refactor!: New SignalGroup that does not subclass SignalInstance

benchmarks/benchmarks.py

@@ -141,20 +141,21 @@ class Model(EventedModel):
             x: int = 1
 
         self.model = Model
+        self.model_instance = Model()
 
     def time_setattr_no_connections(self, n: int) -> None:
         if self.model is None:
             return
 
-        obj = self.model()
+        obj = self.model_instance
         for i in range(n):
             obj.x = i
 
     def time_setattr_with_connections(self, n: int) -> None:
         if self.model is None:
             return
 
-        obj = self.model()
+        obj = self.model_instance
         obj.events.x.connect(callback)
         for i in range(n):
             obj.x = i

src/psygnal/__init__.py

@@ -23,8 +23,8 @@
     "_compiled",
     "debounced",
     "EmissionInfo",
-    "EmitLoopError",
     "emit_queued",
+    "EmitLoopError",
     "evented",
     "EventedModel",
     "get_evented_namespace",
@@ -33,6 +33,7 @@
     "SignalGroup",
     "SignalGroupDescriptor",
     "SignalInstance",
+    "SignalRelay",
     "throttled",
 ]
 
@@ -50,7 +51,7 @@
 
 from ._evented_decorator import evented
 from ._exceptions import EmitLoopError
-from ._group import EmissionInfo, SignalGroup
+from ._group import EmissionInfo, SignalGroup, SignalRelay
 from ._group_descriptor import (
     SignalGroupDescriptor,
     get_evented_namespace,

src/psygnal/_evented_model_v1.py

@@ -347,7 +347,7 @@
         if (
             name == "_events"
             or not hasattr(self, "_events")  # can happen on init
-            or name not in self._events.signals
+            or name not in self._events
         ):
             # fallback to default behavior
             return self._super_setattr_(name, value)
@@ -357,16 +357,17 @@
         # dependent properties.
         # note that ALL signals will have at least one listener simply by nature of
         # being in the `self._events` SignalGroup.
-        signal_instance: SignalInstance = getattr(self._events, name)
+        group = self._events
+        signal_instance: SignalInstance = group[name]
         deps_with_callbacks = {
             dep_name
             for dep_name in self.__field_dependents__.get(name, ())
-            if len(getattr(self._events, dep_name)) > 1
+            if len(group[dep_name]) > 1
         }
         if (
             len(signal_instance) < 2  # the signal itself has no listeners
             and not deps_with_callbacks  # no dependent properties with listeners
-            and not len(self._events)  # no listeners on the SignalGroup
+            and not len(group._psygnal_relay)  # no listeners on the SignalGroup
         ):
             return self._super_setattr_(name, value)
 
@@ -433,7 +434,7 @@
         if not isinstance(values, dict):  # pragma: no cover
             raise TypeError(f"values must be a dict or BaseModel. got {type(values)}")
 
-        with self.events.paused():  # TODO: reduce?
+        with self.events._psygnal_relay.paused():  # TODO: reduce?
             for key, value in values.items():
                 field = getattr(self, key)
                 if isinstance(field, EventedModel) and recurse:

src/psygnal/_evented_model_v2.py

@@ -332,9 +332,9 @@ def _super_setattr_(self, name: str, value: Any) -> None:
     def __setattr__(self, name: str, value: Any) -> None:
         if (
             name == "_events"
-            or not hasattr(self, "_events")
-            or name not in self._events.signals
-        ):  # can happen on init
+            or not hasattr(self, "_events")  # can happen on init
+            or name not in self._events
+        ):
             # fallback to default behavior
             return self._super_setattr_(name, value)
 
@@ -343,16 +343,17 @@ def __setattr__(self, name: str, value: Any) -> None:
         # dependent properties.
         # note that ALL signals will have sat least one listener simply by nature of
         # being in the `self._events` SignalGroup.
-        signal_instance: SignalInstance = getattr(self._events, name)
+        group = self._events
+        signal_instance: SignalInstance = group[name]
         deps_with_callbacks = {
             dep_name
             for dep_name in self.__field_dependents__.get(name, ())
-            if len(getattr(self._events, dep_name)) > 1
+            if len(group[dep_name]) > 1
         }
         if (
             len(signal_instance) < 2  # the signal itself has no listeners
             and not deps_with_callbacks  # no dependent properties with listeners
-            and not len(self._events)  # no listeners on the SignalGroup
+            and not len(group._psygnal_relay)  # no listeners on the SignalGroup
         ):
             return self._super_setattr_(name, value)
 
@@ -419,7 +420,7 @@ def update(self, values: Union["EventedModel", dict], recurse: bool = True) -> N
         if not isinstance(values, dict):  # pragma: no cover
             raise TypeError(f"values must be a dict or BaseModel. got {type(values)}")
 
-        with self.events.paused():  # TODO: reduce?
+        with self.events._psygnal_relay.paused():  # TODO: reduce?
             for key, value in values.items():
                 field = getattr(self, key)
                 if isinstance(field, EventedModel) and recurse: