public static int WritePacketHeader(byte[] packetBuffer, byte channelID, ushort sequence, ushort ack, uint ackBits)
{
using (ByteArrayReaderWriter byteArrayReaderWriter = ByteArrayReaderWriter.Get(packetBuffer))
{
byte b = 0;
if ((ackBits & 0xFF) != 255)
{
b = (byte)(b | 2);
}
if ((ackBits & 0xFF00) != 65280)
{
b = (byte)(b | 4);
}
if ((ackBits & 0xFF0000) != 16711680)
{
b = (byte)(b | 8);
}
if (((int)ackBits & -16777216) != -16777216)
{
b = (byte)(b | 0x10);
}
int num = sequence - ack;
if (num < 0)
{
num += 65536;
}
if (num <= 255)
{
b = (byte)(b | 0x20);
}
byteArrayReaderWriter.Write(b);
byteArrayReaderWriter.Write(channelID);
byteArrayReaderWriter.Write(sequence);
if (num <= 255)
{
byteArrayReaderWriter.Write((byte)num);
}
else
{
byteArrayReaderWriter.Write(ack);
}
if ((ackBits & 0xFF) != 255)
{
byteArrayReaderWriter.Write((byte)(ackBits & 0xFF));
}
if ((ackBits & 0xFF00) != 65280)
{
byteArrayReaderWriter.Write((byte)((ackBits & 0xFF00) >> 8));
}
if ((ackBits & 0xFF0000) != 16711680)
{
byteArrayReaderWriter.Write((byte)((ackBits & 0xFF0000) >> 16));
}
if (((int)ackBits & -16777216) != -16777216)
{
byteArrayReaderWriter.Write((byte)((uint)((int)ackBits & -16777216) >> 24));
}
return((int)byteArrayReaderWriter.WritePosition);
}
}
public static void Release(ByteArrayReaderWriter reader)
{
lock (readerPool)
{
readerPool.Enqueue(reader);
}
}
public static int WriteAckPacket(byte[] packetBuffer, byte channelID, ushort ack, uint ackBits)
{
using (var writer = ByteArrayReaderWriter.Get(packetBuffer))
{
byte prefixByte = 0x80; // top bit set, indicates ack packet
if ((ackBits & 0x000000FF) != 0x000000FF)
{
prefixByte |= (1 << 1);
}
if ((ackBits & 0x0000FF00) != 0x0000FF00)
{
prefixByte |= (1 << 2);
}
if ((ackBits & 0x00FF0000) != 0x00FF0000)
{
prefixByte |= (1 << 3);
}
if ((ackBits & 0xFF000000) != 0xFF000000)
{
prefixByte |= (1 << 4);
}
writer.Write(prefixByte);
writer.Write(channelID);
writer.Write(ack);
if ((ackBits & 0x000000FF) != 0x000000FF)
{
writer.Write((byte)((ackBits & 0x000000FF)));
}
if ((ackBits & 0x0000FF00) != 0x0000FF00)
{
writer.Write((byte)((ackBits & 0x0000FF00) >> 8));
}
if ((ackBits & 0x00FF0000) != 0x00FF0000)
{
writer.Write((byte)((ackBits & 0x00FF0000) >> 16));
}
if ((ackBits & 0xFF000000) != 0xFF000000)
{
writer.Write((byte)((ackBits & 0xFF000000) >> 24));
}
return((int)writer.WritePosition);
}
}
public static ByteArrayReaderWriter Get(byte[] byteArray)
{
ByteArrayReaderWriter byteArrayReaderWriter = null;
lock (readerPool)
{
byteArrayReaderWriter = ((readerPool.Count <= 0) ? new ByteArrayReaderWriter() : readerPool.Dequeue());
}
byteArrayReaderWriter.SetStream(byteArray);
return(byteArrayReaderWriter);
}
public static int ReadFragmentHeader(byte[] packetBuffer, int offset, int bufferLength, int maxFragments, int fragmentSize, out int fragmentID, out int numFragments, out int fragmentBytes, out ushort sequence, out ushort ack, out uint ackBits, out byte channelID)
{
if (bufferLength < 6)
{
throw new FormatException("Buffer too small for packet header");
}
