public static void SkipBlock(Stream input)
{
if (input == null)
{
throw new ArgumentNullException("input");
}
var header = CompressionHeader.Read(input);
if (header.CompressionFlags == CompressionFlags.None)
{
throw new NotSupportedException();
header.CompressionType = header.CompressedBlockSize == header.UncompressedBlockSize
? CompressionType.None
: CompressionType.Zlib;
header.CompressionFlags = (CompressionFlags)7;
}
switch (header.CompressionType)
{
case CompressionType.None:
case CompressionType.Zstd:
{
input.Seek(header.CompressedBlockSize, SeekOrigin.Current);
break;
}
default:
{
throw new NotSupportedException();
}
}
}
public static void Decompress(Stream input, Stream output, long originalSize)
{
if (input == null)
{
throw new ArgumentNullException("input");
}
if (output == null)
{
throw new ArgumentNullException("output");
}
var remaining = originalSize;
var work = new byte[0];
var buffer = new byte[0];
while (remaining > 0)
{
var header = CompressionHeader.Read(input);
if (header.CompressionFlags == CompressionFlags.None)
{
throw new NotSupportedException();
header.CompressionType = header.CompressedBlockSize == header.UncompressedBlockSize
? CompressionType.None
: CompressionType.Zlib;
header.CompressionFlags = (CompressionFlags)7;
}
var compressedBlockSize = header.CompressedBlockSize;
var uncompressedBlockSize = header.UncompressedBlockSize;
if (buffer.Length < uncompressedBlockSize)
{
Array.Resize(ref buffer, uncompressedBlockSize);
}
switch (header.CompressionType)
{
case CompressionType.None:
{
if (compressedBlockSize != uncompressedBlockSize)
{
throw new InvalidOperationException();
}
output.WriteFromStream(input, compressedBlockSize);
remaining -= compressedBlockSize;
break;
}
case CompressionType.Zstd:
{
if (work.Length < compressedBlockSize)
{
Array.Resize(ref work, compressedBlockSize);
}
var read = input.Read(work, 0, compressedBlockSize);
if (read != compressedBlockSize)
{
throw new EndOfStreamException();
}
var result = Zstd.Decompress(work, 0, compressedBlockSize, buffer, 0, uncompressedBlockSize);
if (Zstd.IsError(result) == true)
{
throw new InvalidOperationException();
}
if (result != (uint)uncompressedBlockSize)
{
throw new InvalidOperationException();
}
output.Write(buffer, 0, uncompressedBlockSize);
remaining -= uncompressedBlockSize;
break;
}
default:
{
throw new NotSupportedException();
}
}
}
}
public static int DecompressBlock(Stream input, byte[] buffer, int offset, int count, byte[] work)
{
if (input == null)
{
throw new ArgumentNullException("input");
}
if (buffer == null)
{
throw new ArgumentNullException("buffer");
}
if (offset < 0 || offset > buffer.Length)
{
throw new ArgumentOutOfRangeException("offset");
}
if (count < 0 || offset + count > buffer.Length)
{
throw new ArgumentOutOfRangeException("count");
}
if (work == null)
{
throw new ArgumentNullException("work");
}
var header = CompressionHeader.Read(input);
/*
* if (header.CompressionFlags == CompressionFlags.None)
* {
* throw new NotSupportedException();
* header.CompressionType = header.CompressedBlockSize == header.UncompressedBlockSize
* ? CompressionType.None
* : CompressionType.Zlib;
* header.CompressionFlags = (CompressionFlags)7;
* }
*/
if (header.UncompressedBlockSize > count)
{
throw new ArgumentOutOfRangeException("count");
}
switch (header.CompressionType)
{
case CompressionType.None:
{
if (header.CompressedBlockSize != header.UncompressedBlockSize)
{
throw new InvalidOperationException();
}
return(input.Read(buffer, offset, Math.Min(count, header.CompressedBlockSize)));
}
case CompressionType.Zstd:
{
var read = input.Read(work, 0, header.CompressedBlockSize);
if (read != header.CompressedBlockSize)
{
throw new EndOfStreamException();
}
var result = Zstd.Decompress(work, 0, header.CompressedBlockSize, buffer, offset, count);
if (Zstd.IsError(result) == true)
{
throw new InvalidOperationException();
}
return((int)result);
}
default:
{
throw new NotSupportedException();
}
}
}
