more refactoring of content script: better modularization of various components

platform/chromium/vapi-client.js

@@ -67,6 +67,23 @@ if ( vAPI.sessionId ) {
 
 /******************************************************************************/
 
+var referenceCounter = 0;
+
+vAPI.lock = function() {
+    referenceCounter += 1;
+};
+
+vAPI.unlock = function() {
+    referenceCounter -= 1;
+    if ( referenceCounter === 0 ) {
+        // Eventually there will be code here to flush the javascript code
+        // from this file out of memory when it ends up unused.
+        
+    }
+};
+
+/******************************************************************************/
+
 vAPI.executionCost = {
     start: function(){},
     stop: function(){}

platform/firefox/vapi-client.js

@@ -56,6 +56,18 @@ var vAPI = self.vAPI = self.vAPI || {};
 
 /******************************************************************************/
 
+var referenceCounter = 0;
+
+vAPI.lock = function() {
+    referenceCounter += 1;
+};
+
+vAPI.unlock = function() {
+    referenceCounter -= 1;
+};
+
+/******************************************************************************/
+
 vAPI.executionCost = {
     start: function(){},
     stop: function(){}

src/js/contentscript.js

@@ -21,9 +21,50 @@
 
 'use strict';
 
-/******************************************************************************/
+/*******************************************************************************
 
-// Injected into content pages
+              +--> [[domSurveyor] --> domFilterer]
+  domWatcher--|
+              +--> [domCollapser]
+
+  domWatcher:
+    Watches for changes in the DOM, and notify the other components about these
+    changes.
+
+  domCollapser:
+    Enforces the collapsing of DOM elements for which a corresponding
+    resource was blocked through network filtering.
+
+  domFilterer:
+    Enforces the filtering of DOM elements, by feeding it cosmetic filters.
+
+  domSurveyor:
+    Surveys the DOM to find new cosmetic filters to apply to the current page.
+
+  If page is whitelisted:
+    - domWatcher: off
+    - domCollapser: off
+    - domFilterer: off
+    - domSurveyor: off
+  I verified that the code in this file is completely flushed out of memory
+  when a page is whitelisted.
+
+  If cosmetic filtering is disabled:
+    - domWatcher: on
+    - domCollapser: on
+    - domFilterer: off
+    - domSurveyor: off
+
+  If generic cosmetic filtering is disabled:
+    - domWatcher: on
+    - domCollapser: on
+    - domFilterer: on
+    - domSurveyor: off
+
+  Additionally, the domSurveyor can turn itself off once it decides that
+  it has become pointless (repeatedly not finding new cosmetic filters).
+
+*/
 
 /******************************************************************************/
 /******************************************************************************/
@@ -32,14 +73,13 @@
 // Abort execution by throwing if an unexpected condition arise.
 // - https://github.com/chrisaljoudi/uBlock/issues/456
 
-if ( typeof vAPI !== 'object' || vAPI.contentscriptInjected ) {
+if ( typeof vAPI !== 'object' ) {
     throw new Error('uBlock Origin: aborting content scripts for ' + window.location);
 }
+vAPI.lock();
 
 vAPI.executionCost.start();
 
-vAPI.contentscriptInjected = true;
-
 vAPI.matchesProp = (function() {
     var docElem = document.documentElement;
     if ( typeof docElem.matches !== 'function' ) {
@@ -119,16 +159,16 @@ var jobQueue = [
 
 var reParserEx = /:(?:matches-css|has|style|xpath)\(.+?\)$/;
 
-var allExceptions = Object.create(null);
+var allExceptions = Object.create(null),
-var allSelectors = Object.create(null);
+    allSelectors = Object.create(null),
-var stagedNodes = [];
+    stagedNodes = [],
-var matchesProp = vAPI.matchesProp;
+    matchesProp = vAPI.matchesProp;
 
 // Complex selectors, due to their nature may need to be "de-committed". A
 // Set() is used to implement this functionality.
 
-var complexSelectorsOldResultSet;
+var complexSelectorsOldResultSet,
-var complexSelectorsCurrentResultSet = new Set();
+    complexSelectorsCurrentResultSet = new Set();
 
 /******************************************************************************/
 
@@ -245,6 +285,7 @@ var domFilterer = {
     enabled: true,
     hiddenId: vAPI.randomToken(),
     hiddenNodeCount: 0,
+    loggerEnabled: undefined,
     styleTags: [],
 
     jobQueue: jobQueue,
@@ -352,6 +393,10 @@ var domFilterer = {
     },
 
     commit_: function() {
+        if ( stagedNodes.length === 0 ) {
+            return;
+        }
+
         var beforeHiddenNodeCount = this.hiddenNodeCount,
             styleText = '', i, n;
 
@@ -423,7 +468,11 @@ var domFilterer = {
         }
 
         // If DOM nodes have been affected, lazily notify core process.
-        if ( commitHit && cosmeticFiltersActivatedTimer === null ) {
+        if (
+            this.loggerEnabled !== false &&
+            commitHit &&
+            cosmeticFiltersActivatedTimer === null
+        ) {
             cosmeticFiltersActivatedTimer = vAPI.setTimeout(
                 cosmeticFiltersActivated,
                 503
@@ -512,6 +561,10 @@ var domFilterer = {
         }
     },
 
+    toggleLogging: function(state) {
+        this.loggerEnabled = state;
+    },
+
     toggleOff: function() {
         this.enabled = false;
     },
@@ -583,49 +636,54 @@ return domFilterer;
 
