glib/gtree.c

   1 /* GLIB - Library of useful routines for C programming
   2  * Copyright (C) 1995-1997  Peter Mattis, Spencer Kimball and Josh MacDonald
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the
  16  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17  * Boston, MA 02111-1307, USA.
  18  */
  19
  20 /*
  21  * Modified by the GLib Team and others 1997-2000.  See the AUTHORS
  22  * file for a list of people on the GLib Team.  See the ChangeLog
  23  * files for a list of changes.  These files are distributed with
  24  * GLib at ftp://ftp.gtk.org/pub/gtk/.
  25  */
  26
  27 /*
  28  * MT safe
  29  */
  30
  31 #include "config.h"
  32
  33 #include "glib.h"
  34 #include "galias.h"
  35
  36
  37 typedef struct _GTreeNode  GTreeNode;
  38
  39 struct _GTree
  40 {
  41   GTreeNode *root;
  42   GCompareDataFunc key_compare;
  43   GDestroyNotify   key_destroy_func;
  44   GDestroyNotify   value_destroy_func;
  45   gpointer         key_compare_data;
  46 };
  47
  48 struct _GTreeNode
  49 {
  50   gint balance;      /* height (left) - height (right) */
  51   GTreeNode *left;   /* left subtree */
  52   GTreeNode *right;  /* right subtree */
  53   gpointer key;      /* key for this node */
  54   gpointer value;    /* value stored at this node */
  55 };
  56
  57
  58 static GTreeNode* g_tree_node_new                   (gpointer          key,
  59                                                      gpointer          value);
  60 static void       g_tree_node_destroy               (GTreeNode        *node,
  61                                                      GDestroyNotify    key_destroy_func,
  62                                                      GDestroyNotify    value_destroy_func);
  63 static GTreeNode* g_tree_node_insert                (GTree            *tree,
  64                                                      GTreeNode        *node,
  65                                                      gpointer          key,
  66                                                      gpointer          value,
  67                                                      gboolean          replace,
  68                                                      gboolean         *inserted);
  69 static GTreeNode* g_tree_node_remove                (GTree            *tree,
  70                                                      GTreeNode        *node,
  71                                                      gconstpointer     key,
  72                                                      gboolean          notify);
  73 static GTreeNode* g_tree_node_balance               (GTreeNode        *node);
  74 static GTreeNode* g_tree_node_remove_leftmost       (GTreeNode        *node,
  75                                                      GTreeNode       **leftmost);
  76 static GTreeNode* g_tree_node_restore_left_balance  (GTreeNode        *node,
  77                                                      gint              old_balance);
  78 static GTreeNode* g_tree_node_restore_right_balance (GTreeNode        *node,
  79                                                      gint              old_balance);
  80 static GTreeNode* g_tree_node_lookup                (GTreeNode        *node,
  81                                                      GCompareDataFunc  compare,
  82                                                      gpointer          comp_data,
  83                                                      gconstpointer     key);
  84 static gint       g_tree_node_count                 (GTreeNode        *node);
  85 static gint       g_tree_node_pre_order             (GTreeNode        *node,
  86                                                      GTraverseFunc     traverse_func,
  87                                                      gpointer          data);
  88 static gint       g_tree_node_in_order              (GTreeNode        *node,
  89                                                      GTraverseFunc     traverse_func,
  90                                                      gpointer          data);
  91 static gint       g_tree_node_post_order            (GTreeNode        *node,
  92                                                      GTraverseFunc     traverse_func,
  93                                                      gpointer          data);
  94 static gpointer   g_tree_node_search                (GTreeNode        *node,
  95                                                      GCompareFunc      search_func,
  96                                                      gconstpointer     data);
