/// <summary>
/// </summary>
/// <returns>Docking station event</returns>
public DockingStationEvent Execute()
{
UploadDatabaseEvent uploadEvent = new UploadDatabaseEvent(this);
CompressDatabase(uploadEvent);
#if DEBUG
// UncompressDatabase( uploadEvent ); // unit test. Temporarily uncomment it to run it.
#endif
return(uploadEvent);
}
/// <summary>
///
/// </summary>
/// <remarks>
/// System.IO.Packaging.ZipPackage can handle .zip files, but it is not supported in Compact Framework.
/// We therefore use the freeware SharpZipLib to do our uncompression.
/// </remarks>
/// <param name="uploadEvent"></param>
private void CompressDatabase(UploadDatabaseEvent uploadEvent)
{
string dbFilePath = Controller.FLASHCARD_PATH + Controller.INET_DB_NAME;
FileInfo finfo = new FileInfo(dbFilePath);
long totalLength = finfo.Length;
using (FileStream dbFileStream = new FileStream(dbFilePath, FileMode.Open))
{
MemoryStream outputMemStream = new MemoryStream();
ZipOutputStream zipStream = new ZipOutputStream(outputMemStream);
// We just use default compression leve, which I think is actually 6.
zipStream.SetLevel(Deflater.DEFAULT_COMPRESSION); // 0-9, 9 being the highest compression, 0 being no compression
ZipEntry newEntry = new ZipEntry(Controller.INET_DB_NAME);
newEntry.DateTime = DateTime.UtcNow;
zipStream.PutNextEntry(newEntry);
// Assign the entry's size to what the file size is expected to be when
// uncompressed. This is necessary to get Window's built-in extractor to work,
// according to SharpZipLib sample code.
newEntry.Size = finfo.Length;
DateTime startTime = DateTime.UtcNow;
// Copy the file into the zip stream. The ZipStream
// compresses the data as it's fed into it.
const int bufferSize = 8196;
long logThreshold = bufferSize * 50;
byte[] buffer = new byte[bufferSize];
int bytesRead;
long totalBytesRead = 0;
while ((bytesRead = dbFileStream.Read(buffer, 0, bufferSize)) > 0)
{
zipStream.Write(buffer, 0, bytesRead);
totalBytesRead += bytesRead;
if ((totalBytesRead % logThreshold) == 0)
{
LogCompression(totalBytesRead, totalLength, outputMemStream.Length);
}
}
zipStream.CloseEntry();
zipStream.IsStreamOwner = false; // False stops the Close also Closing the underlying stream.
zipStream.Close(); // Must finish the ZipOutputStream before using outputMemStream.
outputMemStream.Position = 0;
DateTime endTime = DateTime.UtcNow;
TimeSpan elapsed = endTime - startTime;
LogCompression(totalBytesRead, totalLength, outputMemStream.Length);
Log.Debug(string.Format("Compression finished. Elapsed time: {0} seconds.", (int)elapsed.TotalSeconds));
// ToArray is the cleaner and easiest to use correctly with the penalty of duplicating allocated memory.
uploadEvent.File = outputMemStream.ToArray();
// Alternative: GetBuffer returns a raw buffer raw and so you need to account for the true length yourself.
//byte[] byteArrayOut = outputMemStream.GetBuffer();
//long len = outputMemStream.Length;
uploadEvent.FileName = newEntry.Name + ".zip";
}
}
