Source code for windows.pipe

import windows
from windows import winproxy
import windows.generated_def as gdef
import ctypes

from windows.pycompat import is_py3, urepr_encode

if is_py3:
    from multiprocessing.connection import PipeConnection as native_PipeConnection
else:
    from _multiprocessing import PipeConnection as native_PipeConnection

# Inspired from 'multiprocessing\connection.py'

[docs] def full_pipe_address(addr): """Return the full address of the pipe `addr`""" if isinstance(addr, bytes): addr = addr.decode("ascii") if addr.startswith(u"\\\\"): return addr return u"\\\\.\\pipe" + u"\\" + addr
[docs] class PipeConnection(object): # Cannot inherit: crash the interpreter """A wrapper arround :class:`_multiprocessing.PipeConnection` able to work as a ContextManager""" BUFFER_SIZE = 0x2000 def __init__(self, connection, name=None, server=False): self.handle = connection.fileno() self.connection = connection self.name = name self.server = server
[docs] @classmethod def from_handle(cls, phandle, *args, **kwargs): """Create a :class:`PipeConnection` from pipe handle `phandle`""" connection = native_PipeConnection(phandle) return cls(connection, *args, **kwargs)
[docs] @classmethod def create(cls, addr, security_descriptor=None): """Create a namedpipe pipe ``addr`` :returns type: :class:`PipeConnection` """ addr = full_pipe_address(addr) security_attributes = None if security_descriptor is not None: if isinstance(security_descriptor, str): security_descriptor = windows.security.SecurityDescriptor.from_string(security_descriptor) security_attributes = gdef.SECURITY_ATTRIBUTES() security_attributes.nLength = ctypes.sizeof(security_attributes) security_attributes.lpSecurityDescriptor = security_descriptor # Accept as arg ? security_attributes.bInheritHandle = True # Accept as arg ? pipehandle = winproxy.CreateNamedPipeW( addr, gdef.PIPE_ACCESS_DUPLEX, gdef.PIPE_TYPE_MESSAGE | gdef.PIPE_READMODE_MESSAGE | gdef.PIPE_WAIT, gdef.PIPE_UNLIMITED_INSTANCES, cls.BUFFER_SIZE, cls.BUFFER_SIZE, gdef.NMPWAIT_WAIT_FOREVER, security_attributes ) return cls.from_handle(pipehandle, name=addr, server=True)
[docs] @classmethod def connect(cls, addr): """Connect to the named pipe ``addr`` :returns type: :class:`PipeConnection` """ addr = full_pipe_address(addr) pipehandle = winproxy.CreateFileW(addr, gdef.GENERIC_READ | gdef.GENERIC_WRITE, 0, None, gdef.OPEN_EXISTING, 0, None) winproxy.SetNamedPipeHandleState(pipehandle, gdef.ULONG(gdef.PIPE_READMODE_MESSAGE), None, None) return cls.from_handle(pipehandle, name=addr, server=False)
[docs] def send(self, *args, **kwargs): """Send an object on the pipe""" return self.connection.send(*args, **kwargs)
[docs] def recv(self, *args, **kwargs): """Send an object from the pipe""" return self.connection.recv(*args, **kwargs)
[docs] def wait_connection(self): """Wait for a client process to connect to the named pipe""" return winproxy.ConnectNamedPipe(self.handle, None)
def get_security_descriptor(self): return windows.security.SecurityDescriptor.from_handle(self.handle) def set_security_descriptor(self, sd): if isinstance(sd, basestring): sd = windows.security.SecurityDescriptor.from_string(sd) sd._apply_to_handle_and_type(self.handle) security_descriptor = property(get_security_descriptor, set_security_descriptor)
[docs] def close(self): """Close the handle of the pipe""" self.connection.close() self.handle = None
def __enter__(self): return self def __exit__(self, *args, **kwargs): self.close() def __repr__(self): return urepr_encode(u"""<{0} name="{1}" server={2}>""".format(type(self).__name__, self.name, self.server))
connect = PipeConnection.connect create = PipeConnection.create
[docs] def send_object(addr, obj): """Send `obj` on pipe ``addr``""" with connect(addr) as np: np.send(obj) return None
[docs] def recv_object(addr): """Receive an object from pipe ``addr``""" with create(addr) as np: np.wait_connection() return np.recv()