | balance = q_tree_node_balance(balance); |
| 882 | if (!bparent) { |
| 883 | tree->root = balance; |
| 884 | } else if (left_node) { |
| 885 | bparent->left = balance; |
| 886 | } else { |
| 887 | bparent->right = balance; |
| 888 | } |
| 889 | } |
| 890 | |
| 891 | if (balance->balance != 0 || !bparent) { |
| 892 | break; |
| 893 | } |
| 894 | |
| 895 | if (left_node) { |
| 896 | bparent->balance += 1; |
| 897 | } else { |
| 898 | bparent->balance -= 1; |
| 899 | } |
| 900 | |
| 901 | balance = bparent; |
| 902 | } |
| 903 | } |
| 904 | |
| 905 | if (!steal) { |
| 906 | if (tree->key_destroy_func) { |
| 907 | tree->key_destroy_func(node->key); |
| 908 | } |
| 909 | if (tree->value_destroy_func) { |
| 910 | tree->value_destroy_func(node->value); |
| 911 | } |
| 912 | } |
| 913 | |
| 914 | g_free(node); |
| 915 | |
| 916 | tree->nnodes--; |
| 917 | |
| 918 | return TRUE; |
| 919 | } |
| 920 | |
| 921 | /** |
| 922 | * q_tree_lookup_node: |
| 923 | * @tree: a #QTree |
| 924 | * @key: the key to look up |
| 925 | * |
| 926 | * Gets the tree node corresponding to the given key. Since a #QTree is |
| 927 | * automatically balanced as key/value pairs are added, key lookup |
| 928 | * is O(log n) (where n is the number of key/value pairs in the tree). |
| 929 | * |
| 930 | * Returns: (nullable) (transfer none): the tree node corresponding to |
| 931 | * the key, or %NULL if the key was not found |
| 932 | * |
| 933 | * Since: 2.68 in GLib. Internal in Qtree, i.e. not in the public API. |
| 934 | */ |
| 935 | static QTreeNode * |
| 936 | q_tree_lookup_node(QTree *tree, |
| 937 | gconstpointer key) |
| 938 | { |
| 939 | g_return_val_if_fail(tree != NULL, NULL); |
| 940 | |
| 941 | return q_tree_find_node(tree, key); |
| 942 | } |
| 943 | |
| 944 | /** |
| 945 | * q_tree_lookup: |
| 946 | * @tree: a #QTree |
| 947 | * @key: the key to look up |
| 948 | * |
| 949 | * Gets the value corresponding to the given key. Since a #QTree is |
| 950 | * automatically balanced as key/value pairs are added, key lookup |
| 951 | * is O(log n) (where n is the number of key/value pairs in the tree). |
| 952 | * |
| 953 | * Returns: the value corresponding to the key, or %NULL |
| 954 | * if the key was not found |
| 955 | */ |
| 956 | gpointer |
| 957 | q_tree_lookup(QTree *tree, |
| 958 | gconstpointer key) |
| 959 | { |
| 960 | QTreeNode *node; |
| 961 | |
| 962 | node = q_tree_lookup_node(tree, key); |
| 963 | |
| 964 | return node ? node->value : NULL; |
| 965 | } |
| 966 | |
| 967 | /** |
| 968 | * q_tree_lookup_extended: |
| 969 | * @tree: a #QTree |
| 970 | * @lookup_key: the key to look up |
| 971 | * @orig_key: (out) (optional) (nullable): returns the original key |
| 972 | * @value: (out) (optional) (nullable): returns the value associated with |
| 973 | * the key |
| 974 | * |
| 975 | * Looks up a key in the #QTree, returning the original key and the |
| 976 | * associated value. This is useful if you need to free the memory |
| 977 | * allocated for the original key, for example before calling |