  97 static gint       g_tree_node_height                (GTreeNode        *node);
  98 static GTreeNode* g_tree_node_rotate_left           (GTreeNode        *node);
  99 static GTreeNode* g_tree_node_rotate_right          (GTreeNode        *node);
 100 static void       g_tree_node_check                 (GTreeNode        *node);
 101
 102
 103 G_LOCK_DEFINE_STATIC (g_tree_global);
 104 static GMemChunk *node_mem_chunk = NULL;
 105 static GTreeNode *node_free_list = NULL;
 106
 107
 108 static GTreeNode*
 109 g_tree_node_new (gpointer key,
 110                  gpointer value)
 111 {
 112   GTreeNode *node;
 113
 114   G_LOCK (g_tree_global);
 115   if (node_free_list)
 116     {
 117       node = node_free_list;
 118       node_free_list = node->right;
 119     }
 120   else
 121     {
 122       if (!node_mem_chunk)
 123         node_mem_chunk = g_mem_chunk_new ("GLib GTreeNode mem chunk",
 124                                           sizeof (GTreeNode),
 125                                           1024,
 126                                           G_ALLOC_ONLY);
 127
 128       node = g_chunk_new (GTreeNode, node_mem_chunk);
 129    }
 130   G_UNLOCK (g_tree_global);
 131
 132   node->balance = 0;
 133   node->left = NULL;
 134   node->right = NULL;
 135   node->key = key;
 136   node->value = value;
 137
 138   return node;
 139 }
 140
 141 static void
 142 g_tree_node_destroy (GTreeNode      *node,
 143                      GDestroyNotify  key_destroy_func,
 144                      GDestroyNotify  value_destroy_func)
 145 {
 146   if (node)
 147     {
 148       g_tree_node_destroy (node->right,
 149                            key_destroy_func, value_destroy_func);
 150       g_tree_node_destroy (node->left,
 151                            key_destroy_func, value_destroy_func);
 152
 153       if (key_destroy_func)
 154         key_destroy_func (node->key);
 155       if (value_destroy_func)
 156         value_destroy_func (node->value);
 157
 158 #ifdef ENABLE_GC_FRIENDLY
 159       node->left = NULL;
 160       node->key = NULL;
 161       node->value = NULL;
 162 #endif /* ENABLE_GC_FRIENDLY */
 163
 164       G_LOCK (g_tree_global);
 165       node->right = node_free_list;
 166       node_free_list = node;
 167       G_UNLOCK (g_tree_global);
 168    }
 169 }
 170
 171 /**
 172  * g_tree_new:
 173  * @key_compare_func: the function used to order the nodes in the #GTree.
 174  *   It should return values similar to the standard strcmp() function -
 175  *   0 if the two arguments are equal, a negative value if the first argument
 176  *   comes before the second, or a positive value if the first argument comes
 177  *   after the second.
 178  *
 179  * Creates a new #GTree.
 180  *
 181  * Return value: a new #GTree.
 182  **/
 183 GTree*
 184 g_tree_new (GCompareFunc key_compare_func)
 185 {
 186   g_return_val_if_fail (key_compare_func != NULL, NULL);
 187
 188   return g_tree_new_full ((GCompareDataFunc) key_compare_func, NULL,
 189                           NULL, NULL);
 190 }
 191
 192 /**
 193  * g_tree_new_with_data:
 194  * @key_compare_func: qsort()-style comparison function.
 195  * @key_compare_data: data to pass to comparison function.
 196  *
 197  * Creates a new #GTree with a comparison function that accepts user data.
 198  * See g_tree_new() for more details.
 199  *
 200  * Return value: a new #GTree.
 201  **/
 202 GTree*
 203 g_tree_new_with_data (GCompareDataFunc key_compare_func,
 204                       gpointer         key_compare_data)
 205 {
 206   g_return_val_if_fail (key_compare_func != NULL, NULL);
 207
 208   return g_tree_new_full (key_compare_func, key_compare_data,
 209                           NULL, NULL);
 210 }
 211
 212 /**
 213  * g_tree_new_full:
 214  * @key_compare_func: qsort()-style comparison function.
 215  * @key_compare_data: data to pass to comparison function.
 216  * @key_destroy_func: a function to free the memory allocated for the key
 217  *   used when removing the entry from the #GTree or %NULL if you don't
 218  *   want to supply such a function.
 219  * @value_destroy_func: a function to free the memory allocated for the
 220  *   value used when removing the entry from the #GTree or %NULL if you
 221  *   don't want to supply such a function.
 222  *
 223  * Creates a new #GTree like g_tree_new() and allows to specify functions
 224  * to free the memory allocated for the key and value that get called when
 225  * removing the entry from the #GTree.
 226  *
 227  * Return value: a new #GTree.