using (ByteArrayReaderWriter byteArrayReaderWriter = ByteArrayReaderWriter.Get(packetBuffer))
{
byte b = byteArrayReaderWriter.ReadByte();
if ((b & 1) != 1)
{
throw new FormatException("Packet header indicates non-fragment packet");
}
channelID = byteArrayReaderWriter.ReadByte();
sequence = byteArrayReaderWriter.ReadUInt16();
fragmentID = byteArrayReaderWriter.ReadByte();
numFragments = byteArrayReaderWriter.ReadByte() + 1;
if (numFragments > maxFragments)
{
throw new FormatException("Packet header indicates fragments outside of max range");
}
if (fragmentID >= numFragments)
{
throw new FormatException("Packet header indicates fragment ID outside of fragment count");
}
fragmentBytes = bufferLength - 6;
ushort sequence2 = 0;
ushort ack2 = 0;
uint ackBits2 = 0u;
byte channelID2 = 0;
if (fragmentID == 0)
{
int num = ReadPacketHeader(packetBuffer, 6, bufferLength, out channelID2, out sequence2, out ack2, out ackBits2);
if (sequence2 != sequence)
{
throw new FormatException("Bad packet sequence in fragment");
}
fragmentBytes = bufferLength - num - 6;
}
ack = ack2;
ackBits = ackBits2;
if (fragmentBytes > fragmentSize)
{
throw new FormatException("Fragment bytes remaining > indicated fragment size");
}
if (fragmentID != numFragments - 1 && fragmentBytes != fragmentSize)
{
throw new FormatException("Fragment size invalid");
}
return((int)byteArrayReaderWriter.ReadPosition - offset);
}
}
/// <summary>
/// Get a reader/writer for the given byte array
/// </summary>
public static ByteArrayReaderWriter Get(byte[] byteArray)
{
ByteArrayReaderWriter reader = null;
if (readerPool.Count > 0)
{
reader = readerPool.Dequeue();
}
else
{
reader = new ByteArrayReaderWriter();
}
reader.SetStream(byteArray);
return(reader);
}
public static int WriteAckPacket(byte[] packetBuffer, byte channelID, ushort ack, uint ackBits)
{
using (ByteArrayReaderWriter byteArrayReaderWriter = ByteArrayReaderWriter.Get(packetBuffer))
{
byte b = 128;
if ((ackBits & 0xFF) != 255)
{
b = (byte)(b | 2);
}
if ((ackBits & 0xFF00) != 65280)
{
b = (byte)(b | 4);
}
if ((ackBits & 0xFF0000) != 16711680)
{
b = (byte)(b | 8);
}
if (((int)ackBits & -16777216) != -16777216)
{
b = (byte)(b | 0x10);
}
byteArrayReaderWriter.Write(b);
byteArrayReaderWriter.Write(channelID);
byteArrayReaderWriter.Write(ack);
if ((ackBits & 0xFF) != 255)
{
byteArrayReaderWriter.Write((byte)(ackBits & 0xFF));
}
if ((ackBits & 0xFF00) != 65280)
{
byteArrayReaderWriter.Write((byte)((ackBits & 0xFF00) >> 8));
}
if ((ackBits & 0xFF0000) != 16711680)
{
byteArrayReaderWriter.Write((byte)((ackBits & 0xFF0000) >> 16));
}
if (((int)ackBits & -16777216) != -16777216)
{
byteArrayReaderWriter.Write((byte)((uint)((int)ackBits & -16777216) >> 24));
}
return((int)byteArrayReaderWriter.WritePosition);
}
}
public static int WritePacketHeader(byte[] packetBuffer, byte channelID, ushort sequence, ushort ack, uint ackBits)
{
using (var writer = ByteArrayReaderWriter.Get(packetBuffer))
{
byte prefixByte = 0;
if ((ackBits & 0x000000FF) != 0x000000FF)
{
prefixByte |= (1 << 1);
}
if ((ackBits & 0x0000FF00) != 0x0000FF00)
{
prefixByte |= (1 << 2);
}
