summaryrefslogtreecommitdiff
path: root/deps/v8/tools/splaytree.js
diff options
context:
space:
mode:
Diffstat (limited to 'deps/v8/tools/splaytree.js')
-rw-r--r--deps/v8/tools/splaytree.js327
1 files changed, 0 insertions, 327 deletions
diff --git a/deps/v8/tools/splaytree.js b/deps/v8/tools/splaytree.js
deleted file mode 100644
index d272a9e182..0000000000
--- a/deps/v8/tools/splaytree.js
+++ /dev/null
@@ -1,327 +0,0 @@
-// Copyright 2009 the V8 project authors. All rights reserved.
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-// * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-// * 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.
-// * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived
-// from this software without specific prior written permission.
-//
-// 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
-// OWNER 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.
-
-
-/**
- * Constructs a Splay tree. A splay tree is a self-balancing binary
- * search tree with the additional property that recently accessed
- * elements are quick to access again. It performs basic operations
- * such as insertion, look-up and removal in O(log(n)) amortized time.
- *
- * @constructor
- */
-function SplayTree() {
-};
-
-
-/**
- * Pointer to the root node of the tree.
- *
- * @type {SplayTree.Node}
- * @private
- */
-SplayTree.prototype.root_ = null;
-
-
-/**
- * @return {boolean} Whether the tree is empty.
- */
-SplayTree.prototype.isEmpty = function() {
- return !this.root_;
-};
-
-
-
-/**
- * Inserts a node into the tree with the specified key and value if
- * the tree does not already contain a node with the specified key. If
- * the value is inserted, it becomes the root of the tree.
- *
- * @param {number} key Key to insert into the tree.
- * @param {*} value Value to insert into the tree.
- */
-SplayTree.prototype.insert = function(key, value) {
- if (this.isEmpty()) {
- this.root_ = new SplayTree.Node(key, value);
- return;
- }
- // Splay on the key to move the last node on the search path for
- // the key to the root of the tree.
- this.splay_(key);
- if (this.root_.key == key) {
- return;
- }
- var node = new SplayTree.Node(key, value);
- if (key > this.root_.key) {
- node.left = this.root_;
- node.right = this.root_.right;
- this.root_.right = null;
- } else {
- node.right = this.root_;
- node.left = this.root_.left;
- this.root_.left = null;
- }
- this.root_ = node;
-};
-
-
-/**
- * Removes a node with the specified key from the tree if the tree
- * contains a node with this key. The removed node is returned. If the
- * key is not found, an exception is thrown.
- *
- * @param {number} key Key to find and remove from the tree.
- * @return {SplayTree.Node} The removed node.
- */
-SplayTree.prototype.remove = function(key) {
- if (this.isEmpty()) {
- throw Error('Key not found: ' + key);
- }
- this.splay_(key);
- if (this.root_.key != key) {
- throw Error('Key not found: ' + key);
- }
- var removed = this.root_;
- if (!this.root_.left) {
- this.root_ = this.root_.right;
- } else {
- var right = this.root_.right;
- this.root_ = this.root_.left;
- // Splay to make sure that the new root has an empty right child.
- this.splay_(key);
- // Insert the original right child as the right child of the new
- // root.
- this.root_.right = right;
- }
- return removed;
-};
-
-
-/**
- * Returns the node having the specified key or null if the tree doesn't contain
- * a node with the specified key.
- *
- * @param {number} key Key to find in the tree.
- * @return {SplayTree.Node} Node having the specified key.
- */
-SplayTree.prototype.find = function(key) {
- if (this.isEmpty()) {
- return null;
- }
- this.splay_(key);
- return this.root_.key == key ? this.root_ : null;
-};
-
-
-/**
- * @return {SplayTree.Node} Node having the minimum key value.
- */
-SplayTree.prototype.findMin = function() {
- if (this.isEmpty()) {
- return null;
- }
- var current = this.root_;
- while (current.left) {
- current = current.left;
- }
- return current;
-};
-
-
-/**
- * @return {SplayTree.Node} Node having the maximum key value.