 228  **/
 229 GTree*
 230 g_tree_new_full (GCompareDataFunc key_compare_func,
 231                  gpointer         key_compare_data,
 232                  GDestroyNotify   key_destroy_func,
 233                  GDestroyNotify   value_destroy_func)
 234 {
 235   GTree *tree;
 236
 237   g_return_val_if_fail (key_compare_func != NULL, NULL);
 238
 239   tree = g_new (GTree, 1);
 240   tree->root               = NULL;
 241   tree->key_compare        = key_compare_func;
 242   tree->key_destroy_func   = key_destroy_func;
 243   tree->value_destroy_func = value_destroy_func;
 244   tree->key_compare_data   = key_compare_data;
 245
 246   return tree;
 247 }
 248
 249 /**
 250  * g_tree_destroy:
 251  * @tree: a #GTree.
 252  *
 253  * Destroys the #GTree. If keys and/or values are dynamically allocated, you
 254  * should either free them first or create the #GTree using g_tree_new_full().
 255  * In the latter case the destroy functions you supplied will be called on
 256  * all keys and values before destroying the #GTree.
 257  **/
 258 void
 259 g_tree_destroy (GTree *tree)
 260 {
 261   g_return_if_fail (tree != NULL);
 262
 263   g_tree_node_destroy (tree->root,
 264                        tree->key_destroy_func,
 265                        tree->value_destroy_func);
 266
 267   g_free (tree);
 268 }
 269
 270 /**
 271  * g_tree_insert:
 272  * @tree: a #GTree.
 273  * @key: the key to insert.
 274  * @value: the value corresponding to the key.
 275  *
 276  * Inserts a key/value pair into a #GTree. If the given key already exists
 277  * in the #GTree its corresponding value is set to the new value. If you
 278  * supplied a value_destroy_func when creating the #GTree, the old value is
 279  * freed using that function. If you supplied a @key_destroy_func when
 280  * creating the #GTree, the passed key is freed using that function.
 281  *
 282  * The tree is automatically 'balanced' as new key/value pairs are added,
 283  * so that the distance from the root to every leaf is as small as possible.
 284  **/
 285 void
 286 g_tree_insert (GTree    *tree,
 287                gpointer  key,
 288                gpointer  value)
 289 {
 290   gboolean   inserted;
 291
 292   g_return_if_fail (tree != NULL);
 293
 294   inserted = FALSE;
 295   tree->root = g_tree_node_insert (tree,
 296                                    tree->root,
 297                                    key, value,
 298                                    FALSE, &inserted);
 299 }
 300
 301 /**
 302  * g_tree_replace:
 303  * @tree: a #GTree.
 304  * @key: the key to insert.
 305  * @value: the value corresponding to the key.
 306  *
 307  * Inserts a new key and value into a #GTree similar to g_tree_insert().
 308  * The difference is that if the key already exists in the #GTree, it gets
 309  * replaced by the new key. If you supplied a @value_destroy_func when
 310  * creating the #GTree, the old value is freed using that function. If you
 311  * supplied a @key_destroy_func when creating the #GTree, the old key is
 312  * freed using that function.
 313  *
 314  * The tree is automatically 'balanced' as new key/value pairs are added,
 315  * so that the distance from the root to every leaf is as small as possible.
 316  **/
 317 void
 318 g_tree_replace (GTree    *tree,
 319                 gpointer  key,
 320                 gpointer  value)
 321 {
 322   gboolean   inserted;
 323
 324   g_return_if_fail (tree != NULL);
 325
 326   inserted = FALSE;
 327   tree->root = g_tree_node_insert (tree,
 328                                    tree->root,
 329                                    key, value,
 330                                    TRUE, &inserted);
 331 }
 332
 333 /**
 334  * g_tree_remove:
 335  * @tree: a #GTree.
 336  * @key: the key to remove.
 337  *
 338  * Removes a key/value pair from a #GTree.
 339  *
 340  * If the #GTree was created using g_tree_new_full(), the key and value
 341  * are freed using the supplied destroy functions, otherwise you have to
 342  * make sure that any dynamically allocated values are freed yourself.
 343  **/
 344 void
 345 g_tree_remove (GTree         *tree,
 346                gconstpointer  key)
 347 {
 348   g_return_if_fail (tree != NULL);
 349
 350   tree->root = g_tree_node_remove (tree, tree->root, key, TRUE);
 351 }
 352
 353 /**
 354  * g_tree_steal:
 355  * @tree: a #GTree.
