Refactor call proxy class generation

Change-Id: I9d79d4fd07fcb455b9830d76965abacf409c0ab8

tobiko/__init__.py

@@ -85,12 +85,11 @@ get_operation = _operation.get_operation
 get_operation_name = _operation.get_operation_name
 operation_config = _operation.operation_config
 
-Protocol = _proxy.Protocol
-list_protocols = _proxy.list_protocols
 call_proxy = _proxy.call_proxy
 call_proxy_class = _proxy.call_proxy_class
+list_protocols = _proxy.list_protocols
+protocol = _proxy.protocol
 CallHandler = _proxy.CallHandler
-CallProxy = _proxy.CallProxy
 
 retry = _retry.retry
 retry_attempt = _retry.retry_attempt

tobiko/actor/_actor.py

@@ -26,18 +26,15 @@ import tobiko
 from tobiko.actor import _request
 
 
+T = typing.TypeVar('T')
+
+
 class ActorRef(tobiko.CallHandler):
 
-    def __init__(self,
-                 actor_id: str,
-                 requests: _request.ActorRequestQueue,
-                 protocols: typing.Iterable[typing.Type[tobiko.Protocol]]):
+    def __init__(self, actor_id: str, requests: _request.ActorRequestQueue):
+        super().__init__()
         self.actor_id = actor_id
         self._requests = requests
-        self._interfaces: typing.Dict[
-            typing.Type[tobiko.Protocol],
-            typing.Any] = {protocol: None
-                           for protocol in protocols}
 
     def send_request(self, method: str, **arguments):
         return self._requests.send_request(method=method, arguments=arguments)
@@ -48,19 +45,6 @@ class ActorRef(tobiko.CallHandler):
         arguments.pop('self', None)
         return self.send_request(method.__name__, **arguments)
 
-    def get_interface(self, protocol: typing.Type[tobiko.Protocol]):
-        try:
-            interface = self._interfaces[protocol]
-        except KeyError as ex:
-            raise TypeError(
-                f"Protocol '{protocol}' is not supported by actor "
-                f"'{self.actor_id}") from ex
-
-        if interface is None:
-            self._interfaces[protocol] = interface = tobiko.call_proxy(
-                protocol, self._handle_call)
-        return interface
-
 
 def is_actor_method(obj):
     return getattr(obj, '__tobiko_actor_method__', False)
@@ -87,14 +71,14 @@ class Actor(tobiko.SharedFixture):
     log: logging.LoggerAdapter
     loop: asyncio.AbstractEventLoop
 
-    ref: ActorRef
+    base_ref_class = ActorRef
 
+    _actor_methods: typing.Dict[str, typing.Callable]
+    _ref_class: type
+    _ref: ActorRef
     _requests: _request.ActorRequestQueue
     _run_actor_task: asyncio.Task
 
-    _protocols: typing.Sequence[typing.Type[tobiko.Protocol]]
-    _actor_methods: typing.Dict[str, typing.Callable]
-
     @property
     def actor_id(self) -> str:
         return self.fixture_name
@@ -103,13 +87,33 @@ class Actor(tobiko.SharedFixture):
         self.loop = self.get_loop()
         self.log = self.create_log()
         self._requests = self.create_request_queue()
-        self._protocols = tobiko.list_protocols(type(self))
-        self.ref = ActorRef(actor_id=self.actor_id,
-                            requests=self._requests,
-                            protocols=self._protocols)
+
         self._run_actor_task = self.loop.create_task(
             self._run_actor())
 
+    @classmethod
+    def ref_class(cls) -> type:
+        try:
+            return cls._ref_class
+        except AttributeError:
+            pass
+        name = cls.__name__ + 'Ref'
+        bases = cls.base_ref_class,
+        namespace = {'__module__': cls.__module__,
+                     'protocol_class': cls}
+        return type(name, bases, namespace)
+
+    @property
+    def ref(self) -> ActorRef:
+        try:
+            return self._ref
+        except AttributeError:
+            pass
+        ref_class = self.ref_class()
+        self._ref = ref = ref_class(actor_id=self.actor_id,
+                                    requests=self._requests)
+        return ref
+
     def get_loop(self) -> asyncio.AbstractEventLoop:
         return asyncio.get_event_loop()
 

tobiko/common/_proxy.py

@@ -13,7 +13,6 @@
 #    under the License.
 from __future__ import absolute_import
 