 (function domIsLoading() {
 
-    // Domain-based ABP cosmetic filters.
+    var responseHandler = function(response) {
-    // These can be inserted before the DOM is loaded.
+        // cosmetic filtering engine aka 'cfe'
-
+        var cfeDetails = response && response.specificCosmeticFilters;
-    var cosmeticFilters = function(details) {
+        if ( !cfeDetails || !cfeDetails.ready ) {
-        var domFilterer = vAPI.domFilterer;
+            vAPI.domWatcher = vAPI.domCollapser = vAPI.domFilterer =
-        domFilterer.addExceptions(details.cosmeticDonthide);
+            vAPI.domSurveyor = vAPI.domIsLoaded = null;
-        // https://github.com/chrisaljoudi/uBlock/issues/143
+            vAPI.unlock();
-        domFilterer.addSelectors(details.cosmeticHide);
-        domFilterer.commit(undefined, true);
-    };
-
-    var netFilters = function(details) {
-        var parent = document.head || document.documentElement;
-        if ( !parent ) {
             return;
         }
-        var styleTag = document.createElement('style');
+
-        styleTag.setAttribute('type', 'text/css');
+        vAPI.executionCost.start();
-        var text = details.netHide.join(',\n');
+
-        var css = details.netCollapse ?
+        if ( response.noCosmeticFiltering ) {
+            vAPI.domFilterer = null;
+            vAPI.domSurveyor = null;
+        } else {
+            var domFilterer = vAPI.domFilterer;
+            domFilterer.toggleLogging(response.loggerEnabled);
+            if ( response.noGenericCosmeticFiltering || cfeDetails.noDOMSurveying ) {
+                vAPI.domSurveyor = null;
+            }
+            if ( cfeDetails.cosmeticHide.length !== 0 || cfeDetails.cosmeticDonthide.length !== 0 ) {
+                domFilterer.addExceptions(cfeDetails.cosmeticDonthide);
+                domFilterer.addSelectors(cfeDetails.cosmeticHide);
+                domFilterer.commit(undefined, true);
+            }
+        }
+
+        var parent = document.head || document.documentElement;
+        if ( parent ) {
+            var elem, text;
+            if ( cfeDetails.netHide.length !== 0 ) {
+                elem = document.createElement('style');
+                elem.setAttribute('type', 'text/css');
+                text = cfeDetails.netHide.join(',\n');
+                text += response.collapseBlocked ?
                     '\n{display:none !important;}' :
                     '\n{visibility:hidden !important;}';
-        styleTag.appendChild(document.createTextNode(text + css));
+                elem.appendChild(document.createTextNode(text));
-        parent.appendChild(styleTag);
+                parent.appendChild(elem);
-    };
-
-    // Create script tags and assign data URIs looked up from our library of
-    // redirection resources: Sometimes it is useful to use these resources as
-    // standalone scriptlets. These scriptlets are injected from within the
-    // content scripts because what must be injected, if anything, depends on
-    // the currently active filters, as selected by the user.
-    // Library of redirection resources is located at:
-    // https://github.com/gorhill/uBlock/blob/master/assets/ublock/resources.txt
-
-    var injectScripts = function(scripts) {
-        var parent = document.head || document.documentElement;
-        if ( !parent ) {
-            return;
             }
-        var scriptTag = document.createElement('script');
+            // Library of resources is located at:
+            // https://github.com/gorhill/uBlock/blob/master/assets/ublock/resources.txt
+            if ( cfeDetails.scripts ) {
+                elem = document.createElement('script');
                 // Have the injected script tag remove itself when execution completes:
                 // to keep DOM as clean as possible.
-        scripts +=
+                text = cfeDetails.scripts +
                     "\n" +
                     "(function() {\n" +
                     "    var c = document.currentScript,\n" +
@@ -634,38 +692,21 @@ return domFilterer;
                     "        p.removeChild(c);\n" +
                     "    }\n" +
                     "})();";
-        scriptTag.appendChild(document.createTextNode(scripts));
+                elem.appendChild(document.createTextNode(text));
-        parent.appendChild(scriptTag);
+                parent.appendChild(elem);
-        vAPI.injectedScripts = scripts;
+                vAPI.injectedScripts = text;
-    };
-
-    var responseHandler = function(details) {
-        vAPI.executionCost.start();
-
-        if ( details ) {
-            vAPI.skipCosmeticFiltering = details.skipCosmeticFiltering;
-            vAPI.skipCosmeticSurveying = details.skipCosmeticSurveying;
-            if (
-                (details.skipCosmeticFiltering !== true) &&
-                (details.cosmeticHide.length !== 0 || details.cosmeticDonthide.length !== 0)
-            ) {
-                cosmeticFilters(details);
             }
-            if ( details.netHide.length !== 0 ) {
-                netFilters(details);
-            }
-            if ( details.scripts ) {
-                injectScripts(details.scripts);
-            }
-            // The port will never be used again at this point, disconnecting
-            // allows the browser to flush this script from memory.
         }
 
