Issue 6815 - Avoid multiple copies of domain maps

lib/filterClasses.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
@@ skipping 386 matching lines @@
    */
   domainSourceIsLowerCase: false,
 
   /**
    * Map containing domains that this filter should match on/not match
    * on or null if the filter should match on all domains
    * @type {?Map.<string,boolean>}
    */
   get domains()
   {
-    let prop = Object.getOwnPropertyDescriptor(this, "_domains");
-    if (prop)
-    {
-      let {value} = prop;
-      return typeof value == "string" ?
-               new Map([[value, true], ["", false]]) : value;
-    }
-
     let domains = null;
 
     if (this.domainSource)
     {
       let source = this.domainSource;
       if (!this.domainSourceIsLowerCase)
       {
         // RegExpFilter already have lowercase domains
         source = source.toLowerCase();
       }
 
       let knownMap = knownDomainMaps.get(source);
       if (knownMap)
       {
         domains = knownMap;
       }
       else
       {
         let list = source.split(this.domainSeparator);
         if (list.length == 1 && list[0][0] != "~")
         {
           // Fast track for the common one-domain scenario
-          domains = list[0];
+          domains = new Map([[list[0], true], ["", false]]);
         }
         else
         {
           let hasIncludes = false;
           for (let i = 0; i < list.length; i++)
           {
             let domain = list[i];
             if (domain == "")
               continue;
 
             let include;
             if (domain[0] == "~")
             {
               include = false;
               domain = domain.substr(1);
             }
             else
             {
               include = true;
               hasIncludes = true;
             }
 
             if (!domains)
               domains = new Map();
 
             domains.set(domain, include);
           }
 
           if (domains)
-          {
             domains.set("", !hasIncludes);
-            knownDomainMaps.set(source, domains);
-          }
         }
+
+        if (domains)
+          knownDomainMaps.set(source, domains);
       }
 
       this.domainSource = null;
     }
 
-    Object.defineProperty(this, "_domains", {value: domains});
+    Object.defineProperty(this, "domains", {value: domains});
     return this.domains;
   },
 
   /**
    * Array containing public keys of websites that this filter should apply to
    * @type {?string[]}
    */
   sitekeys: null,
 
   /**
    * Checks whether this filter is active on a domain.
    * @param {string} [docDomain] domain name of the document that loads the URL
    * @param {string} [sitekey] public key provided by the document
    * @return {boolean} true in case of the filter being active
    */
   isActiveOnDomain(docDomain, sitekey)
   {
     // Sitekeys are case-sensitive so we shouldn't convert them to
     // upper-case to avoid false positives here. Instead we need to
     // change the way filter options are parsed.
     if (this.sitekeys &&
         (!sitekey || this.sitekeys.indexOf(sitekey.toUpperCase()) < 0))
     {
       return false;
     }
 
+    let {domains} = this;
+
     // If no domains are set the rule matches everywhere
-    if (!this.domains)
+    if (!domains)
       return true;
 
     // If the document has no host name, match only if the filter
     // isn't restricted to specific domains
     if (!docDomain)
-      return this.domains.get("");
+      return domains.get("");
 
     docDomain = docDomain.replace(/\.+$/, "").toLowerCase();
 
     while (true)
     {
-      let isDomainIncluded = this.domains.get(docDomain);
+      let isDomainIncluded = domains.get(docDomain);
       if (typeof isDomainIncluded != "undefined")
         return isDomainIncluded;
 
       let nextDot = docDomain.indexOf(".");
       if (nextDot < 0)
         break;
       docDomain = docDomain.substr(nextDot + 1);
     }
-    return this.domains.get("");
+    return domains.get("");
   },
 
   /**
    * Checks whether this filter is active only on a domain and its subdomains.
    * @param {string} docDomain
    * @return {boolean}
    */
   isActiveOnlyOnDomain(docDomain)
   {
-    if (!docDomain || !this.domains || this.domains.get(""))
+    let {domains} = this;
+
+    if (!docDomain || !domains || domains.get(""))
       return false;
 
     docDomain = docDomain.replace(/\.+$/, "").toLowerCase();
 
-    for (let [domain, isIncluded] of this.domains)
+    for (let [domain, isIncluded] of domains)
     {
       if (isIncluded && domain != docDomain)
       {
         if (domain.length <= docDomain.length)
           return false;
 
         if (!domain.endsWith("." + docDomain))
           return false;
       }
     }
 
     return true;
   },
 
   /**
    * Checks whether this filter is generic or specific
    * @return {boolean}
    */
   isGeneric()
   {
-    return !(this.sitekeys && this.sitekeys.length) &&
-            (!this.domains || this.domains.get(""));
+    let {sitekeys, domains} = this;
+
+    return !(sitekeys && sitekeys.length) && (!domains || domains.get(""));
   },
 
   /**
    * See Filter.serialize()
    * @inheritdoc
    */
   serialize(buffer)
   {
     if (this._disabled || this._hitCount || this._lastHit)
     {
@@ skipping 612 matching lines @@
 
   /**
    * Script that should be executed
    * @type {string}
    */
   get script()
   {
     return this.body;
   }
 });