Add a benchmark extension.

chrome/test/data/extensions/samples/benchmark/jst/util.js

+// Copyright 2006 Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+// implied. See the License for the specific language governing
+// permissions and limitations under the License.
+/**
+ * @fileoverview Miscellaneous constants and functions referenced in
+ * the main source files.
+ *
+ * @author Steffen Meschkat (mesch@google.com)
+ */
+
+var MAPS_DEBUG = false;
+
+function log(msg) {}
+
+// String literals defined globally and not to be inlined. (IE6 perf)
+/** @const */ var STRING_empty = '';
+
+/** @const */ var CSS_display = 'display';
+/** @const */ var CSS_position = 'position';
+
+// Constants for possible values of the typeof operator.
+var TYPE_boolean = 'boolean';
+var TYPE_number = 'number';
+var TYPE_object = 'object';
+var TYPE_string = 'string';
+var TYPE_function = 'function';
+var TYPE_undefined = 'undefined';
+
+
+/**
+ * Wrapper for the eval() builtin function to evaluate expressions and
+ * obtain their value. It wraps the expression in parentheses such
+ * that object literals are really evaluated to objects. Without the
+ * wrapping, they are evaluated as block, and create syntax
+ * errors. Also protects against other syntax errors in the eval()ed
+ * code and returns null if the eval throws an exception.
+ *
+ * @param {string} expr
+ * @return {Object|null}
+ */
+function jsEval(expr) {
+  try {
+    // NOTE(mesch): An alternative idiom would be:
+    //
+    //   eval('(' + expr + ')');
+    //
+    // Note that using the square brackets as below, "" evals to undefined.
+    // The alternative of using parentheses does not work when evaluating
+    // function literals in IE.
+    // e.g. eval("(function() {})") returns undefined, and not a function
+    // object, in IE.
+    return eval('[' + expr + '][0]');
+  } catch (e) {
+    log('EVAL FAILED ' + expr + ': ' + e);
+    return null;
+  }
+}
+
+function jsLength(obj) {
+  return obj.length;
+}
+
+function assert(obj) {}
+
+/**
+ * Copies all properties from second object to the first.  Modifies to.
+ *
+ * @param {Object} to  The target object.
+ * @param {Object} from  The source object.
+ */
+function copyProperties(to, from) {
+  for (var p in from) {
+    to[p] = from[p];
+  }
+}
+
+
+/**
+ * @param {Object|null|undefined} value The possible value to use.
+ * @param {Object} defaultValue The default if the value is not set.
+ * @return {Object} The value, if it is
+ * defined and not null; otherwise the default
+ */
+function getDefaultObject(value, defaultValue) {
+  if (typeof value != TYPE_undefined && value != null) {
+    return /** @type Object */(value);
+  } else {
+    return defaultValue;
+  }
+}
+
+/**
+ * Detect if an object looks like an Array.
+ * Note that instanceof Array is not robust; for example an Array
+ * created in another iframe fails instanceof Array.
+ * @param {Object|null} value Object to interrogate
+ * @return {boolean} Is the object an array?
+ */
+function isArray(value) {
+  return value != null &&
+      typeof value == TYPE_object &&
+      typeof value.length == TYPE_number;
+}
+
+
+/**
+ * Finds a slice of an array.
+ *
+ * @param {Array} array  Array to be sliced.
+ * @param {number} start  The start of the slice.
+ * @param {number} opt_end  The end of the slice (optional).
+ * @return {Array} array  The slice of the array from start to end.
+ */
+function arraySlice(array, start, opt_end) {
+  // Use
+  //   return Function.prototype.call.apply(Array.prototype.slice, arguments);
+  // instead of the simpler
+  //   return Array.prototype.slice.call(array, start, opt_end);
+  // here because of a bug in the FF and IE implementations of
+  // Array.prototype.slice which causes this function to return an empty list
+  // if opt_end is not provided.
+  return Function.prototype.call.apply(Array.prototype.slice, arguments);
+}
+
+
+/**
+ * Jscompiler wrapper for parseInt() with base 10.
+ *
+ * @param {string} s string repersentation of a number.
+ *
+ * @return {number} The integer contained in s, converted on base 10.
+ */
+function parseInt10(s) {
+  return parseInt(s, 10);
+}
+
+
+/**
+ * Clears the array by setting the length property to 0. This usually
+ * works, and if it should turn out not to work everywhere, here would
+ * be the place to implement the browser specific workaround.
+ *
+ * @param {Array} array  Array to be cleared.
+ */
+function arrayClear(array) {
+  array.length = 0;
+}
+
+
+/**
+ * Prebinds "this" within the given method to an object, but ignores all 
+ * arguments passed to the resulting function.
