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Diffstat (limited to 'toolkit/components/thumbnails/BackgroundPageThumbs.sys.mjs')
| -rw-r--r-- | toolkit/components/thumbnails/BackgroundPageThumbs.sys.mjs | 788 |
1 files changed, 788 insertions, 0 deletions
diff --git a/toolkit/components/thumbnails/BackgroundPageThumbs.sys.mjs b/toolkit/components/thumbnails/BackgroundPageThumbs.sys.mjs new file mode 100644 index 0000000000..c50d5ca1da --- /dev/null +++ b/toolkit/components/thumbnails/BackgroundPageThumbs.sys.mjs @@ -0,0 +1,788 @@ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +const DEFAULT_CAPTURE_TIMEOUT = 30000; // ms +// For testing, the above timeout is excessive, and makes our tests overlong. +const TESTING_CAPTURE_TIMEOUT = 5000; // ms + +const DESTROY_BROWSER_TIMEOUT = 60000; // ms + +// Let the page settle for this amount of milliseconds before capturing to allow +// for any in-page changes or redirects. +const SETTLE_WAIT_TIME = 2500; +// For testing, the above timeout is excessive, and makes our tests overlong. +const TESTING_SETTLE_WAIT_TIME = 0; + +const TELEMETRY_HISTOGRAM_ID_PREFIX = "FX_THUMBNAILS_BG_"; + +const ABOUT_NEWTAB_SEGREGATION_PREF = + "privacy.usercontext.about_newtab_segregation.enabled"; + +import { + PageThumbs, + PageThumbsStorage, +} from "resource://gre/modules/PageThumbs.sys.mjs"; + +// possible FX_THUMBNAILS_BG_CAPTURE_DONE_REASON_2 telemetry values +const TEL_CAPTURE_DONE_OK = 0; +const TEL_CAPTURE_DONE_TIMEOUT = 1; +// 2 and 3 were used when we had special handling for private-browsing. +const TEL_CAPTURE_DONE_CRASHED = 4; +const TEL_CAPTURE_DONE_BAD_URI = 5; +const TEL_CAPTURE_DONE_LOAD_FAILED = 6; +const TEL_CAPTURE_DONE_IMAGE_ZERO_DIMENSION = 7; + +const lazy = {}; + +ChromeUtils.defineESModuleGetters(lazy, { + ContextualIdentityService: + "resource://gre/modules/ContextualIdentityService.sys.mjs", +}); + +export const BackgroundPageThumbs = { + /** + * Asynchronously captures a thumbnail of the given URL. + * + * The page is loaded anonymously, and plug-ins are disabled. + * + * @param url The URL to capture. + * @param options An optional object that configures the capture. Its + * properties are the following, and all are optional: + * @opt onDone A function that will be asynchronously called when the + * capture is complete or times out. It's called as + * onDone(url), + * where `url` is the captured URL. + * @opt timeout The capture will time out after this many milliseconds have + * elapsed after the capture has progressed to the head of + * the queue and started. Defaults to 30000 (30 seconds). + * @opt isImage If true, backgroundPageThumbsContent will attempt to render + * the url directly to canvas. Note that images will mostly get + * detected and rendered as such anyway, but this will ensure it. + * @opt targetWidth The target width when capturing an image. + * @opt backgroundColor The background colour when capturing an image. + * @opt dontStore If set to true, the image blob won't be stored to disk, an + * object will instead be passed as third argument to onDone: + * { + * data: an ArrayBuffer containing the data + * contentType: the data content-type + * originalUrl: the originally requested url + * currentUrl: the final url after redirects + * } + * @opt contentType can be set to an image contentType for the capture, + * defaults to PageThumbs.contentType. + */ + capture(url, options = {}) { + if (!PageThumbs._prefEnabled()) { + if (options.onDone) { + schedule(() => options.onDone(url)); + } + return; + } + this._captureQueue = this._captureQueue || []; + this._capturesByURL = this._capturesByURL || new Map(); + + tel("QUEUE_SIZE_ON_CAPTURE", this._captureQueue.length); + + // We want to avoid duplicate captures for the same URL. If there is an + // existing one, we just add the callback to that one and we are done. + let existing = this._capturesByURL.get(url); + if (existing) { + if (options.onDone) { + existing.doneCallbacks.push(options.onDone); + } + // The queue is already being processed, so nothing else to do... + return; + } + let cap = new Capture(url, this._onCaptureOrTimeout.bind(this), options); + this._captureQueue.push(cap); + this._capturesByURL.set(url, cap); + this._processCaptureQueue(); + }, + + /** + * Asynchronously captures a thumbnail of the given URL if one does not + * already exist. Otherwise does nothing. + * + * @param url The URL to capture. + * @param options An optional object that configures the capture. See + * capture() for description. + * unloadingPromise This option is resolved when the calling context is + * unloading, so things can be cleaned up to avoid leak. + * @return {Promise} A Promise that resolves when this task completes + */ + async captureIfMissing(url, options = {}) { + // Short circuit this function if pref is enabled, or else we leak observers. + // See Bug 1400562 + if (!PageThumbs._prefEnabled()) { + if (options.onDone) { + options.onDone(url); + } + return url; + } + // The fileExistsForURL call is an optimization, potentially but unlikely + // incorrect, and no big deal when it is. After the capture is done, we + // atomically test whether the file exists before writing it. + let exists = await PageThumbsStorage.fileExistsForURL(url); + if (exists) { + if (options.onDone) { + options.onDone(url); + } + return url; + } + let thumbPromise = new Promise((resolve, reject) => { + let observe = (subject, topic, data) => { + if (data === url) { + switch (topic) { + case "page-thumbnail:create": + resolve(); + break; + case "page-thumbnail:error": + reject(new Error("page-thumbnail:error")); + break; + } + cleanup(); + } + }; + Services.obs.addObserver(observe, "page-thumbnail:create"); + Services.obs.addObserver(observe, "page-thumbnail:error"); + + // Make sure to clean up to avoid leaks by removing observers when + // observed or when our caller is unloading + function cleanup() { + if (observe) { + Services.obs.removeObserver(observe, "page-thumbnail:create"); + Services.obs.removeObserver(observe, "page-thumbnail:error"); + observe = null; + } + } + if (options.unloadingPromise) { + options.unloadingPromise.then(cleanup); + } + }); + try { + this.capture(url, options); + await thumbPromise; + } catch (err) { + if (options.onDone) { + options.onDone(url); + } + throw err; + } + return url; + }, + + /** + * Tell the service that the thumbnail browser should be recreated at next + * call of _ensureBrowser(). + */ + renewThumbnailBrowser() { + this._renewThumbBrowser = true; + }, + + get useFissionBrowser() { + return Services.appinfo.fissionAutostart; + }, + + /** + * Ensures that initialization of the thumbnail browser's parent window has + * begun. + * + * @return True if the parent window is completely initialized and can be + * used, and false if initialization has started but not completed. + */ + _ensureParentWindowReady() { + if (this._parentWin) { + // Already fully initialized. + return true; + } + if (this._startedParentWinInit) { + // Already started initializing. + return false; + } + + this._startedParentWinInit = true; + + // Create a windowless browser and load our hosting + // (privileged) document in it. + const flags = this.useFissionBrowser + ? Ci.nsIWebBrowserChrome.CHROME_REMOTE_WINDOW | + Ci.nsIWebBrowserChrome.CHROME_FISSION_WINDOW + : 0; + let wlBrowser = Services.appShell.createWindowlessBrowser(true, flags); + wlBrowser.QueryInterface(Ci.nsIInterfaceRequestor); + let webProgress = wlBrowser.getInterface(Ci.nsIWebProgress); + this._listener = { + QueryInterface: ChromeUtils.generateQI([ + "nsIWebProgressListener", + "nsIWebProgressListener2", + "nsISupportsWeakReference", + ]), + }; + this._listener.onStateChange = (wbp, request, stateFlags, status) => { + if (!request) { + return; + } + if ( + stateFlags & Ci.nsIWebProgressListener.STATE_STOP && + stateFlags & Ci.nsIWebProgressListener.STATE_IS_NETWORK + ) { + webProgress.removeProgressListener(this._listener); + delete this._listener; + // Get the window reference via the document. + this._parentWin = wlBrowser.document.defaultView; + this._processCaptureQueue(); + } + }; + webProgress.addProgressListener( + this._listener, + Ci.nsIWebProgress.NOTIFY_STATE_ALL + ); + let loadURIOptions = { + triggeringPrincipal: Services.scriptSecurityManager.getSystemPrincipal(), + }; + wlBrowser.loadURI( + Services.io.newURI("chrome://global/content/backgroundPageThumbs.xhtml"), + loadURIOptions + ); + this._windowlessContainer = wlBrowser; + + return false; + }, + + _init() { + Services.prefs.addObserver(ABOUT_NEWTAB_SEGREGATION_PREF, this); + Services.obs.addObserver(this, "profile-before-change"); + }, + + observe(subject, topic, data) { + if (topic == "profile-before-change") { + this._destroy(); + } else if ( + topic == "nsPref:changed" && + data == ABOUT_NEWTAB_SEGREGATION_PREF + ) { + BackgroundPageThumbs.renewThumbnailBrowser(); + } + }, + + /** + * Destroys the service. Queued and pending captures will never complete, and + * their consumer callbacks will never be called. + */ + _destroy() { + if (this._captureQueue) { + this._captureQueue.forEach(cap => cap.destroy()); + } + this._destroyBrowser(); + if (this._windowlessContainer) { + this._windowlessContainer.close(); + } + delete this._captureQueue; + delete this._windowlessContainer; + delete this._startedParentWinInit; + delete this._parentWin; + delete this._listener; + }, + + QueryInterface: ChromeUtils.generateQI([ + Ci.nsIWebProgressListener, + Ci.nsIWebProgressListener2, + Ci.nsISupportsWeakReference, + ]), + + onStateChange(wbp, request, stateFlags, status) { + if (!request || !wbp.isTopLevel) { + return; + } + + if ( + stateFlags & Ci.nsIWebProgressListener.STATE_STOP && + stateFlags & Ci.nsIWebProgressListener.STATE_IS_NETWORK + ) { + // If about:blank is being loaded after a capture, move on + // to the next capture, otherwise ignore about:blank loads. + if ( + request instanceof Ci.nsIChannel && + request.URI.spec == "about:blank" + ) { + if (this._expectingAboutBlank) { + this._expectingAboutBlank = false; + if (this._captureQueue.length) { + this._processCaptureQueue(); + } + } + return; + } + + if (!this._captureQueue.length) { + return; + } + + let currentCapture = this._captureQueue[0]; + if ( + Components.isSuccessCode(status) || + status === Cr.NS_BINDING_ABORTED + ) { + this._thumbBrowser.ownerGlobal.requestIdleCallback(() => { + currentCapture.pageLoaded(this._thumbBrowser); + }); + } else { + currentCapture._done( + this._thumbBrowser, + null, + currentCapture.timedOut + ? TEL_CAPTURE_DONE_TIMEOUT + : TEL_CAPTURE_DONE_LOAD_FAILED + ); + } + } + }, + + /** + * Creates the thumbnail browser if it doesn't already exist. + */ + _ensureBrowser() { + if (this._thumbBrowser && !this._renewThumbBrowser) { + return; + } + + this._destroyBrowser(); + this._renewThumbBrowser = false; + + let browser = this._parentWin.document.createXULElement("browser"); + browser.setAttribute("type", "content"); + browser.setAttribute("remote", "true"); + if (this.useFissionBrowser) { + browser.setAttribute("maychangeremoteness", "true"); + } + browser.setAttribute("disableglobalhistory", "true"); + browser.setAttribute("messagemanagergroup", "thumbnails"); + + if (Services.prefs.getBoolPref(ABOUT_NEWTAB_SEGREGATION_PREF)) { + // Use the private container for thumbnails. + let privateIdentity = lazy.ContextualIdentityService.getPrivateIdentity( + "userContextIdInternal.thumbnail" + ); + browser.setAttribute("usercontextid", privateIdentity.userContextId); + } + + // Size the browser. Make its aspect ratio the same as the canvases' that + // the thumbnails are drawn into; the