         // https://github.com/chrisaljoudi/uBlock/issues/587
         // If no filters were found, maybe the script was injected before
         // uBlock's process was fully initialized. When this happens, pages
         // won't be cleaned right after browser launch.
-        vAPI.contentscriptInjected = details && details.ready;
+        if ( document.readyState !== 'loading' ) {
+            window.requestAnimationFrame(vAPI.domIsLoaded);
+        } else {
+            document.addEventListener('DOMContentLoaded', vAPI.domIsLoaded);
+        }
 
         vAPI.executionCost.stop('domIsLoading/responseHandler');
     };
@@ -674,7 +715,7 @@ return domFilterer;
     vAPI.messaging.send(
         'contentscript',
         {
-            what: 'retrieveDomainCosmeticSelectors',
+            what: 'retrieveContentScriptParameters',
             pageURL: url,
             locationURL: url
         },
@@ -687,7 +728,137 @@ return domFilterer;
 /******************************************************************************/
 /******************************************************************************/
 
-var domCollapser = (function() {
+vAPI.domWatcher = (function() {
+
+    var domLayoutObserver = null,
+        ignoreTags = { 'head': 1, 'link': 1, 'meta': 1, 'script': 1, 'style': 1 },
+        addedNodeLists = [],
+        addedNodes = [],
+        removedNodes = false,
+        safeObserverHandlerTimer = null,
+        listeners = [];
+
+    var safeObserverHandler = function() {
+        vAPI.executionCost.start();
+
+        safeObserverHandlerTimer = null;
+        var i = addedNodeLists.length,
+            nodeList, iNode, node;
+        while ( i-- ) {
+            nodeList = addedNodeLists[i];
+            iNode = nodeList.length;
+            while ( iNode-- ) {
+                node = nodeList[iNode];
+                if ( node.nodeType !== 1 ) {
+                    continue;
+                }
+                if ( ignoreTags[node.localName] === 1 ) {
+                    continue;
+                }
+                addedNodes.push(node);
+            }
+        }
+        addedNodeLists.length = 0;
+        if ( addedNodes.length !== 0 ) {
+            listeners[0](addedNodes, removedNodes);
+            if ( listeners[1] ) {
+                listeners[1](addedNodes, removedNodes);
+            }
+            addedNodes.length = 0;
+            removedNodes = false;
+        }
+
+        vAPI.executionCost.stop('domWatcher/safeObserverHandler');
+    };
+
+    // https://github.com/chrisaljoudi/uBlock/issues/205
+    // Do not handle added node directly from within mutation observer.
+    var observerHandler = function(mutations) {
+        vAPI.executionCost.start();
+
+        var nodeList, mutation,
+            i = mutations.length;
+        while ( i-- ) {
+            mutation = mutations[i];
+            nodeList = mutation.addedNodes;
+            if ( nodeList.length !== 0 ) {
+                addedNodeLists.push(nodeList);
+            }
+            if ( mutation.removedNodes.length !== 0 ) {
+                removedNodes = true;
+            }
+        }
+        if ( (addedNodeLists.length !== 0 || removedNodes) && safeObserverHandlerTimer === null ) {
+            safeObserverHandlerTimer = window.requestAnimationFrame(safeObserverHandler);
+        }
+
+        vAPI.executionCost.stop('domWatcher/observerHandler');
+    };
+
+    var addListener = function(listener) {
+        if ( listeners.indexOf(listener) !== -1 ) {
+            return;
+        }
+        listeners.push(listener);
+        if ( domLayoutObserver !== null ) {
+            return;
+        }
+        domLayoutObserver = new MutationObserver(observerHandler);
+        domLayoutObserver.observe(document.documentElement, {
+            //attributeFilter: [ 'class', 'id' ],
+            //attributes: true,
+            childList: true,
+            subtree: true
+        });
+    };
+
+    var removeListener = function(listener) {
+        var pos = listeners.indexOf(listener);
+        if ( pos === -1 ) {
+            return;
+        }
+        listeners.splice(pos, 1);
+        if ( listeners.length !== 0 || domLayoutObserver === null ) {
+            return;
+        }
+        domLayoutObserver.disconnect();
+        domLayoutObserver = null;
+    };
+
+    var stop = function() {
+        if ( domLayoutObserver !== null ) {
+            domLayoutObserver.disconnect();
+            domLayoutObserver = null;
+        }
+        if ( safeObserverHandlerTimer !== null ) {
+            window.cancelAnimationFrame(safeObserverHandlerTimer);
+        }
+    };
+
+    var start = function() {
+        // Observe changes in the DOM only if...
+        // - there is a document.body
+        // - there is at least one `script` tag
+        if ( document.body === null || document.querySelector('script') === null ) {
+            vAPI.domWatcher = null;
+            return;
+        }
+        // https://github.com/gorhill/uMatrix/issues/144
+        vAPI.shutdown.add(stop);
+    };
+
+    return {
+        addListener: addListener,
+        removeListener: removeListener,
+        start: start
+    };
+})();
+
+/******************************************************************************/
+/******************************************************************************/
+/******************************************************************************/
+
+vAPI.domCollapser = (function() {
     var timer = null;
     var pendingRequests = Object.create(null);
     var roundtripRequests = [];
@@ -913,18 +1084,64 @@ var domCollapser = (function() {
         }
     };
 
