First Commit

For Azeroth!

src/server/game/Server/WorldSocket.h

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+/*
+ * Copyright (C) 
+ * Copyright (C) 
+ *
+ * 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 2 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/>.
+ */
+
+/** \addtogroup u2w User to World Communication
+ * @{
+ * \file WorldSocket.h
+ * \author Derex <derex101@gmail.com>
+ */
+
+#ifndef _WORLDSOCKET_H
+#define _WORLDSOCKET_H
+
+#include <ace/Basic_Types.h>
+#include <ace/Synch_Traits.h>
+#include <ace/Svc_Handler.h>
+#include <ace/SOCK_Stream.h>
+#include <ace/Thread_Mutex.h>
+#include <ace/Guard_T.h>
+#include <ace/Unbounded_Queue.h>
+#include <ace/Message_Block.h>
+
+#if !defined (ACE_LACKS_PRAGMA_ONCE)
+#pragma once
+#endif /* ACE_LACKS_PRAGMA_ONCE */
+
+#include "Common.h"
+#include "AuthCrypt.h"
+
+class ACE_Message_Block;
+class WorldPacket;
+class WorldSession;
+
+/// Handler that can communicate over stream sockets.
+typedef ACE_Svc_Handler<ACE_SOCK_STREAM, ACE_NULL_SYNCH> WorldHandler;
+
+/**
+ * WorldSocket.
+ *
+ * This class is responsible for the communication with
+ * remote clients.
+ * Most methods return -1 on failure.
+ * The class uses reference counting.
+ *
+ * For output the class uses one buffer (64K usually) and
+ * a queue where it stores packet if there is no place on
+ * the queue. The reason this is done, is because the server
+ * does really a lot of small-size writes to it, and it doesn't
+ * scale well to allocate memory for every. When something is
+ * written to the output buffer the socket is not immediately
+ * activated for output (again for the same reason), there
+ * is 10ms celling (thats why there is Update() method).
+ * This concept is similar to TCP_CORK, but TCP_CORK
+ * uses 200ms celling. As result overhead generated by
+ * sending packets from "producer" threads is minimal,
+ * and doing a lot of writes with small size is tolerated.
+ *
+ * The calls to Update() method are managed by WorldSocketMgr
+ * and ReactorRunnable.
+ *
+ * For input, the class uses one 4096 bytes buffer on stack
+ * to which it does recv() calls. And then received data is
+ * distributed where its needed. 4096 matches pretty well the
+ * traffic generated by client for now.
+ *
+ * The input/output do speculative reads/writes (AKA it tryes
+ * to read all data available in the kernel buffer or tryes to
+ * write everything available in userspace buffer),
+ * which is ok for using with Level and Edge Triggered IO
+ * notification.
+ *
+ */
+class WorldSocket : public WorldHandler
+{
+    public:
+        WorldSocket (void);
+        virtual ~WorldSocket (void);
+
+        friend class WorldSocketMgr;
+
+        /// Mutex type used for various synchronizations.
+        typedef ACE_Thread_Mutex LockType;
+        typedef ACE_Guard<LockType> GuardType;
+
+        /// Check if socket is closed.
+        bool IsClosed (void) const;
+
+        /// Close the socket.
+        void CloseSocket (void);
+
+        /// Get address of connected peer.
+        const std::string& GetRemoteAddress (void) const;
+
+        /// Send A packet on the socket, this function is reentrant.
+        /// @param pct packet to send
+        /// @return -1 of failure
+        int SendPacket(const WorldPacket& pct);
+
+        /// Add reference to this object.
+        long AddReference (void);
+
+        /// Remove reference to this object.
+        long RemoveReference (void);
+
+        /// things called by ACE framework.
+
+        /// Called on open, the void* is the acceptor.
+        virtual int open (void *);
+
+        /// Called on failures inside of the acceptor, don't call from your code.
+        virtual int close (u_long);
+
+        /// Called when we can read from the socket.
+        virtual int handle_input (ACE_HANDLE = ACE_INVALID_HANDLE);
+
+        /// Called when the socket can write.
+        virtual int handle_output (ACE_HANDLE = ACE_INVALID_HANDLE);
+
+        /// Called when connection is closed or error happens.
+        virtual int handle_close (ACE_HANDLE = ACE_INVALID_HANDLE,
+            ACE_Reactor_Mask = ACE_Event_Handler::ALL_EVENTS_MASK);
+
+        /// Called by WorldSocketMgr/ReactorRunnable.
+        int Update (void);
+
+    private:
+        /// Helper functions for processing incoming data.
+        int handle_input_header (void);
+        int handle_input_payload (void);
+        int handle_input_missing_data (void);
+
+        /// Help functions to mark/unmark the socket for output.
+        /// @param g the guard is for m_OutBufferLock, the function will release it
+        int cancel_wakeup_output (GuardType& g);
+        int schedule_wakeup_output (GuardType& g);
+
+        /// Drain the queue if its not empty.
+        int handle_output_queue (GuardType& g);
+
+        /// process one incoming packet.
+        /// @param new_pct received packet, note that you need to delete it.
+        int ProcessIncoming (WorldPacket* new_pct);
+
+        /// Called by ProcessIncoming() on CMSG_AUTH_SESSION.
+        int HandleAuthSession (WorldPacket& recvPacket);
+
+        /// Called by ProcessIncoming() on CMSG_PING.
+        int HandlePing (WorldPacket& recvPacket);
+
+    private:
+        /// Time in which the last ping was received
+        ACE_Time_Value m_LastPingTime;
+
+        /// Keep track of over-speed pings, to prevent ping flood.
+        uint32 m_OverSpeedPings;
+
+        /// Address of the remote peer
+        std::string m_Address;
+
+        /// Class used for managing encryption of the headers
+        AuthCrypt m_Crypt;
+
+        /// Mutex lock to protect m_Session
+        LockType m_SessionLock;
+
+        /// Session to which received packets are routed
+        WorldSession* m_Session;
+
+        /// here are stored the fragments of the received data
+        WorldPacket* m_RecvWPct;
+
+        /// This block actually refers to m_RecvWPct contents,
+        /// which allows easy and safe writing to it.
+        /// It wont free memory when its deleted. m_RecvWPct takes care of freeing.
+        ACE_Message_Block m_RecvPct;
+
+        /// Fragment of the received header.
+        ACE_Message_Block m_Header;
+
+        /// Mutex for protecting output related data.
+        LockType m_OutBufferLock;
+
+        /// Buffer used for writing output.
+        ACE_Message_Block* m_OutBuffer;
+
+        /// Size of the m_OutBuffer.
+        size_t m_OutBufferSize;
+
+        /// True if the socket is registered with the reactor for output
+        bool m_OutActive;
+
+        uint32 m_Seed;
+
+};
+
+#endif  /* _WORLDSOCKET_H */
+
+/// @}
+