canvases' aspect ratio is the same as + // the screen's, so use that. Aim for a size in the ballpark of 1024x768. + let [swidth, sheight] = [{}, {}]; + Cc["@mozilla.org/gfx/screenmanager;1"] + .getService(Ci.nsIScreenManager) + .primaryScreen.GetRectDisplayPix({}, {}, swidth, sheight); + let bwidth = Math.min(1024, swidth.value); + // Setting the width and height attributes doesn't work -- the resulting + // thumbnails are blank and transparent -- but setting the style does. + browser.style.width = bwidth + "px"; + browser.style.height = (bwidth * sheight.value) / swidth.value + "px"; + browser.style.colorScheme = "env(-moz-content-preferred-color-scheme)"; + + this._parentWin.document.documentElement.appendChild(browser); + + browser.addProgressListener(this, Ci.nsIWebProgress.NOTIFY_STATE_WINDOW); + browser.mute(); + + // an event that is sent if the remote process crashes - no need to remove + // it as we want it to be there as long as the browser itself lives. + browser.addEventListener("oop-browser-crashed", event => { + if (!event.isTopFrame) { + // It was a subframe that crashed. We'll ignore this. + return; + } + + console.error("BackgroundThumbnails remote process crashed - recovering"); + this._destroyBrowser(); + let curCapture = this._captureQueue.length ? this._captureQueue[0] : null; + // we could retry the pending capture, but it's possible the crash + // was due directly to it, so trying again might just crash again. + // We could keep a flag to indicate if it previously crashed, but + // "resetting" the capture requires more work - so for now, we just + // discard it. + if (curCapture) { + // Continue queue processing by calling curCapture._done(). Do it after + // this crashed listener returns, though. A new browser will be created + // immediately (on the same stack as the _done call stack) if there are + // any more queued-up captures, and that seems to mess up the new + // browser's message manager if it happens on the same stack as the + // listener. Trying to send a message to the manager in that case + // throws NS_ERROR_NOT_INITIALIZED. + Services.tm.dispatchToMainThread(() => { + curCapture._done(browser, null, TEL_CAPTURE_DONE_CRASHED); + }); + } + // else: we must have been idle and not currently doing a capture (eg, + // maybe a GC or similar crashed) - so there's no need to attempt a + // queue restart - the next capture request will set everything up. + }); + + this._thumbBrowser = browser; + browser.docShellIsActive = false; + }, + + _destroyBrowser() { + if (!this._thumbBrowser) { + return; + } + this._expectingAboutBlank = false; + this._thumbBrowser.remove(); + delete this._thumbBrowser; + }, + + async _loadAboutBlank() { + if (this._expectingAboutBlank) { + return; + } + + this._expectingAboutBlank = true; + + let loadURIOptions = { + triggeringPrincipal: Services.scriptSecurityManager.getSystemPrincipal(), + loadFlags: Ci.nsIWebNavigation.LOAD_FLAGS_STOP_CONTENT, + }; + this._thumbBrowser.loadURI( + Services.io.newURI("about:blank"), + loadURIOptions + ); + }, + + /** + * Starts the next capture if the queue is not empty and the service is fully + * initialized. + */ + _processCaptureQueue() { + if (!this._captureQueue.length) { + if (this._thumbBrowser) { + BackgroundPageThumbs._loadAboutBlank(); + } + return; + } + + if ( + this._captureQueue[0].pending || + !this._ensureParentWindowReady() || + this._expectingAboutBlank + ) { + return; + } + + // Ready to start the first capture in the queue. + this._ensureBrowser(); + this._captureQueue[0].start(this._thumbBrowser); + if (this._destroyBrowserTimer) { + this._destroyBrowserTimer.cancel(); + delete this._destroyBrowserTimer; + } + }, + + /** + * Called when the current capture completes or fails (eg, times out, remote + * process crashes.) + */ + _onCaptureOrTimeout(capture, reason) { + // Since timeouts start as an item is being processed, only the first + // item in the queue can be passed to this method. + if (capture !