/* libavl - library for manipulation of binary trees. Copyright (C) 1998-2002, 2004 Free Software Foundation, Inc. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. The author may be contacted at on the Internet, or write to Ben Pfaff, Stanford University, Computer Science Dept., 353 Serra Mall, Stanford CA 94305, USA. */ #include #include #include #include "rtavl.h" /* Creates and returns a new table with comparison function |compare| using parameter |param| and memory allocator |allocator|. Returns |NULL| if memory allocation failed. */ struct rtavl_table * rtavl_create (rtavl_comparison_func *compare, void *param, struct libavl_allocator *allocator) { struct rtavl_table *tree; assert (compare != NULL); if (allocator == NULL) allocator = &rtavl_allocator_default; tree = allocator->libavl_malloc (allocator, sizeof *tree); if (tree == NULL) return NULL; tree->rtavl_root = NULL; tree->rtavl_compare = compare; tree->rtavl_param = param; tree->rtavl_alloc = allocator; tree->rtavl_count = 0; return tree; } /* Search |tree| for an item matching |item|, and return it if found. Otherwise return |NULL|. */ void * rtavl_find (const struct rtavl_table *tree, const void *item) { const struct rtavl_node *p; int dir; assert (tree != NULL && item != NULL); if (tree->rtavl_root == NULL) return NULL; for (p = tree->rtavl_root; ; p = p->rtavl_link[dir]) { int cmp = tree->rtavl_compare (item, p->rtavl_data, tree->rtavl_param); if (cmp == 0) return p->rtavl_data; dir = cmp > 0; if (dir == 0) { if (p->rtavl_link[0] == NULL) return NULL; } else /* |dir == 1| */ { if (p->rtavl_rtag == RTAVL_THREAD) return NULL; } } } /* Inserts |item| into |tree| and returns a pointer to |item|'s address. If a duplicate item is found in the tree, returns a pointer to the duplicate without inserting |item|. Returns |NULL| in case of memory allocation failure. */ void ** rtavl_probe (struct rtavl_table *tree, void *item) { struct rtavl_node *y, *z; /* Top node to update balance factor, and parent. */ struct rtavl_node *p, *q; /* Iterator, and parent. */ struct rtavl_node *n; /* Newly inserted node. */ struct rtavl_node *w; /* New root of rebalanced subtree. */ int dir; /* Direction to descend. */ unsigned char da[RTAVL_MAX_HEIGHT]; /* Cached comparison results. */ int k = 0; /* Number of cached results. */ assert (tree != NULL && item != NULL); z = (struct rtavl_node *) &tree->rtavl_root; y = tree->rtavl_root; if (tree->rtavl_root != NULL) for (q = z, p = y; ; q = p, p = p->rtavl_link[dir]) { int cmp = tree->rtavl_compare (item, p->rtavl_data, tree->rtavl_param); if (cmp == 0) return &p->rtavl_data; if (p->rtavl_balance != 0) z = q, y = p, k = 0; da[k++] = dir = cmp > 0; if (dir == 0) { if (p->rtavl_link[0] == NULL) break; } else /* |dir == 1| */ { if (p->rtavl_rtag == RTAVL_THREAD) break; } } else { p = (struct rtavl_node *) &tree->rtavl_root; dir = 0; } n = tree->rtavl_alloc->libavl_malloc (tree->rtavl_alloc, sizeof *n); if (n == NULL) return NULL; tree->rtavl_count++; n->rtavl_data = item; n->rtavl_link[0] = NULL; if (dir == 0) n->rtavl_link[1] = p; else /* |dir == 1| */ { p->rtavl_rtag = RTAVL_CHILD; n->rtavl_link[1] = p->rtavl_link[1]; } n->rtavl_rtag = RTAVL_THREAD; n->rtavl_balance = 0; p->rtavl_link[dir] = n; if (y == NULL) { n->rtavl_link[1] = NULL; return &n->rtavl_data; } for (p = y, k = 0; p != n; p = p->rtavl_link[da[k]], k++) if (da[k] == 0) p->rtavl_balance--; else p->rtavl_balance++; if (y->rtavl_balance == -2) { struct rtavl_node *x = y->rtavl_link[0]; if (x->rtavl_balance == -1) { w = x; if (x->rtavl_rtag == RTAVL_THREAD) { x->rtavl_rtag = RTAVL_CHILD; y->rtavl_link[0] = NULL; } else y->rtavl_link[0] = x->rtavl_link[1]; x->rtavl_link[1] = y; x->rtavl_balance = y->rtavl_balance = 0; } else { assert (x->rtavl_balance == +1); w = x->rtavl_link[1]; x->rtavl_link[1] = w->rtavl_link[0]; w->rtavl_link[0] = x; y->rtavl_link[0] = w->rtavl_link[1]; w->rtavl_link[1] = y; if (w->rtavl_balance == -1) x->rtavl_balance = 0, y->rtavl_balance = +1; else if (w->rtavl_balance == 0) x->rtavl_balance = y->rtavl_balance = 0; else /* |w->rtavl_balance == +1| */ x->rtavl_balance = -1, y->rtavl_balance = 0; w->rtavl_balance = 0; if (x->rtavl_link[1] == NULL) { x->rtavl_rtag = RTAVL_THREAD; x->rtavl_link[1] = w; } if (w->rtavl_rtag == RTAVL_THREAD) { y->rtavl_link[0] = NULL; w->rtavl_rtag = RTAVL_CHILD; } } } else if (y->rtavl_balance == +2) { struct rtavl_node *x = y->rtavl_link[1]; if (x->rtavl_balance == +1) { w = x; if (x->rtavl_link[0] == NULL) { y->rtavl_rtag = RTAVL_THREAD; y->rtavl_link[1] = x; } else y->rtavl_link[1] = x->rtavl_link[0]; x->rtavl_link[0] = y; x->rtavl_balance = y->rtavl_balance = 0; } else { assert (x->rtavl_balance == -1); w = x->rtavl_link[0]; x->rtavl_link[0] = w->rtavl_link[1]; w->rtavl_link[1] = x; y->rtavl_link[1] = w->rtavl_link[0]; w->rtavl_link[0] = y; if (w->rtavl_balance == +1) x->rtavl_balance = 0, y->rtavl_balance = -1; else if (w->rtavl_balance == 0) x->rtavl_balance = y->rtavl_balance = 0; else /* |w->rtavl_balance == -1| */ x->rtavl_balance = +1, y->rtavl_balance = 0; w->rtavl_balance = 0; if (y->rtavl_link[1] == NULL) { y->rtavl_rtag = RTAVL_THREAD; y->rtavl_link[1] = w; } if (w->rtavl_rtag == RTAVL_THREAD) { x->rtavl_link[0] = NULL; w->rtavl_rtag = RTAVL_CHILD; } } } else return &n->rtavl_data; z->rtavl_link[y != z->rtavl_link[0]] = w; return &n->rtavl_data; } /* Inserts |item| into |table|. Returns |NULL| if |item| was successfully inserted or if a memory allocation error occurred. Otherwise, returns the duplicate item. */ void * rtavl_insert (struct rtavl_table *table, void *item) { void **p = rtavl_probe (table, item); return p == NULL || *p == item ? NULL : *p; } /* Inserts |item| into |table|, replacing any duplicate item. Returns |NULL| if |item| was inserted without replacing a duplicate, or if a memory allocation error occurred. Otherwise, returns the item that was replaced. */ void * rtavl_replace (struct rtavl_table *table, void *item) { void **p = rtavl_probe (table, item); if (p == NULL || *p == item) return NULL; else { void *r = *p; *p = item; return r; } } /* Deletes from |tree| and returns an item matching |item|. Returns a null pointer if no matching item found. */ void * rtavl_delete (struct rtavl_table *tree, const void *item) { /* Stack of nodes. */ struct rtavl_node *pa[RTAVL_MAX_HEIGHT]; /* Nodes. */ unsigned char da[RTAVL_MAX_HEIGHT]; /* |rtavl_link[]| indexes. */ int k; /* Stack pointer. */ struct rtavl_node *p; /* Traverses tree to find node to delete. */ assert (tree != NULL && item != NULL); k = 1; da[0] = 0; pa[0] = (struct rtavl_node *) &tree->rtavl_root; p = tree->rtavl_root; if (p == NULL) return NULL; for (;;) { int cmp, dir; cmp = tree->rtavl_compare (item, p->rtavl_data, tree->rtavl_param); if (cmp == 0) break; dir = cmp > 0; if (dir == 0) { if (p->rtavl_link[0] == NULL) return NULL; } else /* |dir == 1| */ { if (p->rtavl_rtag == RTAVL_THREAD) return