| 978 | * q_tree_remove(). |
| 979 | * |
| 980 | * Returns: %TRUE if the key was found in the #QTree |
| 981 | */ |
| 982 | gboolean |
| 983 | q_tree_lookup_extended(QTree *tree, |
| 984 | gconstpointer lookup_key, |
| 985 | gpointer *orig_key, |
| 986 | gpointer *value) |
| 987 | { |
| 988 | QTreeNode *node; |
| 989 | |
| 990 | g_return_val_if_fail(tree != NULL, FALSE); |
| 991 | |
| 992 | node = q_tree_find_node(tree, lookup_key); |
| 993 | |
| 994 | if (node) { |
| 995 | if (orig_key) { |
| 996 | *orig_key = node->key; |
| 997 | } |
| 998 | if (value) { |
| 999 | *value = node->value; |
| 1000 | } |
| 1001 | return TRUE; |
| 1002 | } else { |
| 1003 | return FALSE; |
| 1004 | } |
| 1005 | } |
| 1006 | |
| 1007 | /** |
| 1008 | * q_tree_foreach: |
| 1009 | * @tree: a #QTree |
| 1010 | * @func: the function to call for each node visited. |
| 1011 | * If this function returns %TRUE, the traversal is stopped. |
| 1012 | * @user_data: user data to pass to the function |
| 1013 | * |
| 1014 | * Calls the given function for each of the key/value pairs in the #QTree. |
| 1015 | * The function is passed the key and value of each pair, and the given |
| 1016 | * @data parameter. The tree is traversed in sorted order. |
| 1017 | * |
| 1018 | * The tree may not be modified while iterating over it (you can't |
| 1019 | * add/remove items). To remove all items matching a predicate, you need |
| 1020 | * to add each item to a list in your #GTraverseFunc as you walk over |
| 1021 | * the tree, then walk the list and remove each item. |
| 1022 | */ |
| 1023 | void |
| 1024 | q_tree_foreach(QTree *tree, |
| 1025 | GTraverseFunc func, |
| 1026 | gpointer user_data) |
| 1027 | { |
| 1028 | QTreeNode *node; |
| 1029 | |
| 1030 | g_return_if_fail(tree != NULL); |
| 1031 | |
| 1032 | if (!tree->root) { |
| 1033 | return; |
| 1034 | } |
| 1035 | |
| 1036 | node = q_tree_node_first(tree); |
| 1037 | |
| 1038 | while (node) { |
| 1039 | if ((*func)(node->key, node->value, user_data)) { |
| 1040 | break; |
| 1041 | } |
| 1042 | |
| 1043 | node = q_tree_node_next(node); |
| 1044 | } |
| 1045 | } |
| 1046 | |
| 1047 | /** |
| 1048 | * q_tree_search_node: |
| 1049 | * @tree: a #QTree |
| 1050 | * @search_func: a function used to search the #QTree |
| 1051 | * @user_data: the data passed as the second argument to @search_func |
| 1052 | * |
| 1053 | * Searches a #QTree using @search_func. |
| 1054 | * |
| 1055 | * The @search_func is called with a pointer to the key of a key/value |
| 1056 | * pair in the tree, and the passed in @user_data. If @search_func returns |
| 1057 | * 0 for a key/value pair, then the corresponding node is returned as |
| 1058 | * the result of q_tree_search(). If @search_func returns -1, searching |
| 1059 | * will proceed among the key/value pairs that have a smaller key; if |
| 1060 | * @search_func returns 1, searching will proceed among the key/value |
| 1061 | * pairs that have a larger key. |
| 1062 | * |
| 1063 | * Returns: (nullable) (transfer none): the node corresponding to the |
| 1064 | * found key, or %NULL if the key was not found |
| 1065 | * |
| 1066 | * Since: 2.68 in GLib. Internal in Qtree, i.e. not in the public API. |
| 1067 | */ |
| 1068 | static QTreeNode * |
| 1069 | q_tree_search_node(QTree *tree, |
| 1070 | GCompareFunc search_func, |
| 1071 | gconstpointer user_data) |
| 1072 | { |
| 1073 | g_return_val_if_fail(tree != NULL, NULL); |
| 1074 | |
| 1075 | if (!tree->root) { |
| 1076 | return NULL; |
| 1077 | } |
| 1078 | |
| 1079 | return q_tree_node_search(tree->root, search_func, user_data); |
| 1080 | } |
| 1081 | |
| 1082 | /** |
| 1083 | * q_tree_search: |
| 1084 | * @tree: a #QTree |
| 1085 | * @search_func: a function used to search the #QTree |
| 1086 | * @user_data: the data passed as the second argument to @search_func |
| 1087 | * |
| 1088 | * Searches a #QTree using @search_func. |
| 1089 | * |
| 1090 | * The @search_func is called with a pointer to the key of a key/value |
| 1091 | * pair in the tree, and the passed in @user_data. If @search_func returns |
| 1092 | * 0 for a key/value pair, then the corresponding value is returned as |
| 1093 | * the result of q_tree_search(). If @search_func returns -1, searching |
| 1094 | * will proceed among the key/value pairs that have a smaller key; if |
| 1095 | * @search_func returns 1, searching will proceed among the key/value |
| 1096 | * pairs that have a larger key. |
| 1097 | * |
| 1098 | * Returns: the value corresponding to the found key, or %NULL |
| 1099 | * if the key was not found |
| 1100 | */ |
| 1101 | gpointer |
| 1102 | q_tree_search(QTree *tree, |
| 1103 | GCompareFunc search_func, |
| 1104 | gconstpointer user_data) |
| 1105 | { |
| 1106 | QTreeNode *node; |
| 1107 | |
| 1108 | node = q_tree_search_node(tree, search_func, user_data); |
| 1109 | |
| 1110 | return node ? node->value : NULL; |
| 1111 | } |
| 1112 | |
| 1113 | /** |
| 1114 | * q_tree_height: |
| 1115 | * @tree: a #QTree |
| 1116 | * |
| 1117 | * Gets the height of a #QTree. |
| 1118 | * |
| 1119 | * If the #QTree contains no nodes, the height is 0. |
| 1120 | * If the #QTree contains only one root node the height is 1. |
| 1121 | * If the root node has children the height is 2, etc. |
| 1122 | * |
| 1123 | * Returns: the height of @tree |
| 1124 | */ |
| 1125 | gint |
| 1126 | q_tree_height(QTree *tree) |
| 1127 | { |
| 1128 | QTreeNode *node; |
| 1129 | gint height; |
| 1130 | |
| 1131 | g_return_val_if_fail(tree != NULL, 0); |
| 1132 | |
| 1133 | if (!tree->root) { |
| 1134 | return 0; |
| 1135 | } |
| 1136 | |
| 1137 | height = 0; |
| 1138 | node = tree->root; |
| 1139 | |
| 1140 | while (1) { |
| 1141 | height += 1 + MAX(node->balance, 0); |
| 1142 | |
| 1143 | if (!node->left_child) { |
| 1144 | return height; |
| 1145 | } |
| 1146 | |
| 1147 | node = node->left; |
| 1148 | } |
| 1149 | } |
| 1150 | |
| 1151 | /** |
| 1152 | * q_tree_nnodes: |
| 1153 | * @tree: a #QTree |
| 1154 | * |
| 1155 | * Gets the number of nodes in a #QTree. |
| 1156 | * |
| 1157 | * Returns: the number of nodes in @tree |
