uBlock/platform/safari/vapi-background.js

/*******************************************************************************

    uBlock - a browser extension to block requests.
    Copyright (C) 2015 The uBlock authors

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see {http://www.gnu.org/licenses/}.

    Home: https://github.com/chrisaljoudi/uBlock
*/

/* global self, safari, SafariBrowserTab, µBlock */

// For background page

/******************************************************************************/


(function() {

    "use strict";

    var vAPI = self.vAPI = self.vAPI || {};
 
    vAPI.isMainProcess = true;
    vAPI.safari = true;

    /******************************************************************************/

    vAPI.app = {
        name: "uBlock",
        version: safari.extension.displayVersion
    };

    /******************************************************************************/

    if(navigator.userAgent.indexOf("Safari/6") === -1) { // If we're not on at least Safari 8
        var _open = XMLHttpRequest.prototype.open;
        XMLHttpRequest.prototype.open = function(m, u) {
            if(u.lastIndexOf("safari-extension:", 0) === 0) {
                var i = u.length, seeDot = false;
                while(i --) {
                    if(u[i] === ".") {
                        seeDot = true;
                    }
                    else if(u[i] === "/") {
                        break;
                    }
                }
                if(seeDot === false) {
                    throw 'InvalidAccessError'; // Avoid crash
                    return;
                }
            }
            _open.apply(this, arguments);
        };
    }
    /******************************************************************************/

    vAPI.app.restart = function() {
        µBlock.restart();
    };

    /******************************************************************************/

    safari.extension.addContentScriptFromURL(vAPI.getURL("js/subscriber.js"), [
        "https://*.adblockplus.org/*",
        "https://*.adblockplus.me/*",
        "https://www.fanboy.co.nz/*",
        "http://*.adblockplus.org/*",
        "http://*.adblockplus.me/*",
        "http://www.fanboy.co.nz/*"
    ], [], true);

    /******************************************************************************/

    safari.extension.settings.addEventListener('change', function(e) {
        if(e.key === 'open_prefs') {
            vAPI.tabs.open({
                url: 'dashboard.html',
                active: true
            });
        }
    }, false);

    /******************************************************************************/

    initStorageLib(); // Initialize storage library
    
    /******************************************************************************/

    var storageQuota = 104857600; // copied from Info.plist
    localforage.config({
        name: "ublock",
        size: storageQuota,
        storeName: "keyvaluepairs"
    });

    vAPI.storage = {
        QUOTA_BYTES: storageQuota, // copied from Info.plist

        get: function(keys, callback) {
            if(typeof callback !== "function") {
                return;
            }
            
            var result = {};

            if(keys === null) {
                localforage.iterate(function(value, key) {
                    if(typeof value === "string") {
                        result[key] = JSON.parse(value);
                    }
                }, function() {
                    callback(result);
                });
            }
            else if(typeof keys === "string") {
                localforage.getItem(keys, function(err, value) {
                    if(typeof value === "string") {
                        result[keys] = JSON.parse(value);
                    }
                    callback(result);
                });
            }
            else if(Array.isArray(keys)) {
                var toSatisfy = keys.length, n = toSatisfy;
                if(n === 0) {
                    callback(result);
                    return;
                }
                for(var i = 0; i < n; i++) {
                    var key = keys[i];
                    var func = function(err, value) {
                        toSatisfy--;
                        if(typeof value === "string") {
                            result[arguments.callee.myKey] = JSON.parse(value);
                        }
                        if(toSatisfy === 0) {
                            callback(result);
                        }
                    };
                    func.myKey = key;
                    localforage.getItem(key, func);
                }
            }
            else if(typeof keys === "object") {
                for(var key in keys) {
                    if(!keys.hasOwnProperty(key)) {
                        continue;
                    }
                    result[key] = keys[key];
                }
                localforage.iterate(function(value, key) {
                    if(!keys.hasOwnProperty(key)) return;
                    if(typeof value === "string") {
                        result[key] = JSON.parse(value);
                    }
                }, function() {
                    callback(result);
                });
            }
        },

        set: function(details, callback) {
            var toSatisfy = 0;
            for(var key in details) {
                if(!details.hasOwnProperty(key)) {
                    continue;
                }
                toSatisfy++;
            }
            var callbackCaller = function() {
                if (--toSatisfy === 0) {
                    callback && callback();
                }
            };
            for(var key in details) {
                if(!details.hasOwnProperty(key)) {
                    continue;
                }
                localforage.setItem(key, JSON.stringify(details[key]), callbackCaller);
            }
        },

