Handshakes.h

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//
// Handshakes.h
//
// Copyright (c) Shareaza Development Team, 2002-2005.
// This file is part of SHAREAZA (www.shareaza.com)
//
// Shareaza 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.
//
// Shareaza 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 Shareaza; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
//

// CHandshakes listens for remote computers that want to connect to us
// http://wiki.shareaza.com/static/Developers.Code.CHandshakes

// Make the compiler only include the lines here once, this is the same thing as pragma once
#if !defined(AFX_HANDSHAKES_H__2314A7BE_5C51_4F8E_A4C6_6059A7621AE0__INCLUDED_)
#define AFX_HANDSHAKES_H__2314A7BE_5C51_4F8E_A4C6_6059A7621AE0__INCLUDED_

// Only include the lines beneath this one once
#pragma once

// Tell the compiler that a class named CHandshake exists, and is defined in detail elsewhere
class CHandshake; // Lets methods defined here take and return pointers to CHandshake objects

class CHandshakes
{

public:

        // Make the CHandshakes object, and later, delete it
        CHandshakes();
        virtual ~CHandshakes();

public:

        // How many connections our listening socket has received, and how long they've been connected
        DWORD m_nStableCount; // The number of connections our listening socket has received
        DWORD m_tStableTime;  // The time at least one has been connected (do)

protected:

        // The listening socket
        SOCKET m_hSocket; // Our one listening socket
        HANDLE m_hThread; // This thread waits for remote computers to call the listening socket
        CEvent m_pWakeup; // Fire this event when a remote computer calls our listening socket

        // The list of CHandshake objects
        CPtrList         m_pList;    // The list of pointers to CHandshake objects
        CCriticalSection m_pSection; // Use to make sure only one thread accesses the list at a time

public:

        // Start and stop listening on the socket
        BOOL Listen();     // Listen on the socket
        void Disconnect(); // Stop listening

        // Connect to an IP, and determine if we are connected to one
        BOOL PushTo(IN_ADDR* pAddress, WORD nPort, DWORD nIndex = 0); // Connect to the given IP
        BOOL IsConnectedTo(IN_ADDR* pAddress);                        // Looks for the IP in the handshake objects list

protected:

        // Replace and remove CHandshake objects in the m_pList of them
        void Substitute(CHandshake* pOld, CHandshake* pNew); // Replace an old CHandshake object in the list with a new one
        void Remove(CHandshake* pHandshake);                 // Remove a CHandshake object from the list

protected:

        // Loop to listen for connections and accept them
        static UINT     ThreadStart(LPVOID pParam); // The thread that waits while the socket listens starts here
        void OnRun();                           // Accept incoming connections from remote computers
        void RunHandshakes();                   // Send and receive data with each remote computer in the list
        BOOL AcceptConnection();                // Accept a connection, making a new CHandshake object in the list for it
        void CreateHandshake(SOCKET hSocket, SOCKADDR_IN* pHost); // Make the new CHandshake object for the new connection
        void RunStableUpdate();                 // Update the discovery services (do)

        // Tell WSAAccept if we want to accept a connection from a computer that just called us
        static int CALLBACK AcceptCheck(IN LPWSABUF lpCallerId, IN LPWSABUF lpCallerData, IN OUT LPQOS lpSQOS, IN OUT LPQOS lpGQOS, IN LPWSABUF lpCalleeId, OUT LPWSABUF lpCalleeData, OUT GROUP FAR * g, IN DWORD dwCallbackData);

public:

        // Returns an iterator at the start of the list of handshake objects
        inline POSITION GetIterator() const
        {
                // Returns a MFC POSITION iterator, or null if the list is empty
                return m_pList.GetHeadPosition();
        }

        // Given a position in the handshake list, returns the next handshake object
        inline CHandshake* GetNext(POSITION& pos) const
        {
                // Returns the CHandshake object at the current position, and then moves the position iterator to the next one
                return (CHandshake*)m_pList.GetNext( pos ); // Does two things
        }

        // True if the socket is valid, false if its closed
        inline BOOL IsListening() const
        {
                // If the socket is not invalid, it is connected to the remote computer
                return m_hSocket != INVALID_SOCKET;
        }

        // Get complete access to CHandhsake member variables and methods (do)
        friend class CHandshake;
};

// When the program runs, it makes a single global CHandshakes object
extern CHandshakes Handshakes; // Access Handshakes externally here in Handshakes.h, even though it is defined in Handshakes.cpp

// End the group of lines to only include once, pragma once doesn't require an endif at the bottom
#endif // !defined(AFX_HANDSHAKES_H__2314A7BE_5C51_4F8E_A4C6_6059A7621AE0__INCLUDED_)

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