Issue 7003 - Look up whitelist filter only if URL is blocked

lib/matcher.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present 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
  * 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 Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 "use strict";
 
 /**
  * @fileOverview Matcher class implementing matching addresses against
  *               a list of filters.
  */
 
-const {WhitelistFilter} = require("./filterClasses");
+const {RegExpFilter, WhitelistFilter} = require("./filterClasses");
 
 /**
  * Regular expression for matching a keyword in a filter.
  * @type {RegExp}
  */
 const keywordRegExp = /[^a-z0-9%*][a-z0-9%]{3,}(?=[^a-z0-9%*])/;
 
 /**
  * Regular expression for matching all keywords in a filter.
  * @type {RegExp}
  */
 const allKeywordsRegExp = new RegExp(keywordRegExp, "g");
+
+/**
+ * Bitmask for "types" that are for exception rules only, like
+ * <code>$document</code>, <code>$elemhide</code>, and so on.
+ * @type {number}
+ */
+const WHITELIST_ONLY_TYPES = RegExpFilter.typeMap.DOCUMENT |
+                             RegExpFilter.typeMap.ELEMHIDE |
+                             RegExpFilter.typeMap.GENERICHIDE |
+                             RegExpFilter.typeMap.GENERICBLOCK;
 
 /**
  * Checks whether a particular filter is slow.
  * @param {RegExpFilter} filter
  * @returns {boolean}
  */
 function isSlowFilter(filter)
 {
   return !filter.pattern || !keywordRegExp.test(filter.pattern);
 }
@@ skipping 268 matching lines @@
                      specificOnly)
   {
     let candidates = location.toLowerCase().match(/[a-z0-9%]{3,}/g);
     if (candidates === null)
       candidates = [];
     candidates.push("");
 
     let whitelistHit = null;
     let blacklistHit = null;
 
-    for (let i = 0, l = candidates.length; i < l; i++)
-    {
-      let substr = candidates[i];
-      blacklistHit = this.blacklist._checkEntryMatch(
-        substr, location, typeMask, docDomain, thirdParty, sitekey,
-        specificOnly
-      );
-      if (blacklistHit)
-        break;
-    }
-
-    if (blacklistHit)
-    {
-      for (let i = 0, l = candidates.length; i < l; i++)
+    // If the type mask includes no types other than whitelist-only types, we
+    // can skip the blacklist.
+    if ((typeMask & ~WHITELIST_ONLY_TYPES) != 0)
+    {
+      for (let i = 0, l = candidates.length; !blacklistHit && i < l; i++)
       {
-        let substr = candidates[i];
-        whitelistHit = this.whitelist._checkEntryMatch(
-          substr, location, typeMask, docDomain, thirdParty, sitekey
-        );
-        if (whitelistHit)
-          break;
+        blacklistHit = this.blacklist._checkEntryMatch(candidates[i], location,
+                                                       typeMask, docDomain,
+                                                       thirdParty, sitekey,
+                                                       specificOnly);
+      }
+    }
+
+    // If the type mask includes any whitelist-only types, we need to check the
+    // whitelist.
+    if (blacklistHit || (typeMask & WHITELIST_ONLY_TYPES) != 0)
+    {
+      for (let i = 0, l = candidates.length; !whitelistHit && i < l; i++)
+      {
+        whitelistHit = this.whitelist._checkEntryMatch(candidates[i], location,
+                                                       typeMask, docDomain,
+                                                       thirdParty, sitekey);
       }
     }
 
     return whitelistHit || blacklistHit;
   }
 
   /**
    * @see Matcher#matchesAny
    * @inheritdoc
    */
@@ skipping 20 matching lines @@
 
 exports.CombinedMatcher = CombinedMatcher;
 
 /**
  * Shared {@link CombinedMatcher} instance that should usually be used.
  * @type {CombinedMatcher}
  */
 let defaultMatcher = new CombinedMatcher();
 
 exports.defaultMatcher = defaultMatcher;