        remove: function(keys) {
            if(typeof keys === "string") {
                keys = [keys];
            }

            for(var i = 0, n = keys.length; i < n; i++) {
                localforage.removeItem(keys[i]);
            }
        },

        clear: function(callback) {
            this.preferences.clear();
            localforage.clear(function() {
                callback();
            });
        },

        getBytesInUse: function(keys, callback) {
            if(typeof callback !== "function") {
                return;
            }
            var size = 0;
            localforage.iterate(function(value, key) {
                size += (value || "").length;
            }, function() {
                callback(size);
            });
        }
    };
    /******************************************************************************/

    var settingsStorage = {
        _storage: safari.extension.settings,
        get: function(keys, callback) {
            if(typeof callback !== "function") {
                return;
            }

            var i, value, result = {};

            if(keys === null) {
                for(i in this._storage) {
                    if(!this._storage.hasOwnProperty(i)) continue;
                    value = this._storage[i];
                    if(typeof value === "string") {
                        result[i] = JSON.parse(value);
                    }
                }
            }
            else if(typeof keys === "string") {
                value = this._storage[keys];
                if(typeof value === "string") {
                    result[keys] = JSON.parse(value);
                }
            }
            else if(Array.isArray(keys)) {
                for(i = 0; i < keys.length; i++) {
                    value = this._storage[i];

                    if(typeof value === "string") {
                        result[keys[i]] = JSON.parse(value);
                    }
                }
            }
            else if(typeof keys === "object") {
                for(i in keys) {
                    if(!keys.hasOwnProperty(i)) {
                        continue;
                    }
                    value = this._storage[i];

                    if(typeof value === "string") {
                        result[i] = JSON.parse(value);
                    }
                    else {
                        result[i] = keys[i];
                    }
                }
            }
            callback(result);
        },
        set: function(details, callback) {
            for(var key in details) {
                if(!details.hasOwnProperty(key)) {
                    continue;
                }
                this._storage.setItem(key, JSON.stringify(details[key]));
            }
            if(typeof callback === "function") {
                callback();
            }
        },
        remove: function(keys) {
            if(typeof keys === "string") {
                keys = [keys];
            }
            for(var i = 0; i < keys.length; i++) {
                this._storage.removeItem(keys[i]);
            }
        },
        clear: function() {
            this._storage.clear();
        } 
    };

    vAPI.storage.preferences = settingsStorage;

    if(!safari.extension.settings.migratedStorage) { // if we haven't already migrated
        var migrationMap = {
            "cached_asset_content://assets/user/filters.txt": "userFilters"
        };

        var delayed = [];
        
        vAPI.storage.preferences = {
            get: function(a, b) {
                delayed.push(settingsStorage.get.bind(settingsStorage, a, b));
            },
            set: function(a, b) {
                delayed.push(settingsStorage.set.bind(settingsStorage, a, b));
            },
            remove: function(a, b) {
                delayed.push(settingsStorage.remove.bind(settingsStorage, a, b));
            },
            clear: function() {
                delayed.push(settingsStorage.clear.bind(settingsStorage));
            },
        };

        localforage.iterate(function(value, key) {
            if(migrationMap[key]) {
                safari.extension.settings[migrationMap[key]] = value;
                return;
            }
            if(key.lastIndexOf("cached_asset", 0) === 0) {
                return;
            }
            safari.extension.settings[key] = value;
            localforage.removeItem(key);
        }, function() {
            var func;
            while(func = delayed.pop()) {
                func();
            }
            delayed = null;
            vAPI.storage.preferences = settingsStorage;
        });
        safari.extension.settings.migratedStorage = true;
    }

    /******************************************************************************/

    vAPI.tabs = {
        stack: {},
        stackId: 1
    };

    /******************************************************************************/

    vAPI.isBehindTheSceneTabId = function(tabId) {
        return tabId.toString() === this.noTabId;
    };

    vAPI.noTabId = '-1';

