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Diffstat (limited to 'toolkit/components/thumbnails/PageThumbs.jsm')
| -rw-r--r-- | toolkit/components/thumbnails/PageThumbs.jsm | 901 |
1 files changed, 901 insertions, 0 deletions
diff --git a/toolkit/components/thumbnails/PageThumbs.jsm b/toolkit/components/thumbnails/PageThumbs.jsm new file mode 100644 index 000000000..9bd3ae4b3 --- /dev/null +++ b/toolkit/components/thumbnails/PageThumbs.jsm @@ -0,0 +1,901 @@ +/* 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/. */ + +"use strict"; + +this.EXPORTED_SYMBOLS = ["PageThumbs", "PageThumbsStorage"]; + +const Cu = Components.utils; +const Cc = Components.classes; +const Ci = Components.interfaces; + +const PREF_STORAGE_VERSION = "browser.pagethumbnails.storage_version"; +const LATEST_STORAGE_VERSION = 3; + +const EXPIRATION_MIN_CHUNK_SIZE = 50; +const EXPIRATION_INTERVAL_SECS = 3600; + +var gRemoteThumbId = 0; + +// If a request for a thumbnail comes in and we find one that is "stale" +// (or don't find one at all) we automatically queue a request to generate a +// new one. +const MAX_THUMBNAIL_AGE_SECS = 172800; // 2 days == 60*60*24*2 == 172800 secs. + +/** + * Name of the directory in the profile that contains the thumbnails. + */ +const THUMBNAIL_DIRECTORY = "thumbnails"; + +Cu.import("resource://gre/modules/XPCOMUtils.jsm", this); +Cu.import("resource://gre/modules/PromiseWorker.jsm", this); +Cu.import("resource://gre/modules/Promise.jsm", this); +Cu.import("resource://gre/modules/osfile.jsm", this); + +Cu.importGlobalProperties(['FileReader']); + +XPCOMUtils.defineLazyModuleGetter(this, "NetUtil", + "resource://gre/modules/NetUtil.jsm"); + +XPCOMUtils.defineLazyModuleGetter(this, "Services", + "resource://gre/modules/Services.jsm"); + +XPCOMUtils.defineLazyModuleGetter(this, "FileUtils", + "resource://gre/modules/FileUtils.jsm"); + +XPCOMUtils.defineLazyModuleGetter(this, "PlacesUtils", + "resource://gre/modules/PlacesUtils.jsm"); + +XPCOMUtils.defineLazyServiceGetter(this, "gUpdateTimerManager", + "@mozilla.org/updates/timer-manager;1", "nsIUpdateTimerManager"); + +XPCOMUtils.defineLazyGetter(this, "gCryptoHash", function () { + return Cc["@mozilla.org/security/hash;1"].createInstance(Ci.nsICryptoHash); +}); + +XPCOMUtils.defineLazyGetter(this, "gUnicodeConverter", function () { + let converter = Cc["@mozilla.org/intl/scriptableunicodeconverter"] + .createInstance(Ci.nsIScriptableUnicodeConverter); + converter.charset = 'utf8'; + return converter; +}); + +XPCOMUtils.defineLazyModuleGetter(this, "Task", + "resource://gre/modules/Task.jsm"); +XPCOMUtils.defineLazyModuleGetter(this, "Deprecated", + "resource://gre/modules/Deprecated.jsm"); +XPCOMUtils.defineLazyModuleGetter(this, "AsyncShutdown", + "resource://gre/modules/AsyncShutdown.jsm"); +XPCOMUtils.defineLazyModuleGetter(this, "PageThumbUtils", + "resource://gre/modules/PageThumbUtils.jsm"); +XPCOMUtils.defineLazyModuleGetter(this, "PrivateBrowsingUtils", + "resource://gre/modules/PrivateBrowsingUtils.jsm"); + +/** + * Utilities for dealing with promises and Task.jsm + */ +const TaskUtils = { + /** + * Read the bytes from a blob, asynchronously. + * + * @return {Promise} + * @resolve {ArrayBuffer} In case of success, the bytes contained in the blob. + * @reject {DOMError} In case of error, the underlying DOMError. + */ + readBlob: function readBlob(blob) { + let deferred = Promise.defer(); + let reader = new FileReader(); + reader.onloadend = function onloadend() { + if (reader.readyState != FileReader.DONE) { + deferred.reject(reader.error); + } else { + deferred.resolve(reader.result); + } + }; + reader.readAsArrayBuffer(blob); + return