-    var iframesFromNode = function(node) {
+    var domChangedHandler = function(nodes) {
+        var node;
+        for ( var i = 0, ni = nodes.length; i < ni; i++ ) {
+            node = nodes[i];
             if ( node.localName === 'iframe' ) {
                 addIFrame(node);
-            process();
             }
             if ( node.children.length !== 0 ) {
                 var iframes = node.getElementsByTagName('iframe');
                 if ( iframes.length !== 0 ) {
                     addIFrames(iframes);
+                }
+            }
+        }
         process();
+    };
+
+    var onResourceFailed = function(ev) {
+        vAPI.executionCost.start();
+        vAPI.domCollapser.add(ev.target);
+        vAPI.domCollapser.process();
+        vAPI.executionCost.stop('domIsLoaded/onResourceFailed');
+    };
+
+    var start = function() {
+        // Listener to collapse blocked resources.
+        // - Future requests not blocked yet
+        // - Elements dynamically added to the page
+        // - Elements which resource URL changes
+
+        // https://github.com/chrisaljoudi/uBlock/issues/7
+        // Preferring getElementsByTagName over querySelectorAll:
+        //   http://jsperf.com/queryselectorall-vs-getelementsbytagname/145
+        var elems = document.images || document.getElementsByTagName('img'),
+            i = elems.length, elem;
+        while ( i-- ) {
+            elem = elems[i];
+            if ( elem.complete ) {
+                add(elem);
             }
         }
+        addMany(document.embeds || document.getElementsByTagName('embed'));
+        addMany(document.getElementsByTagName('object'));
+        addIFrames(document.getElementsByTagName('iframe'));
+        process(0);
+
+        document.addEventListener('error', onResourceFailed, true);
+        if ( vAPI.domWatcher ) {
+            vAPI.domWatcher.addListener(domChangedHandler);
+        }
+
+        // https://github.com/gorhill/uMatrix/issues/144
+        vAPI.shutdown.add(function() {
+            document.removeEventListener('error', onResourceFailed, true);
+            if ( vAPI.domWatcher ) {
+                vAPI.domWatcher.removeListener(domChangedHandler);
+            }
+        });
     };
 
     return {
@@ -932,8 +1149,8 @@ var domCollapser = (function() {
         addMany: addMany,
         addIFrame: addIFrame,
         addIFrames: addIFrames,
-        iframesFromNode: iframesFromNode,
+        process: process,
-        process: process
+        start: start
     };
 })();
 
@@ -941,62 +1158,20 @@ var domCollapser = (function() {
 /******************************************************************************/
 /******************************************************************************/
 
-var domIsLoaded = function(ev) {
+vAPI.domSurveyor = (function() {
-
-/******************************************************************************/
-
-if ( ev ) {
-    document.removeEventListener('DOMContentLoaded', domIsLoaded);
-}
-
-// I've seen this happens on Firefox
-if ( window.location === null ) {
-    return;
-}
-
-// https://github.com/chrisaljoudi/uBlock/issues/587
-// Pointless to execute without the start script having done its job.
-if ( !vAPI.contentscriptInjected ) {
-    return;
-}
-
-vAPI.executionCost.start();
-
-/*******************************************************************************
-
-skip-survey=false: survey-phase-1 => survey-phase-2 => survey-phase-3 => commit
- skip-survey=true: commit
-
-*/
-
-// Cosmetic filtering.
-
-(function() {
-    if ( vAPI.skipCosmeticFiltering ) {
-        //console.debug('Abort cosmetic filtering');
-        return;
-    }
-
     // https://github.com/chrisaljoudi/uBlock/issues/789
     // https://github.com/gorhill/uBlock/issues/873
     // Be sure that our style tags used for cosmetic filtering are still
     // applied.
-    var domFilterer = vAPI.domFilterer;
-    domFilterer.checkStyleTags(false);
-    domFilterer.commit();
 
-    var contextNodes = [ document.documentElement ],
+    var domFilterer = null,
-        messaging = vAPI.messaging;
+        messaging = vAPI.messaging,
-
+        surveyPhase3Nodes = [],
-    var domSurveyor = (function() {
+        cosmeticSurveyingMissCount = 0,
-        if ( vAPI.skipCosmeticSurveying === true ) {
-            return;
-        }
-
-        var cosmeticSurveyingMissCount = 0,
         highGenerics = null,
         lowGenericSelectors = [],
-            queriedSelectors = Object.create(null);
+        queriedSelectors = Object.create(null),
+        removedNodesHandlerMissCount = 0;
 
     // Handle main process' response.
 
@@ -1050,22 +1225,20 @@ skip-survey=false: survey-phase-1 => survey-phase-2 => survey-phase-3 => commit
         // Shutdown surveyor if too many consecutive empty resultsets.
         if ( domFilterer.job0._0.length === 0 ) {
             cosmeticSurveyingMissCount += 1;
-                if ( cosmeticSurveyingMissCount > 255 ) {
-                    domSurveyor = undefined;
-                }
         } else {
             cosmeticSurveyingMissCount = 0;
         }
 
-            domFilterer.commit(contextNodes);
+        domFilterer.commit(surveyPhase3Nodes);
-            contextNodes = [];
+        surveyPhase3Nodes = [];
 
         vAPI.executionCost.stop('domIsLoaded/surveyPhase2');
     };
 
     // Query main process.
 