+ * I.e. var_args are all the arguments that method is invoked with when
+ * invoking the bound function.
+ *
+ * @param {Object|null} object  The object that the method call targets.
+ * @param {Function} method  The target method.
+ * @return {Function}  Method with the target object bound to it and curried by
+ *                     the provided arguments.
+ */
+function bindFully(object, method, var_args) {
+  var args = arraySlice(arguments, 2);
+  return function() {
+    return method.apply(object, args);
+  }
+}
+
+// Based on <http://www.w3.org/TR/2000/ REC-DOM-Level-2-Core-20001113/
+// core.html#ID-1950641247>.
+var DOM_ELEMENT_NODE = 1;
+var DOM_ATTRIBUTE_NODE = 2;
+var DOM_TEXT_NODE = 3;
+var DOM_CDATA_SECTION_NODE = 4;
+var DOM_ENTITY_REFERENCE_NODE = 5;
+var DOM_ENTITY_NODE = 6;
+var DOM_PROCESSING_INSTRUCTION_NODE = 7;
+var DOM_COMMENT_NODE = 8;
+var DOM_DOCUMENT_NODE = 9;
+var DOM_DOCUMENT_TYPE_NODE = 10;
+var DOM_DOCUMENT_FRAGMENT_NODE = 11;
+var DOM_NOTATION_NODE = 12;
+
+
+
+function domGetElementById(document, id) {
+  return document.getElementById(id);
+}
+
+/**
+ * Creates a new node in the given document
+ *
+ * @param {Document} doc  Target document.
+ * @param {string} name  Name of new element (i.e. the tag name)..
+ * @return {Element}  Newly constructed element.
+ */
+function domCreateElement(doc, name) {
+  return doc.createElement(name);
+}
+
+/**
+ * Traverses the element nodes in the DOM section underneath the given
+ * node and invokes the given callback as a method on every element
+ * node encountered.
+ *
+ * @param {Element} node  Parent element of the subtree to traverse.
+ * @param {Function} callback  Called on each node in the traversal.
+ */
+function domTraverseElements(node, callback) {
+  var traverser = new DomTraverser(callback);
+  traverser.run(node);
+}
+
+/**
+ * A class to hold state for a dom traversal.
+ * @param {Function} callback  Called on each node in the traversal.
+ * @constructor
+ * @class
+ */
+function DomTraverser(callback) {
+  this.callback_ = callback;
+}
+
+/**
+ * Processes the dom tree in breadth-first order.
+ * @param {Element} root  The root node of the traversal.
+ */
+DomTraverser.prototype.run = function(root) {
+  var me = this;
+  me.queue_ = [ root ];
+  while (jsLength(me.queue_)) {
+    me.process_(me.queue_.shift());
+  }
+}
+
+/**
+ * Processes a single node.
+ * @param {Element} node  The current node of the traversal.
+ */
+DomTraverser.prototype.process_ = function(node) {
+  var me = this;
+
+  me.callback_(node);
+
+  for (var c = node.firstChild; c; c = c.nextSibling) {
+    if (c.nodeType == DOM_ELEMENT_NODE) {
+      me.queue_.push(c);
+    }
+  }
+}
+
+/**
+ * Get an attribute from the DOM.  Simple redirect, exists to compress code.
+ *
+ * @param {Element} node  Element to interrogate.
+ * @param {string} name  Name of parameter to extract.
+ * @return {string|null}  Resulting attribute.
+ */
+function domGetAttribute(node, name) {
+  return node.getAttribute(name);
+  // NOTE(mesch): Neither in IE nor in Firefox, HTML DOM attributes
+  // implement namespaces. All items in the attribute collection have
+  // null localName and namespaceURI attribute values. In IE, we even
+  // encounter DIV elements that don't implement the method
+  // getAttributeNS().
+}
+
+
+/**
+ * Set an attribute in the DOM.  Simple redirect to compress code.
+ *
+ * @param {Element} node  Element to interrogate.
+ * @param {string} name  Name of parameter to set.
+ * @param {string|number} value  Set attribute to this value.
+ */
+function domSetAttribute(node, name, value) {
+  node.setAttribute(name, value);
+}
+
+/**
+ * Remove an attribute from the DOM.  Simple redirect to compress code.
+ *
+ * @param {Element} node  Element to interrogate.
+ * @param {string} name  Name of parameter to remove.
+ */
+function domRemoveAttribute(node, name) {
+  node.removeAttribute(name);
+}
+
+/**
+ * Clone a node in the DOM.
+ *
+ * @param {Node} node  Node to clone.