 356  * @key: the key to remove.
 357  *
 358  * Removes a key and its associated value from a #GTree without calling
 359  * the key and value destroy functions.
 360  **/
 361 void
 362 g_tree_steal (GTree         *tree,
 363               gconstpointer  key)
 364 {
 365   g_return_if_fail (tree != NULL);
 366
 367   tree->root = g_tree_node_remove (tree, tree->root, key, FALSE);
 368 }
 369
 370 /**
 371  * g_tree_lookup:
 372  * @tree: a #GTree.
 373  * @key: the key to look up.
 374  *
 375  * Gets the value corresponding to the given key. Since a #GTree is
 376  * automatically balanced as key/value pairs are added, key lookup is very
 377  * fast.
 378  *
 379  * Return value: the value corresponding to the key.
 380  **/
 381 gpointer
 382 g_tree_lookup (GTree         *tree,
 383                gconstpointer  key)
 384 {
 385   GTreeNode *node;
 386
 387   g_return_val_if_fail (tree != NULL, NULL);
 388
 389   node = g_tree_node_lookup (tree->root,
 390                              tree->key_compare, tree->key_compare_data, key);
 391
 392   return node ? node->value : NULL;
 393 }
 394
 395 /**
 396  * g_tree_lookup_extended:
 397  * @tree: a #GTree.
 398  * @lookup_key: the key to look up.
 399  * @orig_key: returns the original key.
 400  * @value: returns the value associated with the key.
 401  *
 402  * Looks up a key in the #GTree, returning the original key and the
 403  * associated value and a #gboolean which is %TRUE if the key was found. This
 404  * is useful if you need to free the memory allocated for the original key,
 405  * for example before calling g_tree_remove().
 406  *
 407  * Return value: %TRUE if the key was found in the #GTree.
 408  **/
 409 gboolean
 410 g_tree_lookup_extended (GTree         *tree,
 411                         gconstpointer  lookup_key,
 412                         gpointer      *orig_key,
 413                         gpointer      *value)
 414 {
 415   GTreeNode *node;
 416
 417   g_return_val_if_fail (tree != NULL, FALSE);
 418
 419   node = g_tree_node_lookup (tree->root,
 420                              tree->key_compare, tree->key_compare_data, lookup_key);
 421
 422   if (node)
 423     {
 424       if (orig_key)
 425         *orig_key = node->key;
 426       if (value)
 427         *value = node->value;
 428       return TRUE;
 429     }
 430   else
 431     return FALSE;
 432 }
 433
 434 /**
 435  * g_tree_foreach:
 436  * @tree: a #GTree.
 437  * @func: the function to call for each node visited. If this function
 438  *   returns %TRUE, the traversal is stopped.
 439  * @user_data: user data to pass to the function.
 440  *
 441  * Calls the given function for each of the key/value pairs in the #GTree.
 442  * The function is passed the key and value of each pair, and the given
 443  * @data parameter. The tree is traversed in sorted order.
 444  *
 445  * The tree may not be modified while iterating over it (you can't
 446  * add/remove items). To remove all items matching a predicate, you need
 447  * to add each item to a list in your #GTraverseFunc as you walk over
 448  * the tree, then walk the list and remove each item.
 449  **/
 450 void
 451 g_tree_foreach (GTree         *tree,
 452                 GTraverseFunc  func,
 453                 gpointer       user_data)
 454 {
 455   g_return_if_fail (tree != NULL);
 456
 457   if (!tree->root)
 458     return;
 459
 460   g_tree_node_in_order (tree->root, func, user_data);
 461 }
 462
 463 /**
 464  * g_tree_traverse:
 465  * @tree: a #GTree.
 466  * @traverse_func: the function to call for each node visited. If this
 467  *   function returns %TRUE, the traversal is stopped.
 468  * @traverse_type: the order in which nodes are visited, one of %G_IN_ORDER,
 469  *   %G_PRE_ORDER and %G_POST_ORDER.
 470  * @user_data: user data to pass to the function.
 471  *
 472  * Calls the given function for each node in the #GTree.