deferred.promise; + } +}; + + + + +/** + * Singleton providing functionality for capturing web page thumbnails and for + * accessing them if already cached. + */ +this.PageThumbs = { + _initialized: false, + + /** + * The calculated width and height of the thumbnails. + */ + _thumbnailWidth : 0, + _thumbnailHeight : 0, + + /** + * The scheme to use for thumbnail urls. + */ + get scheme() { + return "moz-page-thumb"; + }, + + /** + * The static host to use for thumbnail urls. + */ + get staticHost() { + return "thumbnail"; + }, + + /** + * The thumbnails' image type. + */ + get contentType() { + return "image/png"; + }, + + init: function PageThumbs_init() { + if (!this._initialized) { + this._initialized = true; + PlacesUtils.history.addObserver(PageThumbsHistoryObserver, true); + + // Migrate the underlying storage, if needed. + PageThumbsStorageMigrator.migrate(); + PageThumbsExpiration.init(); + } + }, + + uninit: function PageThumbs_uninit() { + if (this._initialized) { + this._initialized = false; + } + }, + + /** + * Gets the thumbnail image's url for a given web page's url. + * @param aUrl The web page's url that is depicted in the thumbnail. + * @return The thumbnail image's url. + */ + getThumbnailURL: function PageThumbs_getThumbnailURL(aUrl) { + return this.scheme + "://" + this.staticHost + + "/?url=" + encodeURIComponent(aUrl) + + "&revision=" + PageThumbsStorage.getRevision(aUrl); + }, + + /** + * Gets the path of the thumbnail file for a given web page's + * url. This file may or may not exist depending on whether the + * thumbnail has been captured or not. + * + * @param aUrl The web page's url. + * @return The path of the thumbnail file. + */ + getThumbnailPath: function PageThumbs_getThumbnailPath(aUrl) { + return PageThumbsStorage.getFilePathForURL(aUrl); + }, + + /** + * Asynchronously returns a thumbnail as a blob for the given + * window. + * + * @param aBrowser The <browser> to capture a thumbnail from. + * @return {Promise} + * @resolve {Blob} The thumbnail, as a Blob. + */ + captureToBlob: function PageThumbs_captureToBlob(aBrowser) { + if (!this._prefEnabled()) { + return null; + } + + let deferred = Promise.defer(); + + let canvas = this.createCanvas(aBrowser.contentWindow); + this.captureToCanvas(aBrowser, canvas, () => { + canvas.toBlob(blob => { + deferred.resolve(blob, this.contentType); + }); + }); + + return deferred.promise; + }, + + /** + * Captures a thumbnail from a given window and draws it to the given canvas. + * Note, when dealing with remote content, this api draws into the passed + * canvas asynchronously. Pass aCallback to receive an async callback after + * canvas painting has completed. + * @param aBrowser The browser to capture a thumbnail from. + * @param aCanvas The canvas to draw to. The thumbnail will be scaled to match + * the dimensions of this canvas. If callers pass a 0x0 canvas, the canvas + * will be resized to default thumbnail dimensions just prior to painting. + * @param aCallback (optional) A callback invoked once the thumbnail has been + * rendered to aCanvas. + * @param aArgs (optional) Additional named parameters: + * fullScale - request that a non-downscaled image be returned. + */ + captureToCanvas: function (aBrowser, aCanvas, aCallback, aArgs) { + let telemetryCaptureTime = new Date(); + let args = { + fullScale: aArgs ? aArgs.fullScale : false + }; + this._captureToCanvas(aBrowser, aCanvas, args, (aCanvas) => { + Services.telemetry + .getHistogramById("FX_THUMBNAILS_CAPTURE_TIME_MS") + .add(new Date() - telemetryCaptureTime); + if (aCallback) { + aCallback(aCanvas); + } + }); + }, + + /** + * Asynchronously check the state of aBrowser to see if it