public override void WriteBody(PacketWriter writer)
{
int packetCount = Packets.Count;
if (packetCount > 255)
{
throw new IOException("Too many packets inside batch packet!");
}
writer.WriteByte((byte)packetCount);
byte packetLastId = 0;
int packetLastNetId = 0;
for (int i = 0; i < packetCount; i++)
{
var packet = Packets[i];
var packetData = packet.GetBytes();
var newPacketId = packetData[0];
byte[] newPacketNetIdBuffer = new byte[4];
Buffer.BlockCopy(packetData, 1, newPacketNetIdBuffer, 0, 4);
if (!BitConverter.IsLittleEndian)
{
Array.Reverse(newPacketNetIdBuffer);
}
int newPacketNetId = BitConverter.ToInt32(newPacketNetIdBuffer, 0);
if (packetData.Length < 5)
{
throw new IOException("Packet too small for batch < 5!");
}
if (i == 0)
{
if (packetData.Length > 255)
{
throw new IOException("First packet too big for batch > 255!");
}
writer.WriteByte((byte)packetData.Length);
writer.WriteBytes(packetData);
}
else
{
if (packetData.Length > 260)
{
throw new IOException("Non-first packet too big for batch > 260!");
}
bool hasId = true;
bool hasNetId = true;
bool hasSize = true;
int packetSize = packetData.Length - 5;
byte bitfield = 0;
if (newPacketId == packetLastId)
{
hasId = false;
bitfield |= 1;
}
else
{
hasId = true;
}
int packetNetIdDiff = newPacketNetId - packetLastNetId;
if (packetNetIdDiff <= SByte.MaxValue && packetNetIdDiff >= SByte.MinValue)
{
hasNetId = false;
bitfield |= 2;
}
else
{
hasNetId = true;
}
if (packetSize < 63)
{
hasSize = false;
bitfield |= (byte)((byte)packetSize << 2);
}
else
{
hasSize = true;
bitfield |= (63 << 2);
}
writer.WriteByte(bitfield);
if (hasId)
{
writer.WriteByte(newPacketId);
}
if (hasNetId)
{
writer.WriteInt32(newPacketNetId);
}
else
{
writer.WriteSByte((SByte)packetNetIdDiff);
}
if (hasSize)
{
writer.WriteByte((byte)packetSize);
}
byte[] remainData = new byte[packetSize];
Buffer.BlockCopy(packetData, 5, remainData, 0, packetSize);
writer.WriteBytes(remainData);
}
packetLastId = newPacketId;
packetLastNetId = newPacketNetId;
}
}
public BatchPacket(PacketReader reader, ChannelID channel)
{
int count = reader.ReadByte();
long totalSize = reader.Stream.Length - 2;
if (totalSize < 1 || count == 0)
{
return;
}
byte packetSize = reader.ReadByte();
if (packetSize < 5)
{
throw new IOException("Too small packet in batch!");
}
byte packetLastID = reader.ReadByte();
int packetLastNetID = reader.ReadInt32();
byte[] packetData = reader.ReadBytes(packetSize - 5);
using (var stream = new MemoryStream())
{
using (var packetWriter = new PacketWriter(stream, true))
{
packetWriter.WriteByte(packetLastID);
packetWriter.WriteInt32(packetLastNetID);
packetWriter.WriteBytes(packetData);
}
stream.Seek(0, SeekOrigin.Begin);
using (var packetReader = new PacketReader(stream, true))
{
var packet = reader.ReadPacket(channel);
Packets.Add(packet);
}
}
for (int i = 1; i < count; i++)
{
byte bitfield = reader.ReadByte();
if ((bitfield & 1) == 0) //if this is true re-use old packetID
{
packetLastID = reader.ReadByte();
}
if ((bitfield & 2) != 0)
{
packetLastNetID += reader.ReadSByte();
}
else
{
packetLastNetID = reader.ReadInt32();
}
packetSize = (byte)(bitfield >> 2);
if (packetSize == 63)
{
packetSize = reader.ReadByte();
}
packetData = reader.ReadBytes(packetSize);
using (var stream = new MemoryStream())
{
using (var packetWriter = new PacketWriter(stream, true))
{
packetWriter.WriteByte(packetLastID);
packetWriter.WriteInt32(packetLastNetID);
packetWriter.WriteBytes(packetData);
}
stream.Seek(0, SeekOrigin.Begin);
using (var packetReader = new PacketReader(stream, true))
{
var packet = reader.ReadPacket(channel);
Packets.Add(packet);
}
}
}
}
public void Write(PacketWriter writer)
{
WriteHeader(writer);
WriteBody(writer);
writer.WriteBytes(ExtraBytes);
}