+ * @return {Node}  Cloned node.
+ */
+function domCloneNode(node) {
+  return node.cloneNode(true);
+  // NOTE(mesch): we never so far wanted to use cloneNode(false),
+  // hence the default.
+}
+
+/**
+ * Clone a element in the DOM.
+ *
+ * @param {Element} element  Element to clone.
+ * @return {Element}  Cloned element.
+ */
+function domCloneElement(element) {
+  return /** @type {Element} */(domCloneNode(element));
+}
+
+/**
+ * Returns the document owner of the given element. In particular,
+ * returns window.document if node is null or the browser does not
+ * support ownerDocument.  If the node is a document itself, returns
+ * itself.
+ *
+ * @param {Node|null|undefined} node  The node whose ownerDocument is required.
+ * @returns {Document}  The owner document or window.document if unsupported.
+ */
+function ownerDocument(node) {
+  if (!node) {
+    return document;
+  } else if (node.nodeType == DOM_DOCUMENT_NODE) {
+    return /** @type Document */(node);
+  } else {
+    return node.ownerDocument || document;
+  }
+}
+
+/**
+ * Creates a new text node in the given document.
+ *
+ * @param {Document} doc  Target document.
+ * @param {string} text  Text composing new text node.
+ * @return {Text}  Newly constructed text node.
+ */
+function domCreateTextNode(doc, text) {
+  return doc.createTextNode(text);
+}
+
+/**
+ * Appends a new child to the specified (parent) node.
+ *
+ * @param {Element} node  Parent element.
+ * @param {Node} child  Child node to append.
+ * @return {Node}  Newly appended node.
+ */
+function domAppendChild(node, child) {
+  return node.appendChild(child);
+}
+
+/**
+ * Sets display to default.
+ *
+ * @param {Element} node  The dom element to manipulate.
+ */
+function displayDefault(node) {
+  node.style[CSS_display] = '';
+}
+
+/**
+ * Sets display to none. Doing this as a function saves a few bytes for
+ * the 'style.display' property and the 'none' literal.
+ *
+ * @param {Element} node  The dom element to manipulate.
+ */
+function displayNone(node) {
+  node.style[CSS_display] = 'none';
+}
+
+
+/**
+ * Sets position style attribute to absolute.
+ *
+ * @param {Element} node  The dom element to manipulate.
+ */
+function positionAbsolute(node) {
+  node.style[CSS_position] = 'absolute';
+}
+
+
+/**
+ * Inserts a new child before a given sibling.
+ *
+ * @param {Node} newChild  Node to insert.
+ * @param {Node} oldChild  Sibling node.
+ * @return {Node}  Reference to new child.
+ */
+function domInsertBefore(newChild, oldChild) {
+  return oldChild.parentNode.insertBefore(newChild, oldChild);
+}
+
+/**
+ * Replaces an old child node with a new child node.
+ *
+ * @param {Node} newChild  New child to append.
+ * @param {Node} oldChild  Old child to remove.
+ * @return {Node}  Replaced node.
+ */
+function domReplaceChild(newChild, oldChild) {
+  return oldChild.parentNode.replaceChild(newChild, oldChild);
+}
+
+/**
+ * Removes a node from the DOM.
+ *
+ * @param {Node} node  The node to remove.
+ * @return {Node}  The removed node.
+ */
+function domRemoveNode(node) {
+  return domRemoveChild(node.parentNode, node);
+}
+
+/**
+ * Remove a child from the specified (parent) node.
+ *
+ * @param {Element} node  Parent element.
+ * @param {Node} child  Child node to remove.
+ * @return {Node}  Removed node.
+ */
+function domRemoveChild(node, child) {
+  return node.removeChild(child);
+}
+
+
+/**
+ * Trim whitespace from begin and end of string.
+ *
+ * @see testStringTrim();
+ *
+ * @param {string} str  Input string.
+ * @return {string}  Trimmed string.
+ */
+function stringTrim(str) {
+  return stringTrimRight(stringTrimLeft(str));
+}
+
+/**
+ * Trim whitespace from beginning of string.
+ *
+ * @see testStringTrimLeft();
+ *
+ * @param {string} str  Input string.
+ * @return {string}  Trimmed string.
+ */
+function stringTrimLeft(str) {
+  return str.replace(/^\s+/, "");
+}
+
+/**
+ * Trim whitespace from end of string.
+ *
+ * @see testStringTrimRight();
+ *
+ * @param {string} str  Input string.
+ * @return {string}  Trimmed string.
+  */
+function stringTrimRight(str) {
+  return str.replace(/\s+$/, "");
+}
+