--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/ucx/avl.c Mon May 23 12:28:32 2016 +0200
@@ -0,0 +1,272 @@
+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
+ *
+ * Copyright 2015 Olaf Wintermann. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "avl.h"
+
+#define ptrcast(ptr) ((void*)(ptr))
+
+static void ucx_avl_connect(UcxAVLTree *tree,
+ UcxAVLNode *node, UcxAVLNode *child, intptr_t nullkey) {
+ if (child) {
+ child->parent = node;
+ }
+ // if child is NULL, nullkey decides if left or right pointer is cleared
+ if (tree->cmpfunc(
+ ptrcast(child ? child->key : nullkey),
+ ptrcast(node->key), tree->userdata) > 0) {
+ node->right = child;
+ } else {
+ node->left = child;
+ }
+ size_t lh = node->left ? node->left->height : 0;
+ size_t rh = node->right ? node->right->height : 0;
+ node->height = 1 + (lh > rh ? lh : rh);
+}
+
+#define avlheight(node) ((node) ? (node)->height : 0)
+
+static UcxAVLNode* avl_rotright(UcxAVLTree *tree, UcxAVLNode *l0) {
+ UcxAVLNode *p = l0->parent;
+ UcxAVLNode *l1 = l0->left;
+ if (p) {
+ ucx_avl_connect(tree, p, l1, 0);
+ } else {
+ l1->parent = NULL;
+ }
+ ucx_avl_connect(tree, l0, l1->right, l1->key);
+ ucx_avl_connect(tree, l1, l0, 0);
+ return l1;
+}
+
+static UcxAVLNode* avl_rotleft(UcxAVLTree *tree, UcxAVLNode *l0) {
+ UcxAVLNode *p = l0->parent;
+ UcxAVLNode *l1 = l0->right;
+ if (p) {
+ ucx_avl_connect(tree, p, l1, 0);
+ } else {
+ l1->parent = NULL;
+ }
+ ucx_avl_connect(tree, l0, l1->left, l1->key);
+ ucx_avl_connect(tree, l1, l0, 0);
+ return l1;
+}
+
+static void ucx_avl_balance(UcxAVLTree *tree, UcxAVLNode *n) {
+ int lh = avlheight(n->left);
+ int rh = avlheight(n->right);
+ n->height = 1 + (lh > rh ? lh : rh);
+
+ if (lh - rh == 2) {
+ UcxAVLNode *c = n->left;
+ if (avlheight(c->right) - avlheight(c->left) == 1) {
+ avl_rotleft(tree, c);
+ }
+ n = avl_rotright(tree, n);
+ } else if (rh - lh == 2) {
+ UcxAVLNode *c = n->right;
+ if (avlheight(c->left) - avlheight(c->right) == 1) {
+ avl_rotright(tree, c);
+ }
+ n = avl_rotleft(tree, n);
+ }
+
+ if (n->parent) {
+ ucx_avl_balance(tree, n->parent);
+ } else {
+ tree->root = n;
+ }
+}
+
+UcxAVLTree *ucx_avl_new(cmp_func cmpfunc) {
+ return ucx_avl_new_a(cmpfunc, ucx_default_allocator());
+}
+
+UcxAVLTree *ucx_avl_new_a(cmp_func cmpfunc, UcxAllocator *allocator) {
+ UcxAVLTree *tree = almalloc(allocator, sizeof(UcxAVLTree));
+ if (tree) {
+ tree->allocator = allocator;
+ tree->cmpfunc = cmpfunc;
+ tree->root = NULL;
+ tree->userdata = NULL;
+ }
+
+ return tree;
+}
+
+static void ucx_avl_free_node(UcxAllocator *al, UcxAVLNode *node) {
+ if (node) {
+ ucx_avl_free_node(al, node->left);
+ ucx_avl_free_node(al, node->right);
+ alfree(al, node);
+ }
+}
+
+void ucx_avl_free(UcxAVLTree *tree) {
+ UcxAllocator *al = tree->allocator;
+ ucx_avl_free_node(al, tree->root);
+ alfree(al, tree);
+}
+
+UcxAVLNode *ucx_avl_get_node(UcxAVLTree *tree, intptr_t key) {
+ UcxAVLNode *n = tree->root;