    /******************************************************************************/

    vAPI.tabs.registerListeners = function() {
        safari.application.addEventListener("beforeNavigate", function(e) {
            if(!vAPI.tabs.popupCandidate || !e.target || e.url === "about:blank") {
                return;
            }
            var url = e.url,
                tabId = vAPI.tabs.getTabId(e.target);
            var details = {
                targetURL: url,
                targetTabId: tabId.toString(),
                openerTabId: vAPI.tabs.popupCandidate
            };
            vAPI.tabs.popupCandidate = false;
            if(vAPI.tabs.onPopup(details)) {
                e.preventDefault();
                if(vAPI.tabs.stack[details.openerTabId]) {
                    vAPI.tabs.stack[details.openerTabId].activate();
                }
            }
        }, true);
        // onClosed handled in the main tab-close event
        // onUpdated handled via monitoring the history.pushState on web-pages
        // onPopup is handled in window.open on web-pages
    };

    /******************************************************************************/

    vAPI.tabs.getTabId = function(tab) {
        if(typeof tab.uBlockCachedID !== "undefined") {
            return tab.uBlockCachedID;
        }
        for(var i in vAPI.tabs.stack) {
            if(vAPI.tabs.stack[i] === tab) {
                return (tab.uBlockCachedID = +i);
            }
        }

        return -1;
    };

    /******************************************************************************/

    vAPI.tabs.get = function(tabId, callback) {
        var tab;

        if(tabId === null) {
            tab = safari.application.activeBrowserWindow.activeTab;
            tabId = this.getTabId(tab);
        } else {
            tab = this.stack[tabId];
        }

        if(!tab) {
            callback();
            return;
        }

        callback({
            id: tabId,
            index: tab.browserWindow.tabs.indexOf(tab),
            windowId: safari.application.browserWindows.indexOf(tab.browserWindow),
            active: tab === tab.browserWindow.activeTab,
            url: tab.url || "about:blank",
            title: tab.title
        });
    };

    /******************************************************************************/

    // properties of the details object:
    //   url: 'URL', // the address that will be opened
    //   tabId: 1, // the tab is used if set, instead of creating a new one
    //   index: -1, // undefined: end of the list, -1: following tab, or after index
    //   active: false, // opens the tab in background - true and undefined: foreground
    //   select: true // if a tab is already opened with that url, then select it instead of opening a new one

    vAPI.tabs.open = function(details) {
        if(!details.url) {
            return null;
        }
        // extension pages
        if(/^[\w-]{2,}:/.test(details.url) === false) {
            details.url = vAPI.getURL(details.url);
        }

        var curWin, tab;

        if(details.select) {
            tab = safari.application.browserWindows.some(function(win) {
                var rgxHash = /#.*/;
                // this is questionable
                var url = details.url.replace(rgxHash, '');

                for(var i = 0; i < win.tabs.length; i++) {
                    // Some tabs don't have a URL
                    if(win.tabs[i].url &&
                       win.tabs[i].url.replace(rgxHash, '') === url) {
                        win.tabs[i].activate();
                        return true;
                    }
                }
            });

            if(tab) {
                return;
            }
        }

        if(details.active === undefined) {
            details.active = true;
        }

        curWin = safari.application.activeBrowserWindow;

        // it must be calculated before opening a new tab,
        // otherwise the new tab will be the active tab here
        if(details.index === -1) {
            details.index = curWin.tabs.indexOf(curWin.activeTab) + 1;
        }

        tab = (details.tabId ? this.stack[details.tabId] : curWin.openTab(details.active ? 'foreground' : 'background'));

        if(details.index !== undefined) {
            curWin.insertTab(tab, details.index);
        }

        tab.url = details.url;
    };

    /******************************************************************************/

    // Replace the URL of a tab. Noop if the tab does not exist.

    vAPI.tabs.replace = function(tabId, url) {
        var targetURL = url;

        // extension pages
        if ( /^[\w-]{2,}:/.test(targetURL) !== true ) {
            targetURL = vAPI.getURL(targetURL);
        }

        var tab = this.stack[tabId];
        if ( tab ) {
            tab.url = targetURL;
        }
    };

    /******************************************************************************/

    vAPI.tabs.remove = function(tabIds) {
        if(tabIds instanceof SafariBrowserTab) {
            tabIds = this.getTabId(tabIds);
        }

        if(!Array.isArray(tabIds)) {
            tabIds = [tabIds];
        }

        for(var i = 0; i < tabIds.length; i++) {
            if(this.stack[tabIds[i]]) {
                this.stack[tabIds[i]].close();
            }
        }
    };

