+/*
+ splay_tree.c -- splay tree and linked list convenience
+ Copyright (C) 2004 Guus Sliepen <guus@tinc-vpn.org>
+
+ 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+ $Id: splay_tree.c 1374 2004-03-21 14:21:22Z guus $
+*/
+
+#include "system.h"
+
+#include "splay_tree.h"
+#include "xalloc.h"
+
+/* Splay operation */
+
+static splay_node_t *splay_top_down(splay_tree_t *tree, const void *data, int *result) {
+ splay_node_t left = {0}, right = {0};
+ splay_node_t *leftbottom = &left, *rightbottom = &right, *child;
+ splay_node_t *node = tree->root;
+ int c;
+
+ while((c = tree->compare(data, node->data))) {
+ if(c < 0) {
+ child = node->left;
+
+ if(child) {
+ c = tree->compare(data, child->data);
+
+ if(c < 0) {
+ rightbottom->left = child;
+ child->parent = rightbottom;
+ rightbottom = child;
+
+ node->left = child->right;
+ child->right = node;
+ node->parent = child;
+ node = child->left;
+ child->left = NULL;
+ } else if (c > 0) {
+ if(!child->right)
+ break;
+
+ leftbottom->right = child;
+ child->parent = leftbottom;
+ leftbottom = child;
+
+ rightbottom->left = node;
+ node->parent = rightbottom;
+ rightbottom = node;
+
+ node->left = NULL;
+ node = child->right;
+ child->right = NULL;
+ } else {
+ rightbottom->left = node;
+ node->parent = rightbottom;
+ rightbottom = node;
+
+ node->left = NULL;
+ child->parent = NULL;
+ node = child;
+ break;
+ }
+ } else {
+ break;
+ }
+ } else {
+ child = node->right;
+
+ if(child) {
+ c = tree->compare(data, child->data);
+
+ if(c > 0) {
+ leftbottom->right = child;
+ child->parent = leftbottom;
+ leftbottom = child;
+
+ node->right = child->left;
+ child->left = node;
+ node->parent = child;
+ node = child->right;
+ child->right = NULL;
+ } else if (c < 0) {
+ if(!child->left)
+ break;
+
+ rightbottom->left = child;
+ child->parent = rightbottom;
+ rightbottom = child;
+
+ leftbottom->right = node;
+ node->parent = leftbottom;
+ leftbottom = node;
+
+ node->right = NULL;
+ node = child->left;
+ child->left = NULL;
+ } else {
+ leftbottom->right = node;
+ node->parent = leftbottom;
+ leftbottom = node;
+
+ node->right = NULL;
+ child->parent = NULL;
+ node = child;
+ break;
+ }
+ } else {
+ break;
+ }
+ }
+ }
+
+ tree->root = node;
+
+ /* Merge trees */
+
+ if(left.right) {
+ if(node->left) {
+ leftbottom->right = node->left;
+ node->left->parent = leftbottom;
+ }
+ node->left = left.right;
+ left.right->parent = node;
+ }
+
+ if(right.left) {
+ if(node->right) {
+ rightbottom->left = node->right;
+ node->right->parent = rightbottom;
+ }
+ node->right = right.left;
+ right.left->parent = node;
+ }
+
+ if(result)
+ *result = c;
+
+ return node;
+}
+
+
+static void splay_bottom_up(splay_tree_t *tree, splay_node_t *node) {
+ splay_node_t *parent, *grandparent;
+
+ while(node->parent) {
+ parent = node->parent;
+ grandparent = node->parent->parent;
+
+ if(!grandparent) { /* zig */
+ if(node == parent->left) {
+ parent->left = node->right;
+ node->right = parent;
+ } else {
+ parent->right = node->left;
+ node->left = parent;
+ }
+
+ parent->parent = node;
+ node->parent = NULL;
+ } else {
+ if(node == grandparent->left->left) { /* left zig-zig */
+ grandparent->left = parent->right;
+ parent->right = grandparent;
+ grandparent->parent = parent;
+
+ parent->left = node->right;
+ node->right = parent;
+ parent->parent = node;
+
+ } else if(node == grandparent->right->right) { /* right zig-zig */
+ grandparent->right = parent->left;
+ parent->left = grandparent;
+ grandparent->parent = parent;
+
+ parent->right = node->left;
+ node->left = parent;
+ parent->parent = node;
+
+ } else if(node == grandparent->left->right) { /* left-right zig-zag */
+ parent->right = node->left;
+ node->left = parent;
+ parent->parent = node;
+
+ grandparent->left = node->right;
+ node->right = grandparent;
+ grandparent->parent = node;
+
+ } else { /* right-left zig-zag */
+ parent->left = node->right;
+ node->right = parent;
+ parent->parent = node;
+
+ grandparent->right = node->left;
+ node->left = grandparent;
+ grandparent->parent = node;
+ }
+
+ node->parent = grandparent->parent;
+
+ if(node->parent) {
+ if(grandparent == node->parent->left)
+ node->parent->left = node;
+ else
+ node->parent->right = node;
+ }
+ }
+ }
+
+ tree->root = node;
+}
+
+/* (De)constructors */
+
+splay_tree_t *splay_alloc_tree(splay_compare_t compare, splay_action_t delete) {
+ splay_tree_t *tree;
+
+ tree = xmalloc_and_zero(sizeof(splay_tree_t));
+ tree->compare = compare;
+ tree->delete = delete;
+
+ return tree;
+}
+
+void splay_free_tree(splay_tree_t *tree) {
+ free(tree);
+}
+
+splay_node_t *splay_alloc_node(void) {
+ return xmalloc_and_zero(sizeof(splay_node_t));
+}
+
+void splay_free_node(splay_tree_t *tree, splay_node_t *node) {
+ if(node->data && tree->delete)
+ tree->delete(node->data);
+
+ free(node);
+}
+
+/* Searching */
+
+void *splay_search(splay_tree_t *tree, const void *data) {
+ splay_node_t *node;
+
+ node = splay_search_node(tree, data);
+
+ return node ? node->data : NULL;
+}
+
+void *splay_search_closest(splay_tree_t *tree, const void *data, int *result) {
+ splay_node_t *node;
+
+ node = splay_search_closest_node(tree, data, result);
+
+ return node ? node->data : NULL;
+}
+
+void *splay_search_closest_smaller(splay_tree_t *tree, const void *data) {
+ splay_node_t *node;
+
+ node = splay_search_closest_smaller_node(tree, data);
+
+ return node ? node->data : NULL;
+}
+
+void *splay_search_closest_greater(splay_tree_t *tree, const void *data) {
+ splay_node_t *node;
+
+ node = splay_search_closest_greater_node(tree, data);
+
+ return node ? node->data : NULL;
+}
+
+splay_node_t *splay_search_node(splay_tree_t *tree, const void *data) {
+ splay_node_t *node;
+ int result;
+
+ node = splay_search_closest_node(tree, data, &result);
+
+ return result ? NULL : node;
+}
+
+splay_node_t *splay_search_closest_node_nosplay(const splay_tree_t *tree, const void *data, int *result) {
+ splay_node_t *node;
+ int c;
+
+ node = tree->root;
+
+ if(!node) {
+ if(result)
+ *result = 0;
+ return NULL;
+ }
+
+ for(;;) {
+ c = tree->compare(data, node->data);
+
+ if(c < 0) {
+ if(node->left)
+ node = node->left;
+ else {
+ if(result)
+ *result = -1;
+ break;
+ }
+ } else if(c > 0) {
+ if(node->right)
+ node = node->right;
+ else {
+ if(result)
+ *result = 1;
+ break;
+ }
+ } else {
+ if(result)
+ *result = 0;
+ break;
+ }
+ }
+
+ return node;
+}
+
+splay_node_t *splay_search_closest_node(splay_tree_t *tree, const void *data, int *result) {
+ return splay_top_down(tree, data, result);
+}
+
+splay_node_t *splay_search_closest_smaller_node(splay_tree_t *tree, const void *data) {
+ splay_node_t *node;
+ int result;
+
+ node = splay_search_closest_node(tree, data, &result);
+
+ if(result < 0)
+ node = node->prev;
+
+ return node;
+}
+
+splay_node_t *splay_search_closest_greater_node(splay_tree_t *tree, const void *data) {
+ splay_node_t *node;
+ int result;
+
+ node = splay_search_closest_node(tree, data, &result);
+
+ if(result > 0)
+ node = node->next;
+
+ return node;
+}
+
+/* Insertion and deletion */
+
+splay_node_t *splay_insert(splay_tree_t *tree, void *data) {
+ splay_node_t *closest, *new;
+ int result;
+
+ if(!tree->root) {
+ new = splay_alloc_node();
+ new->data = data;
+ splay_insert_top(tree, new);
+ } else {
+ closest = splay_search_closest_node_nosplay(tree, data, &result);
