def from_named_pipe(cls, name, buffer_size=4096, default_timeout=100, max_instances=5):
handle = m_k32.CreateNamedPipeW(
'\\\\.\\pipe\\' + name, # _In_ LPCTSTR lpName
PIPE_ACCESS_DUPLEX | FILE_FLAG_OVERLAPPED, # _In_ DWORD dwOpenMode
PIPE_TYPE_MESSAGE | PIPE_READMODE_MESSAGE, # _In_ DWORD dwPipeMode
max_instances, # _In_ DWORD nMaxInstances
buffer_size, # _In_ DWORD nInBufferSize
buffer_size, # _In_ DWORD nOutBufferSize
default_timeout, # _In_ DWORD nDefaultTimeout
None # _In_opt_ LPSECURITY_ATTRIBUTES lpSecurityAttributes
)
if handle == INVALID_HANDLE_VALUE:
raise ctypes.WinError()
success = lambda: cls(handle, buffer_size=buffer_size)
overlapped = wintypes.OVERLAPPED()
overlapped.hEvent = m_k32.CreateEventW(None, True, False, None)
if m_k32.ConnectNamedPipe(handle, ctypes.byref(overlapped)):
m_k32.CloseHandle(overlapped.hEvent)
return success()
error = m_k32.GetLastError()
if error == ERROR_IO_PENDING and _wait_overlapped_io(overlapped, default_timeout):
m_k32.CloseHandle(overlapped.hEvent)
return success()
m_k32.CloseHandle(overlapped.hEvent)
if error == ERROR_PIPE_CONNECTED:
return success()
m_k32.CloseHandle(handle)
raise ctypes.WinError()
def read(self):
ctarray = (ctypes.c_byte * self.buffer_size)()
bytes_read = wintypes.DWORD(0)
overlapped = wintypes.OVERLAPPED()
overlapped.hEvent = m_k32.CreateEventW(None, True, False, None)
if m_k32.ReadFile(self.handle, ctypes.byref(ctarray), self.buffer_size, ctypes.byref(bytes_read), ctypes.byref(overlapped)):
return utilities.ctarray_to_bytes(ctarray)[:bytes_read.value]
error = m_k32.GetLastError()
if error == ERROR_IO_PENDING and _wait_overlapped_io(overlapped):
return utilities.ctarray_to_bytes(ctarray)[:overlapped.InternalHigh]
if error == ERROR_BROKEN_PIPE:
return None
raise ctypes.WinError()