-import abc
 import functools
 import inspect
 import typing
@@ -21,23 +20,17 @@ import typing
 import decorator
 
 
-class ProtocolMeta(abc.ABCMeta):
-
-    def __new__(mcls, name, bases, namespace, **kwargs):
-        cls = super().__new__(mcls, name, bases, namespace, **kwargs)
-        cls._is_protocol = True
-        return cls
-
-
-class Protocol(abc.ABC, metaclass=ProtocolMeta):
-    pass
-
-
-T = typing.TypeVar('T')
+def protocol(cls: type) -> type:
+    name = cls.__name__
+    bases = inspect.getmro(cls)[1:]
+    namespace = dict(cls.__dict__,
+                     _is_protocol=True,
+                     __module__=cls.__module__)
+    return type(name, bases, namespace)
 
 
 def is_protocol_class(cls):
-    return cls.__dict__.get('_is_protocol', False)
+    return inspect.isclass(cls) and cls.__dict__.get('_is_protocol', False)
 
 
 def is_public_function(obj):
@@ -45,60 +38,85 @@ def is_public_function(obj):
             getattr(obj, '__name__', '_')[0] != '_')
 
 
-class CallHandler(abc.ABC):
-
-    def _handle_call(self, method: typing.Callable, *args, **kwargs):
-        raise NotImplementedError
+T = typing.TypeVar('T')
 
 
-class CallProxy(CallHandler):
+class CallHandlerMeta(type):
 
-    _handle_call: typing.Callable
+    def __new__(mcls, name, bases, namespace, **kwargs):
+        protocol_class = namespace.get('protocol_class')
+        if protocol_class is not None:
+            proxy_class = call_proxy_class(protocol_class)
+            bases += proxy_class,
+        return super().__new__(mcls, name, bases, namespace, **kwargs)
 
-    def __init__(self, handle_call: typing.Callable):
-        setattr(self, '_handle_call', handle_call)
 
+class CallHandler(metaclass=CallHandlerMeta):
 
-@functools.lru_cache()
-def call_proxy_class(protocol_class: type,
-                     class_name: typing.Optional[str] = None,
-                     handler_class: typing.Type[CallHandler] = CallProxy) \
-        -> type:
-    if not is_protocol_class(protocol_class):
-        raise TypeError(f"{protocol_class} is not a subclass of {Protocol}")
-    if class_name is None:
-        class_name = protocol_class.__name__ + 'Proxy'
-    namespace: typing.Dict[str, typing.Any] = {}
-    for name, member in protocol_class.__dict__.items():
-        if is_public_function(member):
-            method = call_proxy_method(member)
-            namespace[name] = method
+    protocol_class: type
 
-    return type(class_name, (handler_class, protocol_class), namespace)
+    def __init__(self,
+                 handle_call: typing.Optional[typing.Callable] = None):
+        if handle_call is not None:
+            assert callable(handle_call)
+            setattr(self, '_handle_call', handle_call)
 
+    def _handle_call(self, method: typing.Callable, *args, **kwargs):
+        pass
 
-def call_proxy(protocol_class: typing.Type[T], handle_call: typing.Callable) \
-        -> T:
-    proxy_class = call_proxy_class(typing.cast(type, protocol_class))
-    return proxy_class(handle_call)
+    def use_as(self, cls: typing.Type[T]) -> T:
+        assert isinstance(self, cls)
+        return typing.cast(T, self)
 