| 1158 | */ |
| 1159 | gint |
| 1160 | q_tree_nnodes(QTree *tree) |
| 1161 | { |
| 1162 | g_return_val_if_fail(tree != NULL, 0); |
| 1163 | |
| 1164 | return tree->nnodes; |
| 1165 | } |
| 1166 | |
| 1167 | static QTreeNode * |
| 1168 | q_tree_node_balance(QTreeNode *node) |
| 1169 | { |
| 1170 | if (node->balance < -1) { |
| 1171 | if (node->left->balance > 0) { |
| 1172 | node->left = q_tree_node_rotate_left(node->left); |
| 1173 | } |
| 1174 | node = q_tree_node_rotate_right(node); |
| 1175 | } else if (node->balance > 1) { |
| 1176 | if (node->right->balance < 0) { |
| 1177 | node->right = q_tree_node_rotate_right(node->right); |
| 1178 | } |
| 1179 | node = q_tree_node_rotate_left(node); |
| 1180 | } |
| 1181 | |
| 1182 | return node; |
| 1183 | } |
| 1184 | |
| 1185 | static QTreeNode * QEMU_DISABLE_CFI |
| 1186 | q_tree_find_node(QTree *tree, |
| 1187 | gconstpointer key) |
| 1188 | { |
| 1189 | QTreeNode *node; |
| 1190 | gint cmp; |
| 1191 | |
| 1192 | node = tree->root; |
| 1193 | if (!node) { |
| 1194 | return NULL; |
| 1195 | } |
| 1196 | |
| 1197 | while (1) { |
| 1198 | cmp = tree->key_compare(key, node->key, tree->key_compare_data); |
| 1199 | if (cmp == 0) { |
| 1200 | return node; |
| 1201 | } else if (cmp < 0) { |
| 1202 | if (!node->left_child) { |
| 1203 | return NULL; |
| 1204 | } |
| 1205 | |
| 1206 | node = node->left; |
| 1207 | } else { |
| 1208 | if (!node->right_child) { |
| 1209 | return NULL; |
| 1210 | } |
| 1211 | |
| 1212 | node = node->right; |
| 1213 | } |
| 1214 | } |
| 1215 | } |
| 1216 | |
| 1217 | static QTreeNode * |
| 1218 | q_tree_node_search(QTreeNode *node, |
| 1219 | GCompareFunc search_func, |
| 1220 | gconstpointer data) |
| 1221 | { |
| 1222 | gint dir; |
| 1223 | |
| 1224 | if (!node) { |
| 1225 | return NULL; |
| 1226 | } |
| 1227 | |
| 1228 | while (1) { |
| 1229 | dir = (*search_func)(node->key, data); |
| 1230 | if (dir == 0) { |
| 1231 | return node; |
| 1232 | } else if (dir < 0) { |
| 1233 | if (!node->left_child) { |
| 1234 | return NULL; |
| 1235 | } |
| 1236 | |
| 1237 | node = node->left; |
| 1238 | } else { |
| 1239 | if (!node->right_child) { |
| 1240 | return NULL; |
| 1241 | } |
| 1242 | |
| 1243 | node = node->right; |
| 1244 | } |
| 1245 | } |
| 1246 | } |
| 1247 | |
| 1248 | static QTreeNode * |
| 1249 | q_tree_node_rotate_left(QTreeNode *node) |
| 1250 | { |
| 1251 | QTreeNode *right; |
| 1252 | gint a_bal; |
| 1253 | gint b_bal; |
| 1254 | |
| 1255 | right = node->right; |
| 1256 | |
| 1257 | if (right->left_child) { |
| 1258 | node->right = right->left; |
| 1259 | } else { |
| 1260 | node->right_child = FALSE; |
| 1261 | right->left_child = TRUE; |
| 1262 | } |
| 1263 | right->left = node; |
| 1264 | |
| 1265 | a_bal = node->balance; |
| 1266 | b_bal = right->balance; |
| 1267 | |
| 1268 | if (b_bal <= 0) { |
| 1269 | if (a_bal >= 1) { |
| 1270 | right->balance = b_bal - 1; |
| 1271 | } else { |
| 1272 | right->balance = a_bal + b_bal - 2; |
| 1273 | } |
| 1274 | node->balance = a_bal - 1; |
| 1275 | } else { |
