public static UncompressedPacket Decompress(CompressedPacket packet, IBufferPoolScope <byte> bufferPool, uint threshold, UncompressedPacket targetPacket = null)
{
if (packet.DataLength != 0 && packet.DataLength < threshold)
{
throw new InvalidDataException("Uncompressed data length is lower than threshold.");
}
bool useCompression = packet.DataLength != 0;
var dataLength = useCompression ? packet.DataLength : (uint)packet.CompressedData.Length;
targetPacket = targetPacket ?? new UncompressedPacket();
using (var stream = new MemoryStream(packet.CompressedData))
using (var br = new BinaryReader(useCompression ? (Stream) new ZlibStream(stream, CompressionMode.Decompress, CompressionLevel.BestSpeed) : stream))
{
targetPacket.PacketId = br.ReadAsVarInt(out var packetIdLen);
targetPacket.Data = bufferPool.Rent((int)(dataLength - packetIdLen));
br.Read(targetPacket.Data.Array, targetPacket.Data.Offset, targetPacket.Data.Count);
}
targetPacket.Length = packet.DataLength;
return(targetPacket);
}
public static CompressedPacket Compress(UncompressedPacket packet, IBufferPoolScope <byte> bufferPool, uint threshold)
{
var targetPacket = new CompressedPacket();
using (var stream = new MemoryStream())
{
var dataLength = packet.PacketId.SizeOfVarInt() + (uint)packet.Data.Count;
bool useCompression = dataLength >= threshold;
targetPacket.DataLength = useCompression ? dataLength : 0;
using (var bw = new BinaryWriter(useCompression ? (Stream) new ZlibStream(stream, CompressionMode.Compress, CompressionLevel.BestSpeed) : stream))
{
bw.WriteAsVarInt(packet.PacketId, out _);
bw.Write(packet.Data.Array, packet.Data.Offset, packet.Data.Count);
bw.Flush();
}
targetPacket.CompressedData = stream.ToArray();
}
return(targetPacket);
}
public static async Task <UncompressedPacket> DeserializeAsync(Stream stream, IBufferPoolScope <byte> bufferPool, UncompressedPacket packet = null)
{
packet = packet ?? new UncompressedPacket();
int packetIdLen;
using (var br = new BinaryReader(stream, Encoding.UTF8, true))
{
packet.Length = br.ReadAsVarInt(out _);
Protocol.ValidatePacketLength(packet.Length);
packet.PacketId = br.ReadAsVarInt(out packetIdLen);
}
packet.Data = bufferPool.Rent((int)(packet.Length - packetIdLen));
await stream.ReadExactAsync(packet.Data.Array, packet.Data.Offset, packet.Data.Count);
return(packet);
}