if ((ackBits & 0x00FF0000) != 0x00FF0000)
{
prefixByte |= (1 << 3);
}
if ((ackBits & 0xFF000000) != 0xFF000000)
{
prefixByte |= (1 << 4);
}
int sequenceDiff = sequence - ack;
if (sequenceDiff < 0)
{
sequenceDiff += 65536;
}
if (sequenceDiff <= 255)
{
prefixByte |= (1 << 5);
}
writer.Write(prefixByte);
writer.Write(channelID);
writer.Write(sequence);
if (sequenceDiff <= 255)
{
writer.Write((byte)sequenceDiff);
}
else
{
writer.Write(ack);
}
if ((ackBits & 0x000000FF) != 0x000000FF)
{
writer.Write((byte)((ackBits & 0x000000FF)));
}
if ((ackBits & 0x0000FF00) != 0x0000FF00)
{
writer.Write((byte)((ackBits & 0x0000FF00) >> 8));
}
if ((ackBits & 0x00FF0000) != 0x00FF0000)
{
writer.Write((byte)((ackBits & 0x00FF0000) >> 16));
}
if ((ackBits & 0xFF000000) != 0xFF000000)
{
writer.Write((byte)((ackBits & 0xFF000000) >> 24));
}
return((int)writer.WritePosition);
}
}
public static int ReadPacketHeader(byte[] packetBuffer, int offset, int bufferLength, out byte channelID, out ushort sequence, out ushort ack, out uint ackBits)
{
if (bufferLength < 4)
{
throw new FormatException("Buffer too small for packet header");
}
using (var reader = ByteArrayReaderWriter.Get(packetBuffer))
{
reader.SeekRead(offset);
byte prefixByte = reader.ReadByte();
if ((prefixByte & 1) != 0)
{
throw new InvalidOperationException("Header does not indicate regular packet");
}
channelID = reader.ReadByte();
// ack packets don't have sequence numbers
if ((prefixByte & 0x80) == 0)
{
sequence = reader.ReadUInt16();
}
else
{
sequence = 0;
}
if ((prefixByte & (1 << 5)) != 0)
{
if (bufferLength < 2 + 1)
{
throw new FormatException("Buffer too small for packet header");
}
byte sequenceDiff = reader.ReadByte();
ack = (ushort)(sequence - sequenceDiff);
}
else
{
if (bufferLength < 2 + 2)
{
throw new FormatException("Buffer too small for packet header");
}
ack = reader.ReadUInt16();
}
int expectedBytes = 0;
for (int i = 0; i <= 4; i++)
{
if ((prefixByte & (1 << i)) != 0)
{
expectedBytes++;
}
}
if (bufferLength < (bufferLength - reader.ReadPosition) + expectedBytes)
{
throw new FormatException("Buffer too small for packet header");
}
ackBits = 0xFFFFFFFF;
if ((prefixByte & (1 << 1)) != 0)
{
ackBits &= 0xFFFFFF00;
ackBits |= reader.ReadByte();
}
if ((prefixByte & (1 << 2)) != 0)
{
ackBits &= 0xFFFF00FF;
ackBits |= (uint)(reader.ReadByte() << 8);
}
if ((prefixByte & (1 << 3)) != 0)
{
ackBits &= 0xFF00FFFF;
ackBits |= (uint)(reader.ReadByte() << 16);
}
if ((prefixByte & (1 << 4)) != 0)
{
ackBits &= 0x00FFFFFF;
ackBits |= (uint)(reader.ReadByte() << 24);
}
return((int)reader.ReadPosition - offset);
}
}
public static int ReadFragmentHeader(byte[] packetBuffer, int offset, int bufferLength, int maxFragments, int fragmentSize, out int fragmentID, out int numFragments, out int fragmentBytes,
out ushort sequence, out ushort ack, out uint ackBits, out byte channelID)
{
if (bufferLength < Defines.FRAGMENT_HEADER_BYTES)
{
throw new FormatException("Buffer too small for packet header");
}
using (var reader = ByteArrayReaderWriter.Get(packetBuffer))
{
byte prefixByte = reader.ReadByte();
if (prefixByte != 1)