 
-@functools.lru_cache()
-def stack_classes(name: str, cls: type, *classes) -> type:
-    return type(name, (cls,) + classes, {})
+def call_proxy_class(
+        cls: type,
+        *bases: type,
+        class_name: typing.Optional[str] = None,
+        namespace: typing.Optional[dict] = None) \
+        -> type:
+    if not inspect.isclass(cls):
+        raise TypeError(f"Object {cls} is not a class")
+    if class_name is None:
+        class_name = cls.__name__ + 'Proxy'
+    protocol_classes = list_protocols(cls)
+    if not protocol_classes:
+        raise TypeError(f"Class {cls} doesn't implement any protocol")
+    if namespace is None:
+        namespace = {}
+    for protocol_class in reversed(protocol_classes):
+        for name, member in protocol_class.__dict__.items():
+            if is_public_function(member):
+                method = call_proxy_method(member)
+                namespace[name] = method
+    # Skip empty protocols
+    if not namespace:
+        raise TypeError(f"Class {cls} has any protocol specification")
+    namespace['__module__'] = cls.__module__
+    proxy_class = type(class_name, bases + protocol_classes, namespace)
+    assert not is_protocol_class(proxy_class)
+    assert not is_protocol_class(proxy_class)
+    return proxy_class
+
+
+def call_proxy(cls: type, handle_call: typing.Callable) -> CallHandler:
+    proxy_class = call_proxy_class(cls, CallHandler)
+    return proxy_class(handle_call)
 
 
 @functools.lru_cache()
-def list_protocols(cls: type) -> typing.Tuple[typing.Type[Protocol], ...]:
+def list_protocols(cls: type) -> typing.Tuple[type, ...]:
     subclasses = inspect.getmro(cls)
-    protocols = tuple(typing.cast(typing.Type[Protocol], cls)
+    protocols = tuple(cls
                       for cls in subclasses
                       if is_protocol_class(cls))
     return tuple(protocols)
 
 
 def call_proxy_method(func: typing.Callable) -> typing.Callable:
-    return decorator.decorate(func, _call_proxy_method)
+    method = decorator.decorate(func, _call_proxy_method)
+    assert method is not func
+    return method
 
 
 def _call_proxy_method(func, self: CallHandler, *args, **kwargs):

tobiko/tests/unit/actor/test_actor.py

@@ -22,22 +22,29 @@ from tobiko.tests import unit
 from tobiko import actor
 
 
-class Greeter(tobiko.Protocol):
+@tobiko.protocol
+class Greeter:
 
     async def greet(self, whom: str, greeted: 'Greeted'):
         raise NotImplementedError
 
 
-class Greeted(tobiko.Protocol):
+@tobiko.protocol
+class Greeted:
 
     def greeted(self, whom: str, greeter: Greeter):
         raise NotImplementedError
 
 
+class GreeterRef(actor.ActorRef):
+    pass
+
+
 class GreeterActor(Greeter, actor.Actor):
 
     setup_called = False
     cleanup_called = False
+    base_ref_class = GreeterRef
 
     async def setup_actor(self):
         self.setup_called = True
@@ -53,15 +60,21 @@ class GreeterActor(Greeter, actor.Actor):
             raise ValueError("'whom' parameter can't be empty")
 
         self.log.info(f"Hello {whom}!")
-        greeted.greeted(whom=whom, greeter=self.ref.get_interface(Greeter))
+        greeted.greeted(whom=whom, greeter=self.ref.use_as(Greeter))
 
 
 class ActorTest(unit.TobikoUnitTest):
 
+    def test_greeter_ref_class(self):
+        ref_class = GreeterActor.ref_class()
+        self.assertTrue(issubclass(ref_class, actor.ActorRef))
+        self.assertTrue(issubclass(ref_class, GreeterRef))
+        self.assertTrue(issubclass(ref_class, Greeter))
+
     async def test_async_request(self):
-        actor_ref = actor.create_actor(GreeterActor)
-        self.assertIsInstance(actor_ref, actor.ActorRef)
-        greeter = actor_ref.get_interface(Greeter)
+        greeter = actor.create_actor(GreeterActor).use_as(Greeter)
+        self.assertIsInstance(greeter, actor.ActorRef)
+        self.assertIsInstance(greeter, GreeterRef)
         self.assertIsInstance(greeter, Greeter)
         greeted = mock.MagicMock(spec=Greeted)
 
