redirection engine: code review

assets/checksums.txt

@@ -1,11 +1,11 @@
 d644ffec21b802b4efb76365a576b86f assets/ublock/unbreak.txt
+e65fbcaa573c028770f1d0afada55672 assets/ublock/redirect-resources.txt
 7a04294b44b88baa34cf3e4bfe0e59db assets/ublock/privacy.txt
 b2dbf435507aa0262b289c67cbef2142 assets/ublock/filters.txt
 146704ad1c0393e342afdb416762c183 assets/ublock/badware.txt
 4b3df06f0b27c57cea0006ae559e078b assets/ublock/redirect.txt
 c9c5cc56bec563bc1885847f925b9be2 assets/ublock/mirror-candidates.txt
 f9455a47b5024cc08ff3675ce79b58a9 assets/ublock/filter-lists.json
-b7781a2ab4094b0ffa363caa6e29801d assets/ublock/redirect-rules.txt
 94c0a3eab74c42783855f07b22a429cf assets/thirdparties/home.fredfiber.no/langsholt/adblock.txt
 a82cb5ba5caf035ce00e97de81db5de7 assets/thirdparties/www.zoso.ro/pages/rolist.txt
 72373316d0e7ad22604d307c2d93e7cc assets/thirdparties/adblock.gardar.net/is.abp.txt

assets/ublock/redirect-resources.txt

@@ -1,4 +1,12 @@
-redirects:
+# Resources to be used as redirect destinations.
+#
+# - Each distinct resource entry is separated by an empty line.
+# - The first line in a resource entry is: token mime-type[;encoding]
+# - All following lines are the data. An empty line signals the end of the
+#   data.
+#
+# If the encoding is absent, the data will be converted to base64, and the
+# encoding will be set to `;base64`.
 
 hd-main.js application/javascript
 var L = (function(){
@@ -11,3 +19,6 @@ var L = (function(){
   return l;
 })();
 
+# http://probablyprogramming.com/2009/03/15/the-tiniest-gif-ever
+handtinytrans.gif image/gif;base64
+R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==

src/js/redirect-engine.js

@@ -40,7 +40,7 @@ var toBroaderHostname = function(hostname) {
 /******************************************************************************/
 
 var RedirectEngine = function() {
-    this.redirects = Object.create(null);
+    this.resources = Object.create(null);
     this.reset();
 };
 
@@ -77,7 +77,7 @@ RedirectEngine.prototype.lookup = function(context) {
                     while ( i-- ) {
                         entry = entries[i];
                         if ( entry.c.test(reqURL) ) {
-                            return this.redirects[entry.r];
+                            return this.resources[entry.r];
                         }
                     }
                 }
@@ -96,8 +96,6 @@ RedirectEngine.prototype.lookup = function(context) {
 
 /******************************************************************************/
 
-// TODO: combine same key-redirect pairs into a single regex.
-
 RedirectEngine.prototype.addRule = function(src, des, type, pattern, redirect) {
     var typeEntry = this.rules[type];
     if ( typeEntry === undefined ) {
@@ -159,7 +157,13 @@ RedirectEngine.prototype.compileRuleFromStaticFilter = function(line) {
         }
     }
 
-    if ( redirect === '' || types.length === 0 ) {
+    // Need a resource token.
+    if ( redirect === '' ) {
+        return '';
+    }
+
+    // Need one single type (not negated).
+    if ( types.length !== 1 || types[0].charAt(0) === '~' ) {
         return '';
     }
 
@@ -172,12 +176,13 @@ RedirectEngine.prototype.compileRuleFromStaticFilter = function(line) {
     }
 
     var out = [];
-    var i = srcs.length, j;
+    var i = srcs.length, src;
     while ( i-- ) {
-        j = types.length;
-        while ( j-- ) {
-            out.push(srcs[i] + '\t' + des + '\t' + types[j] + '\t' + pattern + '\t' + redirect);
+        src = srcs[i];
+        if ( src.charAt(0) === '~' ) {
+            continue;
         }
+        out.push(srcs[i] + '\t' + des + '\t' + types[0] + '\t' + pattern + '\t' + redirect);
     }
 
     return out;
@@ -203,12 +208,12 @@ RedirectEngine.prototype.supportedTypes = (function() {
 
 // TODO: combine same key-redirect pairs into a single regex.
 
