C++ IsOpened函数代码示例

bool wxDir::GetFirst(wxString *filename,
                     const wxString& filespec,
                     int flags) const
{
    wxCHECK_MSG( IsOpened(), false, wxT("must wxDir::Open() first") );

    M_DIR->Rewind();

    M_DIR->SetFileSpec(filespec);
    M_DIR->SetFlags(flags);

    return GetNext(filename);
}

void CLCDOutput::OnDisconnecting(int hConnection)
{
    UNREFERENCED_PARAMETER(hConnection);
    LOGITRACE(_T("CLCDOutput::OnDisconnecting\n"));
    // let's hope our device is already gone
    LOGIASSERT(!IsOpened());

    if (LGLCD_INVALID_CONNECTION != m_hConnection)
    {
        lgLcdDisconnect(m_hConnection);
        m_hConnection = LGLCD_INVALID_CONNECTION;
    }
}

bool CFile::SetLength(size_t new_len)
{
	MULE_VALIDATE_STATE(IsOpened(), wxT("CFile: Cannot set length when no file is open."));

#ifdef __WXMSW__
	int result = chsize(m_fd, new_len);
#else
	int result = ftruncate(m_fd, new_len);
#endif

	SYSCALL_CHECK((result != -1), wxT("truncating file"));	

	return (result != -1);
}

bool wxFFile::Flush()
{
    if ( IsOpened() )
    {
        if ( fflush(m_fp) != 0 )
        {
            wxLogSysError(_("failed to flush the file '%s'"), m_name.c_str());

            return false;
        }
    }

    return true;
}

void CompilationDatabase::DropTables()
{
    if(!IsOpened()) return;

    try {

        // Create the schema
        m_db->ExecuteUpdate("DROP TABLE COMPILATION_TABLE");
        m_db->ExecuteUpdate("DROP TABLE SCHEMA_VERSION");

    } catch(wxSQLite3Exception& e) {
        wxUnusedVar(e);
    }
}

void CLCDOutput::OnDisconnecting(int hConnection)
{
    UNREFERENCED_PARAMETER(hConnection);
    LCDUITRACE(_T("CLCDOutput::OnDisconnecting\n"));
    // let's hope our device is already gone
    LCDUIASSERT(!IsOpened());

    if (LGLCD_INVALID_CONNECTION != m_hConnection)
    {
        lgLcdDisconnect(m_hConnection);
        m_hConnection = LGLCD_INVALID_CONNECTION;
        ZeroMemory(m_pLastBitmap, sizeof(lgLcdBitmap160x43x1));
    }
}

void TCPSocket::Bind( const sockaddr_in& addr )
{
	int error;
	if (!IsOpened())
	{
		throw TCPException("Socket::bind","Socket没有打开");
	}
	const sockaddr* socketAddress = reinterpret_cast<const sockaddr*>(&addr);
	error = ::bind(m_descriptor,socketAddress,sizeof(addr));
	if(error == SOCKET_ERROR )
	{
		throw TCPException("Socket::bind","绑定Socket失败",error);
	}
}

void TCPSocket::Connect( const sockaddr_in& addr ) throw(TCPException)
{
	int error;
	if(!IsOpened())
	{
		throw TCPException("Socket::connect", "Socket没有打开");
	}
	const sockaddr* socketAddress = reinterpret_cast<const sockaddr*>(&addr);
	error = ::connect(m_descriptor, socketAddress, sizeof(addr));
	if (error ==  SOCKET_ERROR)
	{
		//throw TCPException("Socket::connect","Socket连接出错",error);
	}
}

// read
ssize_t wxFile::Read(void *pBuf, size_t nCount)
{
    wxCHECK( (pBuf != NULL) && IsOpened(), 0 );

    ssize_t iRc = wxRead(m_fd, pBuf, nCount);

    if ( CheckForError(iRc) )
    {
        wxLogSysError(_("can't read from file descriptor %d"), m_fd);
        return wxInvalidOffset;
    }

    return iRc;
}

bool AdbIOCompletion::GetOvelappedIoResult(LPOVERLAPPED ovl_data,
                                           ULONG* bytes_transferred,
                                           bool wait) {
  if (NULL != bytes_transferred)
    *bytes_transferred = 0;

  if (!IsOpened()) {
    SetLastError(ERROR_INVALID_HANDLE);
    return false;
  }

  ULONG transfer;
  bool ret = GetOverlappedResult(parent_io_object()->usb_handle(),
                                 overlapped(),
                                 &transfer,
                                 wait) ? true :
                                         false;