- */
-SplayTree.prototype.findMax = function(opt_startNode) {
- if (this.isEmpty()) {
- return null;
- }
- var current = opt_startNode || this.root_;
- while (current.right) {
- current = current.right;
- }
- return current;
-};
-
-
-/**
- * @return {SplayTree.Node} Node having the maximum key value that
- * is less or equal to the specified key value.
- */
-SplayTree.prototype.findGreatestLessThan = function(key) {
- if (this.isEmpty()) {
- return null;
- }
- // Splay on the key to move the node with the given key or the last
- // node on the search path to the top of the tree.
- this.splay_(key);
- // Now the result is either the root node or the greatest node in
- // the left subtree.
- if (this.root_.key <= key) {
- return this.root_;
- } else if (this.root_.left) {
- return this.findMax(this.root_.left);
- } else {
- return null;
- }
-};
-
-
-/**
- * @return {Array<*>} An array containing all the values of tree's nodes paired
- * with keys.
- */
-SplayTree.prototype.exportKeysAndValues = function() {
- var result = [];
- this.traverse_(function(node) { result.push([node.key, node.value]); });
- return result;
-};
-
-
-/**
- * @return {Array<*>} An array containing all the values of tree's nodes.
- */
-SplayTree.prototype.exportValues = function() {
- var result = [];
- this.traverse_(function(node) { result.push(node.value); });
- return result;
-};
-
-
-/**
- * Perform the splay operation for the given key. Moves the node with
- * the given key to the top of the tree. If no node has the given
- * key, the last node on the search path is moved to the top of the
- * tree. This is the simplified top-down splaying algorithm from:
- * "Self-adjusting Binary Search Trees" by Sleator and Tarjan
- *
- * @param {number} key Key to splay the tree on.
- * @private
- */
-SplayTree.prototype.splay_ = function(key) {
- if (this.isEmpty()) {
- return;
- }
- // Create a dummy node. The use of the dummy node is a bit
- // counter-intuitive: The right child of the dummy node will hold
- // the L tree of the algorithm. The left child of the dummy node
- // will hold the R tree of the algorithm. Using a dummy node, left
- // and right will always be nodes and we avoid special cases.
- var dummy, left, right;
- dummy = left = right = new SplayTree.Node(null, null);
- var current = this.root_;
- while (true) {
- if (key < current.key) {
- if (!current.left) {
- break;
- }
- if (key < current.left.key) {
- // Rotate right.
- var tmp = current.left;
- current.left = tmp.right;
- tmp.right = current;
- current = tmp;
- if (!current.left) {
- break;
- }
- }
- // Link right.
- right.left = current;
- right = current;
- current = current.left;
- } else if (key > current.key) {
- if (!current.right) {
- break;
- }
- if (key > current.right.key) {
- // Rotate left.
- var tmp = current.right;
- current.right = tmp.left;
- tmp.left = current;
- current = tmp;
- if (!current.right) {
- break;
- }
- }
- // Link left.
- left.right = current;
- left = current;
- current = current.right;
- } else {
- break;
- }
- }
- // Assemble.
- left.right = current.left;
- right.left = current.right;
- current.left = dummy.right;
- current.right = dummy.left;
- this.root_ = current;
-};
-
-
-/**
- * Performs a preorder traversal of the tree.
- *
- * @param {function(SplayTree.Node)} f Visitor function.
- * @private
- */
-SplayTree.prototype.traverse_ = function(f) {
- var nodesToVisit = [this.root_];
- while (nodesToVisit.length > 0) {
- var node = nodesToVisit.shift();
- if (node == null) {
- continue;
- }
- f(node);
- nodesToVisit.push(node.left);
- nodesToVisit.push(node.right);
- }
-};
-
-
-/**
- * Constructs a Splay tree node.
- *
- * @param {number} key Key.
- * @param {*} value Value.
- */
-SplayTree.Node = function(key, value) {
- this.key = key;
- this.value = value;
-};
-
-
-/**
- * @type {SplayTree.Node}
- */
-SplayTree.Node.prototype.left = null;
-
-
-/**
- * @type {SplayTree.Node}
- */
-SplayTree.Node.prototype.right = null;