@@ -70,9 +83,8 @@ class ActorTest(unit.TobikoUnitTest):
                                            greeter=greeter)
 
     async def test_async_request_failure(self):
-        actor_ref = actor.create_actor(GreeterActor)
-        self.assertIsInstance(actor_ref, actor.ActorRef)
-        greeter = actor_ref.get_interface(Greeter)
+        greeter = actor.create_actor(GreeterActor).use_as(Greeter)
+        self.assertIsInstance(greeter, actor.ActorRef)
         self.assertIsInstance(greeter, Greeter)
         greeted = mock.MagicMock(spec=Greeted)
 

tobiko/tests/unit/test_proxy.py

@@ -15,14 +15,14 @@ from __future__ import absolute_import
 
 import inspect
 import typing
-
-import mock
+from unittest import mock
 
 import tobiko
 from tobiko.tests import unit
 
 
-class MyProto1(tobiko.Protocol):
+@tobiko.protocol
+class MyProto:
     # pylint: disable=unused-argument
 
     def call_one(self, arg='a') -> int:
@@ -35,31 +35,50 @@ class MyProto1(tobiko.Protocol):
         return 42
 
 
+class MyProtoHandler(tobiko.CallHandler):
+
+    protocol_class = MyProto
+
+
 class ProxyTest(unit.TobikoUnitTest):
 
-    def test_call_proxy(self):
+    def handle_call(self, method: typing.Callable, *_args, **_kwargs):
+        self.assertTrue(inspect.isfunction(method))
 
-        def handle_call(method: typing.Callable, *_args, **_kwargs):
-            self.assertTrue(inspect.isfunction(method))
+    def mock_handler(self) -> typing.Callable:
+        return typing.cast(typing.Callable,
+                           mock.MagicMock(side_effect=self.handle_call))
 
-        handler = mock.MagicMock(side_effect=handle_call)
-        proxy = tobiko.call_proxy(MyProto1,
-                                  typing.cast(typing.Callable, handler))
-        self.assertIsInstance(proxy, MyProto1)
+    def test_call_handler(self):
+        handler = self.mock_handler()
+        proxy = MyProtoHandler(handler).use_as(MyProto)
+        self.assertIsInstance(proxy, MyProto)
+        self.assertTrue(callable(proxy.call_one))
+        self.assertEqual(inspect.signature(MyProto.call_one),
+                         inspect.signature(type(proxy).call_one))
+        self.assertIsNot(MyProto.call_one,
+                         proxy.call_one)
+        proxy.call_one()
+        handler.assert_called_with(MyProto.call_one, 'a')
+
+    def test_call_proxy(self):
+        handler = self.mock_handler()
+        proxy = tobiko.call_proxy(MyProto, handler).use_as(MyProto)
+        self.assertIsInstance(proxy, MyProto)
         self.assertTrue(callable(proxy.call_one))
-        self.assertEqual(inspect.signature(MyProto1.call_one),
+        self.assertEqual(inspect.signature(MyProto.call_one),
                          inspect.signature(type(proxy).call_one))
-        self.assertIsNot(MyProto1.call_one,
+        self.assertIsNot(MyProto.call_one,
                          proxy.call_one)
         proxy.call_one()
-        handler.assert_called_with(MyProto1.call_one, 'a')
+        handler.assert_called_with(MyProto.call_one, 'a')
         proxy.call_one('b')
-        handler.assert_called_with(MyProto1.call_one, 'b')
+        handler.assert_called_with(MyProto.call_one, 'b')
         proxy.call_one(arg='c')
-        handler.assert_called_with(MyProto1.call_one, 'c')
+        handler.assert_called_with(MyProto.call_one, 'c')
 
         proxy.call_two(1, 2, 3)
-        handler.assert_called_with(MyProto1.call_two, 1, 2, 3)
+        handler.assert_called_with(MyProto.call_two, 1, 2, 3)
 
         proxy.call_three(a='a', b='b')
-        handler.assert_called_with(MyProto1.call_three, a='a', b='b')
+        handler.assert_called_with(MyProto.call_three, a='a', b='b')