-        var surveyPhase2 = function() {
+    var surveyPhase2 = function(addedNodes) {
+        surveyPhase3Nodes = surveyPhase3Nodes.concat(addedNodes);
         if ( lowGenericSelectors.length !== 0 || highGenerics === null ) {
             messaging.send(
                 'contentscript',
@@ -1100,7 +1273,7 @@ skip-survey=false: survey-phase-1 => survey-phase-2 => survey-phase-3 => commit
         var attr, attrValue, nodeList, iNode, node;
         var selector;
         while ( (attr = attrs.pop()) ) {
-                nodeList = selectNodes('[' + attr + ']');
+            nodeList = selectNodes('[' + attr + ']', surveyPhase3Nodes);
             iNode = nodeList.length;
             while ( iNode-- ) {
                 node = nodeList[iNode];
@@ -1128,7 +1301,7 @@ skip-survey=false: survey-phase-1 => survey-phase-2 => survey-phase-3 => commit
     // - [href^="http"]
 
     var processHighMediumGenerics = function(generics) {
-            var stagedNodes = contextNodes,
+        var stagedNodes = surveyPhase3Nodes,
             i = stagedNodes.length;
         if ( i === 1 && stagedNodes[0] === document.documentElement ) {
             processHighMediumGenericsForNodes(document.links, generics);
@@ -1191,7 +1364,7 @@ skip-survey=false: survey-phase-1 => survey-phase-2 => survey-phase-3 => commit
         ) {
             tstart = window.performance.now();
             var matchesProp = vAPI.matchesProp,
-                    nodes = contextNodes,
+                nodes = surveyPhase3Nodes,
                 i = nodes.length, node;
             while ( i-- ) {
                 node = nodes[i];
@@ -1216,7 +1389,6 @@ skip-survey=false: survey-phase-1 => survey-phase-2 => survey-phase-3 => commit
             if ( document.querySelector(highGenerics.hideHighComplex) !== null ) {
                 highHighComplexGenericsInjected = true;
                 domFilterer.addSelectors(highGenerics.hideHighComplex.split(',\n'));
-                    domFilterer.commit();
             }
             highHighComplexGenericsCost += window.performance.now() - tstart;
         }
@@ -1224,8 +1396,8 @@ skip-survey=false: survey-phase-1 => survey-phase-2 => survey-phase-3 => commit
 
     // Extract and return the staged nodes which (may) match the selectors.
 
-        var selectNodes = function(selector) {
+    var selectNodes = function(selector, nodes) {
-            var stagedNodes = contextNodes,
+        var stagedNodes = nodes,
             i = stagedNodes.length;
         if ( i === 1 && stagedNodes[0] === document.documentElement ) {
             return document.querySelectorAll(selector);
@@ -1252,8 +1424,8 @@ skip-survey=false: survey-phase-1 => survey-phase-2 => survey-phase-3 => commit
     // http://www.w3.org/TR/2014/REC-html5-20141028/infrastructure.html#space-separated-tokens
     // http://jsperf.com/enumerate-classes/6
 
-        var surveyPhase1 = function() {
+    var surveyPhase1 = function(addedNodes) {
-            var nodes = selectNodes('[class],[id]');
+        var nodes = selectNodes('[class],[id]', addedNodes);
         var qq = queriedSelectors;
         var ll = lowGenericSelectors;
         var node, v, vv, j;
@@ -1289,209 +1461,80 @@ skip-survey=false: survey-phase-1 => survey-phase-2 => survey-phase-3 => commit
                 }
             }
         }
-            surveyPhase2();
+        surveyPhase2(addedNodes);
     };
 
-        return surveyPhase1;
+    var domChangedHandler = function(addedNodes, removedNodes) {
-    })();
+        if ( cosmeticSurveyingMissCount < 256 ) {
-
+            surveyPhase1(addedNodes);
-    // Start cosmetic filtering.
-
-    if ( domSurveyor ) {
-        domSurveyor();
-    }
-
-    //console.debug('%f: uBlock: survey time', timer.now() - tStart);
-
-    // Below this point is the code which takes care to observe changes in
-    // the page and to add if needed relevant CSS rules as a result of the
-    // changes.
-
-    // Observe changes in the DOM only if...
-    // - there is a document.body
-    // - there is at least one `script` tag
-    if ( !document.body || !document.querySelector('script') ) {
-        return;
-    }
-
-    // https://github.com/chrisaljoudi/uBlock/issues/618
-    // Following is to observe dynamically added iframes:
-    // - On Firefox, the iframes fails to fire a `load` event
-
-    var ignoreTags = {
-        'link': true,
-        'meta': true,
-        'script': true,
-        'style': true
-    };
-
-    // Added node lists will be cumulated here before being processed
-    var addedNodeLists = [],
-        addedNodeListsTimer = null,
-        removedNodeListsTimer = null,
-        removedNodesHandlerMissCount = 0,
-        collapser = domCollapser;
-
-    var addedNodesHandler = function() {
-        vAPI.executionCost.start();
-
-        addedNodeListsTimer = null;
-        var iNodeList = addedNodeLists.length,
-            nodeList, iNode, node;
-        while ( iNodeList-- ) {
-            nodeList = addedNodeLists[iNodeList];
-            iNode = nodeList.length;
-            while ( iNode-- ) {
-                node = nodeList[iNode];
-                if ( node.nodeType !== 1 ) {
-                    continue;
-                }
-                if ( ignoreTags.hasOwnProperty(node.localName) ) {
-                    continue;
-                }
-                contextNodes.push(node);
-                collapser.iframesFromNode(node);
-            }
-        }
-        addedNodeLists.length = 0;
-        if ( contextNodes.length !== 0 ) {
-            if ( domSurveyor ) {
-                domSurveyor();
         } else {
-                domFilterer.commit(contextNodes);
+            domFilterer.commit(addedNodes);
-                contextNodes = [];
-                if ( domFilterer.commitMissCount > 255 ) {
-                    domLayoutObserver.disconnect();
         }
-            }
-        }
-
-        vAPI.executionCost.stop('domIsLoaded/addedNodesHandler');
-    };
-
         // https://github.com/gorhill/uBlock/issues/873
         // This will ensure our style elements will stay in the DOM.
-    var removedNodesHandler = function() {
+        if ( removedNodes && removedNodesHandlerMissCount < 16 ) {
             if ( domFilterer.checkStyleTags(true) === false ) {
                 removedNodesHandlerMissCount += 1;
             }
-        if ( removedNodesHandlerMissCount < 16 ) {
-            removedNodeListsTimer = null;
         }
     };
 