 473  *
 474  * Deprecated: The order of a balanced tree is somewhat arbitrary. If you
 475  * just want to visit all nodes in sorted order, use g_tree_foreach()
 476  * instead. If you really need to visit nodes in a different order, consider
 477  * using an <link linkend="glib-N-ary-Trees">N-ary Tree</link>.
 478  **/
 479 void
 480 g_tree_traverse (GTree         *tree,
 481                  GTraverseFunc  traverse_func,
 482                  GTraverseType  traverse_type,
 483                  gpointer       user_data)
 484 {
 485   g_return_if_fail (tree != NULL);
 486
 487   if (!tree->root)
 488     return;
 489
 490   switch (traverse_type)
 491     {
 492     case G_PRE_ORDER:
 493       g_tree_node_pre_order (tree->root, traverse_func, user_data);
 494       break;
 495
 496     case G_IN_ORDER:
 497       g_tree_node_in_order (tree->root, traverse_func, user_data);
 498       break;
 499
 500     case G_POST_ORDER:
 501       g_tree_node_post_order (tree->root, traverse_func, user_data);
 502       break;
 503
 504     case G_LEVEL_ORDER:
 505       g_warning ("g_tree_traverse(): traverse type G_LEVEL_ORDER isn't implemented.");
 506       break;
 507     }
 508 }
 509
 510 /**
 511  * g_tree_search:
 512  * @tree: a #GTree.
 513  * @search_func: a function used to search the #GTree.
 514  * @user_data: the data passed as the second argument to the @search_func
 515  * function.
 516  *
 517  * Searches a #GTree using @search_func.
 518  *
 519  * The @search_func is called with a pointer to the key of a key/value pair in the tree,
 520  * and the passed in @user_data. If @search_func returns 0 for a key/value pair, then
 521  * g_tree_search_func() will return the value of that pair. If @search_func returns -1,
 522  * searching will proceed among the key/value pairs that have a smaller key; if @search_func
 523  * returns 1, searching will proceed among the key/value pairs that have a larger key.
 524  *
 525  * Return value: the value corresponding to the found key, or %NULL if the key
 526  * was not found.
 527  **/
 528 gpointer
 529 g_tree_search (GTree         *tree,
 530                GCompareFunc   search_func,
 531                gconstpointer  user_data)
 532 {
 533   g_return_val_if_fail (tree != NULL, NULL);
 534
 535   if (tree->root)
 536     return g_tree_node_search (tree->root, search_func, user_data);
 537   else
 538     return NULL;
 539 }
 540
 541 /**
 542  * g_tree_height:
 543  * @tree: a #GTree.
 544  *
 545  * Gets the height of a #GTree.
 546  *
 547  * If the #GTree contains no nodes, the height is 0.
 548  * If the #GTree contains only one root node the height is 1.
 549  * If the root node has children the height is 2, etc.
 550  *
 551  * Return value: the height of the #GTree.
 552  **/
 553 gint
 554 g_tree_height (GTree *tree)
 555 {
 556   g_return_val_if_fail (tree != NULL, 0);
 557
 558   if (tree->root)
 559     return g_tree_node_height (tree->root);
 560   else
 561     return 0;
 562 }
 563
 564 /**
 565  * g_tree_nnodes:
 566  * @tree: a #GTree.
 567  *
 568  * Gets the number of nodes in a #GTree.
 569  *
 570  * Return value: the number of nodes in the #GTree.