+ int cmpresult;
+ while (n && (cmpresult = tree->cmpfunc(
+ ptrcast(key), ptrcast(n->key), tree->userdata))) {
+ n = cmpresult > 0 ? n->right : n->left;
+ }
+ return n;
+}
+
+void *ucx_avl_get(UcxAVLTree *tree, intptr_t key) {
+ UcxAVLNode *n = ucx_avl_get_node(tree, key);
+ return n ? n->value : NULL;
+}
+
+int ucx_avl_put(UcxAVLTree *tree, intptr_t key, void *value) {
+ return ucx_avl_put_s(tree, key, value, NULL);
+}
+
+int ucx_avl_put_s(UcxAVLTree *tree, intptr_t key, void *value,
+ void **oldvalue) {
+ if (tree->root) {
+ UcxAVLNode *n = tree->root;
+ int cmpresult;
+ while ((cmpresult = tree->cmpfunc(
+ ptrcast(key), ptrcast(n->key), tree->userdata))) {
+ UcxAVLNode *m = cmpresult > 0 ? n->right : n->left;
+ if (m) {
+ n = m;
+ } else {
+ break;
+ }
+ }
+
+ if (cmpresult) {
+ UcxAVLNode *e = almalloc(tree->allocator, sizeof(UcxAVLNode));
+ if (e) {
+ e->key = key; e->value = value; e->height = 1;
+ e->parent = e->left = e->right = NULL;
+ ucx_avl_connect(tree, n, e, 0);
+ ucx_avl_balance(tree, n);
+ return 0;
+ } else {
+ return 1;
+ }
+ } else {
+ if (oldvalue) {
+ *oldvalue = n->value;
+ }
+ n->value = value;
+ return 0;
+ }
+ } else {
+ tree->root = almalloc(tree->allocator, sizeof(UcxAVLNode));
+ if (tree->root) {
+ tree->root->key = key; tree->root->value = value;
+ tree->root->height = 1;
+ tree->root->parent = tree->root->left = tree->root->right = NULL;
+
+ if (oldvalue) {
+ *oldvalue = NULL;
+ }
+
+ return 0;
+ } else {
+ return 1;
+ }
+ }
+}
+
+int ucx_avl_remove(UcxAVLTree *tree, intptr_t key) {
+ return ucx_avl_remove_s(tree, key, NULL, NULL);
+}
+
+int ucx_avl_remove_node(UcxAVLTree *tree, UcxAVLNode *node) {
+ return ucx_avl_remove_s(tree, node->key, NULL, NULL);
+}
+
+int ucx_avl_remove_s(UcxAVLTree *tree, intptr_t key,
+ intptr_t *oldkey, void **oldvalue) {
+
+ UcxAVLNode *n = tree->root;
+ int cmpresult;
+ while (n && (cmpresult = tree->cmpfunc(
+ ptrcast(key), ptrcast(n->key), tree->userdata))) {
+ n = cmpresult > 0 ? n->right : n->left;
+ }
+ if (n) {
+ if (oldkey) {
+ *oldkey = n->key;
+ }
+ if (oldvalue) {
+ *oldvalue = n->value;
+ }
+
+ UcxAVLNode *p = n->parent;
+ if (n->left && n->right) {
+ UcxAVLNode *s = n->right;
+ while (s->left) {
+ s = s->left;
+ }
+ ucx_avl_connect(tree, s->parent, s->right, s->key);
+ n->key = s->key; n->value = s->value;
+ p = s->parent;
+ alfree(tree->allocator, s);
+ } else {
+ if (p) {
+ ucx_avl_connect(tree, p, n->right ? n->right:n->left, n->key);
+ } else {
+ tree->root = n->right ? n->right : n->left;
+ if (tree->root) {
+ tree->root->parent = NULL;
+ }
+ }
+ alfree(tree->allocator, n);
+ }
+
+ if (p) {
+ ucx_avl_balance(tree, p);
+ }
+
+ return 0;
+ } else {
+ return 1;
+ }
+}
+
+static size_t ucx_avl_countn(UcxAVLNode *node) {
+ if (node) {
+ return 1 + ucx_avl_countn(node->left) + ucx_avl_countn(node->right);
+ } else {
+ return 0;
+ }
+}
+
+size_t ucx_avl_count(UcxAVLTree *tree) {
+ return ucx_avl_countn(tree->root);
+}