  // TODO: This is bizzare but I've seen it happening
  // that GetOverlappedResult with wait set to true returns "prematurely",
  // with wrong transferred bytes value and GetLastError reporting
  // ERROR_IO_PENDING. So, lets give it an up to a 20 ms loop!
  ULONG error = GetLastError();

  if (wait && ret && (0 == transfer) && (0 != expected_transfer_size_) &&
      ((ERROR_IO_INCOMPLETE == error) || (ERROR_IO_PENDING == error))) {
    for (int trying = 0; trying < 10; trying++) {
      Sleep(2);
      ret = GetOverlappedResult(parent_io_object()->usb_handle(),
                                overlapped(),
                                &transfer,
                                wait) ? true :
                                        false;
      error = GetLastError();
      if (!ret || (0 != transfer) ||
          ((ERROR_IO_INCOMPLETE != error) && (ERROR_IO_PENDING != error))) {
        break;
      }
    }
  }

  if (NULL != ovl_data)
    CopyMemory(ovl_data, overlapped(), sizeof(OVERLAPPED));

  if (NULL != bytes_transferred)
    *bytes_transferred = is_write_ioctl() ? transferred_bytes_ : transfer;

  return ret;
}

bool AdbInterfaceObject::GetUsbDeviceDescriptor(USB_DEVICE_DESCRIPTOR* desc) {
  if (!IsOpened()) {
    SetLastError(ERROR_INVALID_HANDLE);
    return false;
  }

  if (NULL == desc) {
    SetLastError(ERROR_INVALID_PARAMETER);
    return false;
  }

  CopyMemory(desc, usb_device_descriptor(), sizeof(USB_DEVICE_DESCRIPTOR));

  return true;
}

sint64 CFile::doSeek(sint64 offset) const
{
	MULE_VALIDATE_STATE(IsOpened(), wxT("Cannot seek on closed file."));
	MULE_VALIDATE_PARAMS(offset >= 0, wxT("Invalid position, must be positive."));

	sint64 result = SEEK_FD(m_fd, offset, SEEK_SET);

	if (result == offset) {
		return result;
	} else if (result == wxInvalidOffset) {
		throw CSeekFailureException(wxString(wxT("Seeking failed: ")) + wxSysErrorMsg());
	} else {
		throw CSeekFailureException(wxT("Seeking returned incorrect position"));
	}
}

// close
bool wxFile::Close()
{
    if ( IsOpened() ) {
        if ( CheckForError(wxClose(m_fd)) )
        {
            wxLogSysError(_("can't close file descriptor %d"), m_fd);
            m_fd = fd_invalid;
            return false;
        }
        else
            m_fd = fd_invalid;
    }

    return true;
}

bool wxPipeInputStream::CanRead() const
{
    // we can read if there's something in the put back buffer
    // even pipe is closed
    if ( m_wbacksize > m_wbackcur )
        return true;

    wxPipeInputStream * const self = wxConstCast(this, wxPipeInputStream);

    if ( !IsOpened() )
    {
        // set back to mark Eof as it may have been unset by Ungetch()
        self->m_lasterror = wxSTREAM_EOF;
        return false;
    }

    DWORD nAvailable;

    // function name is misleading, it works with anon pipes as well
    DWORD rc = ::PeekNamedPipe
                    (
                      m_hInput,     // handle
                      NULL, 0,      // ptr to buffer and its size
                      NULL,         // [out] bytes read
                      &nAvailable,  // [out] bytes available
                      NULL          // [out] bytes left
                    );

    if ( !rc )
    {
        if ( ::GetLastError() != ERROR_BROKEN_PIPE )
        {
            // unexpected error
            wxLogLastError(wxT("PeekNamedPipe"));
        }

        // don't try to continue reading from a pipe if an error occurred or if
        // it had been closed
        ::CloseHandle(m_hInput);

        self->m_hInput = INVALID_HANDLE_VALUE;
        self->m_lasterror = wxSTREAM_EOF;

        nAvailable = 0;
    }

    return nAvailable != 0;
}

int Tcp::Connect(/* [in] */ const Address &addr,
                            /* [in] */ OutConnectHandler *handler)
{
    assert(IsOpened());

    int result = uv_tcp_connect(&m_connectReq,
                                *this,
                                addr,
                                OnConnected);
    if(! result) {
        Ref();
        m_pOutConnectHandler = handler;
    }

    return result;
}