socket.cpp

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// A note on how events are processed, which is probably the most
// difficult thing to get working right while keeping the same API
// and functionality for all platforms.
//
// When GSocket detects an event, it calls wx_socket_callback, which in
// turn just calls wxSocketBase::OnRequest in the corresponding wxSocket
// object. OnRequest does some housekeeping, and if the event is to be
// propagated to the user, it creates a new wxSocketEvent object and
// posts it. The event is not processed immediately, but delayed with
// AddPendingEvent instead. This is necessary in order to decouple the
// event processing from wx_socket_callback; otherwise, subsequent IO
// calls made from the user event handler would fail, as gtk callbacks
// are not reentrant.
//
// Note that, unlike events, user callbacks (now deprecated) are _not_
// decoupled from wx_socket_callback and thus they suffer from a variety
// of problems. Avoid them where possible and use events instead.

extern "C"
void LINKAGEMODE wx_socket_callback(GSocket * WXUNUSED(socket),
                                    GSocketEvent notification,
                                    char *cdata)
{
  wxSocketBase *sckobj = (wxSocketBase *)cdata;

  sckobj->OnRequest((wxSocketNotify) notification);
}

void wxSocketBase::OnRequest(wxSocketNotify notification)
{
  // NOTE: We duplicate some of the code in _Wait, but this doesn't
  //   hurt. It has to be here because the (GSocket) event might arrive
  //   a bit delayed, and it has to be in _Wait as well because we don't
  //   know whether the Wait functions are being used.

  switch(notification)
  {
    case wxSOCKET_CONNECTION:
      m_establishing = false;
      m_connected = true;
      break;

    // If we are in the middle of a R/W operation, do not
    // propagate events to users. Also, filter 'late' events
    // which are no longer valid.

    case wxSOCKET_INPUT:
      if (m_reading || !m_socket->Select(GSOCK_INPUT_FLAG))
        return;
      break;

    case wxSOCKET_OUTPUT:
      if (m_writing || !m_socket->Select(GSOCK_OUTPUT_FLAG))
        return;
      break;

    case wxSOCKET_LOST:
      m_connected = false;
      m_establishing = false;
      break;

    default:
      break;
  }

  // Schedule the event

  wxSocketEventFlags flag = 0;
  wxUnusedVar(flag);
  switch (notification)
  {
    case GSOCK_INPUT:      flag = GSOCK_INPUT_FLAG; break;
    case GSOCK_OUTPUT:     flag = GSOCK_OUTPUT_FLAG; break;
    case GSOCK_CONNECTION: flag = GSOCK_CONNECTION_FLAG; break;
    case GSOCK_LOST:       flag = GSOCK_LOST_FLAG; break;
    default:
      wxLogWarning(_("wxSocket: unknown event!."));
      return;
  }

  if (((m_eventmask & flag) == flag) && m_notify)
  {
    if (m_handler)
    {
      wxSocketEvent event(m_id);
      event.m_event      = notification;
      event.m_clientData = m_clientData;
      event.SetEventObject(this);

      m_handler->AddPendingEvent(event);
    }
  }
}

void wxSocketBase::Notify(bool notify)
{
  m_notify = notify;
}

void wxSocketBase::SetNotify(wxSocketEventFlags flags)
{
  m_eventmask = flags;
}

void wxSocketBase::SetEventHandler(wxEvtHandler& handler, int id)
{
  m_handler = &handler;
  m_id      = id;
}

// --------------------------------------------------------------------------
// Pushback buffer
// --------------------------------------------------------------------------

void wxSocketBase::Pushback(const void *buffer, wxUint32 size)
{
  if (!size) return;

  if (m_unread == NULL)
    m_unread = malloc(size);
  else
  {
    void *tmp;

    tmp = malloc(m_unrd_size + size);
    memcpy((char *)tmp + size, m_unread, m_unrd_size);
    free(m_unread);

    m_unread = tmp;
  }

  m_unrd_size += size;

  memcpy(m_unread, buffer, size);
}

wxUint32 wxSocketBase::GetPushback(void *buffer, wxUint32 size, bool peek)
{
  if (!m_unrd_size)
    return 0;

  if (size > (m_unrd_size-m_unrd_cur))
    size = m_unrd_size-m_unrd_cur;

  memcpy(buffer, (char *)m_unread + m_unrd_cur, size);

  if (!peek)
  {
    m_unrd_cur += size;
    if (m_unrd_size == m_unrd_cur)
    {
      free(m_unread);
      m_unread = NULL;
      m_unrd_size = 0;
      m_unrd_cur  = 0;
    }
  }

  return size;
}


// ==========================================================================
// wxSocketServer
// ==========================================================================