| 1276 | if (a_bal <= b_bal) { |
| 1277 | right->balance = a_bal - 2; |
| 1278 | } else { |
| 1279 | right->balance = b_bal - 1; |
| 1280 | } |
| 1281 | node->balance = a_bal - b_bal - 1; |
| 1282 | } |
| 1283 | |
| 1284 | return right; |
| 1285 | } |
| 1286 | |
| 1287 | static QTreeNode * |
| 1288 | q_tree_node_rotate_right(QTreeNode *node) |
| 1289 | { |
| 1290 | QTreeNode *left; |
| 1291 | gint a_bal; |
| 1292 | gint b_bal; |
| 1293 | |
| 1294 | left = node->left; |
| 1295 | |
| 1296 | if (left->right_child) { |
| 1297 | node->left = left->right; |
| 1298 | } else { |
| 1299 | node->left_child = FALSE; |
| 1300 | left->right_child = TRUE; |
| 1301 | } |
| 1302 | left->right = node; |
| 1303 | |
| 1304 | a_bal = node->balance; |
| 1305 | b_bal = left->balance; |
| 1306 | |
| 1307 | if (b_bal <= 0) { |
| 1308 | if (b_bal > a_bal) { |
| 1309 | left->balance = b_bal + 1; |
| 1310 | } else { |
| 1311 | left->balance = a_bal + 2; |
| 1312 | } |
| 1313 | node->balance = a_bal - b_bal + 1; |
| 1314 | } else { |
| 1315 | if (a_bal <= -1) { |
| 1316 | left->balance = b_bal + 1; |
| 1317 | } else { |
| 1318 | left->balance = a_bal + b_bal + 2; |
| 1319 | } |
| 1320 | node->balance = a_bal + 1; |
| 1321 | } |
| 1322 | |
| 1323 | return left; |
| 1324 | } |
| 1325 | |
| 1326 | #ifdef Q_TREE_DEBUG |
| 1327 | static gint |
| 1328 | q_tree_node_height(QTreeNode *node) |
| 1329 | { |
| 1330 | gint left_height; |
| 1331 | gint right_height; |
| 1332 | |
| 1333 | if (node) { |
| 1334 | left_height = 0; |
| 1335 | right_height = 0; |
| 1336 | |
| 1337 | if (node->left_child) { |
| 1338 | left_height = q_tree_node_height(node->left); |
| 1339 | } |
| 1340 | |
| 1341 | if (node->right_child) { |
| 1342 | right_height = q_tree_node_height(node->right); |
| 1343 | } |
| 1344 | |
| 1345 | return MAX(left_height, right_height) + 1; |
| 1346 | } |
| 1347 | |
| 1348 | return 0; |
| 1349 | } |
| 1350 | |
| 1351 | static void q_tree_node_check(QTreeNode *node) |
| 1352 | { |
| 1353 | gint left_height; |
| 1354 | gint right_height; |
| 1355 | gint balance; |
| 1356 | QTreeNode *tmp; |
| 1357 | |
| 1358 | if (node) { |
| 1359 | if (node->left_child) { |
| 1360 | tmp = q_tree_node_previous(node); |
| 1361 | g_assert(tmp->right == node); |
| 1362 | } |
| 1363 | |
| 1364 | if (node->right_child) { |
| 1365 | tmp = q_tree_node_next(node); |
| 1366 | g_assert(tmp->left == node); |
| 1367 | } |
| 1368 | |
| 1369 | left_height = 0; |
| 1370 | right_height = 0; |
| 1371 | |
| 1372 | if (node->left_child) { |
| 1373 | left_height = q_tree_node_height(node->left); |
| 1374 | } |
| 1375 | if (node->right_child) { |
| 1376 | right_height = q_tree_node_height(node->right); |
| 1377 | } |
| 1378 | |
| 1379 | balance = right_height - left_height; |
| 1380 | g_assert(balance == node->balance); |
| 1381 | |
| 1382 | if (node->left_child) { |
| 1383 | q_tree_node_check(node->left); |
| 1384 | } |
| 1385 | if (node->right_child) { |
| 1386 | q_tree_node_check(node->right); |
| 1387 | } |
| 1388 | } |
| 1389 | } |
| 1390 | #endif |