private void WriteCompressedBlock(FileStream outputFileStream, int blockNumber, byte[] compressedData)
{
var compressedBlock = new ArchiveBlock
{
BlockNumber = blockNumber,
CompressedData = compressedData
};
List <ArchiveBlock> buffer = null;
lock (_writeToBufferLocker)
{
_buffer.Add(compressedBlock);
_writtenBlocksAmount++;
if (BufferIsFilled())
{
buffer = _buffer;
InitializeBuffer();
}
}
if (buffer != null)
{
WriteBufferToOutputFileStream(buffer, outputFileStream);
}
if (buffer == null && CurrentBlockIsLast())
{
WriteBufferToOutputFileStream(_buffer, outputFileStream);
}
}
private long GetDecompressedBlockPosition(ArchiveBlock archiveBlock, FileStream outputFileStream)
{
long blockPosition = FormatConstants.BlockSize * archiveBlock.BlockNumber;
if (blockPosition >= outputFileStream.Length)
{
throw new FormatException(
$"Incorrect archive format. Block position {archiveBlock.BlockNumber} does not correspond to original file size = {outputFileStream.Length} bytes.");
}
return(blockPosition);
}
private void FillBuffer(FileStream inputArchiveFileStream)
{
if (Monitor.TryEnter(_bufferFillingLocker))
{
try
{
while (!_buffer.IsFull())
{
var compressedDataBlockNumber = GetIntegerFromInputStream(inputArchiveFileStream);
if (compressedDataBlockNumber == null)
{
_readingCompleted = true;
return;
}
var compressedDataBlockSize = GetIntegerFromInputStream(inputArchiveFileStream);
if (compressedDataBlockSize == null)
{
throw new FormatException(
$"Incorrect archive format. Block with information about following compressed data block length should be {sizeof(int)} bytes size, but was 0 bytes.");
}
var compressedData = new byte[compressedDataBlockSize.Value];
var numberOfBytesRead = inputArchiveFileStream.Read(compressedData, 0,
compressedDataBlockSize.Value);
if (numberOfBytesRead != compressedDataBlockSize.Value)
{
throw new FormatException(
$"Incorrect archive format. Block with compressed data block should be {compressedDataBlockSize.Value} bytes size, but was {numberOfBytesRead} bytes.");
}
var block = new ArchiveBlock
{
CompressedData = compressedData,
BlockNumber = compressedDataBlockNumber.Value
};
_buffer.Push(block);
}
}
finally
{
Monitor.Exit(_bufferFillingLocker);
}
}
}
private DecompressedArchiveBlockData DecompressBlock(ArchiveBlock archiveBlock)
{
var decompressedData = new byte[FormatConstants.BlockSize];
int numberOfBytesDecompressed;
using (var memoryStream = new MemoryStream(archiveBlock.CompressedData))
{
using (var gZipStream = new GZipStream(memoryStream, CompressionMode.Decompress))
{
numberOfBytesDecompressed = gZipStream.Read(decompressedData, 0, FormatConstants.BlockSize);
}
}
return(new DecompressedArchiveBlockData
{
DecompressedData = decompressedData,
DecompressedDataLength = numberOfBytesDecompressed
});
}