    /******************************************************************************/

    vAPI.tabs.reload = function(tabId) {
        var tab = this.stack[tabId];

        if(tab) {
            tab.url = tab.url;
        }
    };

    /******************************************************************************/

    vAPI.tabs.injectScript = function(tabId, details, callback) {
        var tab;

        if(tabId) {
            tab = this.stack[tabId];
        } else {
            tab = safari.application.activeBrowserWindow.activeTab;
        }

        if(details.file) {
            var xhr = new XMLHttpRequest();
            xhr.open('GET', details.file, true);
            xhr.addEventListener("readystatechange", function() {
                if(this.readyState === 4) {
                    details.code = xhr.responseText;
                    tab.page.dispatchMessage('broadcast', {
                        channelName: 'vAPI',
                        msg: {
                            cmd: 'injectScript',
                            details: details
                        }
                    });
                    if(typeof callback === 'function') {
                        setTimeout(callback, 13);
                    }
                }
            });
            xhr.send();
        }
    };

    /******************************************************************************/

    // reload the popup when it's opened
    safari.application.addEventListener("popover", function(event) {
        var w = event.target.contentWindow, body = w.document.body, child;
        while(child = body.firstChild) {
            body.removeChild(child);
        }
        w.location.reload();
    }, true);

    /******************************************************************************/

    var ICON_URLS = {
        "on": vAPI.getURL("img/browsericons/safari-icon16.png"),
        "off": vAPI.getURL("img/browsericons/safari-icon16-off.png")
    };

    var IconState = function(badge, img, icon) {
        this.badge = badge;
            // ^ a number -- the badge 'value'
        this.img = img;
            // ^ a string -- 'on' or 'off'
        this.active = false;
            // ^ is this IconState active for rendering?
        this.icon = typeof icon !== "undefined" ? icon : null;
            // ^ the corresponding browser toolbar-icon object
        this.dirty = (1 << 1) | (1 << 0);
            /* ^ bitmask AB: two bits, A and B
                    where A is whether img has changed and needs render
                    and B is whether badge has changed and needs render */
    };

    var iconStateForTabId = {}; // {tabId: IconState}

    var getIconForWindow = function(whichWindow) {
        // do we already have the right icon cached?
        if(typeof whichWindow.uBlockIcon !== "undefined") {
            return whichWindow.uBlockIcon;
        }

        // iterate through the icons to find the one which
        // belongs to this window (whichWindow)
        var items = safari.extension.toolbarItems;
        for(var i = 0; i < items.length; i++) {
            if(items[i].browserWindow === whichWindow) {
                return (whichWindow.uBlockIcon = items[i]);
            }
        }
    };

    safari.application.addEventListener("activate", function(event) {
        if(!(event.target instanceof SafariBrowserTab)) {
            return;
        }

        // when a tab is activated...
        var tab = event.target;
        if(tab.browserWindow !== tab.oldBrowserWindow) {
            // looks like tab is now associated with a new window
            tab.oldBrowserWindow = tab.browserWindow;
            // so, unvalidate icon
            tab.uBlockKnowsIcon = false;
        }

        var tabId = vAPI.tabs.getTabId(tab),
            state = iconStateForTabId[tabId];
        if(typeof state === "undefined") {
            state = iconStateForTabId[tabId] = new IconState(0, "on");
            // need to get the icon for this newly-encountered tab...
            // uBlockKnowsIcon should be undefined here, so in theory
            // we don't need this -- but to be sure,
            // go ahead and explicitly unvalidate
            tab.uBlockKnowsIcon = false;
        }

        if(!tab.uBlockKnowsIcon) {
            // need to find the icon for this tab's window
            state.icon = getIconForWindow(tab.browserWindow);
            tab.uBlockKnowsIcon = true;
        }
        state.active = true;
        // force re-render since we probably switched tabs
        state.dirty = (1 << 1) | (1 << 0);
        renderIcon(state);
    }, true);

    safari.application.addEventListener("deactivate", function(event) {
        if(!(event.target instanceof SafariBrowserTab)) {
            return;
        }
        // when a tab is deactivated...
        var tabId = vAPI.tabs.getTabId(event.target),
            state = iconStateForTabId[tabId];
        if(typeof state === "undefined") {
            return;
        }
        // mark its iconState as inactive so we don't visually
        // render changes for now
        state.active = false;
    }, true);

