netplay.cpp

著名SFC模拟器Snes9x的源代码。

                    S9xNPSendReady (NP_CLNT_RECEIVED_ROM_IMAGE);
                break;
            case NP_SERV_SRAM_DATA:
#ifdef NP_DEBUG
                printf ("CLIENT: SRAM_DATA received @%ld\n", S9xGetMilliTime () - START);
#endif
                S9xNPDiscardHeartbeats ();
                S9xNPGetSRAMData (len - 7);
                break;
            case NP_SERV_FREEZE_FILE:
#ifdef NP_DEBUG
                printf ("CLIENT: FREEZE_FILE received @%ld\n", S9xGetMilliTime () - START);
#endif
                S9xNPDiscardHeartbeats ();
                S9xNPGetFreezeFile (len - 7);
                S9xNPResetJoypadReadPos ();
                S9xNPSendReady ();
                break;
            default:
#ifdef NP_DEBUG
                printf ("CLIENT: UNKNOWN received @%ld\n", S9xGetMilliTime () - START);
#endif
                S9xNPDisconnect ();
                return (FALSE);
	    }
	}
    }

    S9xNPDisconnect ();
    return (FALSE);
}

bool8 S9xNPLoadROMDialog (const char *rom_name)
{
    NetPlay.Answer = FALSE;

#ifdef __WIN32__
    ResetEvent (NetPlay.ReplyEvent); 

#ifdef NP_DEBUG
    printf ("CLIENT: Asking GUI thread to open ROM load dialog...\n");
#endif

    PostMessage (GUI.hWnd, WM_USER + 3, (uint32) rom_name, (uint32) rom_name);

#ifdef NP_DEBUG
    printf ("CLIENT: Waiting for reply from GUI thread...\n");
#endif

    WaitForSingleObject (NetPlay.ReplyEvent, INFINITE);

#ifdef NP_DEBUG
    printf ("CLIENT: Got reply from GUI thread (%d)\n", NetPlay.Answer);
#endif
#endif

    return (NetPlay.Answer);
}

bool8 S9xNPLoadROM (uint32 len)
{
    uint8 *data = new uint8 [len];
    
    S9xNPSetAction ("Receiving ROM name...");
    if (!S9xNPGetData (NetPlay.Socket, data, len))
    {
        S9xNPSetError ("Error while receiving ROM name.");
        delete data;
        S9xNPDisconnect ();
        return (FALSE);
    }
    
    S9xNPSetAction ("Opening LoadROM dialog...");
    if (!S9xNPLoadROMDialog ((char *) data))
    {
        S9xNPSetError ("Disconnected from NetPlay server because you are playing a different game!");
        delete data;
        S9xNPDisconnect ();
        return (FALSE);
    }
    delete data;
    return (TRUE);
}

bool8 S9xNPGetROMImage (uint32 len)
{
    uint8 rom_info [5];

    S9xNPSetAction ("Receiving ROM information...");
    if (!S9xNPGetData (NetPlay.Socket, rom_info, 5))
    {
        S9xNPSetError ("Error while receiving ROM information.");
        S9xNPDisconnect ();
        return (FALSE);
    }
    uint32 CalculatedSize = READ_LONG (&rom_info [1]);
#ifdef NP_DEBUG
    printf ("CLIENT: Hi-ROM: %s, Size: %04x\n", rom_info [0] ? "Y" : "N", CalculatedSize);
#endif
    if (CalculatedSize + 5 >= len || 
        CalculatedSize >= CMemory::MAX_ROM_SIZE)
    {
        S9xNPSetError ("Size error in ROM image data received from server.");
        S9xNPDisconnect ();
        return (FALSE);
    }
    
    Memory.HiROM = rom_info [0];
    Memory.LoROM = !Memory.HiROM;
    Memory.HeaderCount = 0;
    Memory.CalculatedSize = CalculatedSize;

