[Feature] Add Task Registry

dramatiq/registry.py

@@ -0,0 +1,65 @@
+from .actor import Actor, _queue_name_re
+
+
+class Registry:
+    """
+    A Registry allows defining a collection of Actors not directly bound to a Broker.
+
+    This allows your code to declar Actors before configuring a Broker.
+    """
+    def __init__(self):
+        self.actors = {}
+        self.broker = None
+
+    def actor(self, fn=None, *, actor_class=Actor, actor_name=None, queue_name="default", priority=0, **options):
+        """
+        Mimics `actor.actor` decorator, but skips the actor options check, and passes `self` as broker.
+        """
+
+        def decorator(fn):
+            if not _queue_name_re.fullmatch(queue_name):
+                raise ValueError(
+                    "Queue names must start with a letter or an underscore followed "
+                    "by any number of letters, digits, dashes or underscores."
+                )
+
+            return actor_class(
+                fn,
+                actor_name=actor_name or fn.__name__,
+                queue_name=queue_name,
+                priority=priority,
+                broker=self,
+                options=options,
+            )
+
+        if fn is None:
+            return decorator
+        return decorator(fn)
+
+    def __getattr__(self, name):
+        # Proxy everything else to our Broker, if set.
+        return getattr(self.broker, name)
+
+    def declare_actor(self, actor):
+        """
+        Intercept when Actor class tries to register itself.
+        """
+        if self.broker:
+            self.broker.declare_actor(actor)
+        else:
+            self.actors[actor.actor_name] = actor
+
+    def bind_broker(self, broker):
+        self.broker = broker
+
+        for actor_name, actor in self.actors.items():
+            invalid_options = set(actor.options) - broker.actor_options
+            if invalid_options:
+                invalid_options_list = ", ".join(invalid_options)
+                raise ValueError((
+                    "Actor %s specified the following options which are not "
+                    "supported by this broker: %s. Did you forget to add a "
+                    "middleware to your Broker?"
+                ) % (actor_name, invalid_options_list))
+
+            broker.declar_actor(actor)

tests/test_registry.py

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+import dramatiq
+from dramatiq.registry import Registry
+
+
+def test_registry_can_be_declared():
+
+    Registry()
+
+
+def test_actor_can_be_declared_on_registry():
+    # When I have a Registry
+    reg = Registry()
+
+    # Given that I've decorated a function with @registry.actor
+    @reg.actor
+    def add(x, y):
+        return x + y
+
+    # I expect that function to become an instance of Actor
+    assert isinstance(add, dramatiq.Actor)
+    assert add.broker is reg
+    assert len(reg.actors) == 1