public async Task <UpdateInfo> CheckForUpdate( string localReleaseFile, string updateUrlOrPath, bool ignoreDeltaUpdates = false, Action <int> progress = null, IFileDownloader urlDownloader = null, bool startOverIfNone = false) { progress = progress ?? (_ => { }); var localReleases = Enumerable.Empty <ReleaseEntry>(); bool shouldInitialize = false; try { localReleases = Utility.LoadLocalReleases(localReleaseFile); } catch (Exception ex) { // Something has gone pear-shaped, let's start from scratch this.Log().WarnException("Failed to load local releases, starting from scratch", ex); shouldInitialize = true; } restart: if (shouldInitialize) { await initializeClientAppDirectory(); } string releaseFile; var latestLocalRelease = localReleases.Count() > 0 ? localReleases.MaxBy(x => x.Version).First() : default(ReleaseEntry); // Fetch the remote RELEASES file, whether it's a local dir or an // HTTP URL if (Utility.IsHttpUrl(updateUrlOrPath)) { if (updateUrlOrPath.EndsWith("/")) { updateUrlOrPath = updateUrlOrPath.Substring(0, updateUrlOrPath.Length - 1); } this.Log().Info("Downloading RELEASES file from {0}", updateUrlOrPath); int retries = 3; retry: try { var uri = Utility.AppendPathToUri(new Uri(updateUrlOrPath), "RELEASES"); if (latestLocalRelease != null) { uri = Utility.AddQueryParamsToUri(uri, new Dictionary <string, string> { { "id", latestLocalRelease.PackageName }, { "localVersion", latestLocalRelease.Version.ToString() }, { "arch", Environment.Is64BitOperatingSystem ? "amd64" : "x86" } }); } var data = await urlDownloader.DownloadUrl(uri.ToString()); releaseFile = Encoding.UTF8.GetString(data); } catch (WebException ex) { this.Log().InfoException("Download resulted in WebException (returning blank release list)", ex); if (retries <= 0) { throw; } retries--; goto retry; } progress(33); } else { this.Log().Info("Reading RELEASES file from {0}", updateUrlOrPath); if (!Directory.Exists(updateUrlOrPath)) { var message = String.Format( "The directory {0} does not exist, something is probably broken with your application", updateUrlOrPath); throw new Exception(message); } var fi = new FileInfo(Path.Combine(updateUrlOrPath, "RELEASES")); if (!fi.Exists) { var message = String.Format( "The file {0} does not exist, something is probably broken with your application", fi.FullName); this.Log().Warn(message); var packages = (new DirectoryInfo(updateUrlOrPath)).GetFiles("*.nupkg"); if (packages.Length == 0) { throw new Exception(message); } // NB: Create a new RELEASES file since we've got a directory of packages ReleaseEntry.WriteReleaseFile( packages.Select(x => ReleaseEntry.GenerateFromFile(x.FullName)), fi.FullName); } releaseFile = File.ReadAllText(fi.FullName, Encoding.UTF8); progress(33); } var ret = default(UpdateInfo); var remoteReleases = ReleaseEntry.ParseReleaseFile(releaseFile); progress(66); if (!remoteReleases.Any()) { throw new Exception("Remote release File is empty or corrupted"); } ret = determineUpdateInfo(localReleases, remoteReleases, ignoreDeltaUpdates); progress(100); if (startOverIfNone && !ret.ReleasesToApply.Any()) { // User has apparently re-run the installer for the version already installed. // Assume the intent is to repair a broken installation. // These rather awkward steps cause it to erase the installed-version directory // and re-create it, much like a first-time install (though it won't run the app // with the special arguments for first-time). shouldInitialize = true; localReleases = Enumerable.Empty <ReleaseEntry>(); goto restart; } return(ret); }