    var renderIcon = function(iconState) {
        if(iconState.dirty === 0) {
            // quit if we don't need to touch the "DOM"
            return;
        }
        var icon = iconState.icon;
        // only update the image if needed:
        if(iconState.dirty & 2) {
            icon.badge = iconState.badge;
        }
        if((iconState.dirty & 1) && icon.image !== ICON_URLS[iconState.img]) {
            icon.image = ICON_URLS[iconState.img];
        }
        iconState.dirty = 0;
    };

    vAPI.setIcon = function(tabId, iconStatus, badge) {
        badge = badge || 0;

        var state = iconStateForTabId[tabId];
        if(typeof state === "undefined") {
            state = iconStateForTabId[tabId] = new IconState(badge, iconStatus);
        }
        else {
            state.dirty = ((state.badge !== badge) << 1) | ((state.img !== iconStatus) << 0);
            state.badge = badge;
            state.img = iconStatus;
        }
        if(state.active === true) {
            renderIcon(state);
        }
    };

    /******************************************************************************/

    // bind tabs to unique IDs

    (function() {
        var wins = safari.application.browserWindows,
            i = wins.length,
            j,
            curTab,
            curTabId,
            curWindow;
        while(i--) {
            curWindow = wins[i];
            j = curWindow.tabs.length;
            while(j--) {
                curTab = wins[i].tabs[j], curTabId = vAPI.tabs.stackId++;
                iconStateForTabId[curTabId] = new IconState(0, "on", getIconForWindow(curWindow));
                curTab.uBlockKnowsIcon = true;
                if(curWindow.activeTab === curTab) {
                    iconStateForTabId[curTabId].active = true;
                }
                vAPI.tabs.stack[curTabId] = curTab;
            }
        }
    })();

    /******************************************************************************/

    safari.application.addEventListener('open', function(e) {
        // ignore windows
        if(e.target instanceof SafariBrowserTab) {
            vAPI.tabs.stack[vAPI.tabs.stackId++] = e.target;
        }
    }, true);

    /******************************************************************************/

    safari.application.addEventListener('close', function(e) {
        // ignore windows
        if(!(e.target instanceof SafariBrowserTab)) {
            return;
        }

        var tabId = vAPI.tabs.getTabId(e.target);

        if(tabId !== -1) {
            // to not add another listener, put this here
            // instead of vAPI.tabs.registerListeners
            if(typeof vAPI.tabs.onClosed === 'function') {
                vAPI.tabs.onClosed(tabId);
            }

            delete vAPI.tabs.stack[tabId];
            delete iconStateForTabId[tabId];
        }
    }, true);

    /******************************************************************************/
    vAPI.messaging = {
        listeners: {},
        defaultHandler: null,
        NOOPFUNC: function() {},
        UNHANDLED: 'vAPI.messaging.notHandled'
    };

    /******************************************************************************/

    vAPI.messaging.listen = function(listenerName, callback) {
        this.listeners[listenerName] = callback;
    };

    /******************************************************************************/

    var CallbackWrapper = function(request, port) {
        // No need to bind every single time
        this.callback = this.proxy.bind(this);
        this.messaging = vAPI.messaging;
        this.init(request, port);
    };
    CallbackWrapper.junkyard = [];

    CallbackWrapper.factory = function(request, port) {
        var wrapper = CallbackWrapper.junkyard.pop();
        if(wrapper) {
            wrapper.init(request, port);
            return wrapper;
        }
        return new CallbackWrapper(request, port);
    };
    CallbackWrapper.prototype.init = function(request, port) {
        this.request = request;
        this.port = port;
    };
    CallbackWrapper.prototype.proxy = function(response) {
        this.port.dispatchMessage(this.request.name, {
            requestId: this.request.message.requestId,
            channelName: this.request.message.channelName,
            msg: response !== undefined ? response: null
        });
        this.port = this.request = null;
        CallbackWrapper.junkyard.push(this);
    };

    vAPI.messaging.onMessage = function(request) {
        var callback = vAPI.messaging.NOOPFUNC;
        if(request.message.requestId !== undefined) {
            callback = CallbackWrapper.factory(request, request.target.page).callback;
        }

        var sender = {
            tab: {
                id: vAPI.tabs.getTabId(request.target)
            }
        };

