#!/usr/bin/env python3 import inspect import os import reprlib import unittest from framework import VppTestCase from multiprocessing import Process, Pipe from pickle import dumps import sys from enum import IntEnum, IntFlag class SerializableClassCopy: """ Empty class used as a basis for a serializable copy of another class. """ pass def __repr__(self): return "<SerializableClassCopy dict=%s>" % self.__dict__ class RemoteClassAttr: """ Wrapper around attribute of a remotely executed class. """ def __init__(self, remote, attr): self._path = [attr] if attr else [] self._remote = remote def path_to_str(self): return ".".join(self._path) def get_remote_value(self): return self._remote._remote_exec(RemoteClass.GET, self.path_to_str()) def __repr__(self): return self._remote._remote_exec(RemoteClass.REPR, self.path_to_str()) def __str__(self): return self._remote._remote_exec(RemoteClass.STR, self.path_to_str()) def __getattr__(self, attr): if attr[0] == "_": if not (attr.startswith("__") and attr.endswith("__")): raise AttributeError("tried to get private attribute: %s ", attr) self._path.append(attr) return self def __setattr__(self, attr, val): if attr[0] == "_": if not (attr.startswith("__") and attr.endswith("__")): super(RemoteClassAttr, self).__setattr__(attr, val) return self._path.append(attr) self._remote._remote_exec(RemoteClass.SETATTR, self.path_to_str(), value=val) def __call__(self, *args, **kwargs): return self._remote._remote_exec( RemoteClass.CALL, self.path_to_str(), *args, **kwargs ) class RemoteClass(Process): """ This class can wrap around and adapt the interface of another class, and then delegate its execution to a newly forked child process. Usage: #. Create a remotely executed instance of MyClass. :: object = RemoteClass(MyClass, arg1='foo', arg2='bar') object.start_remote() #. Access the object normally as if it was an instance of your class. :: object.my_attribute = 20 print object.my_attribute print object.my_method(object.my_attribute) object.my_attribute.nested_attribute = 'test' #. If you need the value of a remote attribute, use .get_remote_value method. This method is automatically called when needed in the context of a remotely executed class. E.g. :: if (object.my_attribute.get_remote_value() > 20): object.my_attribute2 = object.my_attribute #. Destroy the instance. :: object.quit_remote() object.terminate() """ GET = 0 # Get attribute remotely CALL = 1 # Call method remotely SETATTR = 2 # Set attribute remotely REPR = 3 # Get representation of a remote object STR = 4 # Get string representation of a remote object QUIT = 5 # Quit remote execution PIPE_PARENT = 0 # Parent end of the pipe PIPE_CHILD = 1 # Child end of the pipe DEFAULT_TIMEOUT = 2 # default timeout for an operation to execute def __init__(self, cls, *args, **kwargs): super(RemoteClass, self).__init__() self._cls = cls self._args = args self._kwargs = kwargs self._timeout = RemoteClass.DEFAULT_TIMEOUT self._pipe = Pipe() # pipe for input/output arguments def __repr__(self): return reprlib.repr(RemoteClassAttr(self, None)) def __str__(self): return str(RemoteClassAttr(self, None)) def __call__(self, *args, **kwargs): return self.RemoteClassAttr(self, None)() def __getattr__(self, attr): if attr[0] == "_" or not self.is_alive(): if not (attr.startswith("__") and attr.endswith("__")): if hasattr(super(RemoteClass, self), "__getattr__"): return super(RemoteClass, self).__getattr__(attr) raise AttributeError("missing: %s", attr) return RemoteClassAttr(self, attr) def __setattr__(self, attr, val): if attr[0] == "_" or not self.is_alive(): if not (attr.startswith("__") and attr.endswith("__")): super(RemoteClass, self).__setattr__(attr, val) return setattr(RemoteClassAttr(self, None), attr, val) def _remote_exec(self, op, path=None, *args, **kwargs): """ Execute given operation on a given, possibly nested, member remotely. """ # automatically resolve remote objects in the arguments mutable_args = list(args) for i, val in enumerate(mutable_args): if isinstance(val, RemoteClass) or isinstance(val, RemoteClassAttr): mutable_args[i] = val.get_remote_value() args = tuple(mutable_args) for key, val in kwargs.items(): if isinstance(val, RemoteClass) or isinstance(val, RemoteClassAttr): kwargs[key] = val.get_remote_value() # send request args = self._make_serializable(args) kwargs = self._make_serializable(kwargs) self._pipe[RemoteClass.PIPE_PARENT].send((op, path, args, kwargs)) timeout = self._timeout # adjust timeout specifically for the .sleep method if path is not None and path.split(".")[-1] == "sleep": if args and isinstance(args[0], (long, int)): timeout += args[0] elif "timeout" in kwargs: timeout += kwargs["timeout"] if not self._pipe[RemoteClass.PIPE_PARENT].poll(timeout): return None try: rv = self._pipe[RemoteClass.PIPE_PARENT].recv() rv = self._deserialize(rv) return rv except EOFError: return None def _get_local_object(self, path): """ Follow the path to obtain a reference on the addressed nested attribute """ obj = self._instance for attr in path: obj = getattr(obj, attr) return obj def _get_local_value(self, path): try: return self._get_local_object(path) except AttributeError: return None def _call_local_method(self, path, *args, **kwargs): try: method = self._get_local_object(path) return method(*args, **kwargs) except AttributeError: return None def _set_local_attr(self, path, value): try: obj = self._get_local_object(path[:-1]) setattr(obj, path[-1], value) except AttributeError: pass return None def _get_local_repr(self, path): try: obj = self._get_local_object(path) return reprlib.repr(obj) except AttributeError: return None def _get_local_str(self, path): try: obj = self._get_local_object(path) return str(obj) except AttributeError: return None def _serializable(self, obj): """Test if the given object is serializable""" try: dumps(obj) return True except: return False def _make_obj_serializable(self, obj): """ Make a serializable copy of an object. Members which are difficult/impossible to serialize are stripped. """ if self._serializable(obj): return obj # already serializable copy = SerializableClassCopy() """ Dictionaries can hold complex values, so we split keys and values into separate lists and serialize them individually. """ if type(obj) is dict: copy.type = type(obj) copy.k_list = list() copy.v_list = list() for k, v in obj.items(): copy.k_list.append(self._make_serializable(k)) copy.v_list.append(self._make_serializable(v)) return copy # copy at least serializable attributes and properties for name, member in inspect.getmembers(obj): # skip private members and non-writable dunder methods. if name[0] == "_": if name in ["__weakref__"]: continue if name in ["__dict__"]: continue if not (name.startswith("__") and name.endswith("__")): continue if callable(member) and not isinstance(member, property): continue if not self._serializable(member): member = self._make_serializable(member) setattr(copy, name, member) return copy def _make_serializable(self, obj): """ Make a serializable copy of an object or a list/tuple of objects. Members which are difficult/impossible to serialize are stripped. """ if (type(obj) is list) or (type(obj) is tuple): rv = [] for item in obj: rv.append(self._make_serializable(item)) if type(obj) is tuple: rv = tuple(rv) return rv elif isinstance(obj, IntEnum) or isinstance(obj, IntFlag): return obj.value else: return self._make_obj_serializable(obj) def _deserialize_obj(self, obj): if hasattr(obj, "type"): if obj.type is dict: _obj = dict() for k, v in zip(obj.k_list, obj.v_list): _obj[self._deserialize(k)] = self._deserialize(v) return _obj return obj def _deserialize(self, obj): if (type(obj) is list) or (type(obj) is tuple): rv = [] for item in obj: rv.append(self._deserialize(item)) if type(obj) is tuple: rv = tuple(rv) return rv else: return self._deserialize_obj(obj) def start_remote(self): """Start remote execution""" self.start() def quit_remote(self): """Quit remote execution""" self._remote_exec(RemoteClass.QUIT, None) def get_remote_value(self): """Get value of a remotely held object""" return RemoteClassAttr(self, None).get_remote_value() def set_request_timeout(self, timeout): """Change request timeout""" self._timeout = timeout def run(self): """ Create instance of the wrapped class and execute operations on it as requested by the parent process. """ self._instance = self._cls(*self._args, **self._kwargs) while True: try: rv = None # get request from the parent process (op, path, args, kwargs) = self._pipe[RemoteClass.PIPE_CHILD].recv() args = self._deserialize(args) kwargs = self._deserialize(kwargs) path = path.split(".") if path else [] if op == RemoteClass.GET: rv = self._get_local_value(path) elif op == RemoteClass.CALL: rv = self._call_local_method(path, *args, **kwargs) elif op == RemoteClass.SETATTR and "value" in kwargs: self._set_local_attr(path, kwargs["value"]) elif op == RemoteClass.REPR: rv = self._get_local_repr(path) elif op == RemoteClass.STR: rv = self._get_local_str(path) elif op == RemoteClass.QUIT: break else: continue # send return value if not self._serializable(rv): rv = self._make_serializable(rv) self._pipe[RemoteClass.PIPE_CHILD].send(rv) except EOFError: break self._instance = None # destroy the instance @unittest.skip("Remote Vpp Test Case Class") class RemoteVppTestCase(VppTestCase): """Re-use VppTestCase to create remote VPP segment In your test case:: @classmethod def setUpClass(cls): # fork new process before client connects to VPP cls.remote_test = RemoteClass(RemoteVppTestCase) # start remote process cls.remote_test.start_remote() # set up your test case super(MyTestCase, cls).setUpClass() # set up remote test cls.remote_test.setUpClass(cls.tempdir) @classmethod def tearDownClass(cls): # tear down remote test cls.remote_test.tearDownClass() # stop remote process cls.remote_test.quit_remote() # tear down your test case super(MyTestCase, cls).tearDownClass() """ def __init__(self): super(RemoteVppTestCase, self).__init__("emptyTest") # Note: __del__ is a 'Finalizer" not a 'Destructor'. # https://docs.python.org/3/reference/datamodel.html#object.__del__ def __del__(self): if hasattr(self, "vpp"): self.vpp.poll() if self.vpp.returncode is None: self.vpp.terminate() self.vpp.communicate() @classmethod def setUpClass(cls, tempdir): # disable features unsupported in remote VPP orig_env = dict(os.environ) if "STEP" in os.environ: del os.environ["STEP"] if "DEBUG" in os.environ: del os.environ["DEBUG"] cls.tempdir_prefix = os.path.basename(tempdir) + "/" super(RemoteVppTestCase, cls).setUpClass() os.environ = orig_env @classmethod def tearDownClass(cls): super(RemoteVppTestCase, cls).tearDownClass() @unittest.skip("Empty test") def emptyTest(self): """Do nothing""" pass def setTestFunctionInfo(self, name, doc): """ Store the name and documentation string of currently executed test in the main VPP for logging purposes. """ self._testMethodName = name self._testMethodDoc = doc