 571  **/
 572 gint
 573 g_tree_nnodes (GTree *tree)
 574 {
 575   g_return_val_if_fail (tree != NULL, 0);
 576
 577   if (tree->root)
 578     return g_tree_node_count (tree->root);
 579   else
 580     return 0;
 581 }
 582
 583 static GTreeNode*
 584 g_tree_node_insert (GTree     *tree,
 585                     GTreeNode *node,
 586                     gpointer   key,
 587                     gpointer   value,
 588                     gboolean   replace,
 589                     gboolean  *inserted)
 590 {
 591   gint  old_balance;
 592   gint  cmp;
 593
 594   if (!node)
 595     {
 596       *inserted = TRUE;
 597       return g_tree_node_new (key, value);
 598     }
 599
 600   cmp = tree->key_compare (key, node->key, tree->key_compare_data);
 601   if (cmp == 0)
 602     {
 603       *inserted = FALSE;
 604
 605       if (tree->value_destroy_func)
 606         tree->value_destroy_func (node->value);
 607
 608       node->value = value;
 609
 610       if (replace)
 611         {
 612           if (tree->key_destroy_func)
 613             tree->key_destroy_func (node->key);
 614
 615           node->key = key;
 616         }
 617       else
 618         {
 619           /* free the passed key */
 620           if (tree->key_destroy_func)
 621             tree->key_destroy_func (key);
 622         }
 623
 624       return node;
 625     }
 626
 627   if (cmp < 0)
 628     {
 629       if (node->left)
 630         {
 631           old_balance = node->left->balance;
 632           node->left = g_tree_node_insert (tree,
 633                                            node->left,
 634                                            key, value,
 635                                            replace, inserted);
 636
 637           if ((old_balance != node->left->balance) && node->left->balance)
 638             node->balance -= 1;
 639         }
 640       else
 641         {
 642           *inserted = TRUE;
 643           node->left = g_tree_node_new (key, value);
 644           node->balance -= 1;
 645         }
 646     }
 647   else if (cmp > 0)
 648     {
 649       if (node->right)
 650         {
 651           old_balance = node->right->balance;
 652           node->right = g_tree_node_insert (tree,
 653                                             node->right,
 654                                             key, value,
 655                                             replace, inserted);
 656
 657           if ((old_balance != node->right->balance) && node->right->balance)
 658             node->balance += 1;
 659         }
 660       else
 661         {
 662           *inserted = TRUE;
 663           node->right = g_tree_node_new (key, value);
 664           node->balance += 1;
 665         }
 666     }
 667
 668   if (*inserted)
 669     {
 670       if ((node->balance < -1) || (node->balance > 1))
 671         node = g_tree_node_balance (node);
 672     }
 673
 674   return node;
 675 }
 676
 677 static GTreeNode*
 678 g_tree_node_remove (GTree         *tree,
 679                     GTreeNode     *node,
 680                     gconstpointer  key,
 681                     gboolean       notify)
 682 {
 683   GTreeNode *new_root;
 684   gint old_balance;
 685   gint cmp;
 686
 687   if (!node)
 688     return NULL;
 689
 690   cmp = tree->key_compare (key, node->key, tree->key_compare_data);
 691   if (cmp == 0)
 692     {
 693       GTreeNode *garbage;
 694
 695       garbage = node;
 696
 697       if (!node->right)
 698         {
 699           node = node->left;
 700         }
 701       else
 702         {
 703           old_balance = node->right->balance;
 704           node->right = g_tree_node_remove_leftmost (node->right, &new_root);
 705           new_root->left = node->left;
 706           new_root->right = node->right;
 707           new_root->balance = node->balance;
 708           node = g_tree_node_restore_right_balance (new_root, old_balance);
 709         }
 710
 711       if (notify)
 712         {
 713           if (tree->key_destroy_func)
 714             tree->key_destroy_func (garbage->key);
 715           if (tree->value_destroy_func)
 716             tree->value_destroy_func (garbage->value);
 717         }
 718
 719 #ifdef ENABLE_GC_FRIENDLY
 720       garbage->left = NULL;
 721       garbage->key = NULL;
 722       garbage->value = NULL;
 723 #endif /* ENABLE_GC_FRIENDLY */
 724
 725       G_LOCK (g_tree_global);
 726       garbage->right = node_free_list;