passes a set of + * predefined security checks. Consumers should refrain from storing + * thumbnails if these checks fail. Note the final result of this call is + * transitory as it is based on current navigation state and the type of + * content being displayed. + * + * @param aBrowser The target browser + * @param aCallback(aResult) A callback invoked once security checks have + * completed. aResult is a boolean indicating the combined result of the + * security checks performed. + */ + shouldStoreThumbnail: function (aBrowser, aCallback) { + // Don't capture in private browsing mode. + if (PrivateBrowsingUtils.isBrowserPrivate(aBrowser)) { + aCallback(false); + return; + } + if (aBrowser.isRemoteBrowser) { + let mm = aBrowser.messageManager; + let resultFunc = function (aMsg) { + mm.removeMessageListener("Browser:Thumbnail:CheckState:Response", resultFunc); + aCallback(aMsg.data.result); + } + mm.addMessageListener("Browser:Thumbnail:CheckState:Response", resultFunc); + try { + mm.sendAsyncMessage("Browser:Thumbnail:CheckState"); + } catch (ex) { + Cu.reportError(ex); + // If the message manager is not able send our message, taking a content + // screenshot is also not going to work: return false. + resultFunc({ data: { result: false } }); + } + } else { + aCallback(PageThumbUtils.shouldStoreContentThumbnail(aBrowser.contentDocument, + aBrowser.docShell)); + } + }, + + // The background thumbnail service captures to canvas but doesn't want to + // participate in this service's telemetry, which is why this method exists. + _captureToCanvas: function (aBrowser, aCanvas, aArgs, aCallback) { + if (aBrowser.isRemoteBrowser) { + Task.spawn(function* () { + let data = + yield this._captureRemoteThumbnail(aBrowser, aCanvas.width, + aCanvas.height, aArgs); + let canvas = data.thumbnail; + let ctx = canvas.getContext("2d"); + let imgData = ctx.getImageData(0, 0, canvas.width, canvas.height); + aCanvas.width = canvas.width; + aCanvas.height = canvas.height; + aCanvas.getContext("2d").putImageData(imgData, 0, 0); + if (aCallback) { + aCallback(aCanvas); + } + }.bind(this)); + return; + } + // The content is a local page, grab a thumbnail sync. + PageThumbUtils.createSnapshotThumbnail(aBrowser.contentWindow, + aCanvas, + aArgs); + + if (aCallback) { + aCallback(aCanvas); + } + }, + + /** + * Asynchrnously render an appropriately scaled thumbnail to canvas. + * + * @param aBrowser The browser to capture a thumbnail from. + * @param aWidth The desired canvas width. + * @param aHeight The desired canvas height. + * @param aArgs (optional) Additional named parameters: + * fullScale - request that a non-downscaled image be returned. + * @return a promise + */ + _captureRemoteThumbnail: function (aBrowser, aWidth, aHeight, aArgs) { + let deferred = Promise.defer(); + + // The index we send with the request so we can identify the + // correct response. + let index = gRemoteThumbId++; + + // Thumbnail request response handler + let mm = aBrowser.messageManager; + + // Browser:Thumbnail:Response handler + let thumbFunc = function (aMsg) { + // Ignore events unrelated to our request + if (aMsg.data.id != index) { + return; + } + + mm.removeMessageListener("Browser:Thumbnail:Response", thumbFunc); + let imageBlob = aMsg.data.thumbnail; + let doc = aBrowser.parentElement.ownerDocument; + let reader = new FileReader(); + reader.addEventListener("loadend", function() { + let image = doc.createElementNS(PageThumbUtils.HTML_NAMESPACE, "img"); + image.onload = function () { + let thumbnail = doc.createElementNS(PageThumbUtils.HTML_NAMESPACE, "canvas"); + thumbnail.width = image.naturalWidth; + thumbnail.height = image.naturalHeight; + let