// Copies all source file into storage file
private void Store(ref ZipEntry entry, Stream source)
{
uint totalRead = 0;
Stream outStream;
long posStart = this.zipFileStream.Position;
long sourceStart = source.Position;
outStream = this.zipFileStream;
var inStream = new CrcStream(source);
switch (entry.Method)
{
case Compression.LZMA:
var encoder = new SevenZip.Compression.LZMA.Encoder();
// LZMA "magic bytes" (7-zip requires them)
var magicBytes = BitConverter.GetBytes(0x00051409);
outStream.Write(magicBytes, 0, magicBytes.Length);
encoder.WriteCoderProperties(outStream);
encoder.Code(inStream, outStream, -1, -1, null);
break;
case Compression.Deflate:
//using (var outPutStream = new ZOutputStream(outStream, zlibConst.Z_DEFAULT_COMPRESSION))
var outPutStream = new Ionic.Zlib.DeflateStream(outStream, Ionic.Zlib.CompressionMode.Compress, CompressionLevel.BestCompression, true);
{
outPutStream.FlushMode = FlushType.Full;
int buffSize = ZlibConstants.WorkingBufferSizeDefault;
byte[] buff = new byte[buffSize];
int size = 0;
do
{
size = inStream.Read(buff, 0, buffSize);
if (size > 0)
{
outPutStream.Write(buff, 0, size);
}
} while (size > 0);
}
break;
default: //case Compression.Store:
inStream.CopyTo(outStream);
break;
}
entry.Crc32 = inStream.ReadCrc;
outStream.Flush();
entry.FileSize = (uint)(source.Position - sourceStart);
entry.CompressedSize = (uint)(this.zipFileStream.Position - posStart);
// Verify for real compression
if (entry.Method != Compression.Store && !this.ForceDeflating && source.CanSeek && entry.CompressedSize > entry.FileSize)
{
// Start operation again with Store algorithm
entry.Method = Compression.Store;
this.zipFileStream.Position = posStart;
this.zipFileStream.SetLength(posStart);
source.Position = sourceStart;
this.Store(ref entry, source);
}
}
/// <summary>
/// Copy the contents of a stored file into an opened stream
/// </summary>
/// <param name="entry">Entry information of file to extract</param>
/// <param name="_stream">Stream to store the uncompressed data</param>
/// <returns>True if success, false if not.</returns>
/// <remarks>Unique compression methods are Store and Deflate</remarks>
public bool ExtractFile(ZipEntry entry, Stream stream)
{
if (!stream.CanWrite)
{
throw new InvalidOperationException("Stream cannot be written");
}
// check signature
byte[] signature = new byte[4];
this.zipFileStream.Seek(entry.HeaderOffset, SeekOrigin.Begin);
this.zipFileStream.Read(signature, 0, 4);
if (BitConverter.ToUInt32(signature, 0) != 0x04034b50)
{
return(false);
}
// Prepare streams
stream.SetLength(entry.FileSize);
var outStream = new CrcStream(stream);
this.zipFileStream.Seek(entry.FileOffset, SeekOrigin.Begin);
// Select input stream for inflating or just reading
Stream inStream = new SegmentStream(this.zipFileStream, entry.CompressedSize);
if (entry.Method == Compression.Deflate)
{
using (var intPutStream = new Ionic.Zlib.DeflateStream(inStream, Ionic.Zlib.CompressionMode.Decompress))
{
intPutStream.FlushMode = FlushType.Full;
int buffSize = 4096;
byte[] buff = new byte[buffSize];
int size = 0;
do
{
size = intPutStream.Read(buff, 0, buffSize);
if (size > 0)
{
outStream.Write(buff, 0, size);
}
} while (size > 0);
}
//inStream = new DeflateStream(inStream, CompressionMode.Decompress, true);
}
// Decompress
if (entry.Method == Compression.LZMA)
{
var decoder = new SevenZip.Compression.LZMA.Decoder();
const int PropsLength = 5;
var buffer = new byte[PropsLength];
inStream.Read(buffer, 0, sizeof(int));
if (BitConverter.ToInt32(buffer, 0) != 0x00051409)
{
throw new Exception("Invalid LZMA stream signature");
}
if (inStream.Read(buffer, 0, PropsLength) != PropsLength)
{
throw new Exception("Invalid LZMA properties length");
}
decoder.SetDecoderProperties(buffer);
decoder.Code(inStream, outStream, entry.CompressedSize, entry.FileSize, null);
}
else
{
inStream.CopyTo(outStream);
}
stream.Flush();
//if (entry.Method == Compression.Deflate)
inStream.Dispose();
if (entry.Crc32 != outStream.WriteCrc)
{
throw new Exception("Uncompressed file CRC mismatch");
}
return(true);
}