== this._captureQueue[0]) { + throw new Error("The capture should be at the head of the queue."); + } + + this._captureQueue.shift(); + this._capturesByURL.delete(capture.url); + if (reason != TEL_CAPTURE_DONE_OK) { + Services.obs.notifyObservers(null, "page-thumbnail:error", capture.url); + } + + // Start the destroy-browser timer *before* processing the capture queue. + let timer = Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer); + timer.initWithCallback( + this._destroyBrowser.bind(this), + this._destroyBrowserTimeout, + Ci.nsITimer.TYPE_ONE_SHOT + ); + this._destroyBrowserTimer = timer; + + this._processCaptureQueue(); + }, + + _destroyBrowserTimeout: DESTROY_BROWSER_TIMEOUT, +}; + +BackgroundPageThumbs._init(); + +/** + * Represents a single capture request in the capture queue. + * + * @param url The URL to capture. + * @param captureCallback A function you want called when the capture + * completes. + * @param options The capture options. + */ +function Capture(url, captureCallback, options) { + this.url = url; + this.captureCallback = captureCallback; + this.redirectTimer = null; + this.timedOut = false; + this.options = options; + this.id = Capture.nextID++; + this.creationDate = new Date(); + this.doneCallbacks = []; + if (options.onDone) { + this.doneCallbacks.push(options.onDone); + } +} + +Capture.prototype = { + get pending() { + return !!this._timeoutTimer; + }, + + /** + * Sends a message to the content script to start the capture. + * + * @param browser The thumbnail browser. + */ + start(browser) { + this.startDate = new Date(); + tel("CAPTURE_QUEUE_TIME_MS", this.startDate - this.creationDate); + + let fallbackTimeout = Cu.isInAutomation + ? TESTING_CAPTURE_TIMEOUT + : DEFAULT_CAPTURE_TIMEOUT; + + // timeout timer + let timeout = + typeof this.options.timeout == "number" + ? this.options.timeout + : fallbackTimeout; + this._timeoutTimer = Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer); + this._timeoutTimer.initWithCallback( + this, + timeout, + Ci.nsITimer.TYPE_ONE_SHOT + ); + + this._browser = browser; + + if (!browser.browsingContext) { + return; + } + + this._pageLoadStartTime = new Date(); + + BackgroundPageThumbs._expectingAboutBlank = false; + + let thumbnailsActor = browser.browsingContext.currentWindowGlobal.getActor( + "BackgroundThumbnails" + ); + thumbnailsActor + .sendQuery("Browser:Thumbnail:LoadURL", { + url: this.url, + }) + .then( + success => { + // If it failed, then this was likely a bad url. If successful, + // BackgroundPageThumbs.onStateChange will call _done() after the + // load has completed. + if (!success) { + this._done(browser, null, TEL_CAPTURE_DONE_BAD_URI); + } + }, + failure => { + // The query can fail when a crash occurs while loading. The error causes + // thumbnail crash tests to fail with an uninteresting error message. + } + ); + }, + + readBlob: function readBlob(blob) { + return new Promise((resolve, reject) => { + let reader = new FileReader(); + reader.onloadend = function onloadend() { + if (reader.readyState != FileReader.DONE) { + reject(reader.error); + } else { + resolve(reader.result); + } + }; + reader.readAsArrayBuffer(blob); + }); + }, + + async pageLoaded(aBrowser) { + if (this.timedOut) { + this._done(aBrowser, null, TEL_CAPTURE_DONE_TIMEOUT); + return; + } + + let waitTime = Cu.isInAutomation + ? TESTING_SETTLE_WAIT_TIME + : SETTLE_WAIT_TIME; + + // There was additional activity, so restart the wait timer + if (this.redirectTimer) { + this.redirectTimer.delay = waitTime; + return; + } + + // The requested page has loaded or stopped/aborted, so capture the page + // soon but first let it settle in case of in-page redirects + await new Promise(resolve => { + this.redirectTimer = Cc["@mozilla.org/timer;1"].createInstance( + Ci.nsITimer + ); + this.redirectTimer.init(resolve, waitTime, Ci.nsITimer.TYPE_ONE_SHOT); + }); + + this.redirectTimer = null; + + let pageLoadTime = new Date() - this._pageLoadStartTime; + let canvasDrawStartTime = new Date(); + + let canvas = PageThumbs.createCanvas(aBrowser.ownerGlobal, 1, 1); + try { + await PageThumbs.captureToCanvas( + aBrowser, + canvas, + { + isBackgroundThumb: true, + isImage: this.options.isImage, + backgroundColor: this.options.backgroundColor, + }, + true + ); + } catch (ex) { + this._done( + aBrowser, + null, + ex == "IMAGE_ZERO_DIMENSION" + ? TEL_CAPTURE_DONE_IMAGE_ZERO_DIMENSION + : TEL_CAPTURE_DONE_LOAD_FAILED + ); + return; + } + + let canvasDrawTime = new Date() - canvasDrawStartTime; + + let contentType = + (this.options.dontStore && this.options.contentType) || + PageThumbs.contentType; + let imageData = await new Promise(resolve => { + canvas.toBlob(blob => { + resolve(blob, contentType); + }, contentType); + }); + + this._done(aBrowser, imageData, TEL_CAPTURE_DONE_OK, { + CAPTURE_PAGE_LOAD_TIME_MS: pageLoadTime, + CAPTURE_CANVAS_DRAW_TIME_MS: canvasDrawTime, + }); + }, + + /** + * The only intended external use of this method is by the service when it's + * uninitializing and doing things like destroying the thumbnail browser. In + * that case the consumer's completion callback will never be called. + */ + destroy() { + // This method may be called for captures that haven't started yet, so + // guard against not yet having _timeoutTimer, _msgMan etc properties... + if (this._timeoutTimer) { + this._timeoutTimer.cancel(); + delete this._timeoutTimer; + } + delete this.captureCallback; + delete this.doneCallbacks; + delete this.options; + }, + + // Called when the timeout timer fires. + notify() { + this.timedOut = true; + this._browser.stop(); + }, + + _done(browser, imageData, reason, telemetry) { + // Note that _done will be called only once, by either receiveMessage or + // notify, since it calls destroy here, which cancels the timeout timer and + // removes the didCapture message listener. + let { captureCallback, doneCallbacks, options } = this; + this.destroy(); + + if (typeof reason != "number") { + throw new Error("A done reason must be given."); + } + + tel("CAPTURE_DONE_REASON_2", reason); + + if (telemetry) { + // Telemetry is currently disabled in the content process (bug 680508). + for (let id in telemetry) { + tel(id, telemetry[id]); + } + } + + let done = (info = null) => { + captureCallback(this, reason); + for (let callback of doneCallbacks) { + try { + callback.call(options, this.url, reason, info); + } catch (err) { + console.error(err); + } + } + + if (Services.prefs.getBoolPref(ABOUT_NEWTAB_SEGREGATION_PREF)) { + // Clear the data in the private container for thumbnails. + let privateIdentity = lazy.ContextualIdentityService.getPrivateIdentity( + "userContextIdInternal.thumbnail" + ); + if (privateIdentity) { + Services.clearData.deleteDataFromOriginAttributesPattern({ + userContextId: privateIdentity.userContextId, + }); + } + } + }; + + if (!imageData) { + done(); + return; + } + + this.readBlob(imageData).then(buffer => { + if (options.dontStore) { + done({ + data: buffer, + originalUrl: this.url, + finalUrl: browser.currentURI.spec, + contentType: options.contentType || PageThumbs.contentType, + }); + } else { + PageThumbs._store(this.url, browser.currentURI.spec, buffer, true).then( + done, + done + ); + } + }); + }, +}; + +Capture.nextID = 0; + +/** + * Adds a value to one of this module's telemetry histograms. + * + * @param histogramID This is prefixed with this module's ID. + * @param value The value to add. + */ +function tel(histogramID, value) { + let id = TELEMETRY_HISTOGRAM_ID_PREFIX + histogramID; + Services.telemetry.getHistogramById(id).add(value); +} + +function schedule(callback) { + Services.tm.dispatchToMainThread(callback); +} |