ctx = thumbnail.getContext("2d"); + ctx.drawImage(image, 0, 0); + deferred.resolve({ + thumbnail: thumbnail + }); + } + image.src = reader.result; + }); + // xxx wish there was a way to skip this encoding step + reader.readAsDataURL(imageBlob); + } + + // Send a thumbnail request + mm.addMessageListener("Browser:Thumbnail:Response", thumbFunc); + mm.sendAsyncMessage("Browser:Thumbnail:Request", { + canvasWidth: aWidth, + canvasHeight: aHeight, + background: PageThumbUtils.THUMBNAIL_BG_COLOR, + id: index, + additionalArgs: aArgs + }); + + return deferred.promise; + }, + + /** + * Captures a thumbnail for the given browser and stores it to the cache. + * @param aBrowser The browser to capture a thumbnail for. + * @param aCallback The function to be called when finished (optional). + */ + captureAndStore: function PageThumbs_captureAndStore(aBrowser, aCallback) { + if (!this._prefEnabled()) { + return; + } + + let url = aBrowser.currentURI.spec; + let originalURL; + let channelError = false; + + Task.spawn((function* task() { + if (!aBrowser.isRemoteBrowser) { + let channel = aBrowser.docShell.currentDocumentChannel; + originalURL = channel.originalURI.spec; + // see if this was an error response. + channelError = PageThumbUtils.isChannelErrorResponse(channel); + } else { + let resp = yield new Promise(resolve => { + let mm = aBrowser.messageManager; + let respName = "Browser:Thumbnail:GetOriginalURL:Response"; + mm.addMessageListener(respName, function onResp(msg) { + mm.removeMessageListener(respName, onResp); + resolve(msg.data); + }); + mm.sendAsyncMessage("Browser:Thumbnail:GetOriginalURL"); + }); + originalURL = resp.originalURL || url; + channelError = resp.channelError; + } + + let isSuccess = true; + try { + let blob = yield this.captureToBlob(aBrowser); + let buffer = yield TaskUtils.readBlob(blob); + yield this._store(originalURL, url, buffer, channelError); + } catch (ex) { + Components.utils.reportError("Exception thrown during thumbnail capture: '" + ex + "'"); + isSuccess = false; + } + if (aCallback) { + aCallback(isSuccess); + } + }).bind(this)); + }, + + /** + * Checks if an existing thumbnail for the specified URL is either missing + * or stale, and if so, captures and stores it. Once the thumbnail is stored, + * an observer service notification will be sent, so consumers should observe + * such notifications if they want to be notified of an updated thumbnail. + * + * @param aBrowser The content window of this browser will be captured. + * @param aCallback The function to be called when finished (optional). + */ + captureAndStoreIfStale: function PageThumbs_captureAndStoreIfStale(aBrowser, aCallback) { + let url = aBrowser.currentURI.spec; + PageThumbsStorage.isFileRecentForURL(url).then(recent => { + if (!recent && + // Careful, the call to PageThumbsStorage is async, so the browser may + // have navigated away from the URL or even closed. + aBrowser.currentURI && + aBrowser.currentURI.spec == url) { + this.captureAndStore(aBrowser, aCallback); + } else if (aCallback) { + aCallback(true); + } + }, err => { + if (aCallback) + aCallback(false); + }); + }, + + /** + * Stores data to disk for the given URLs. + * + * NB: The background thumbnail service calls this, too. + * + * @param aOriginalURL The URL with which the capture was initiated. + * @param aFinalURL The URL to which aOriginalURL ultimately resolved. + * @param aData An ArrayBuffer containing the image data. + * @param aNoOverwrite If true and files for the URLs already exist, the files + * will not be overwritten. + * @return {Promise} + */ + _store: function PageThumbs__store(aOriginalURL, aFinalURL, aData, aNoOverwrite) { + return