    // Load up ROM image
#ifdef NP_DEBUG
    printf ("CLIENT: Receiving ROM image @%ld...\n", S9xGetMilliTime () - START);
#endif
    S9xNPSetAction ("Receiving ROM image...");
    if (!S9xNPGetData (NetPlay.Socket, Memory.ROM, Memory.CalculatedSize))
    {
        S9xNPSetError ("Error while receiving ROM image from server.");
        Settings.StopEmulation = TRUE; 
        S9xNPDisconnect ();
        return (FALSE);
    }
#ifdef NP_DEBUG
    printf ("CLIENT: Receiving ROM filename @%ld...\n", S9xGetMilliTime () - START);
#endif
    S9xNPSetAction ("Receiving ROM filename...");
    uint32 filename_len = len - Memory.CalculatedSize - 5;
    if (filename_len > _MAX_PATH ||
        !S9xNPGetData (NetPlay.Socket, (uint8 *) Memory.ROMFilename, filename_len))
    {
        S9xNPSetError ("Error while receiving ROM filename from server.");
        S9xNPDisconnect ();
        Settings.StopEmulation = TRUE;
        return (FALSE);
    }
    Memory.InitROM (FALSE);
    S9xReset ();
    S9xNPResetJoypadReadPos ();
    Settings.StopEmulation = FALSE;

#ifdef __WIN32__
    PostMessage (GUI.hWnd, WM_NULL, 0, 0);
#endif
    
    return (TRUE);
}

void S9xNPGetSRAMData (uint32 len)
{
    if (len > 0x10000)
    {
        S9xNPSetError ("Length error in S-RAM data received from server.");
        S9xNPDisconnect ();
        return;
    }
    S9xNPSetAction ("Receiving S-RAM data...");
    if (len > 0 && !S9xNPGetData (NetPlay.Socket, ::SRAM, len))
    {
        S9xNPSetError ("Error while receiving S-RAM data from server.");
        S9xNPDisconnect ();
    }
}

void S9xNPGetFreezeFile (uint32 len)
{
    uint8 frame_count [4];

#ifdef NP_DEBUG
    printf ("CLIENT: Receiving freeze file information @%ld...\n", S9xGetMilliTime () - START);
#endif
    S9xNPSetAction ("Receiving freeze file information...");
    if (!S9xNPGetData (NetPlay.Socket, frame_count, 4))
    {
        S9xNPSetError ("Error while receiving freeze file information from server.");
        S9xNPDisconnect ();
        return;
    }
    NetPlay.FrameCount = READ_LONG (frame_count);

#ifdef NP_DEBUG
    printf ("CLIENT: Receiving freeze file @%ld...\n", S9xGetMilliTime () - START);
#endif
    S9xNPSetAction ("Receiving freeze file...");
    uint8 *data = new uint8 [len];
    if (!S9xNPGetData (NetPlay.Socket, data, len - 4))
    {
        S9xNPSetError ("Error while receiving freeze file from server.");
        S9xNPDisconnect ();
        delete data;
        return;
    }
    char fname [L_tmpnam];
    FILE *tmp;
    if (tmpnam (fname))
    {
        if ((tmp = fopen (fname, "wb")))
        {
            if (fwrite (data, 1, len, tmp) == len)
            {
                fclose (tmp);
                if (!S9xUnfreezeGame (fname))
                    S9xNPSetError ("Unable to load freeze file just received.");
            }
            else
                fclose (tmp);
        }
        remove (fname);
    }
    delete data;
}

uint32 S9xNPGetJoypad (int which1)
{
    if (Settings.NetPlay && which1 < 5)
	return (NetPlay.Joypads [NetPlay.JoypadReadInd][which1]);

