Issue 7052 - Use string-based matching for literal patterns

lib/filterClasses.js

Index: lib/filterClasses.js
===================================================================
--- a/lib/filterClasses.js
+++ b/lib/filterClasses.js
@@ -20,16 +20,18 @@
 /**
  * @fileOverview Definition of Filter class and its subclasses.
  */
 
 const {filterNotifier} = require("./filterNotifier");
 const {extend} = require("./coreUtils");
 const {filterToRegExp} = require("./common");
 
+let tripleAnchorRegExp = new RegExp(filterToRegExp("|||"));
+
 /**
  * All known unique domain sources mapped to their parsed values.
  * @type {Map.<string,Map.<string,boolean>>}
  */
 let knownDomainMaps = new Map();
 
 /**
  * Abstract base class for filters
@@ -659,21 +661,22 @@
  *   letters
  * @param {string} [domains]
  *   Domains that the filter is restricted to, e.g. "foo.com|bar.com|~baz.com"
  * @param {boolean} [thirdParty]
  *   Defines whether the filter should apply to third-party or first-party
  *   content only
  * @param {string} [sitekeys]
  *   Public keys of websites that this filter should apply to
- * @constructor
+ * @param {?string} [rewrite]
+ *   The (optional) rule specifying how to rewrite the URL.
  * @augments ActiveFilter
  */
 function RegExpFilter(text, regexpSource, contentType, matchCase, domains,
-                      thirdParty, sitekeys)
+                      thirdParty, sitekeys, rewrite)
 {
   ActiveFilter.call(this, text, domains);
 
   if (contentType != null)
     this.contentType = contentType;
   if (matchCase)
     this.matchCase = matchCase;
   if (thirdParty != null)
@@ -690,16 +693,24 @@
     let regexp = new RegExp(regexpSource.substr(1, regexpSource.length - 2),
                             this.matchCase ? "" : "i");
     Object.defineProperty(this, "regexp", {value: regexp});
   }
   else
   {
     // No need to convert this filter to regular expression yet, do it on demand
     this.pattern = regexpSource;
+
+    if (rewrite == null)
+    {
+      this.pattern = this.pattern.replace(/^\**/, "").replace(/\**$/, "");
+
+      if (!this.matchCase)
+        this.pattern = this.pattern.toLowerCase();
+    }
   }
 }
 exports.RegExpFilter = RegExpFilter;
 
 RegExpFilter.prototype = extend(ActiveFilter, {
   /**
    * Number of filters contained, will always be 1 (required to
    * optimize {@link Matcher}).
@@ -719,20 +730,27 @@
    */
   pattern: null,
   /**
    * Regular expression to be used when testing against this filter
    * @type {RegExp}
    */
   get regexp()
   {
-    let source = filterToRegExp(this.pattern, this.rewrite != null);
-    let regexp = new RegExp(source, this.matchCase ? "" : "i");
-    Object.defineProperty(this, "regexp", {value: regexp});
-    return regexp;
+    let value = null;
+
+    let {pattern, rewrite} = this;
+    if (rewrite != null || /[*^|]/.test(pattern.replace(/^\|{1,2}/, "")))
+    {
+      value = new RegExp(filterToRegExp(pattern, rewrite != null),
+                         this.matchCase ? "" : "i");
+    }
+
+    Object.defineProperty(this, "regexp", {value});
+    return value;
   },
   /**
    * Content types the filter applies to, combination of values from
    * RegExpFilter.typeMap
    * @type {number}
    */
   contentType: 0x7FFFFFFF,
   /**
@@ -783,17 +801,44 @@
    * @param {string} [sitekey] public key provided by the document
    * @return {boolean} true in case of a match
    */
   matches(location, typeMask, docDomain, thirdParty, sitekey)
   {
     return (this.contentType & typeMask) != 0 &&
            (this.thirdParty == null || this.thirdParty == thirdParty) &&
            this.isActiveOnDomain(docDomain, sitekey) &&
-           this.regexp.test(location);
+           this.matchesLocation(location);
+  },
+
+  matchesLocation(location)
+  {
+    let {regexp} = this;
+
+    if (regexp)
+      return regexp.test(location);
+
+    if (!this.matchCase)
+      location = location.toLowerCase();
+
+    let {pattern} = this;
+
+    if (pattern[0] == "|")
+    {
+      if (pattern[1] == "|")
+      {
+        let index = location.indexOf(pattern.substring(2));
+        return index != -1 && location[index] != "/" &&
+               tripleAnchorRegExp.test(location.substring(0, index));
+      }
+
+      return location.startsWith(pattern.substring(1));
+    }
+
+    return location.includes(pattern);
   }
 });
 
 /**
  * Yields the filter itself (required to optimize {@link Matcher}).
  * @yields {RegExpFilter}
  */
 RegExpFilter.prototype[Symbol.iterator] = function*()
@@ -988,17 +1033,17 @@
  *   BlockingFilter.prototype.rewrite.
  * @constructor
  * @augments RegExpFilter
  */
 function BlockingFilter(text, regexpSource, contentType, matchCase, domains,
                         thirdParty, sitekeys, collapse, csp, rewrite)
 {
   RegExpFilter.call(this, text, regexpSource, contentType, matchCase, domains,
-                    thirdParty, sitekeys);
+                    thirdParty, sitekeys, rewrite);
 
   if (collapse != null)
     this.collapse = collapse;
 
   if (csp != null)
     this.csp = csp;
 
   if (rewrite != null)