-    // https://github.com/chrisaljoudi/uBlock/issues/205
+    var start = function() {
-    // Do not handle added node directly from within mutation observer.
+        domFilterer = vAPI.domFilterer;
-    // I arbitrarily chose 100 ms for now: I have to compromise between the
+        if ( domFilterer === null ) {
-    // overhead of processing too few nodes too often and the delay of many
+            return;
-    // nodes less often.
+        }
-    var domLayoutChanged = function(mutations) {
+        domFilterer.checkStyleTags(false);
+        domFilterer.commit();
+        domChangedHandler([ document.documentElement ]);
+        if ( vAPI.domWatcher ) {
+            vAPI.domWatcher.addListener(domChangedHandler);
+        }
+    };
+
+    return {
+        start: start
+    };
+})();
+
+/******************************************************************************/
+/******************************************************************************/
+/******************************************************************************/
+
+vAPI.domIsLoaded = function(ev) {
+    if ( ev ) {
+        document.removeEventListener('DOMContentLoaded', vAPI.domIsLoaded);
+    }
+    vAPI.domIsLoaded = null;
+
+    // I've seen this happens on Firefox
+    if ( window.location === null ) {
+        return;
+    }
+
     vAPI.executionCost.start();
 
-        var removedNodeLists = false;
+    if ( vAPI.domWatcher ) {
-        var iMutation = mutations.length;
+        vAPI.domWatcher.start();
-        var nodeList, mutation;
-        while ( iMutation-- ) {
-            mutation = mutations[iMutation];
-            nodeList = mutation.addedNodes;
-            if ( nodeList.length !== 0 ) {
-                addedNodeLists.push(nodeList);
-            }
-            if ( mutation.removedNodes.length !== 0 ) {
-                removedNodeLists = true;
-            }
-        }
-        if ( addedNodeLists.length !== 0 && addedNodeListsTimer === null ) {
-            addedNodeListsTimer = window.requestAnimationFrame(addedNodesHandler);
-        }
-        if ( removedNodeLists && removedNodeListsTimer === null ) {
-            removedNodeListsTimer = window.requestAnimationFrame(removedNodesHandler);
     }
 
-        vAPI.executionCost.stop('domIsLoaded/domLayoutChanged');
+    if ( vAPI.domCollapser ) {
-    };
+        vAPI.domCollapser.start();
-
-    //console.debug('Starts cosmetic filtering\'s mutations observer');
-
-    // https://github.com/gorhill/httpswitchboard/issues/176
-    var domLayoutObserver = new MutationObserver(domLayoutChanged);
-    domLayoutObserver.observe(document.documentElement, {
-        childList: true,
-        subtree: true
-    });
-
-    // https://github.com/gorhill/uMatrix/issues/144
-    vAPI.shutdown.add(function() {
-        domLayoutObserver.disconnect();
-        if ( addedNodeListsTimer !== null ) {
-            window.cancelAnimationFrame(addedNodeListsTimer);
     }
-        if ( removedNodeListsTimer !== null ) {
+
-            window.cancelAnimationFrame(removedNodeListsTimer);
+    if ( vAPI.domFilterer && vAPI.domSurveyor ) {
+        vAPI.domSurveyor.start();
     }
-    });
-})();
-
-/******************************************************************************/
-
-// Permanent
-
-// Listener to collapse blocked resources.
-// - Future requests not blocked yet
-// - Elements dynamically added to the page
-// - Elements which resource URL changes
-
-(function() {
-    var onResourceFailed = function(ev) {
-        vAPI.executionCost.start();
-        domCollapser.add(ev.target);
-        domCollapser.process();
-        vAPI.executionCost.stop('domIsLoaded/onResourceFailed');
-    };
-    document.addEventListener('error', onResourceFailed, true);
-
-    // https://github.com/gorhill/uMatrix/issues/144
-    vAPI.shutdown.add(function() {
-        document.removeEventListener('error', onResourceFailed, true);
-    });
-})();
-
-/******************************************************************************/
-
-// https://github.com/chrisaljoudi/uBlock/issues/7
-// Executed only once.
-// Preferring getElementsByTagName over querySelectorAll:
-//   http://jsperf.com/queryselectorall-vs-getelementsbytagname/145
-
-(function() {
-    var collapser = domCollapser,
-        elems = document.images || document.getElementsByTagName('img'),
-        i = elems.length, elem;
-    while ( i-- ) {
-        elem = elems[i];
-        if ( elem.complete ) {
-            collapser.add(elem);
-        }
-    }
-    collapser.addMany(document.embeds || document.getElementsByTagName('embed'));
-    collapser.addMany(document.getElementsByTagName('object'));
-    collapser.addIFrames(document.getElementsByTagName('iframe'));
-    collapser.process(0);
-})();
-
-/******************************************************************************/
 