 727       node_free_list = garbage;
 728       G_UNLOCK (g_tree_global);
 729    }
 730   else if (cmp < 0)
 731     {
 732       if (node->left)
 733         {
 734           old_balance = node->left->balance;
 735           node->left = g_tree_node_remove (tree, node->left, key, notify);
 736           node = g_tree_node_restore_left_balance (node, old_balance);
 737         }
 738     }
 739   else if (cmp > 0)
 740     {
 741       if (node->right)
 742         {
 743           old_balance = node->right->balance;
 744           node->right = g_tree_node_remove (tree, node->right, key, notify);
 745           node = g_tree_node_restore_right_balance (node, old_balance);
 746         }
 747     }
 748
 749   return node;
 750 }
 751
 752 static GTreeNode*
 753 g_tree_node_balance (GTreeNode *node)
 754 {
 755   if (node->balance < -1)
 756     {
 757       if (node->left->balance > 0)
 758         node->left = g_tree_node_rotate_left (node->left);
 759       node = g_tree_node_rotate_right (node);
 760     }
 761   else if (node->balance > 1)
 762     {
 763       if (node->right->balance < 0)
 764         node->right = g_tree_node_rotate_right (node->right);
 765       node = g_tree_node_rotate_left (node);
 766     }
 767
 768   return node;
 769 }
 770
 771 static GTreeNode*
 772 g_tree_node_remove_leftmost (GTreeNode  *node,
 773                              GTreeNode **leftmost)
 774 {
 775   gint old_balance;
 776
 777   if (!node->left)
 778     {
 779       *leftmost = node;
 780       return node->right;
 781     }
 782
 783   old_balance = node->left->balance;
 784   node->left = g_tree_node_remove_leftmost (node->left, leftmost);
 785   return g_tree_node_restore_left_balance (node, old_balance);
 786 }
 787
 788 static GTreeNode*
 789 g_tree_node_restore_left_balance (GTreeNode *node,
 790                                   gint       old_balance)
 791 {
 792   if (!node->left)
 793     node->balance += 1;
 794   else if ((node->left->balance != old_balance) &&
 795            (node->left->balance == 0))
 796     node->balance += 1;
 797
 798   if (node->balance > 1)
 799     return g_tree_node_balance (node);
 800   return node;
 801 }
 802
 803 static GTreeNode*
 804 g_tree_node_restore_right_balance (GTreeNode *node,
 805                                    gint       old_balance)
 806 {
 807   if (!node->right)
 808     node->balance -= 1;
 809   else if ((node->right->balance != old_balance) &&
 810            (node->right->balance == 0))
 811     node->balance -= 1;
 812
 813   if (node->balance < -1)
 814     return g_tree_node_balance (node);
 815   return node;
 816 }
 817
 818 static GTreeNode *
 819 g_tree_node_lookup (GTreeNode        *node,
 820                     GCompareDataFunc  compare,
 821                     gpointer          compare_data,
 822                     gconstpointer     key)
 823 {
 824   gint cmp;
 825
 826   if (!node)
 827     return NULL;
 828
 829   cmp = (* compare) (key, node->key, compare_data);
 830   if (cmp == 0)
 831     return node;
 832
 833   if (cmp < 0)
 834     {
 835       if (node->left)
 836         return g_tree_node_lookup (node->left, compare, compare_data, key);
 837     }
 838   else if (cmp > 0)
 839     {
 840       if (node->right)
 841         return g_tree_node_lookup (node->right, compare, compare_data, key);
 842     }
 843
 844   return NULL;
 845 }
 846
 847 static gint
 848 g_tree_node_count (GTreeNode *node)
 849 {
 850   gint count;
 851
 852   count = 1;
 853   if (node->left)
 854     count += g_tree_node_count (node->left);
 855   if (node->right)
 856     count += g_tree_node_count (node->right);
 857
 858   return count;
 859 }
 860
 861 static gint
 862 g_tree_node_pre_order (GTreeNode     *node,
 863                        GTraverseFunc  traverse_func,
 864                        gpointer       data)
 865 {
 866   if ((*traverse_func) (node->key, node->value, data))
 867     return TRUE;
 868   if (node->left)
 869     {
 870       if (g_tree_node_pre_order (node->left, traverse_func, data))
 871         return TRUE;
 872     }
 873   if (node->right)
 874     {
 875       if (g_tree_node_pre_order (node->right, traverse_func, data))
 876         return TRUE;
 877     }
 878
 879   return FALSE;
 880 }
 881
 882 static gint
 883 g_tree_node_in_order (GTreeNode     *node,
 884                       GTraverseFunc  traverse_func,
 885                       gpointer       data)
