/// <summary>If there already a package in the download directory, this function gets the present downloaded package. If anything is invalid (wrong format of the version file,
/// wrong hash sum), the return value is <c>Null</c>.</summary>
/// <param name="fs">Stream to read the version info from. This must be the opened stream of the VersionInfo.txt file in the download directory.</param>
/// <param name="storagePath">Path to the directory that stores the downloaded package.</param>
/// <param name="packageFile">On successfull return, the opened <see cref="FileStream"/> of the package file is provided here. You are responsible for closing the stream!</param>
/// <returns>The info for the already present package in the download directory. If anything is invalid, the return value is null.</returns>
public static PackageInfo GetPresentDownloadedPackage(Stream fs, string storagePath, out FileStream packageFile)
{
PackageInfo packageInfo = null;
packageFile = null;
try
{
var packageInfos = PackageInfo.FromStream(fs);
packageInfo = PackageInfo.GetHighestVersion(packageInfos);
// test, if the file exists and has the right Hash
var fileInfo = new FileInfo(Path.Combine(storagePath, GetPackageFileName(packageInfo.Version)));
if (!fileInfo.Exists)
{
return(null);
}
// test for the appropriate length
if (fileInfo.Length != packageInfo.FileLength)
{
return(null);
}
packageFile = new FileStream(Path.Combine(storagePath, GetPackageFileName(packageInfo.Version)), FileMode.Open, FileAccess.Read, FileShare.Read);
var hashProvider = new System.Security.Cryptography.SHA1Managed();
var hash = hashProvider.ComputeHash(packageFile);
if (GetHashAsString(hash) != packageInfo.Hash)
{
throw new InvalidOperationException("Hash of downloaded package is not valid");
}
return(packageInfo);
}
catch (Exception)
{
}
return(null);
}
/// <summary>Runs the <see cref="Downloader"/>.</summary>
/// <remarks>
/// The download is done in steps:
/// <para>Firstly, the appropriate version file in the application data directory is locked,
/// so that no other program can use it, until this program ends.</para>
/// <para>Then, the version file is downloaded from the remote location.</para>
/// <para>If there is already a valid version file in the download directory,
/// and the version obtained from the remote version file is equal to the version obtained from the version file in the download directory,
/// then the package was already downloaded before. Then we only check that the package file is also present and that it has the appropriate hash sum.</para>
/// <para>Else, if the version obtained from the remote version file is higher than the program's current version,
/// we download the package file from the remote location.</para>
/// </remarks>
public void Run()
{
if (!Directory.Exists(_storagePath))
{
Directory.CreateDirectory(_storagePath);
SetDownloadDirectoryAccessRights(_storagePath);
}
var versionFileFullName = Path.Combine(_storagePath, PackageInfo.VersionFileName);
using (var fs = new FileStream(versionFileFullName, FileMode.OpenOrCreate, FileAccess.ReadWrite, FileShare.None))
{
fs.Seek(0, SeekOrigin.Begin);
var alreadyDownloadedVersion = PackageInfo.GetPresentDownloadedPackage(fs, _storagePath);
fs.Seek(0, SeekOrigin.Begin);
using (var webClient = new System.Net.WebClient())
{
Console.Write("Starting to download version file ...");
var versionData = webClient.DownloadData(_downloadURL + PackageInfo.VersionFileName);
Console.WriteLine(" ok! ({0} bytes downloaded)", versionData.Length);
// we leave the file open, thus no other process can access it
var parsedVersions = PackageInfo.FromStream(new MemoryStream(versionData));
fs.Write(versionData, 0, versionData.Length);
fs.Flush(); // write the new version to disc in order to change the write date
// from all parsed versions, choose that one that matches the requirements
var parsedVersion = PackageInfo.GetHighestVersion(parsedVersions);
if (null != parsedVersion)
{
Console.WriteLine("The remote package version is: {0}", parsedVersion.Version);
}
else
{
Console.WriteLine("This computer does not match the requirements of any package. The version file contains {0} packages.", parsedVersions.Length);
return;
}
if (Comparer <Version> .Default.Compare(parsedVersion.Version, _currentVersion) > 0) // if the remote version is higher than the currently installed Altaxo version
{
Console.Write("Cleaning download directory ...");
CleanDirectory(versionFileFullName); // Clean old downloaded files from the directory
Console.WriteLine(" ok!");
var packageUrl = _downloadURL + PackageInfo.GetPackageFileName(parsedVersion.Version);
var packageFileName = Path.Combine(_storagePath, PackageInfo.GetPackageFileName(parsedVersion.Version));
Console.WriteLine("Starting download of package file ...");
webClient.DownloadProgressChanged += EhDownloadOfPackageFileProgressChanged;
webClient.DownloadFileCompleted += EhDownloadOfPackageFileCompleted;
_isDownloadOfPackageCompleted = false;
webClient.DownloadFileAsync(new Uri(packageUrl), packageFileName);// download the package asynchronously to get progress messages
for (; !_isDownloadOfPackageCompleted;)
{
System.Threading.Thread.Sleep(250);
}
webClient.DownloadProgressChanged -= EhDownloadOfPackageFileProgressChanged;
webClient.DownloadFileCompleted -= EhDownloadOfPackageFileCompleted;
Console.WriteLine("Download finished!");
// make at least the test for the right length
var fileInfo = new FileInfo(packageFileName);
if (fileInfo.Length != parsedVersion.FileLength)
{
Console.WriteLine("Downloaded file length ({0}) differs from length in VersionInfo.txt {1}, thus the downloaded file will be deleted!", fileInfo.Length, parsedVersion.FileLength);
fileInfo.Delete();
}
else
{
Console.WriteLine("Test file length of downloaded package file ... ok!");
}
}
}
}
}