     // To send mouse coordinates to main process, as the chrome API fails
     // to provide the mouse position to context menu listeners.
-
     // https://github.com/chrisaljoudi/uBlock/issues/1143
     // Also, find a link under the mouse, to try to avoid confusing new tabs
     // as nuisance popups.
-
     // Ref.: https://developer.mozilla.org/en-US/docs/Web/Events/contextmenu
 
     (function() {
-    if ( window !== window.top ) {
+        if ( window !== window.top || !vAPI.domFilterer ) {
             return;
         }
 
@@ -1522,20 +1565,11 @@ skip-survey=false: survey-phase-1 => survey-phase-2 => survey-phase-3 => commit
         });
     })();
 
-/******************************************************************************/
-
     vAPI.executionCost.stop('domIsLoaded');
-
 };
 
 /******************************************************************************/
 /******************************************************************************/
 /******************************************************************************/
 
-if ( document.readyState !== 'loading' ) {
-    window.requestAnimationFrame(domIsLoaded);
-} else {
-    document.addEventListener('DOMContentLoaded', domIsLoaded);
-}
-
 vAPI.executionCost.stop('contentscript.js');

src/js/cosmetic-filtering.js

@@ -1550,16 +1550,17 @@ FilterContainer.prototype.retrieveGenericSelectors = function(request) {
 
 /******************************************************************************/
 
-FilterContainer.prototype.retrieveDomainSelectors = function(request) {
+FilterContainer.prototype.retrieveDomainSelectors = function(request, noCosmeticFiltering) {
     if ( !request.locationURL ) {
         return;
     }
 
     //quickProfiler.start('FilterContainer.retrieve()');
 
-    var hostname = this.µburi.hostnameFromURI(request.locationURL);
+    var hostname = this.µburi.hostnameFromURI(request.locationURL),
-    var domain = this.µburi.domainFromHostname(hostname) || hostname;
+        domain = this.µburi.domainFromHostname(hostname) || hostname,
-    var pos = domain.indexOf('.');
+        pos = domain.indexOf('.'),
+        cacheEntry = this.selectorCache[hostname];
 
     // https://github.com/chrisaljoudi/uBlock/issues/587
     // r.ready will tell the content script the cosmetic filtering engine is
@@ -1572,15 +1573,14 @@ FilterContainer.prototype.retrieveDomainSelectors = function(request) {
         ready: this.frozen,
         domain: domain,
         entity: pos === -1 ? domain : domain.slice(0, pos - domain.length),
-        skipCosmeticSurveying: false,
+        noDOMSurveying: false,
-        skipCosmeticFiltering: this.acceptedCount === 0,
         cosmeticHide: [],
-        cosmeticDonthide: this.genericDonthide.slice(),
+        cosmeticDonthide: [],
         netHide: [],
-        netCollapse: µb.userSettings.collapseBlocked,
         scripts: this.retrieveScriptTags(domain, hostname)
     };
 
+    if ( !noCosmeticFiltering ) {
         var hash, bucket;
         hash = makeHash(0, domain, this.domainHashMask);
         if ( (bucket = this.hostnameFilters[hash]) ) {
@@ -1596,7 +1596,15 @@ FilterContainer.prototype.retrieveDomainSelectors = function(request) {
         if ( this.entityFilters.hasOwnProperty(r.entity) ) {
             r.cosmeticHide = r.cosmeticHide.concat(this.entityFilters[r.entity]);
         }
-    // No entity exceptions as of now
+
+        // cached cosmetic filters.
+        if ( cacheEntry ) {
+            cacheEntry.retrieve('cosmetic', r.cosmeticHide);
+            r.noDOMSurveying = cacheEntry.cosmeticSurveyingMissCount > cosmeticSurveyingMissCountMax;
+        }
+
+        // Exception cosmetic filters.
+        r.cosmeticDonthide = this.genericDonthide.slice();
 
         hash = makeHash(1, domain, this.domainHashMask);
         if ( (bucket = this.hostnameFilters[hash]) ) {
@@ -1608,22 +1616,16 @@ FilterContainer.prototype.retrieveDomainSelectors = function(request) {
         if ( (bucket = this.hostnameFilters[this.type1NoDomainHash]) ) {
             bucket.retrieve(hostname, r.cosmeticDonthide);
         }
+        // No entity exceptions as of now
+    }
 
-    var cacheEntry = this.selectorCache[hostname];
+    // Collapsible blocked resources.
     if ( cacheEntry ) {
-        cacheEntry.retrieve('cosmetic', r.cosmeticHide);
         cacheEntry.retrieve('net', r.netHide);
-        r.skipCosmeticSurveying = cacheEntry.cosmeticSurveyingMissCount > cosmeticSurveyingMissCountMax;
     }
 
     //quickProfiler.stop();
 