// --------------------------------------------------------------------------
// Ctor
// --------------------------------------------------------------------------

wxSocketServer::wxSocketServer(wxSockAddress& addr_man,
                               wxSocketFlags flags)
              : wxSocketBase(flags, wxSOCKET_SERVER)
{
    wxLogTrace( wxTRACE_Socket, _T("Opening wxSocketServer") );

    m_socket = GSocket_new();

    if (!m_socket)
    {
        wxLogTrace( wxTRACE_Socket, _T("*** GSocket_new failed") );
        return;
    }

        // Setup the socket as server

    m_socket->SetLocal(addr_man.GetAddress());

    if (GetFlags() & wxSOCKET_REUSEADDR) {
        m_socket->SetReusable();
    }

    if (m_socket->SetServer() != GSOCK_NOERROR)
    {
        delete m_socket;
        m_socket = NULL;

        wxLogTrace( wxTRACE_Socket, _T("*** GSocket_SetServer failed") );
        return;
    }

    m_socket->SetTimeout(m_timeout * 1000);
    m_socket->SetCallback(GSOCK_INPUT_FLAG | GSOCK_OUTPUT_FLAG |
                                  GSOCK_LOST_FLAG | GSOCK_CONNECTION_FLAG,
                                  wx_socket_callback, (char *)this);
}

// --------------------------------------------------------------------------
// Accept
// --------------------------------------------------------------------------

bool wxSocketServer::AcceptWith(wxSocketBase& sock, bool wait)
{
  GSocket *child_socket;

  if (!m_socket)
    return false;

  // If wait == false, then the call should be nonblocking.
  // When we are finished, we put the socket to blocking mode
  // again.

  if (!wait)
    m_socket->SetNonBlocking(1);

  child_socket = m_socket->WaitConnection();

  if (!wait)
    m_socket->SetNonBlocking(0);

  if (!child_socket)
    return false;

  sock.m_type = wxSOCKET_BASE;
  sock.m_socket = child_socket;
  sock.m_connected = true;

  sock.m_socket->SetTimeout(sock.m_timeout * 1000);
  sock.m_socket->SetCallback(GSOCK_INPUT_FLAG | GSOCK_OUTPUT_FLAG |
                                     GSOCK_LOST_FLAG | GSOCK_CONNECTION_FLAG,
                                     wx_socket_callback, (char *)&sock);

  return true;
}

wxSocketBase *wxSocketServer::Accept(bool wait)
{
  wxSocketBase* sock = new wxSocketBase();

  sock->SetFlags(m_flags);

  if (!AcceptWith(*sock, wait))
  {
    sock->Destroy();
    sock = NULL;
  }

  return sock;
}

bool wxSocketServer::WaitForAccept(long seconds, long milliseconds)
{
  return _Wait(seconds, milliseconds, GSOCK_CONNECTION_FLAG);
}

bool wxSocketBase::GetOption(int level, int optname, void *optval, int *optlen)
{
    wxASSERT_MSG( m_socket, _T("Socket not initialised") );

    if (m_socket->GetSockOpt(level, optname, optval, optlen)
        != GSOCK_NOERROR)
    {
        return false;
    }
    return true;
}

bool wxSocketBase::SetOption(int level, int optname, const void *optval,
                              int optlen)
{
    wxASSERT_MSG( m_socket, _T("Socket not initialised") );
    
    if (m_socket->SetSockOpt(level, optname, optval, optlen)
        != GSOCK_NOERROR)
    {
        return false;
    }
    return true;
}

// ==========================================================================
// wxSocketClient
// ==========================================================================