NULL; } pa[k] = p; da[k++] = dir; p = p->rtavl_link[dir]; } tree->rtavl_count--; item = p->rtavl_data; if (p->rtavl_link[0] == NULL) { if (p->rtavl_rtag == RTAVL_CHILD) { pa[k - 1]->rtavl_link[da[k - 1]] = p->rtavl_link[1]; } else { pa[k - 1]->rtavl_link[da[k - 1]] = p->rtavl_link[da[k - 1]]; if (da[k - 1] == 1) pa[k - 1]->rtavl_rtag = RTAVL_THREAD; } } else { struct rtavl_node *r = p->rtavl_link[0]; if (r->rtavl_rtag == RTAVL_THREAD) { r->rtavl_link[1] = p->rtavl_link[1]; r->rtavl_rtag = p->rtavl_rtag; r->rtavl_balance = p->rtavl_balance; pa[k - 1]->rtavl_link[da[k - 1]] = r; da[k] = 0; pa[k++] = r; } else { struct rtavl_node *s; int j = k++; for (;;) { da[k] = 1; pa[k++] = r; s = r->rtavl_link[1]; if (s->rtavl_rtag == RTAVL_THREAD) break; r = s; } da[j] = 0; pa[j] = pa[j - 1]->rtavl_link[da[j - 1]] = s; if (s->rtavl_link[0] != NULL) r->rtavl_link[1] = s->rtavl_link[0]; else { r->rtavl_rtag = RTAVL_THREAD; r->rtavl_link[1] = s; } s->rtavl_balance = p->rtavl_balance; s->rtavl_link[0] = p->rtavl_link[0]; s->rtavl_link[1] = p->rtavl_link[1]; s->rtavl_rtag = p->rtavl_rtag; } } tree->rtavl_alloc->libavl_free (tree->rtavl_alloc, p); assert (k > 0); while (--k > 0) { struct rtavl_node *y = pa[k]; if (da[k] == 0) { y->rtavl_balance++; if (y->rtavl_balance == +1) break; else if (y->rtavl_balance == +2) { struct rtavl_node *x = y->rtavl_link[1]; assert (x != NULL); if (x->rtavl_balance == -1) { struct rtavl_node *w; assert (x->rtavl_balance == -1); w = x->rtavl_link[0]; x->rtavl_link[0] = w->rtavl_link[1]; w->rtavl_link[1] = x; y->rtavl_link[1] = w->rtavl_link[0]; w->rtavl_link[0] = y; if (w->rtavl_balance == +1) x->rtavl_balance = 0, y->rtavl_balance = -1; else if (w->rtavl_balance == 0) x->rtavl_balance = y->rtavl_balance = 0; else /* |w->rtavl_balance == -1| */ x->rtavl_balance = +1, y->rtavl_balance = 0; w->rtavl_balance = 0; if (y->rtavl_link[1] == NULL) { y->rtavl_rtag = RTAVL_THREAD; y->rtavl_link[1] = w; } if (w->rtavl_rtag == RTAVL_THREAD) { x->rtavl_link[0] = NULL; w->rtavl_rtag = RTAVL_CHILD; } pa[k - 1]->rtavl_link[da[k - 1]] = w; } else { pa[k - 1]->rtavl_link[da[k - 1]] = x; if (x->rtavl_balance == 0) { y->rtavl_link[1] = x->rtavl_link[0]; x->rtavl_link[0] = y; x->rtavl_balance = -1; y->rtavl_balance = +1; break; } else /* |x->rtavl_balance == +1| */ { if (x->rtavl_link[0] != NULL) y->rtavl_link[1] = x->rtavl_link[0]; else y->rtavl_rtag = RTAVL_THREAD; x->rtavl_link[0] = y; y->rtavl_balance = x->rtavl_balance = 0; } } } } else { y->rtavl_balance--; if (y->rtavl_balance == -1) break; else if (y->rtavl_balance == -2) { struct rtavl_node *x = y->rtavl_link[0]; assert (x != NULL); if (x->rtavl_balance == +1) { struct rtavl_node *w; assert (x->rtavl_balance == +1); w = x->rtavl_link[1]; x->rtavl_link[1] = w->rtavl_link[0]; w->rtavl_link[0] = x; y->rtavl_link[0] = w->rtavl_link[1]; w->rtavl_link[1] = y; if (w->rtavl_balance == -1) x->rtavl_balance = 0, y->rtavl_balance = +1; else if (w->rtavl_balance == 0) x->rtavl_balance = y->rtavl_balance = 0; else /* |w->rtavl_balance == +1| */ x->rtavl_balance = -1, y->rtavl_balance = 0; w->rtavl_balance = 0; if (x->rtavl_link[1] == NULL) { x->rtavl_rtag = RTAVL_THREAD; x->rtavl_link[1] = w; } if (w->rtavl_rtag == RTAVL_THREAD) { y->rtavl_link[0] = NULL; w->rtavl_rtag = RTAVL_CHILD; } pa[k - 1]->rtavl_link[da[k - 1]] = w; } else { pa[k - 1]->rtavl_link[da[k - 1]] = x; if (x->rtavl_balance == 0) { y->rtavl_link[0] = x->rtavl_link[1]; x->rtavl_link[1] = y; x->rtavl_balance = +1; y->rtavl_balance = -1; break; } else /* |x->rtavl_balance == -1| */ { if (x->rtavl_rtag == RTAVL_CHILD) y->rtavl_link[0] = x->rtavl_link[1]; else { y->rtavl_link[0] = NULL; x->rtavl_rtag = RTAVL_CHILD; } x->rtavl_link[1] = y; y->rtavl_balance = x->rtavl_balance = 0; } } } } } return (void *) item; } /* Initializes |trav| for use with |tree| and selects the null node. */ void rtavl_t_init (struct rtavl_traverser *trav, struct rtavl_table *tree) { trav->rtavl_table = tree; trav->rtavl_node = NULL; } /* Initializes |trav| for |tree|. Returns data item in |tree| with the least value, or |NULL| if |tree| is empty. */ void * rtavl_t_first (struct rtavl_traverser *trav, struct rtavl_table *tree) { assert (tree != NULL && trav != NULL); trav->rtavl_table = tree; trav->rtavl_node = tree->rtavl_root; if (trav->rtavl_node != NULL) { while (trav->rtavl_node->rtavl_link[0] != NULL) trav->rtavl_node = trav->rtavl_node->rtavl_link[0]; return trav->rtavl_node->rtavl_data; } else return NULL; } /* Initializes |trav| for |tree|. Returns data item in |tree| with the greatest value, or |NULL| if |tree| is empty. */ void * rtavl_t_last (struct rtavl_traverser *trav, struct rtavl_table *tree) { assert (tree != NULL && trav != NULL); trav->rtavl_table = tree; trav->rtavl_node = tree->rtavl_root; if (trav->rtavl_node != NULL) { while (trav->rtavl_node->rtavl_rtag == RTAVL_CHILD) trav->rtavl_node = trav->rtavl_node->rtavl_link[1]; return trav->rtavl_node->rtavl_data; } else return NULL; } /* Searches for |item| in |tree|. If found, initializes |trav| to the item found and returns the item as well. If there is no matching item, initializes |trav| to the null item and returns |NULL|. */ void * rtavl_t_find (struct rtavl_traverser *trav, struct rtavl_table *tree, void *item) { struct rtavl_node *p; assert (trav != NULL && tree != NULL && item != NULL); trav->rtavl_table = tree; trav->rtavl_node = NULL; p = tree->rtavl_root; if (p == NULL) return NULL; for (;;) { int cmp = tree->rtavl_compare (item, p->rtavl_data, tree->rtavl_param); if (cmp == 0) { trav->rtavl_node = p; return p->rtavl_data; } if (cmp < 0) { p = p->rtavl_link[0]; if (p == NULL) return NULL; } else { if (p->rtavl_rtag == RTAVL_THREAD) return NULL; p = p->rtavl_link[1]; } } } /* Attempts to insert |item| into |tree|. If |item| is inserted successfully, it is returned and |trav| is initialized to its location. If a duplicate is found, it is returned and |trav| is initialized to its location. No replacement of the item occurs. If a memory allocation failure occurs, |NULL| is returned and |trav| is initialized to the null item. */ void * rtavl_t_insert (struct rtavl_traverser *trav, struct rtavl_table *tree, void *item) { void **p; assert (trav != NULL && tree != NULL && item != NULL); p = rtavl_probe (tree, item); if (p != NULL) { trav->rtavl_table = tree; trav->rtavl_node = ((struct rtavl_node *) ((char *) p - offsetof (struct rtavl_node, rtavl_data))); return *p; } else { rtavl_t_init (trav, tree); return NULL; } } /* Initializes |trav| to have the same current node as |src|. */ void * rtavl_t_copy (struct rtavl_traverser *trav, const struct rtavl_traverser *src) { assert (trav != NULL && src != NULL); trav->rtavl_table = src->rtavl_table; trav->rtavl_node = src->rtavl_node; return trav->rtavl_node != NULL ? trav->rtavl_node->rtavl_data : NULL; } /* Returns the next data item in inorder within the tree being traversed with |trav|, or if there are no more data items returns |NULL|. */ void * rtavl_t_next (struct rtavl_traverser *trav) { assert (trav != NULL); if (trav->rtavl_node == NULL) return rtavl_t_first (trav, trav->rtavl_table); else if (trav->rtavl_node->rtavl_rtag == RTAVL_THREAD) { trav->rtavl_node = trav->rtavl_node->rtavl_link[1]; return trav->rtavl_node != NULL ? trav->rtavl_node->rtavl_data : NULL; } else { trav->rtavl_node = trav->rtavl_node->rtavl_link[1]; while (trav->rtavl_node->rtavl_link[0] != NULL) trav->rtavl_node = trav->rtavl_node->rtavl_link[0]; return trav->rtavl_node->rtavl_data; } } /* Returns the previous data item in inorder within the tree being traversed with |trav|, or if there are no more data items returns |NULL|. */ void * rtavl_t_prev (struct rtavl_traverser *trav) { assert (trav != NULL); if (trav->rtavl_node == NULL) return rtavl_t_last (trav, trav->rtavl_table); else if (trav->rtavl_node->rtavl_link[0] == NULL) { rtavl_comparison_func *cmp = trav->rtavl_table->rtavl_compare; void *param = trav->rtavl_table->rtavl_param; struct rtavl_node *node = trav->rtavl_node; struct rtavl_node *i; trav->rtavl_node = NULL; for (i = trav->rtavl_table->rtavl_root; i != node; ) { int dir = cmp (node->rtavl_data, i->rtavl_data, param) > 0; if (dir == 1) trav->rtavl_node = i; i = i->rtavl_link[dir]; } return trav->rtavl_node != NULL ? trav->rtavl_node->rtavl_data : NULL; } else { trav->rtavl_node = trav->rtavl_node->rtavl_link[0]; while (trav->rtavl_node->rtavl_rtag == RTAVL_CHILD) trav->rtavl_node = trav->rtavl_node->rtavl_link[1]; return trav->rtavl_node->rtavl_data; } } /* Returns |trav|'s current item. */ void * rtavl_t_cur (struct rtavl_traverser *trav) { assert (trav != NULL); return trav->rtavl_node != NULL ? trav->rtavl_node->rtavl_data : NULL; } /* Replaces the current item in |trav| by |new| and returns the item replaced. |trav| must not have the null item selected. The new item must not upset the ordering of the tree. */ void * rtavl_t_replace (struct rtavl_traverser *trav, void *new) { void *old; assert (trav != NULL && trav->rtavl_node != NULL && new != NULL); old = trav->rtavl_node->rtavl_data; trav->rtavl_node->rtavl_data = new; return old; } /* Creates a new node as a child of |dst| on side |dir|. Copies data from |src| into the new node, applying |copy()|, if non-null. Returns nonzero only if fully successful. Regardless of success, integrity of the tree structure is assured, though failure may leave a null pointer in a |rtavl_data| member. */ static int copy_node (struct rtavl_table *tree, struct rtavl_node *dst, int dir, const struct rtavl_node *src, rtavl_copy_func *copy) { struct rtavl_node *new = tree->rtavl_alloc->libavl_malloc (tree->rtavl_alloc, sizeof *new); if (new == NULL) return 0; new->rtavl_link[0] = NULL; new->rtavl_rtag = RTAVL_THREAD; if (dir == 0) new->rtavl_link[1] = dst; else { new->rtavl_link[1] = dst->rtavl_link[1]; dst->rtavl_rtag = RTAVL_CHILD; } dst->rtavl_link[dir] = new; new->rtavl_balance = src->rtavl_balance; if (copy == NULL) new->rtavl_data = src->rtavl_data; else { new->rtavl_data = copy (src->rtavl_data, tree->rtavl_param); if (new->rtavl_data == NULL) return 0; } return 1; } /* Destroys |new| with |rtavl_destroy (new, destroy)|, first initializing right links in |new| that have not yet been initialized at time of call. */ static void copy_error_recovery (struct rtavl_table *new, rtavl_item_func *destroy) { struct rtavl_node *p = new->rtavl_root; if (p != NULL) { while (p->rtavl_rtag == RTAVL_CHILD) p = p->rtavl_link[1]; p->rtavl_link[1] = NULL; } rtavl_destroy (new, destroy); } /* Copies |org| to a newly created tree, which is returned. If |copy != NULL|, each data item in |org| is first passed to |copy|, and the return values are inserted into the tree, with |NULL| return values are taken as indications of failure. On failure, destroys the partially created new tree, applying |destroy|, if non-null, to each item in the new tree so far, and returns |NULL|. If |allocator != NULL|, it is used for allocation in the new tree. Otherwise, the same allocator used for |org| is used. */ struct rtavl_table * rtavl_copy (const struct rtavl_table *org, rtavl_copy_func *copy, rtavl_item_func *destroy, struct libavl_allocator *allocator) { struct rtavl_table *new; const struct rtavl_node *p; struct rtavl_node *q; assert (org != NULL); new = rtavl_create (org->rtavl_compare, org->rtavl_param, allocator != NULL ? allocator : org->rtavl_alloc); if (new == NULL) return NULL; new->rtavl_count = org->rtavl_count; if (new->rtavl_count == 0) return new; p = (struct rtavl_node *) &org->rtavl_root; q = (struct rtavl_node *) &new->rtavl_root; for (;;) { if (p->rtavl_link[0] != NULL) { if (!copy_node (new, q, 0, p->rtavl_link[0], copy)) { copy_error_recovery (new, destroy); return NULL; } p = p->rtavl_link[0]; q = q->rtavl_link[0]; } else { while (p->rtavl_rtag == RTAVL_THREAD) { p = p->rtavl_link[1]; if (p == NULL) { q->rtavl_link[1] = NULL; return new; } q = q->rtavl_link[1]; } p = p->rtavl_link[1]; q = q->rtavl_link[1]; } if (p->rtavl_rtag == RTAVL_CHILD) if (!copy_node (new, q, 1, p->rtavl_link[1], copy)) { copy_error_recovery (new, destroy); return NULL; } } } /* Frees storage allocated for |tree|. If |destroy != NULL|, applies it to each data item in inorder. */ void rtavl_destroy (struct rtavl_table *tree, rtavl_item_func *destroy) { struct rtavl_node *p; /* Current node. */ struct rtavl_node *n; /* Next node. */ p = tree->rtavl_root; if (p != NULL) while (p->rtavl_link[0] != NULL) p = p->rtavl_link[0]; while (p != NULL) { n = p->rtavl_link[1]; if (p->rtavl_rtag == RTAVL_CHILD) while (n->rtavl_link[0] != NULL) n = n->rtavl_link[0]; if (destroy != NULL && p->rtavl_data != NULL) destroy (p->rtavl_data, tree->rtavl_param); tree->rtavl_alloc->libavl_free (tree->rtavl_alloc, p); p = n; } tree->rtavl_alloc->libavl_free (tree->rtavl_alloc, tree); } /* Allocates |size| bytes of space using |malloc()|. Returns a null pointer if allocation fails. */ void * rtavl_malloc (struct libavl_allocator *allocator, size_t size) { assert (allocator != NULL && size > 0); return malloc (size); } /* Frees |block|. */ void rtavl_free (struct libavl_allocator *allocator, void *block) { assert (allocator != NULL && block != NULL); free (block); } /* Default memory allocator that uses |malloc()| and |free()|. */ struct libavl_allocator rtavl_allocator_default = { rtavl_malloc, rtavl_free }; #undef NDEBUG #include /* Asserts that |rtavl_insert()| succeeds at inserting |item| into |table|. */ void (rtavl_assert_insert) (struct rtavl_table *table, void *item) { void **p = rtavl_probe (table, item); assert (p != NULL && *p == item); } /* Asserts that |rtavl_delete()| really removes |item| from |table|, and returns the removed item. */ void * (rtavl_assert_delete) (struct rtavl_table *table, void *item) { void *p = rtavl_delete (table, item); assert (p != NULL); return p; }