Mine

public abstract class Packet
	{
		protected PacketWriter m_Stream;
		private int m_PacketID;
		private int m_Length;

		public int PacketID
		{
			get{ return m_PacketID; }
		}

		public Packet( int packetID )
		{
			m_PacketID = packetID;

			PacketProfile prof = PacketProfile.GetOutgoingProfile( (byte)packetID );

			if ( prof != null )
				prof.RegConstruct();
		}

		public void EnsureCapacity( int length )
		{
			m_Stream = PacketWriter.CreateInstance( length );// new PacketWriter( length );
			m_Stream.Write( (byte) m_PacketID );
			m_Stream.Write( (short) 0 );
		}

		public Packet( int packetID, int length )
		{
			m_PacketID = packetID;
			m_Length = length;

			m_Stream = PacketWriter.CreateInstance( length );// new PacketWriter( length );
			m_Stream.Write( (byte) packetID );

			PacketProfile prof = PacketProfile.GetOutgoingProfile( (byte)packetID );

			if ( prof != null )
				prof.RegConstruct();
		}

		public PacketWriter UnderlyingStream
		{
			get
			{
				return m_Stream;
			}
		}

		private byte[] m_CompiledBuffer;

		public byte[] Compile( bool compress )
		{
			if ( m_CompiledBuffer == null )
				InternalCompile( compress );

			return m_CompiledBuffer;
		}

		private void InternalCompile( bool compress )
		{
			if ( m_Length == 0 )
			{
				long streamLen = m_Stream.Length;

				m_Stream.Seek( 1, SeekOrigin.Begin );
				m_Stream.Write( (ushort) streamLen );
			}
			else if ( m_Stream.Length != m_Length )
			{
				int diff = (int)m_Stream.Length - m_Length;

				Console.WriteLine( "Packet: 0x{0:X2}: Bad packet length! ({1}{2} bytes)", m_PacketID, diff >= 0 ? "+" : "", diff );
			}

			MemoryStream ms = m_Stream.UnderlyingStream;

			int length;

			m_CompiledBuffer = ms.GetBuffer();
			length = (int)ms.Length;

			if ( compress )
			{
				try
				{
					Compression.Compress( m_CompiledBuffer, length, out m_CompiledBuffer, out length );
				}
				catch ( IndexOutOfRangeException )
				{
					Console.WriteLine( "Warning: Compression buffer overflowed on packet 0x{0:X2} ('{1}') (length={2})", m_PacketID, GetType().Name, length );

					m_CompiledBuffer = null;
				}
			}

			if ( m_CompiledBuffer != null )
			{
				byte[] old = m_CompiledBuffer;

				m_CompiledBuffer = new byte[length];

				Buffer.BlockCopy( old, 0, m_CompiledBuffer, 0, length );
			}

			PacketWriter.ReleaseInstance( m_Stream );
			m_Stream = null;
		}
	}