Issue 354 - Avoid a string copy that is unnecessary most of the time

lib/filterClasses.js

 /*
  * This file is part of Adblock Plus <http://adblockplus.org/>,
  * Copyright (C) 2006-2014 Eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 285 matching lines @@
   domainSeparator: null,
 
   /**
    * Determines whether the trailing dot in domain names isn't important and
    * should be ignored, must be overridden by subclasses.
    * @type Boolean
    */
   ignoreTrailingDot: true,
 
   /**
+   * Determines whether domainSource is already upper-case,
+   * can be overridden by subclasses.
+   * @type Boolean
+   */
+  domainSourceIsUpperCase: false,
+
+  /**
    * Map containing domains that this filter should match on/not match on or null if the filter should match on all domains
    * @type Object
    */
   get domains()
   {
     let domains = null;
 
     if (this.domainSource)
     {
-      let list = this.domainSource.toUpperCase().split(this.domainSeparator);

[Wladimir Palant, 2014/04/08 12:10:05]

I see, I didn't realize what this was doing.

The domains coming from the RegExpFilter constructor will already be uppercased
- I guess that this operation will be wasteful then. Maybe we should add
ActiveFilter.domainsUpperCased flag or something like this to only call
toUpperCase() for element hiding filters?

+      let source = this.domainSource;
+      if (!this.domainSourceIsUpperCase) {
+        // RegExpFilter already have uppercase domains
+        source = source.toUpperCase();
+      }
+      let list = source.split(this.domainSeparator);
       if (list.length == 1 && list[0][0] != "~")
       {
         // Fast track for the common one-domain scenario
         domains = {__proto__: null, "": false};
         if (this.ignoreTrailingDot)
           list[0] = list[0].replace(/\.+$/, "");
         domains[list[0]] = true;
       }
       else
       {
@@ skipping 134 matching lines @@
     this.regexpSource = regexpSource;
   }
 }
 exports.RegExpFilter = RegExpFilter;
 
 RegExpFilter.prototype =
 {
   __proto__: ActiveFilter.prototype,
 
   /**
+   * @see ActiveFilter.domainSourceIsUpperCase
+   */
+  domainSourceIsUpperCase: true,
+
+  /**
    * Number of filters contained, will always be 1 (required to optimize Matcher).
    * @type Integer
    */
   length: 1,
 
   /**
    * @see ActiveFilter.domainSeparator
    */
   domainSeparator: "|",
 
@@ skipping 90 matching lines @@
   let domains = null;
   let siteKeys = null;
   let thirdParty = null;
   let collapse = null;
   let options;
   let match = (text.indexOf("$") >= 0 ? Filter.optionsRegExp.exec(text) : null);
   if (match)
   {
     options = match[1].toUpperCase().split(",");
     text = match.input.substr(0, match.index);
-    for each (let option in options)
+    for (let option of options)
     {
       let value = null;
       let separatorIndex = option.indexOf("=");
       if (separatorIndex >= 0)
       {
         value = option.substr(separatorIndex + 1);
         option = option.substr(0, separatorIndex);
       }
       option = option.replace(/-/, "_");
       if (option in RegExpFilter.typeMap)
@@ skipping 202 matching lines @@
 {
   if (!selector)
   {
     if (tagName == "*")
       tagName = "";
 
     let id = null;
     let additional = "";
     if (attrRules) {
       attrRules = attrRules.match(/\([\w\-]+(?:[$^*]?=[^\(\)"]*)?\)/g);
-      for each (let rule in attrRules) {
+      for (let rule of attrRules) {
         rule = rule.substr(1, rule.length - 2);
         let separatorPos = rule.indexOf("=");
         if (separatorPos > 0) {
           rule = rule.replace(/=/, '="') + '"';
           additional += "[" + rule + "]";
         }
         else {
           if (id)
           {
             let {Utils} = require("utils");
@@ skipping 51 matching lines @@
 function ElemHideException(text, domains, selector)
 {
   ElemHideBase.call(this, text, domains, selector);
 }
 exports.ElemHideException = ElemHideException;
 
 ElemHideException.prototype =
 {
   __proto__: ElemHideBase.prototype
 };