/// <summary>
/// Compress data in-memory
/// </summary>
/// <param name="data"></param>
/// <param name="offset"></param>
/// <param name="count"></param>
/// <param name="threads"></param>
/// <param name="level">0-9, default is 6, bigger number needs more time and produces smaller compressed data</param>
/// <returns></returns>
public static byte[] CompressBytes(byte[] data, int offset, int count, int threads = 1, int level = 6)
{
if (data == null)
{
throw new ArgumentNullException(nameof(data));
}
if (offset < 0)
{
throw new ArgumentOutOfRangeException(nameof(offset));
}
if (count < 0)
{
throw new ArgumentOutOfRangeException(nameof(count));
}
if (count + offset > data.Length)
{
throw new ArgumentOutOfRangeException(nameof(count), "offset+count > data.length");
}
if (level < 0 || level > 9)
{
throw new ArgumentOutOfRangeException(nameof(level));
}
var _lzma_stream = new lzma_stream();
var ret = CreateEncoder(_lzma_stream, threads, (uint)level);
if (ret == lzma_ret.LZMA_OK)
{
var compressed = CodeBuffer(_lzma_stream, data, offset, count);
Native.lzma_end(_lzma_stream);
return(compressed);
}
throw new Exception($"Can not create lzma stream: {ret}");
}
public static byte[] DecompressBytes(byte[] data, int offset, int count)
{
if (data == null)
{
throw new ArgumentNullException(nameof(data));
}
if (offset < 0)
{
throw new ArgumentOutOfRangeException(nameof(offset));
}
if (count < 0)
{
throw new ArgumentOutOfRangeException(nameof(count));
}
if (count + offset > data.Length)
{
throw new ArgumentOutOfRangeException(nameof(count), "offset+count > data.length");
}
var _lzma_stream = new lzma_stream();
var ret = Native.lzma_auto_decoder(_lzma_stream, ulong.MaxValue, Native.LZMA_CONCATENATED);
if (ret == lzma_ret.LZMA_OK)
{
var decompressed = CodeBuffer(_lzma_stream, data, offset, count);
Native.lzma_end(_lzma_stream);
return(decompressed);
}
throw new Exception($"Can not create lzma stream: {ret}");
}
protected override void Dispose(bool disposing)
{
if (_stream == null)
{
return;
}
Native.lzma_end(_lzma_stream);
Marshal.FreeHGlobal(_inbuf);
Marshal.FreeHGlobal(_outbuf);
_stream.Close();
_stream = null;
}
protected override void Dispose(bool disposing)
{
if (_stream == null)
{
return;
}
try
{
// compress all remaining data
while (true)
{
// do compress, LZMA_FINISH action should return LZMA_OK or LZMA_STREAM_END on success
var ret = Native.lzma_code(_lzma_stream, lzma_action.LZMA_FINISH);
if (ret != lzma_ret.LZMA_STREAM_END && ret != lzma_ret.LZMA_OK)
{
throw new Exception($"lzma_code returns {ret}");
}
// write output buffer to underlying stream
if (_lzma_stream.avail_out == UIntPtr.Zero || ret == lzma_ret.LZMA_STREAM_END)
{
int size = (int)(BUFSIZE - (uint)_lzma_stream.avail_out);
var data = ArrayPool <byte> .Shared.Rent(size);
Marshal.Copy(_outbuf, data, 0, size);
_stream.Write(data, 0, size);
ArrayPool <byte> .Shared.Return(data);
// Reset next_out and avail_out.
_lzma_stream.next_out = _outbuf;
_lzma_stream.avail_out = (UIntPtr)BUFSIZE;
}
if (ret == lzma_ret.LZMA_STREAM_END)
{
break;
}
}
}
finally
{
Native.lzma_end(_lzma_stream);
Marshal.FreeHGlobal(_inbuf);
Marshal.FreeHGlobal(_outbuf);
_stream.Close();
_stream = null;
}
}