        // Specific handler
        var r = vAPI.messaging.UNHANDLED;
        var listener = vAPI.messaging.listeners[request.message.channelName];
        if(typeof listener === 'function') {
            r = listener(request.message.msg, sender, callback);
        }
        if(r !== vAPI.messaging.UNHANDLED) {
            return;
        }

        // Default handler
        r = vAPI.messaging.defaultHandler(request.message.msg, sender, callback);
        if(r !== vAPI.messaging.UNHANDLED) {
            return;
        }

        console.error('µBlock> messaging > unknown request: %o', request.message);

        // Unhandled:
        // Need to callback anyways in case caller expected an answer, or
        // else there is a memory leak on caller's side
        callback();
    };

    /******************************************************************************/

    vAPI.messaging.setup = function(defaultHandler) {
        // Already setup?
        if(this.defaultHandler !== null) {
            return;
        }

        if(typeof defaultHandler !== 'function') {
            defaultHandler = function() {
                return vAPI.messaging.UNHANDLED;
            };
        }
        this.defaultHandler = defaultHandler;

        // the third parameter must stay false (bubbling), so later
        // onBeforeRequest will use true (capturing), where we can invoke
        // stopPropagation() (this way this.onMessage won't be fired)
        safari.application.addEventListener('message', this.onMessage, false);
    };

    /******************************************************************************/

    vAPI.messaging.broadcast = function(message) {
        message = {
            broadcast: true,
            msg: message
        };
        var page;
        for(var tabId in vAPI.tabs.stack) {
            page = vAPI.tabs.stack[tabId].page;
            page && page.dispatchMessage && page.dispatchMessage('broadcast', message);
        }
    };

    /******************************************************************************/

    vAPI.net = {};

    /******************************************************************************/

    // Fast `contains`

    Array.prototype.contains = function(a) {
        var b = this.length;
        while(b--) {
            if(this[b] === a) {
                return true;
            }
        }
        return false;
    };

    /******************************************************************************/

    vAPI.net.registerListeners = function() {
        var µb = µBlock;

        // Until Safari has more specific events, those are instead handled
        // in the onBeforeRequestAdapter; clean them up so they're garbage-collected
        vAPI.net.onBeforeSendHeaders = null;

        var onBeforeRequest = vAPI.net.onBeforeRequest,
            onBeforeRequestClient = onBeforeRequest.callback,
            onHeadersReceivedClient = vAPI.net.onHeadersReceived.callback,
            blockableTypes = onBeforeRequest.types;

        var onBeforeRequestAdapter = function(e) {
            if(e.name !== "canLoad") {
                return;
            }
            e.stopPropagation && e.stopPropagation();
            if(e.message.type === "main_frame") {
                vAPI.tabs.onNavigation({
                    url: e.message.url,
                    frameId: 0,
                    tabId: vAPI.tabs.getTabId(e.target)
                });
                e.message.hostname = µb.URI.hostnameFromURI(e.message.url);
                e.message.tabId = vAPI.tabs.getTabId(e.target);
                e.message.responseHeaders = [];
                onBeforeRequestClient(e.message);
                var blockVerdict = onHeadersReceivedClient(e.message);
                if(blockVerdict && blockVerdict.responseHeaders) {
                    e.message = false;
                }
                else {
                    e.message = true;
                }
                return;
            }
            switch(e.message.type) {
                case "popup":
                    var openerTabId = vAPI.tabs.getTabId(e.target).toString();
                    var shouldBlock = !!vAPI.tabs.onPopup({
                        targetURL: e.message.url,
                        targetTabId: "preempt",
                        openerTabId: openerTabId
                    });
                    if(shouldBlock) {
                        e.message = false;
                    }
                    else {
                        vAPI.tabs.popupCandidate = openerTabId;
                        e.message = true;
                    }
                    break;
                case "popstate":
                    vAPI.tabs.onUpdated(vAPI.tabs.getTabId(e.target), {
                        url: e.message.url
                    }, {
                        url: e.message.url
                    });
                    break;
                default:
                    e.message.hostname = µb.URI.hostnameFromURI(e.message.url);
                    e.message.tabId = vAPI.tabs.getTabId(e.target);
                    var blockVerdict = onBeforeRequestClient(e.message);
                    if(blockVerdict && blockVerdict.cancel) {
                        e.message = false;
                        return;
                    }
                    else {
                        e.message = true;
                        return;
                    }
            }
            return;
        };
        safari.application.addEventListener("message", onBeforeRequestAdapter, true);
    };

