public void StartProcess()
{
FileStream sourceFileStream = null;
try
{
var initialWritePosition = Utils.CreateCompressedFileWithHeader(_compressedFilename);
var fileMetadata = new CompressedFileMetadata();
sourceFileStream = new FileStream(_filenameToCompress, FileMode.Open, FileAccess.Read, FileShare.Read);
var compressTask = GetTask(sourceFileStream, _filenameToCompress, _compressedFilename, fileMetadata, _blockSizeInBytes, initialWritePosition);
_threadManager = GetThreadManager(sourceFileStream, _blockSizeInBytes);
sourceFileStream.Close();
_threadManager.RunInParallel(compressTask);
_threadManager.WaitAll();
Utils.WriteMetadata(_compressedFilename, fileMetadata);
}
catch (Exception ex)
{
Console.WriteLine($"Error occured: {ex.Message}");
Utils.DeleteFile(_compressedFilename);
throw;
}
finally
{
sourceFileStream?.Dispose();
_threadManager?.Dispose();
}
}
public CompressTask(string filenameToCompress, string compressedFilename, FixedSizeBlockGenerator inputStreamPositionGenerator, CompressedFileMetadata fileMetadata, long initialWritePosition)
{
_inputStreamPositionGenerator = inputStreamPositionGenerator;
_filenameToCompress = filenameToCompress;
_compressedFilename = compressedFilename;
_fileMetadata = fileMetadata;
_writePosition = initialWritePosition;
}
public static void WriteMetadata(string compressedFileName, CompressedFileMetadata fileMetadata)
{
using FileStream outputStream = new FileStream(compressedFileName, FileMode.Open, FileAccess.Write);
var metadataPosition = BitConverter.GetBytes(outputStream.Length);
outputStream.Write(metadataPosition);
var serilizedData = JsonSerializer.Serialize(fileMetadata);
using var memStream = new MemoryStream(Encoding.UTF8.GetBytes(serilizedData));
using var zipStream = new GZipStream(outputStream, CompressionMode.Compress);
outputStream.Seek(outputStream.Length, SeekOrigin.Begin);
memStream.CopyTo(zipStream);
}
private ICanceleableTask GetTask(Stream sourceFileStream, string fileNameToCompress, string compressedFileName, CompressedFileMetadata fileMetadata, int blockSize, long initialPosition)
{
var inputStreamPositionGenerator = new FixedSizeBlockGenerator(blockSize, sourceFileStream.Length);
return(new CompressTask(fileNameToCompress, compressedFileName, inputStreamPositionGenerator, fileMetadata, initialPosition));
}
