Issue 6727 - Use string rather than map for single-domain filters

lib/filterClasses.js

Index: lib/filterClasses.js
===================================================================
--- a/lib/filterClasses.js
+++ b/lib/filterClasses.js
@@ -388,19 +388,20 @@
   /**
    * 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 {?Map.<string,boolean>}
+   * String specifying the domain that this filter should match on, or 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>|string}
    */
   get domains()
   {
     // Despite this property being cached, the getter is called
     // several times on Safari, due to WebKit bug 132872
     let prop = Object.getOwnPropertyDescriptor(this, "domains");
     if (prop)
       return prop.value;
@@ -414,17 +415,17 @@
       {
         // 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 = new Map([["", false], [list[0], true]]);
+        domains = list[0];
       }
       else
       {
         let hasIncludes = false;
         for (let i = 0; i < list.length; i++)
         {
           let domain = list[i];
           if (domain == "")
@@ -483,20 +484,26 @@
 
     // If no domains are set the rule matches everywhere
     if (!this.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 typeof this.domains != "string" && this.domains.get("");
 
     docDomain = docDomain.replace(/\.+$/, "").toUpperCase();
 
+    if (typeof this.domains == "string")
+    {
+      return docDomain == this.domains ||
+             docDomain.endsWith("." + this.domains);
+    }
+
     while (true)
     {
       let isDomainIncluded = this.domains.get(docDomain);
       if (typeof isDomainIncluded != "undefined")
         return isDomainIncluded;
 
       let nextDot = docDomain.indexOf(".");
       if (nextDot < 0)
@@ -508,21 +515,30 @@
 
   /**
    * 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(""))
+    if (!docDomain || !this.domains ||
+        typeof this.domains != "string" && this.domains.get(""))
+    {
       return false;
+    }
 
     docDomain = docDomain.replace(/\.+$/, "").toUpperCase();
 
+    if (typeof this.domains == "string")
+    {
+      return docDomain == this.domains ||
+             this.domains.endsWith("." + docDomain);
+    }
+
     for (let [domain, isIncluded] of this.domains)
     {
       if (isIncluded && domain != docDomain)
       {
         if (domain.length <= docDomain.length)
           return false;
 
         if (!domain.endsWith("." + docDomain))
@@ -535,17 +551,18 @@
 
   /**
    * Checks whether this filter is generic or specific
    * @return {boolean}
    */
   isGeneric()
   {
     return !(this.sitekeys && this.sitekeys.length) &&
-            (!this.domains || this.domains.get(""));
+            (!this.domains ||
+             typeof this.domains != "string" && this.domains.get(""));
   },
 
   /**
    * See Filter.serialize()
    * @inheritdoc
    */
   serialize(buffer)
   {