-RedirectEngine.prototype.redirectDataFromString = function(text) {
+RedirectEngine.prototype.resourcesFromString = function(text) {
     var textEnd = text.length;
     var lineBeg = 0, lineEnd;
-    var mode, modeData, line, fields, encoded, data;
+    var line, fields, resource, encoded, data;
 
-    this.redirects = Object.create(null);
+    this.resources = Object.create(null);
 
     while ( lineBeg < textEnd ) {
         lineEnd = text.indexOf('\n', lineBeg);
@@ -225,37 +230,31 @@ RedirectEngine.prototype.redirectDataFromString = function(text) {
             continue;
         }
 
-        if ( line.slice(-1) === ':' ) {
-            mode = line.slice(0, -1);
-            continue;
-        }
-
-        if ( mode === 'redirects' ) {
+        if ( resource === undefined ) {
             fields = line.split(/\s+/);
             if ( fields.length !== 2 ) {
                 continue;
             }
-            mode = 'redirects/redirect';
-            modeData = fields;
+            resource = fields;
             continue;
         }
 
-        if ( mode === 'redirects/redirect' ) {
-            if ( line !== '' ) {
-                modeData.push(line);
-                continue;
-            }
-            encoded = modeData[1].indexOf(';') !== -1;
-            data = modeData.slice(2).join(encoded ? '' : '\n');
-            this.redirects[modeData[0]] =
-                'data:' +
-                modeData[1] + 
-                (encoded ? '' : ';base64') +
-                ',' +
-                (encoded ? data : btoa(data));
-            mode = 'redirects';
+        if ( line !== '' ) {
+            resource.push(line);
             continue;
         }
+
+        // No more data, store the resource.
+        encoded = resource[1].indexOf(';') !== -1;
+        data = resource.slice(2).join(encoded ? '' : '\n');
+        this.resources[resource[0]] =
+            'data:' +
+            resource[1] + 
+            (encoded ? '' : ';base64') +
+            ',' +
+            (encoded ? data : btoa(data));
+
+        resource = undefined;
     }
 };
 

src/js/start.js

@@ -211,7 +211,7 @@ var onFirstFetchReady = function(fetched) {
     fromFetch(µb.restoreBackupSettings, fetched);
     onNetWhitelistReady(fetched.netWhitelist);
     onVersionReady(fetched.version);
-    µb.loadRedirectRules();
+    µb.loadRedirectResources();
 
     // If we have a selfie, skip loading PSL, filters
     if ( onSelfieReady(fetched.selfie) ) {

src/js/static-net-filtering.js

@@ -1503,9 +1503,15 @@ FilterParser.prototype.parseOptions = function(s) {
             continue;
         }
         if ( opt.lastIndexOf('redirect=', 0) === 0 ) {
-            this.redirect = true;
-            continue;
+            if ( this.action === BlockAction ) {
+                this.redirect = true;
+                continue;
+            }
+            this.unsupported = true;
+            break;
         }
+
+        // Unrecognized filter option: ignore whole filter.
         this.unsupported = true;
         break;
     }

src/js/storage.js

@@ -650,20 +650,21 @@
 
 // TODO: toSelfie/fromSelfie.
 
-µBlock.loadRedirectRules = function(callback) {
+µBlock.loadRedirectResources = function(callback) {
     var µb = this;
 
     if ( typeof callback !== 'function' ) {
         callback = this.noopFunc;
     }
-    var onRulesLoaded = function(details) {
+
+    var onResourcesLoaded = function(details) {
         if ( details.content !== '' ) {
-            µb.redirectEngine.redirectDataFromString(details.content);
+            µb.redirectEngine.resourcesFromString(details.content);
         }
         callback();
     };
 
-    this.assets.get('assets/ublock/redirect-rules.txt', onRulesLoaded);
+    this.assets.get('assets/ublock/redirect-resources.txt', onResourcesLoaded);
 };
 
 /******************************************************************************/