    return (0);
}

void S9xNPStepJoypadHistory ()
{
    if ((NetPlay.JoypadReadInd + 1) % NP_JOYPAD_HIST_SIZE != NetPlay.JoypadWriteInd)
    {
        NetPlay.JoypadReadInd = (NetPlay.JoypadReadInd + 1) % NP_JOYPAD_HIST_SIZE;
        if (NetPlay.FrameCount != NetPlay.Frame [NetPlay.JoypadReadInd])
        {
            S9xNPSetWarning ("This Snes9X session may be out of sync with the server.");
#ifdef NP_DEBUG
            printf ("*** CLIENT: client out of sync with server (%d, %d) @%ld\n", NetPlay.FrameCount, NetPlay.Frame [NetPlay.JoypadReadInd], S9xGetMilliTime () - START);
#endif
        }
    }
    else
    {
#ifdef NP_DEBUG
        printf ("*** CLIENT: S9xNPStepJoypadHistory NOT OK@%ld\n", S9xGetMilliTime () - START);
#endif
    }
}


void S9xNPResetJoypadReadPos ()
{
#ifdef NP_DEBUG
    printf ("CLIENT: ResetJoyReadPos @%ld\n", S9xGetMilliTime () - START); fflush (stdout);
#endif
    NetPlay.JoypadWriteInd = 0;
    NetPlay.JoypadReadInd = NP_JOYPAD_HIST_SIZE - 1;
    for (int h = 0; h < NP_JOYPAD_HIST_SIZE; h++)
        memset ((void *) &NetPlay.Joypads [h], 0, sizeof (NetPlay.Joypads [0]));
}

bool8 S9xNPSendJoypadUpdate (uint32 joypad)
{
    uint8 data [7];
    uint8 *ptr = data;

    *ptr++ = NP_CLNT_MAGIC;
    *ptr++ = NetPlay.MySequenceNum++;
    *ptr++ = NP_CLNT_JOYPAD;

    joypad |= 0x80000000;

    WRITE_LONG (ptr, joypad);
    if (!S9xNPSendData (NetPlay.Socket, data, 7))
    {
        S9xNPSetError ("Error while sending joypad data server.");
	S9xNPDisconnect ();
	return (FALSE);
    }
    return (TRUE);
}

void S9xNPDisconnect ()
{
    close (NetPlay.Socket);
    NetPlay.Socket = -1;
    NetPlay.Connected = FALSE;
    Settings.NetPlay = FALSE;
}

bool8 S9xNPSendData (int socket, const uint8 *data, int length)
{
    int len = length;
    const uint8 *ptr = data;

    NetPlay.PercentageComplete = 0;

    do
    {
        if (NetPlay.Abort)
            return (FALSE);

        int num_bytes = len;

        // Write the data in small chunks, allowing this thread to spot an
        // abort request from another thread.
        if (num_bytes > 512)
            num_bytes = 512;

	int sent = write (socket, (char *) ptr, num_bytes);
	if (sent < 0)
	{
	    if (errno == EINTR 
#ifdef EAGAIN
		|| errno == EAGAIN
#endif
#ifdef EWOULDBLOCK
		|| errno == EWOULDBLOCK
#endif
		)
            {
#ifdef NP_DEBUG
                printf ("CLIENT: EINTR, EAGAIN or EWOULDBLOCK while sending data @%ld\n", S9xGetMilliTime () - START);
#endif
		continue;
            }
	    return (FALSE);
	}
	else
	if (sent == 0)
	    return (FALSE);
	len -= sent;
	ptr += sent;

        NetPlay.PercentageComplete = (uint8) (((length - len) * 100) / length);
    } while (len > 0);

    return (TRUE);
}

bool8 S9xNPGetData (int socket, uint8 *data, int length)
{
    int len = length;
    uint8 *ptr = data;
    int chunk = length / 50;

    if (chunk < 1024)
        chunk = 1024;

    NetPlay.PercentageComplete = 0;
    do
    {
        if (NetPlay.Abort)
            return (FALSE);

        int num_bytes = len;

