TShock/TShockAPI/PacketBufferer.cs

/*
TShock, a server mod for Terraria
Copyright (C) 2011 The TShock Team

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.IO;
using System.Net.Sockets;
using System.Text;
using Hooks;
using Terraria;

namespace TShockAPI
{
	public class PacketBufferer : IDisposable
	{
		/// <summary>
		/// Maximum number of bytes to send per update per socket
		/// </summary>
		public int BytesPerUpdate { get; set; }

		private PacketBuffer[] buffers = new PacketBuffer[Netplay.serverSock.Length];

		private int[] Bytes = new int[52];
		private int[] Packets = new int[52];
		private int[] Compressed = new int[52];

#if DEBUG_NET
		Command dump;
		Command flush;
#endif

		public PacketBufferer()
		{
			BytesPerUpdate = 0xFFFF;
			for (int i = 0; i < buffers.Length; i++)
				buffers[i] = new PacketBuffer();

#if DEBUG_NET
			dump = new Command("superadmin", Dump, "netdump");
			flush = new Command("superadmin", Flush, "netflush");
			Commands.ChatCommands.Add(dump);
			Commands.ChatCommands.Add(flush);
#endif

			NetHooks.SendBytes += ServerHooks_SendBytes;
			ServerHooks.SocketReset += ServerHooks_SocketReset;
			GameHooks.PostUpdate += GameHooks_Update;
		}

		~PacketBufferer()
		{
			Dispose(false);
		}

		public void Dispose()
		{
			Dispose(true);
			GC.SuppressFinalize(this);
		}

		protected virtual void Dispose(bool disposing)
		{
			if (disposing)
			{
#if DEBUG_NET
				Commands.ChatCommands.Remove(dump);
				Commands.ChatCommands.Remove(flush);
#endif
				NetHooks.SendBytes -= ServerHooks_SendBytes;
				ServerHooks.SocketReset -= ServerHooks_SocketReset;
				GameHooks.PostUpdate -= GameHooks_Update;
			}
		}

		private void Dump(CommandArgs args)
		{
			var sb = new StringBuilder();
			sb.AppendLine("{0,-25}{1,-25}{2,-25}{3}".SFormat("Name:", "Packets", "Bytes", "Compression"));
			for (int i = 1; i < Bytes.Length; i++)
			{
				sb.AppendLine("{0,-25}{1,-25}{2,-25}{3}".SFormat(Enum.GetName(typeof (PacketTypes), i) + ":", Packets[i], Bytes[i],
																 Compressed[i]));
			}
			File.WriteAllText(Path.Combine(TShock.SavePath, "dmp.txt"), sb.ToString());
		}

		private void Flush(CommandArgs args)
		{
			Bytes = new int[52];
			Packets = new int[52];
			Compressed = new int[52];
		}

		private void GameHooks_Update()
		{
			FlushAll();
		}

		public void FlushAll()
		{
			for (int i = 0; i < Netplay.serverSock.Length; i++)
			{
				Flush(Netplay.serverSock[i]);
			}
		}

		public bool Flush(ServerSock socket)
		{
			try
			{
				if (socket == null || !socket.active)
					return false;

				if (buffers[socket.whoAmI].Count < 1)
					return false;

				byte[] buff = buffers[socket.whoAmI].GetBytes(BytesPerUpdate);
				if (buff == null)
					return false;

				if (SendBytes(socket, buff))
				{
					buffers[socket.whoAmI].Pop(buff.Length);
					return true;
				}
			}
			catch (Exception e)
			{
				Log.ConsoleError(e.ToString());
			}
			return false;
		}


		private void ServerHooks_SocketReset(ServerSock socket)
		{
			buffers[socket.whoAmI] = new PacketBuffer();
		}

		public bool SendBytes(ServerSock socket, byte[] buffer)
		{
			return SendBytes(socket, buffer, 0, buffer.Length);
		}

		public void BufferBytes(ServerSock socket, byte[] buffer)
		{
			BufferBytes(socket, buffer, 0, buffer.Length);
		}

		public void BufferBytes(ServerSock socket, byte[] buffer, int offset, int count)
		{
			lock (buffers[socket.whoAmI])
			{
#if DEBUG_NET
				int size = (count - offset);
				var pt = buffer[offset + 4];

				Packets[pt]++;
				Bytes[pt] += size;
				Compressed[pt] += Compress(buffer, offset, count);
#endif
				using (var ms = new MemoryStream(buffer, offset, count))
				{
					buffers[socket.whoAmI].AddRange(ms.ToArray());
				}
			}
		}

		public bool SendBytes(ServerSock socket, byte[] buffer, int offset, int count)
		{
			try
			{
				if (socket.tcpClient.Client != null && socket.tcpClient.Client.Poll(0, SelectMode.SelectWrite))
				{
					if (Main.runningMono)
						socket.networkStream.Write(buffer, offset, count);
					else
						socket.tcpClient.Client.Send(buffer, offset, count, SocketFlags.None);
					return true;
				}
			}
			catch (ObjectDisposedException e)
			{
                Log.Warn(e.ToString());
			}
			catch (SocketException e)
			{
                Log.Warn(e.ToString());
			}
			catch (IOException e)
			{
                Log.Warn(e.ToString());
			}
			return false;
		}

		private void ServerHooks_SendBytes(ServerSock socket, byte[] buffer, int offset, int count, HandledEventArgs e)
		{
			e.Handled = true;
			BufferBytes(socket, buffer, offset, count);
		}

#if DEBUG_NET
		static int Compress(byte[] buffer, int offset, int count)
		{
			using (var ms = new MemoryStream())
			{
				using (var gzip = new GZipStream(ms, CompressionMode.Compress, true))
				{
					gzip.Write(buffer, offset, count);
				}
				return (int)ms.Length;
			}
		}
#endif
	}

	public class PacketBuffer : List<byte>
	{
		public byte[] GetBytes(int max)
		{
			lock (this)
			{
				if (this.Count < 1)
					return null;

				var ret = new byte[Math.Min(max, this.Count)];
				this.CopyTo(0, ret, 0, ret.Length);
				return ret;
			}
		}

		public void Pop(int count)
		{
			lock (this)
			{
				this.RemoveRange(0, count);
			}
		}
	}
}