/// <summary>
/// learn from 01_compress_easy.c
/// </summary>
/// <param name="buffer"></param>
/// <param name="offset"></param>
/// <param name="count"></param>
public override void Write(byte[] buffer, int offset, int count)
{
if (buffer == null)
{
throw new ArgumentNullException(nameof(buffer));
}
if (offset < 0)
{
throw new ArgumentOutOfRangeException(nameof(offset));
}
if (count < 0)
{
throw new ArgumentOutOfRangeException(nameof(count));
}
if (count + offset > buffer.Length)
{
throw new ArgumentOutOfRangeException(nameof(count), "offset+count > buffer.length");
}
if (count == 0)
{
return;
}
int bytesProcessed = 0;
while (true)
{
// Fill the input buffer if it is empty.
if (_lzma_stream.avail_in == UIntPtr.Zero)
{
int bytesToProcess = Math.Min(count - bytesProcessed, BUFSIZE);
if (bytesToProcess == 0)
{
break; // no more data to compress
}
_lzma_stream.next_in = _inbuf;
_lzma_stream.avail_in = (UIntPtr)bytesToProcess;
Marshal.Copy(buffer, offset + bytesProcessed, _inbuf, bytesToProcess);
bytesProcessed += bytesToProcess;
}
// do compress, RUN action should return LZMA_OK on success
var ret = Native.lzma_code(_lzma_stream, lzma_action.LZMA_RUN);
if (ret != lzma_ret.LZMA_OK)
{
throw new Exception($"lzma_code returns {ret}");
}
// check output buffer
if (_lzma_stream.avail_out == UIntPtr.Zero)
{
var data = ArrayPool <byte> .Shared.Rent(BUFSIZE);
Marshal.Copy(_outbuf, data, 0, BUFSIZE);
_stream.Write(data, 0, BUFSIZE);
ArrayPool <byte> .Shared.Return(data);
// Reset next_out and avail_out.
_lzma_stream.next_out = _outbuf;
_lzma_stream.avail_out = (UIntPtr)BUFSIZE;
}
}
}