Task.spawn(function* () { + let telemetryStoreTime = new Date(); + yield PageThumbsStorage.writeData(aFinalURL, aData, aNoOverwrite); + Services.telemetry.getHistogramById("FX_THUMBNAILS_STORE_TIME_MS") + .add(new Date() - telemetryStoreTime); + + Services.obs.notifyObservers(null, "page-thumbnail:create", aFinalURL); + // We've been redirected. Create a copy of the current thumbnail for + // the redirect source. We need to do this because: + // + // 1) Users can drag any kind of links onto the newtab page. If those + // links redirect to a different URL then we want to be able to + // provide thumbnails for both of them. + // + // 2) The newtab page should actually display redirect targets, only. + // Because of bug 559175 this information can get lost when using + // Sync and therefore also redirect sources appear on the newtab + // page. We also want thumbnails for those. + if (aFinalURL != aOriginalURL) { + yield PageThumbsStorage.copy(aFinalURL, aOriginalURL, aNoOverwrite); + Services.obs.notifyObservers(null, "page-thumbnail:create", aOriginalURL); + } + }); + }, + + /** + * Register an expiration filter. + * + * When thumbnails are going to expire, each registered filter is asked for a + * list of thumbnails to keep. + * + * The filter (if it is a callable) or its filterForThumbnailExpiration method + * (if the filter is an object) is called with a single argument. The + * argument is a callback function. The filter must call the callback + * function and pass it an array of zero or more URLs. (It may do so + * asynchronously.) Thumbnails for those URLs will be except from expiration. + * + * @param aFilter callable, or object with filterForThumbnailExpiration method + */ + addExpirationFilter: function PageThumbs_addExpirationFilter(aFilter) { + PageThumbsExpiration.addFilter(aFilter); + }, + + /** + * Unregister an expiration filter. + * @param aFilter A filter that was previously passed to addExpirationFilter. + */ + removeExpirationFilter: function PageThumbs_removeExpirationFilter(aFilter) { + PageThumbsExpiration.removeFilter(aFilter); + }, + + /** + * Creates a new hidden canvas element. + * @param aWindow The document of this window will be used to create the + * canvas. If not given, the hidden window will be used. + * @return The newly created canvas. + */ + createCanvas: function PageThumbs_createCanvas(aWindow) { + return PageThumbUtils.createCanvas(aWindow); + }, + + _prefEnabled: function PageThumbs_prefEnabled() { + try { + return !Services.prefs.getBoolPref("browser.pagethumbnails.capturing_disabled"); + } + catch (e) { + return true; + } + }, +}; + +this.PageThumbsStorage = { + // The path for the storage + _path: null, + get path() { + if (!this._path) { + this._path = OS.Path.join(OS.Constants.Path.localProfileDir, THUMBNAIL_DIRECTORY); + } + return this._path; + }, + + ensurePath: function Storage_ensurePath() { + // Create the directory (ignore any error if the directory + // already exists). As all writes are done from the PageThumbsWorker + // thread, which serializes its operations, this ensures that + // future operations can proceed without having to check whether + // the directory exists. + return PageThumbsWorker.post("makeDir", + [this.path, {ignoreExisting: true}]).then( + null, + function onError(aReason) { + Components.utils.reportError("Could not create thumbnails directory" + aReason); + }); + }, + + getLeafNameForURL: function Storage_getLeafNameForURL(aURL) { + if (typeof aURL != "string") { + throw new TypeError("Expecting a string"); + } + let hash = this._calculateMD5Hash(aURL); + return hash + ".png"; + }, + + getFilePathForURL: function Storage_getFilePathForURL(aURL) { + return