+
+ if(!result)
+ return NULL;
+
+ new = splay_alloc_node();
+ new->data = data;
+
+ if(result < 0)
+ splay_insert_before(tree, closest, new);
+ else
+ splay_insert_after(tree, closest, new);
+ }
+
+ return new;
+}
+
+splay_node_t *splay_insert_node(splay_tree_t *tree, splay_node_t *node) {
+ splay_node_t *closest;
+ int result;
+
+ if(!tree->root)
+ splay_insert_top(tree, node);
+ else {
+ closest = splay_search_closest_node_nosplay(tree, node->data, &result);
+
+ if(!result)
+ return NULL;
+
+ if(result < 0)
+ splay_insert_before(tree, closest, node);
+ else
+ splay_insert_after(tree, closest, node);
+ }
+
+ return node;
+}
+
+void splay_insert_top(splay_tree_t *tree, splay_node_t *node) {
+ node->prev = node->next = node->parent = NULL;
+ tree->head = tree->tail = tree->root = node;
+}
+
+void splay_insert_before(splay_tree_t *tree, splay_node_t *before, splay_node_t *node) {
+ if(!before) {
+ if(tree->tail)
+ splay_insert_after(tree, tree->tail, node);
+ else
+ splay_insert_top(tree, node);
+ return;
+ }
+
+ node->next = before;
+ node->parent = before;
+ node->prev = before->prev;
+
+ if(before->left) {
+ splay_insert_after(tree, before->prev, node);
+ return;
+ }
+
+ if(before->prev)
+ before->prev->next = node;
+ else
+ tree->head = node;
+
+ before->prev = node;
+ before->left = node;
+
+ splay_bottom_up(tree, node);
+}
+
+void splay_insert_after(splay_tree_t *tree, splay_node_t *after, splay_node_t *node) {
+ if(!after) {
+ if(tree->head)
+ splay_insert_before(tree, tree->head, node);
+ else
+ splay_insert_top(tree, node);
+ return;
+ }
+
+ if(after->right) {
+ splay_insert_before(tree, after->next, node);
+ return;
+ }
+
+ node->prev = after;
+ node->parent = after;
+ node->next = after->next;
+
+ if(after->next)
+ after->next->prev = node;
+ else
+ tree->tail = node;
+
+ after->next = node;
+ after->right = node;
+
+ splay_bottom_up(tree, node);
+}
+
+splay_node_t *splay_unlink(splay_tree_t *tree, void *data) {
+ splay_node_t *node;
+ int result;
+
+ node = splay_search_closest_node_nosplay(tree, data, &result);
+
+ if(node && !result)
+ splay_unlink_node(tree, node);
+
+ return node;
+}
+
+void splay_unlink_node(splay_tree_t *tree, splay_node_t *node) {
+ if(node->prev)
+ node->prev->next = node->next;
+ else
+ tree->head = node->next;
+
+ if(node->next)
+ node->next->prev = node->prev;
+ else
+ tree->tail = node->prev;
+
+ if(node->left) {
+ node->left->parent = NULL;
+ tree->root = node->left;
+
+ if(node->right) {
+ splay_bottom_up(tree, node->prev);
+ node->prev->right = node->right;
+ node->right->parent = node->prev;
+ }
+ } else {
+ node->right->parent = NULL;
+ tree->root = node->right;
+ }
+}
+
+void splay_delete_node(splay_tree_t *tree, splay_node_t *node) {
+ splay_unlink_node(tree, node);
+ splay_free_node(tree, node);
+}
+
+void splay_delete(splay_tree_t *tree, void *data) {
+ splay_node_t *node;
+
+ node = splay_search_node(tree, data);
+
+ if(node)
+ splay_delete_node(tree, node);
+}
+
+/* Fast tree cleanup */
+
+void splay_delete_tree(splay_tree_t *tree) {
+ splay_node_t *node, *next;
+
+ for(node = tree->root; node; node = next) {
+ next = node->next;
+ splay_free_node(tree, node);
+ }
+
+ splay_free_tree(tree);
+}
+
+/* Tree walking */
+
+void splay_foreach(const splay_tree_t *tree, splay_action_t action) {
+ splay_node_t *node, *next;
+
+ for(node = tree->head; node; node = next) {
+ next = node->next;
+ action(node->data);
+ }
+}
+
+void splay_foreach_node(const splay_tree_t *tree, splay_action_t action) {
+ splay_node_t *node, *next;
+
+ for(node = tree->head; node; node = next) {
+ next = node->next;
+ action(node);
+ }
+}
projects / oweals / tinc.git / commitdiff