private void WriteData(Stream stream)
{
if (_originalStream != null)
{
WriteOriginalData(stream);
return;
}
bool closeFileStream = false;
if (_fileStream == null)
{
_fileStream = File.OpenRead(_fileName);
closeFileStream = true;
}
long startPosition = stream.Position;
_uncompressedSize = 0;
_compressedSize = 0;
_crc32 = Crc32Hash.DefaultSeed;
Stream outStream = stream;
if (CompressionMethod == (uint) CompressionType.Deflate)
{
outStream = new DeflateStream(stream, CompressionMode.Compress, CompressionLevel.BestCompression, true);
}
int bytesRead;
var buffer = new byte[WriteBufferSize];
do
{
bytesRead = _fileStream.Read(buffer, 0, WriteBufferSize);
if (bytesRead <= 0) break;
_uncompressedSize += (uint) bytesRead;
outStream.Write(buffer, 0, bytesRead);
_crc32 = Crc32Hash.CalculateHash(_crc32, buffer, bytesRead);
} while (bytesRead == WriteBufferSize);
_crc32 ^= Crc32Hash.DefaultSeed;
outStream.Flush();
if (CompressionMethod == (uint) CompressionType.Deflate)
{
outStream.Close();
}
_compressedSize = (uint) (stream.Position - startPosition);
if (closeFileStream)
{
_fileStream.Close();
_fileStream = null;
}
}
/// <summary>
/// Uncompress a DEFLATE'd byte array into a single string.
/// </summary>
///
/// <seealso cref="DeflateStream.CompressString(String)">DeflateStream.CompressString(String)</seealso>
/// <seealso cref="DeflateStream.UncompressBuffer(byte[])">DeflateStream.UncompressBuffer(byte[])</seealso>
/// <seealso cref="GZipStream.UncompressString(byte[])">GZipStream.UncompressString(byte[])</seealso>
/// <seealso cref="ZlibStream.UncompressString(byte[])">ZlibStream.UncompressString(byte[])</seealso>
///
/// <param name="compressed">
/// A buffer containing DEFLATE-compressed data.
/// </param>
///
/// <returns>The uncompressed string</returns>
public static String UncompressString(byte[] compressed)
{
using (var input = new System.IO.MemoryStream(compressed))
{
System.IO.Stream decompressor =
new DeflateStream(input, CompressionMode.Decompress);
return ZlibBaseStream.UncompressString(compressed, decompressor);
}
}
internal void Extract(Stream stream)
{
if (_originalStream == null)
throw new Exception(string.Format("{0} entry has not been written to archive.", Name));
ReadLocalHeader();
if (_localUncompressedSize == 0) return;
long streamPos = _originalStream.Position;
_originalStream.Position = _dataOffset;
Stream readStream = _originalStream;
if (CompressionMethod != 0)
{
readStream = new DeflateStream(_originalStream, CompressionMode.Decompress, true);
}
var buffer = new byte[WriteBufferSize];
long size = _localUncompressedSize;
while (size > 0)
{
var length = (int) Math.Min(size, buffer.Length);
int bytesRead = readStream.Read(buffer, 0, length);
if (bytesRead <= 0) break;
size -= bytesRead;
stream.Write(buffer, 0, bytesRead);
}
stream.Flush();
if (CompressionMethod != 0)
{
readStream.Dispose();
}
_originalStream.Position = streamPos;
}
/// <summary>
/// Compress a string into a byte array using DEFLATE (RFC 1951).
/// </summary>
///
/// <remarks>
/// Uncompress it with <see cref="DeflateStream.UncompressString(byte[])"/>.
/// </remarks>
///
/// <seealso cref="DeflateStream.UncompressString(byte[])">DeflateStream.UncompressString(byte[])</seealso>
/// <seealso cref="DeflateStream.CompressBuffer(byte[])">DeflateStream.CompressBuffer(byte[])</seealso>
/// <seealso cref="GZipStream.CompressString(string)">GZipStream.CompressString(string)</seealso>
/// <seealso cref="ZlibStream.CompressString(string)">ZlibStream.CompressString(string)</seealso>
///
/// <param name="s">
/// A string to compress. The string will first be encoded
/// using UTF8, then compressed.
/// </param>
///
/// <returns>The string in compressed form</returns>
public static byte[] CompressString(String s)
{
using (var ms = new System.IO.MemoryStream())
{
System.IO.Stream compressor =
new DeflateStream(ms, CompressionMode.Compress, CompressionLevel.BestCompression);
ZlibBaseStream.CompressString(s, compressor);
return ms.ToArray();
}
}