 886 {
 887   if (node->left)
 888     {
 889       if (g_tree_node_in_order (node->left, traverse_func, data))
 890         return TRUE;
 891     }
 892   if ((*traverse_func) (node->key, node->value, data))
 893     return TRUE;
 894   if (node->right)
 895     {
 896       if (g_tree_node_in_order (node->right, traverse_func, data))
 897         return TRUE;
 898     }
 899
 900   return FALSE;
 901 }
 902
 903 static gint
 904 g_tree_node_post_order (GTreeNode     *node,
 905                         GTraverseFunc  traverse_func,
 906                         gpointer       data)
 907 {
 908   if (node->left)
 909     {
 910       if (g_tree_node_post_order (node->left, traverse_func, data))
 911         return TRUE;
 912     }
 913   if (node->right)
 914     {
 915       if (g_tree_node_post_order (node->right, traverse_func, data))
 916         return TRUE;
 917     }
 918   if ((*traverse_func) (node->key, node->value, data))
 919     return TRUE;
 920
 921   return FALSE;
 922 }
 923
 924 static gpointer
 925 g_tree_node_search (GTreeNode     *node,
 926                     GCompareFunc   search_func,
 927                     gconstpointer  data)
 928 {
 929   gint dir;
 930
 931   if (!node)
 932     return NULL;
 933
 934   do {
 935     dir = (* search_func) (node->key, data);
 936     if (dir == 0)
 937       return node->value;
 938
 939     if (dir < 0)
 940       node = node->left;
 941     else if (dir > 0)
 942       node = node->right;
 943   } while (node);
 944
 945   return NULL;
 946 }
 947
 948 static gint
 949 g_tree_node_height (GTreeNode *node)
 950 {
 951   gint left_height;
 952   gint right_height;
 953
 954   if (node)
 955     {
 956       left_height = 0;
 957       right_height = 0;
 958
 959       if (node->left)
 960         left_height = g_tree_node_height (node->left);
 961
 962       if (node->right)
 963         right_height = g_tree_node_height (node->right);
 964
 965       return MAX (left_height, right_height) + 1;
 966     }
 967
 968   return 0;
 969 }
 970
 971 static GTreeNode*
 972 g_tree_node_rotate_left (GTreeNode *node)
 973 {
 974   GTreeNode *right;
 975   gint a_bal;
 976   gint b_bal;
 977
 978   right = node->right;
 979
 980   node->right = right->left;
 981   right->left = node;
 982
 983   a_bal = node->balance;
 984   b_bal = right->balance;
 985
 986   if (b_bal <= 0)
 987     {
 988       if (a_bal >= 1)
 989         right->balance = b_bal - 1;
 990       else
 991         right->balance = a_bal + b_bal - 2;
 992       node->balance = a_bal - 1;
 993     }
 994   else
 995     {
 996       if (a_bal <= b_bal)
 997         right->balance = a_bal - 2;
 998       else
 999         right->balance = b_bal - 1;
1000       node->balance = a_bal - b_bal - 1;
1001     }
1002
1003   return right;
1004 }
1005
1006 static GTreeNode*
1007 g_tree_node_rotate_right (GTreeNode *node)
1008 {
1009   GTreeNode *left;
1010   gint a_bal;
1011   gint b_bal;
1012
1013   left = node->left;
1014
1015   node->left = left->right;
1016   left->right = node;
1017
1018   a_bal = node->balance;
1019   b_bal = left->balance;
1020
1021   if (b_bal <= 0)
1022     {
1023       if (b_bal > a_bal)
1024         left->balance = b_bal + 1;
1025       else
1026         left->balance = a_bal + 2;
1027       node->balance = a_bal - b_bal + 1;
1028     }
1029   else
1030     {
1031       if (a_bal <= -1)
1032         left->balance = b_bal + 1;
1033       else
1034         left->balance = a_bal + b_bal + 2;
1035       node->balance = a_bal + 1;
1036     }
1037
1038   return left;
1039 }
1040
1041 static void
1042 g_tree_node_check (GTreeNode *node)
1043 {
1044   gint left_height;
1045   gint right_height;
1046   gint balance;
1047
1048   if (node)
1049     {
1050       left_height = 0;
1051       right_height = 0;
1052
1053       if (node->left)
1054         left_height = g_tree_node_height (node->left);
1055       if (node->right)
1056         right_height = g_tree_node_height (node->right);
1057
1058       balance = right_height - left_height;
1059       if (balance != node->balance)
1060         g_log (G_LOG_DOMAIN, G_LOG_LEVEL_INFO,
1061                "g_tree_node_check: failed: %d ( %d )\n",
1062                balance, node->balance);
1063
1064       if (node->left)
1065         g_tree_node_check (node->left);
1066       if (node->right)
1067         g_tree_node_check (node->right);
1068     }
1069 }
1070
1071 #define __G_TREE_C__
1072 #include "galiasdef.c"