-    //console.log(
-    //    'µBlock> abp-hide-filters.js: "%s" => %d selectors out',
-    //    request.locationURL,
-    //    r.cosmeticHide.length + r.cosmeticDonthide.length
-    //);
-
     return r;
 };
 

src/js/messaging.js

@@ -518,12 +518,18 @@ var onMessage = function(request, sender, callback) {
     }
 
     switch ( request.what ) {
-    case 'retrieveDomainCosmeticSelectors':
+    case 'retrieveContentScriptParameters':
         if ( pageStore && pageStore.getNetFilteringSwitch() ) {
-            response = µb.cosmeticFilteringEngine.retrieveDomainSelectors(request);
+            response = {
-            if ( response && response.skipCosmeticFiltering !== true ) {
+                loggerEnabled: µb.logger.isEnabled(),
-                response.skipCosmeticFiltering = !pageStore.getSpecificCosmeticFilteringSwitch();
+                collapseBlocked: µb.userSettings.collapseBlocked,
-            }
+                noCosmeticFiltering: µb.cosmeticFilteringEngine.acceptedCount === 0 || pageStore.noCosmeticFiltering === true,
+                noGenericCosmeticFiltering: pageStore.noGenericCosmeticFiltering === true
+            };
+            response.specificCosmeticFilters = µb.cosmeticFilteringEngine.retrieveDomainSelectors(
+                request,
+                response.noCosmeticFiltering
+            );
         }
         break;
 

src/js/pagestore.js

@@ -310,14 +310,28 @@ PageStore.prototype.init = function(tabId) {
     this.largeMediaTimer = null;
     this.netFilteringCache = NetFilteringResultCache.factory();
 
-    // Support `elemhide` filter option. Called at this point so the required
+    this.noCosmeticFiltering = µb.hnSwitches.evaluateZ('no-cosmetic-filtering', tabContext.rootHostname) === true;
-    // context is all setup at this point.
+    if ( µb.logger.isEnabled() && this.noCosmeticFiltering ) {
-    this.skipCosmeticFiltering = µb.staticNetFilteringEngine.matchStringExactType(
+        µb.logger.writeOne(
+            tabId,
+            'cosmetic',
+            µb.hnSwitches.toResultString(),
+            'dom',
+            tabContext.rawURL,
+            this.tabHostname,
+            this.tabHostname
+        );
+    }
+
+    // Support `generichide` filter option.
+    this.noGenericCosmeticFiltering = this.noCosmeticFiltering;
+    if ( this.noGenericCosmeticFiltering !== true ) {
+        this.noGenericCosmeticFiltering = µb.staticNetFilteringEngine.matchStringExactType(
             this.createContextFromPage(),
             tabContext.normalURL,
             'elemhide'
         ) === false;
-    if ( this.skipCosmeticFiltering && µb.logger.isEnabled() ) {
+        if ( µb.logger.isEnabled() && this.noGenericCosmeticFiltering ) {
             // https://github.com/gorhill/uBlock/issues/370
             // Log using `cosmetic-filtering`, not `elemhide`.
             µb.logger.writeOne(
@@ -330,6 +344,8 @@ PageStore.prototype.init = function(tabId) {
                 this.tabHostname
             );
         }
+    }
+
     return this;
 };
 
@@ -458,16 +474,14 @@ PageStore.prototype.getNetFilteringSwitch = function() {
 /******************************************************************************/
 
 PageStore.prototype.getSpecificCosmeticFilteringSwitch = function() {
-    var tabContext = µb.tabContextManager.lookup(this.tabId);
+    return this.noCosmeticFiltering !== true;
-    return tabContext !== null &&
-           µb.hnSwitches.evaluateZ('no-cosmetic-filtering', tabContext.rootHostname) !== true;
 };
 
 /******************************************************************************/
 
 PageStore.prototype.getGenericCosmeticFilteringSwitch = function() {
-    return this.skipCosmeticFiltering !== true &&
+    return this.noGenericCosmeticFiltering !== true &&
-           this.getSpecificCosmeticFilteringSwitch();
+           this.noCosmeticFiltering !== true;
 };
 
 /******************************************************************************/

src/js/scriptlets/cosmetic-logger.js

@@ -27,7 +27,7 @@
 
 /******************************************************************************/
 
-if ( typeof vAPI !== 'object' || typeof vAPI.domFilterer !== 'object' ) {
+if ( typeof vAPI !== 'object' || !vAPI.domFilterer ) {
     return;
 }
 

src/js/scriptlets/cosmetic-off.js

@@ -24,7 +24,7 @@
 /******************************************************************************/
 
 (function() {
-    if ( typeof vAPI !== 'object' || typeof vAPI.domFilterer !== 'object' ) {
+    if ( typeof vAPI !== 'object' || !vAPI.domFilterer ) {
         return;
     }
 

src/js/scriptlets/cosmetic-on.js

@@ -24,7 +24,7 @@
 /******************************************************************************/
 
 (function() {
-    if ( typeof vAPI !== 'object' || typeof vAPI.domFilterer !== 'object' ) {
+    if ( typeof vAPI !== 'object' || !vAPI.domFilterer ) {
         return;
     }
 

src/js/scriptlets/cosmetic-survey.js

@@ -24,7 +24,7 @@
 /******************************************************************************/
 
 (function() {
-    if ( typeof vAPI !== 'object' || typeof vAPI.domFilterer !== 'object' ) {
+    if ( typeof vAPI !== 'object' || !vAPI.domFilterer ) {
         return;
     }
 

src/js/scriptlets/dom-inspector.js

@@ -28,7 +28,7 @@
 
 /******************************************************************************/
 
-if ( typeof vAPI !== 'object' || typeof vAPI.domFilterer !== 'object' ) {
+if ( typeof vAPI !== 'object' || !vAPI.domFilterer ) {
     return;
 }