        // Read the data in small chunks, allowing this thread to spot an
        // abort request from another thread.
        if (num_bytes > chunk)
            num_bytes = chunk;

        int got = read (socket, (char *) ptr, num_bytes);
        if (got < 0)
        {
	    if (errno == EINTR
#ifdef EAGAIN
		|| errno == EAGAIN
#endif
#ifdef EWOULDBLOCK
		|| errno == EWOULDBLOCK
#endif
#ifdef WSAEWOULDBLOCK
                || errno == WSAEWOULDBLOCK
#endif
		)
            {
#ifdef NP_DEBUG
                printf ("CLIENT: EINTR, EAGAIN or EWOULDBLOCK while receiving data @%ld\n", S9xGetMilliTime () - START);
#endif
		continue;
            }
#ifdef WSAEMSGSIZE
            if (errno != WSAEMSGSIZE)
                return (FALSE);
            else
            {
                got = num_bytes;
#ifdef NP_DEBUG
                printf ("CLIENT: WSAEMSGSIZE, actual bytes %d while receiving data @%ld\n", got, S9xGetMilliTime () - START);
#endif
            }
#else
            return (FALSE);
#endif
        }
        else
        if (got == 0)
            return (FALSE);

        len -= got;
        ptr += got;

        if (!Settings.NetPlayServer && length > 1024)
        {
            NetPlay.PercentageComplete = (uint8) (((length - len) * 100) / length);
#ifdef __WIN32__
            PostMessage (GUI.hWnd, WM_USER, NetPlay.PercentageComplete, 
                         NetPlay.PercentageComplete);
            Sleep (0);
#endif
        }
            
    } while (len > 0);

    return (TRUE);
}

bool8 S9xNPInitialise ()
{
    static bool8 initialised = FALSE;

#ifdef __WIN32__
    if (!initialised)
    {
        initialised = TRUE;
        WSADATA data;

#ifdef NP_DEBUG
        START = S9xGetMilliTime ();

        printf ("CLIENT/SERVER: Initialising WinSock @%ld\n", S9xGetMilliTime () - START);
#endif
        S9xNPSetAction ("Initialising Windows sockets interface...");
        if (WSAStartup (MAKEWORD (1, 0), &data) != 0)
        {
            S9xNPSetError ("Call to init Windows sockets failed. Do you have WinSock2 installed?");
            return (FALSE); 
        }
    }
#endif
    return (TRUE); 
}

#endif

void S9xNPDiscardHeartbeats ()
{
    // Discard any pending heartbeats and wait for any frame that is currently
    // being emulated to complete.
#ifdef NP_DEBUG
    printf ("CLIENT: DiscardHeartbeats @%ld, finished @", S9xGetMilliTime () - START);
    fflush (stdout);
#endif

#ifdef __WIN32__
    while (WaitForSingleObject (GUI.ClientSemaphore, 200) == WAIT_OBJECT_0)
        ;
#endif

#ifdef NP_DEBUG
    printf ("%ld\n", S9xGetMilliTime () - START);
#endif
    NetPlay.Waiting4EmulationThread = FALSE;
}

void S9xNPSetAction (const char *action, bool8 force)
{
    if (force || !Settings.NetPlayServer)
    {
        strncpy (NetPlay.ActionMsg, action, NP_MAX_ACTION_LEN - 1);
        NetPlay.ActionMsg [NP_MAX_ACTION_LEN - 1] = 0;
#ifdef __WIN32__
        PostMessage (GUI.hWnd, WM_USER, 0, 0);
        Sleep (0);
#endif
    }
}

void S9xNPSetError (const char *error)
{
    strncpy (NetPlay.ErrorMsg, error, NP_MAX_ACTION_LEN - 1);
    NetPlay.ErrorMsg [NP_MAX_ACTION_LEN - 1] = 0;
#ifdef __WIN32
    PostMessage (GUI.hWnd, WM_USER + 1, 0, 0);
    Sleep (0);
#endif
}

void S9xNPSetWarning (const char *warning)
{
    strncpy (NetPlay.WarningMsg, warning, NP_MAX_ACTION_LEN - 1);
    NetPlay.WarningMsg [NP_MAX_ACTION_LEN - 1] = 0;
#ifdef __WIN32__
    PostMessage (GUI.hWnd, WM_USER + 2, 0, 0);
    Sleep (0);
#endif
}