    /******************************************************************************/

    vAPI.contextMenu = {
        contextMap: {
            frame: 'insideFrame',
            link: 'linkHref',
            image: 'srcUrl',
            editable: 'editable'
        }
    };

    /******************************************************************************/

    vAPI.contextMenu.create = function(details, callback) {
        var contexts = details.contexts;
        var menuItemId = details.id;
        var menuTitle = details.title;

        if(Array.isArray(contexts) && contexts.length) {
            contexts = contexts.indexOf('all') === -1 ? contexts : null;
        } else {
            // default in Chrome
            contexts = ['page'];
        }

        this.onContextMenu = function(e) {
            var uI = e.userInfo;

            if(!uI || /^https?:\/\//i.test(uI.pageUrl) === false) {
                return;
            }

            if(contexts) {
                var invalidContext = true;
                var ctxMap = vAPI.contextMenu.contextMap;

                for(var i = 0; i < contexts.length; i++) {
                    var ctx = contexts[i];

                    if(ctx === 'audio' || ctx === 'video') {
                        if(uI[ctxMap['image']] && uI.tagName === ctx) {
                            invalidContext = false;
                            break;
                        }
                    } else if(uI[ctxMap[ctx]]) {
                        invalidContext = false;
                        break;
                    } else if(ctx === 'page') {
                        if(!(uI.insideFrame || uI.linkHref || uI.mediaType || uI.editable)) {
                            invalidContext = false;
                            break;
                        }
                    }
                }

                if(invalidContext) {
                    return;
                }
            }

            e.contextMenu.appendContextMenuItem(menuItemId, menuTitle);
        };

        this.onContextMenuCmd = function(e) {
            if(e.command === menuItemId) {
                var tab = e.currentTarget.activeBrowserWindow.activeTab;
                e.userInfo.menuItemId = menuItemId;
                callback(e.userInfo, tab ? {
                    id: vAPI.tabs.getTabId(tab),
                    url: tab.url
                } : undefined);
            }
        };

        safari.application.addEventListener('contextmenu', this.onContextMenu);
        safari.application.addEventListener('command', this.onContextMenuCmd);
    };

    /******************************************************************************/

    vAPI.contextMenu.remove = function() {
        safari.application.removeEventListener('contextmenu', this.onContextMenu);
        safari.application.removeEventListener('command', this.onContextMenuCmd);
        this.onContextMenu = null;
        this.onContextMenuCmd = null;
    };

    /******************************************************************************/

    vAPI.lastError = function() {
        return null;
    };

    /******************************************************************************/

    // This is called only once, when everything has been loaded in memory after
    // the extension was launched. It can be used to inject content scripts
    // in already opened web pages, to remove whatever nuisance could make it to
    // the web pages before uBlock was ready.

    vAPI.onLoadAllCompleted = function() {};

    /******************************************************************************/

    vAPI.punycodeHostname = function(hostname) {
        return hostname;
    };

    vAPI.punycodeURL = function(url) {
        return url;
    };