OS.Path.join(this.path, this.getLeafNameForURL(aURL)); + }, + + _revisionTable: {}, + + // Generate an arbitrary revision tag, i.e. one that can't be used to + // infer URL frecency. + _updateRevision(aURL) { + // Initialize with a random value and increment on each update. Wrap around + // modulo _revisionRange, so that even small values carry no meaning. + let rev = this._revisionTable[aURL]; + if (rev == null) + rev = Math.floor(Math.random() * this._revisionRange); + this._revisionTable[aURL] = (rev + 1) % this._revisionRange; + }, + + // If two thumbnails with the same URL and revision are in cache at the + // same time, the image loader may pick the stale thumbnail in some cases. + // Therefore _revisionRange must be large enough to prevent this, e.g. + // in the pathological case image.cache.size (5MB by default) could fill + // with (abnormally small) 10KB thumbnail images if the browser session + // runs long enough (though this is unlikely as thumbnails are usually + // only updated every MAX_THUMBNAIL_AGE_SECS). + _revisionRange: 8192, + + /** + * Return a revision tag for the thumbnail stored for a given URL. + * + * @param aURL The URL spec string + * @return A revision tag for the corresponding thumbnail. Returns a changed + * value whenever the stored thumbnail changes. + */ + getRevision(aURL) { + let rev = this._revisionTable[aURL]; + if (rev == null) { + this._updateRevision(aURL); + rev = this._revisionTable[aURL]; + } + return rev; + }, + + /** + * Write the contents of a thumbnail, off the main thread. + * + * @param {string} aURL The url for which to store a thumbnail. + * @param {ArrayBuffer} aData The data to store in the thumbnail, as + * an ArrayBuffer. This array buffer will be detached and cannot be + * reused after the copy. + * @param {boolean} aNoOverwrite If true and the thumbnail's file already + * exists, the file will not be overwritten. + * + * @return {Promise} + */ + writeData: function Storage_writeData(aURL, aData, aNoOverwrite) { + let path = this.getFilePathForURL(aURL); + this.ensurePath(); + aData = new Uint8Array(aData); + let msg = [ + path, + aData, + { + tmpPath: path + ".tmp", + bytes: aData.byteLength, + noOverwrite: aNoOverwrite, + flush: false /* thumbnails do not require the level of guarantee provided by flush*/ + }]; + return PageThumbsWorker.post("writeAtomic", msg, + msg /* we don't want that message garbage-collected, + as OS.Shared.Type.void_t.in_ptr.toMsg uses C-level + memory tricks to enforce zero-copy*/). + then(() => this._updateRevision(aURL), this._eatNoOverwriteError(aNoOverwrite)); + }, + + /** + * Copy a thumbnail, off the main thread. + * + * @param {string} aSourceURL The url of the thumbnail to copy. + * @param {string} aTargetURL The url of the target thumbnail. + * @param {boolean} aNoOverwrite If true and the target file already exists, + * the file will not be overwritten. + * + * @return {Promise} + */ + copy: function Storage_copy(aSourceURL, aTargetURL, aNoOverwrite) { + this.ensurePath(); + let sourceFile = this.getFilePathForURL(aSourceURL); + let targetFile = this.getFilePathForURL(aTargetURL); + let options = { noOverwrite: aNoOverwrite }; + return PageThumbsWorker.post("copy", [sourceFile, targetFile, options]). + then(() => this._updateRevision(aTargetURL), this._eatNoOverwriteError(aNoOverwrite)); + }, + + /** + * Remove a single thumbnail, off the main thread. + * + * @return {Promise} + */ + remove: function Storage_remove(aURL) { + return PageThumbsWorker.post("remove", [this.getFilePathForURL(aURL)]); + }, + + /** + * Remove all thumbnails, off the main thread. + * + * @return {Promise} + */ + wipe: Task.async(function* Storage_wipe() { + // + // This operation may be launched during shutdown, so we need to + // take a few precautions to ensure that: + // + // 1. it is not interrupted by shutdown, in which case we + // could be leaving privacy-sensitive files on disk; + // 2. it is not launched too late during shutdown, in which + // case this could cause shutdown freezes (see bug 1005487, + // which will eventually be fixed by bug 965309) + // + + let blocker = () => promise; + + // The following operation will rise an error if we have already + // reached profileBeforeChange, in which case it is too late + // to clear the thumbnail wipe. + AsyncShutdown.profileBeforeChange.addBlocker( + "PageThumbs: removing all thumbnails", + blocker); + + // Start the work only now that `profileBeforeChange` has had + // a chance to throw an error. + + let promise = PageThumbsWorker.post("wipe", [this.path]); + try { + yield promise; + } finally { + // Generally, we will be done much before profileBeforeChange, + // so let's not hoard blockers. + if ("removeBlocker" in AsyncShutdown.profileBeforeChange) { + // `removeBlocker` was added with bug 985655. In the interest + // of backporting, let's degrade gracefully if `removeBlocker` + // doesn't exist. + AsyncShutdown.profileBeforeChange.removeBlocker(blocker); + } + } + }), + + fileExistsForURL: function Storage_fileExistsForURL(aURL) { + return PageThumbsWorker.post("exists", [this.getFilePathForURL(aURL)]); + }, + + isFileRecentForURL: function Storage_isFileRecentForURL(aURL) { + return PageThumbsWorker.post("isFileRecent", + [this.getFilePathForURL(aURL), + MAX_THUMBNAIL_AGE_SECS]); + }, + + _calculateMD5Hash: function Storage_calculateMD5Hash(aValue) { + let hash = gCryptoHash; + let value = gUnicodeConverter.convertToByteArray(aValue); + + hash.init(hash.MD5); + hash.update(value, value.length); + return this._convertToHexString(hash.finish(false)); + }, + + _convertToHexString: function Storage_convertToHexString(aData) { + let hex = ""; + for (let i = 0; i < aData.length; i++) + hex += ("0" + aData.charCodeAt(i).toString(16)).slice(-2); + return hex; + }, + + /** + * For functions that take a noOverwrite option, OS.File throws an error if + * the target file exists and noOverwrite is true. We don't consider that an + * error, and we don't want such errors propagated. + * + * @param {aNoOverwrite} The noOverwrite option used in the OS.File operation. + * + * @return {function} A function that should be passed as the second argument + * to then() (the `onError` argument). + */ + _eatNoOverwriteError: function Storage__eatNoOverwriteError(aNoOverwrite) { + return function onError(err) { + if (!aNoOverwrite || + !(err instanceof OS.File.Error) || + !err.becauseExists) { + throw err; + } + }; + }, + + // Deprecated, please do not use + getFileForURL: function Storage_getFileForURL_DEPRECATED(aURL) { + Deprecated.warning("PageThumbs.getFileForURL is deprecated. Please use PageThumbs.getFilePathForURL and OS.File", + "https://developer.mozilla.org/docs/JavaScript_OS.File"); + // Note: Once this method has been removed, we can get rid of the dependency towards FileUtils + return new FileUtils.File(PageThumbsStorage.getFilePathForURL(aURL)); + } +}; + +var PageThumbsStorageMigrator = { + get currentVersion() { + try { + return Services.prefs.getIntPref(PREF_STORAGE_VERSION); + } catch (e) { + // The pref doesn't exist, yet. Return version 0. + return 0; + } + }, + + set currentVersion(aVersion) { + Services.prefs.setIntPref(PREF_STORAGE_VERSION, aVersion); + }, + + migrate: function Migrator_migrate() { + let version = this.currentVersion; + + // Storage version 1 never made it