// --------------------------------------------------------------------------
// Ctor and dtor
// --------------------------------------------------------------------------

wxSocketClient::wxSocketClient(wxSocketFlags flags)
              : wxSocketBase(flags, wxSOCKET_CLIENT)
{
}

wxSocketClient::~wxSocketClient()
{
}

// --------------------------------------------------------------------------
// Connect
// --------------------------------------------------------------------------

bool wxSocketClient::Connect(wxSockAddress& addr_man, bool wait)
{
  GSocketError err;

  if (m_socket)
  {
    // Shutdown and destroy the socket
    Close();
    delete m_socket;
  }

  m_socket = GSocket_new();
  m_connected = false;
  m_establishing = false;

  if (!m_socket)
    return false;

  m_socket->SetTimeout(m_timeout * 1000);
  m_socket->SetCallback(GSOCK_INPUT_FLAG | GSOCK_OUTPUT_FLAG |
                                GSOCK_LOST_FLAG | GSOCK_CONNECTION_FLAG,
                                wx_socket_callback, (char *)this);

  // If wait == false, then the call should be nonblocking.
  // When we are finished, we put the socket to blocking mode
  // again.

  if (!wait)
    m_socket->SetNonBlocking(1);

  m_socket->SetPeer(addr_man.GetAddress());
  err = m_socket->Connect(GSOCK_STREAMED);

  if (!wait)
    m_socket->SetNonBlocking(0);

  if (err != GSOCK_NOERROR)
  {
    if (err == GSOCK_WOULDBLOCK)
      m_establishing = true;

    return false;
  }

  m_connected = true;
  return true;
}

bool wxSocketClient::WaitOnConnect(long seconds, long milliseconds)
{
  if (m_connected)                      // Already connected
    return true;

  if (!m_establishing || !m_socket)     // No connection in progress
    return false;

  return _Wait(seconds, milliseconds, GSOCK_CONNECTION_FLAG |
                                      GSOCK_LOST_FLAG);
}

// ==========================================================================
// wxDatagramSocket
// ==========================================================================

/* NOTE: experimental stuff - might change */

wxDatagramSocket::wxDatagramSocket( wxSockAddress& addr,
                                    wxSocketFlags flags )
                : wxSocketBase( flags, wxSOCKET_DATAGRAM )
{
  // Create the socket
  m_socket = GSocket_new();

  if(!m_socket)
  {
    wxASSERT_MSG( 0, _T("datagram socket not new'd") );
    return;
  }
  // Setup the socket as non connection oriented
  m_socket->SetLocal(addr.GetAddress());
  if( m_socket->SetNonOriented() != GSOCK_NOERROR )
  {
    delete m_socket;
    m_socket = NULL;
    return;
  }

  // Initialize all stuff
  m_connected = false;
  m_establishing = false;
  m_socket->SetTimeout( m_timeout );
  m_socket->SetCallback( GSOCK_INPUT_FLAG | GSOCK_OUTPUT_FLAG |
                                 GSOCK_LOST_FLAG | GSOCK_CONNECTION_FLAG,
                                 wx_socket_callback, (char*)this );

}

wxDatagramSocket& wxDatagramSocket::RecvFrom( wxSockAddress& addr,
                                              void* buf,
                                              wxUint32 nBytes )
{
    Read(buf, nBytes);
    GetPeer(addr);
    return (*this);
}

wxDatagramSocket& wxDatagramSocket::SendTo( wxSockAddress& addr,
                                            const void* buf,
                                            wxUint32 nBytes )
{
    wxASSERT_MSG( m_socket, _T("Socket not initialised") );
    
    m_socket->SetPeer(addr.GetAddress());
    Write(buf, nBytes);
    return (*this);
}

// ==========================================================================
// wxSocketModule
// ==========================================================================

class wxSocketModule : public wxModule
{
public:
    virtual bool OnInit()
    {
        // wxSocketBase will call GSocket_Init() itself when/if needed
        return true;
    }

    virtual void OnExit()
    {
        if ( wxSocketBase::IsInitialized() )
            wxSocketBase::Shutdown();
    }

private:
    DECLARE_DYNAMIC_CLASS(wxSocketModule)
};

IMPLEMENT_DYNAMIC_CLASS(wxSocketModule, wxModule)

#endif
  // wxUSE_SOCKETS

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