{
throw new FormatException("Packet header indicates non-fragment packet");
}
channelID = reader.ReadByte();
sequence = reader.ReadUInt16();
fragmentID = reader.ReadByte();
numFragments = reader.ReadByte() + 1;
if (numFragments > maxFragments)
{
throw new FormatException("Packet header indicates fragments outside of max range");
}
if (fragmentID >= numFragments)
{
throw new FormatException("Packet header indicates fragment ID outside of fragment count");
}
fragmentBytes = bufferLength - Defines.FRAGMENT_HEADER_BYTES;
ushort packetSequence = 0;
ushort packetAck = 0;
uint packetAckBits = 0;
byte packetChannelID = 0;
if (fragmentID == 0)
{
int packetHeaderBytes = ReadPacketHeader(packetBuffer, Defines.FRAGMENT_HEADER_BYTES, bufferLength, out packetChannelID, out packetSequence, out packetAck, out packetAckBits);
if (packetSequence != sequence)
{
throw new FormatException("Bad packet sequence in fragment");
}
fragmentBytes = bufferLength - packetHeaderBytes - Defines.FRAGMENT_HEADER_BYTES;
}
ack = packetAck;
ackBits = packetAckBits;
if (fragmentBytes > fragmentSize)
{
throw new FormatException("Fragment bytes remaining > indicated fragment size");
}
if (fragmentID != numFragments - 1 && fragmentBytes != fragmentSize)
{
throw new FormatException("Fragment size invalid");
}
return((int)reader.ReadPosition - offset);
}
}
public static int ReadPacketHeader(byte[] packetBuffer, int offset, int bufferLength, out byte channelID, out ushort sequence, out ushort ack, out uint ackBits)
{
if (bufferLength < 4)
{
throw new FormatException("Buffer too small for packet header");
}
using (ByteArrayReaderWriter byteArrayReaderWriter = ByteArrayReaderWriter.Get(packetBuffer))
{
byteArrayReaderWriter.SeekRead(offset);
byte b = byteArrayReaderWriter.ReadByte();
if ((b & 1) != 0)
{
throw new InvalidOperationException("Header does not indicate regular packet");
}
channelID = byteArrayReaderWriter.ReadByte();
if ((b & 0x80) == 0)
{
sequence = byteArrayReaderWriter.ReadUInt16();
}
else
{
sequence = 0;
}
if ((b & 0x20) != 0)
{
if (bufferLength < 3)
{
throw new FormatException("Buffer too small for packet header");
}
byte b2 = byteArrayReaderWriter.ReadByte();
ack = (ushort)(sequence - b2);
}
else
{
if (bufferLength < 4)
{
throw new FormatException("Buffer too small for packet header");
}
ack = byteArrayReaderWriter.ReadUInt16();
}
int num = 0;
for (int i = 0; i <= 4; i++)
{
if ((b & (1 << i)) != 0)
{
num++;
}
}
if (bufferLength < bufferLength - byteArrayReaderWriter.ReadPosition + num)
{
throw new FormatException("Buffer too small for packet header");
}
ackBits = uint.MaxValue;
if ((b & 2) != 0)
{
ackBits &= 4294967040u;
ackBits |= byteArrayReaderWriter.ReadByte();
}
if ((b & 4) != 0)
{
ackBits &= 4294902015u;
ackBits |= (uint)(byteArrayReaderWriter.ReadByte() << 8);
}
if ((b & 8) != 0)
{
ackBits &= 4278255615u;
ackBits |= (uint)(byteArrayReaderWriter.ReadByte() << 16);
}
if ((b & 0x10) != 0)
{
ackBits &= 16777215u;
ackBits |= (uint)(byteArrayReaderWriter.ReadByte() << 24);
}
return((int)byteArrayReaderWriter.ReadPosition - offset);
}
}