to beta. + // At the time of writing only Windows had (ProfD != ProfLD) and we + // needed to move thumbnails from the roaming profile to the locale + // one so that they're not needlessly included in backups and/or + // written via SMB. + + // Storage version 2 also never made it to beta. + // The thumbnail folder structure has been changed and old thumbnails + // were not migrated. Instead, we just renamed the current folder to + // "<name>-old" and will remove it later. + + if (version < 3) { + this.migrateToVersion3(); + } + + this.currentVersion = LATEST_STORAGE_VERSION; + }, + + /** + * Bug 239254 added support for having the disk cache and thumbnail + * directories on a local path (i.e. ~/.cache/) under Linux. We'll first + * try to move the old thumbnails to their new location. If that's not + * possible (because ProfD might be on a different file system than + * ProfLD) we'll just discard them. + * + * @param {string*} local The path to the local profile directory. + * Used for testing. Default argument is good for all non-testing uses. + * @param {string*} roaming The path to the roaming profile directory. + * Used for testing. Default argument is good for all non-testing uses. + */ + migrateToVersion3: function Migrator_migrateToVersion3( + local = OS.Constants.Path.localProfileDir, + roaming = OS.Constants.Path.profileDir) { + PageThumbsWorker.post( + "moveOrDeleteAllThumbnails", + [OS.Path.join(roaming, THUMBNAIL_DIRECTORY), + OS.Path.join(local, THUMBNAIL_DIRECTORY)] + ); + } +}; + +var PageThumbsExpiration = { + _filters: [], + + init: function Expiration_init() { + gUpdateTimerManager.registerTimer("browser-cleanup-thumbnails", this, + EXPIRATION_INTERVAL_SECS); + }, + + addFilter: function Expiration_addFilter(aFilter) { + this._filters.push(aFilter); + }, + + removeFilter: function Expiration_removeFilter(aFilter) { + let index = this._filters.indexOf(aFilter); + if (index > -1) + this._filters.splice(index, 1); + }, + + notify: function Expiration_notify(aTimer) { + let urls = []; + let filtersToWaitFor = this._filters.length; + + let expire = function expire() { + this.expireThumbnails(urls); + }.bind(this); + + // No registered filters. + if (!filtersToWaitFor) { + expire(); + return; + } + + function filterCallback(aURLs) { + urls = urls.concat(aURLs); + if (--filtersToWaitFor == 0) + expire(); + } + + for (let filter of this._filters) { + if (typeof filter == "function") + filter(filterCallback) + else + filter.filterForThumbnailExpiration(filterCallback); + } + }, + + expireThumbnails: function Expiration_expireThumbnails(aURLsToKeep) { + let keep = aURLsToKeep.map(url => PageThumbsStorage.getLeafNameForURL(url)); + let msg = [ + PageThumbsStorage.path, + keep, + EXPIRATION_MIN_CHUNK_SIZE + ]; + + return PageThumbsWorker.post( + "expireFilesInDirectory", + msg + ); + } +}; + +/** + * Interface to a dedicated thread handling I/O + */ +var PageThumbsWorker = new BasePromiseWorker("resource://gre/modules/PageThumbsWorker.js"); +// As the PageThumbsWorker performs I/O, we can receive instances of +// OS.File.Error, so we need to install a decoder. +PageThumbsWorker.ExceptionHandlers["OS.File.Error"] = OS.File.Error.fromMsg; + +var PageThumbsHistoryObserver = { + onDeleteURI(aURI, aGUID) { + PageThumbsStorage.remove(aURI.spec); + }, + + onClearHistory() { + PageThumbsStorage.wipe(); + }, + + onTitleChanged: function () {}, + onBeginUpdateBatch: function () {}, + onEndUpdateBatch: function () {}, + onVisit: function () {}, + onPageChanged: function () {}, + onDeleteVisits: function () {}, + + QueryInterface: XPCOMUtils.generateQI([Ci.nsINavHistoryObserver, + Ci.nsISupportsWeakReference]) +}; |