    /******************************************************************************/
    
    function initStorageLib() {
        /*!
    localForage -- Offline Storage, Improved
    Version 1.2.3
    https://mozilla.github.io/localForage
    (c) 2013-2015 Mozilla, Apache License 2.0
*/
!function(){var a,b,c,d;!function(){var e={},f={};a=function(a,b,c){e[a]={deps:b,callback:c}},d=c=b=function(a){function c(b){if("."!==b.charAt(0))return b;for(var c=b.split("/"),d=a.split("/").slice(0,-1),e=0,f=c.length;f>e;e++){var g=c[e];if(".."===g)d.pop();else{if("."===g)continue;d.push(g)}}return d.join("/")}if(d._eak_seen=e,f[a])return f[a];if(f[a]={},!e[a])throw new Error("Could not find module "+a);for(var g,h=e[a],i=h.deps,j=h.callback,k=[],l=0,m=i.length;m>l;l++)k.push("exports"===i[l]?g={}:b(c(i[l])));var n=j.apply(this,k);return f[a]=g||n}}(),a("promise/all",["./utils","exports"],function(a,b){"use strict";function c(a){var b=this;if(!d(a))throw new TypeError("You must pass an array to all.");return new b(function(b,c){function d(a){return function(b){f(a,b)}}function f(a,c){h[a]=c,0===--i&&b(h)}var g,h=[],i=a.length;0===i&&b([]);for(var j=0;j<a.length;j++)g=a[j],g&&e(g.then)?g.then(d(j),c):f(j,g)})}var d=a.isArray,e=a.isFunction;b.all=c}),a("promise/asap",["exports"],function(a){"use strict";function b(){return function(){process.nextTick(e)}}function c(){var a=0,b=new i(e),c=document.createTextNode("");return b.observe(c,{characterData:!0}),function(){c.data=a=++a%2}}function d(){return function(){j.setTimeout(e,1)}}function e(){for(var a=0;a<k.length;a++){var b=k[a],c=b[0],d=b[1];c(d)}k=[]}function f(a,b){var c=k.push([a,b]);1===c&&g()}var g,h="undefined"!=typeof window?window:{},i=h.MutationObserver||h.WebKitMutationObserver,j="undefined"!=typeof global?global:void 0===this?window:this,k=[];g="undefined"!=typeof process&&"[object process]"==={}.toString.call(process)?b():i?c():d(),a.asap=f}),a("promise/config",["exports"],function(a){"use strict";function b(a,b){return 2!==arguments.length?c[a]:void(c[a]=b)}var c={instrument:!1};a.config=c,a.configure=b}),a("promise/polyfill",["./promise","./utils","exports"],function(a,b,c){"use strict";function d(){var a;a="undefined"!=typeof global?global:"undefined"!=typeof window&&window.document?window:self;var b="Promise"in a&&"resolve"in a.Promise&&"reject"in a.Promise&&"all"in a.Promise&&"race"in a.Promise&&function(){var b;return new a.Promise(function(a){b=a}),f(b)}();b||(a.Promise=e)}var e=a.Promise,f=b.isFunction;c.polyfill=d}),a("promise/promise",["./config","./utils","./all","./race","./resolve","./reject","./asap","exports"],function(a,b,c,d,e,f,g,h){"use strict";function i(a){if(!v(a))throw new TypeError("You must pass a resolver function as the first argument to the promise constructor");if(!(this instanceof i))throw new TypeError("Failed to construct 'Promise': Please use the 'new' operator, this object constructor cannot be called as a function.");this._subscribers=[],j(a,this)}function j(a,b){function c(a){o(b,a)}function d(a){q(b,a)}try{a(c,d)}catch(e){d(e)}}function k(a,b,c,d){var e,f,g,h,i=v(c);if(i)try{e=c(d),g=!0}catch(j){h=!0,f=j}else e=d,g=!0;n(b,e)||(i&&g?o(b,e):h?q(b,f):a===D?o(b,e):a===E&&q(b,e))}function l(a,b,c,d){var e=a._subscribers,f=e.length;e[f]=b,e[f+D]=c,e[f+E]=d}function m(a,b){for(var c,d,e=a._subscribers,f=a._detail,g=0;g<e.length;g+=3)c=e[g],d=e[g+b],k(b,c,d,f);a._subscribers=null}function n(a,b){var c,d=null;try{if(a===b)throw new TypeError("A promises callback cannot return that same promise.");if(u(b)&&(d=b.then,v(d)))return d.call(b,function(d){return c?!0:(c=!0,void(b!==d?o(a,d):p(a,d)))},function(b){return c?!0:(c=!0,void q(a,b))}),!0}catch(e){return c?!0:(q(a,e),!0)}return!1}function o(a,b){a===b?p(a,b):n(a,b)||p(a,b)}function p(a,b){a._state===B&&(a._state=C,a._detail=b,t.async(r,a))}function q(a,b){a._state===B&&(a._state=C,a._detail=b,t.async(s,a))}function r(a){m(a,a._state=D)}function s(a){m(a,a._state=E)}var t=a.config,u=(a.configure,b.objectOrFunction),v=b.isFunction,w=(b.now,c.all),x=d.race,y=e.resolve,z=f.reject,A=g.asap;t.async=A;var B=void 0,C=0,D=1,E=2;i.prototype={constructor:i,_state:void 0,_detail:void 0,_subscribers:void 0,then:function(a,b){var c=this,d=new this.constructor(function(){});if(this._state){var e=arguments;t.async(function(){k(c._state,d,e[c._state-1],c._detail)})}else l(this,d,a,b);return 
    }

})();