Add update to ConfigFanAttributeIO (#93)

We now set the value of the fan out only if all the underlying
attributes are the same, else to the default value of the DataType.

In future we will set an alarm when the underlying values are not the
same.

Update to fastcs 0.12 for all_equal helper.

Author: GDYendell

pyproject.toml

@@ -12,7 +12,7 @@ classifiers = [
 description = "FastCS support for the Odin detector software framework"
 dependencies = [
     "aiohttp",
-    "fastcs[epicsca]~=0.11.2",
+    "fastcs[epicsca]~=0.12.0a1",
 ]
 dynamic = ["version"]
 license.file = "LICENSE"

src/fastcs_odin/controllers/odin_data/odin_data_adapter.py

@@ -1,7 +1,7 @@
 import logging
 from collections.abc import Sequence
 
-from fastcs.attributes import AttributeIO, AttributeIORefT, AttrW
+from fastcs.attributes import AttributeIO, AttributeIORefT, AttrRW
 from fastcs.controllers import ControllerVector
 from fastcs.datatypes import DType_T
 
@@ -74,15 +74,15 @@ async def initialise(self):
 
     def _create_config_fan_attributes(self):
         """Search for config attributes in sub controllers to create fan out PVs."""
-        parameter_attribute_map: dict[str, tuple[OdinParameter, list[AttrW]]] = {}
+        parameter_attribute_map: dict[str, tuple[OdinParameter, list[AttrRW]]] = {}
         for sub_controller in get_all_sub_controllers(self):
             match sub_controller:
                 case OdinSubController():
                     for parameter in sub_controller.parameters:
                         mode, key = parameter.uri[0], parameter.uri[-1]
                         if mode == "config" and key not in self._unique_config:
                             try:
-                                attr: AttrW = sub_controller.attributes[parameter.name]  # type: ignore
+                                attr: AttrRW = sub_controller.attributes[parameter.name]  # type: ignore
                                 if parameter.name not in parameter_attribute_map:
                                     parameter_attribute_map[parameter.name] = (
                                         parameter,

src/fastcs_odin/io/config_fan_sender_attribute_io.py

@@ -1,8 +1,8 @@
 import asyncio
-from dataclasses import dataclass
+from dataclasses import KW_ONLY, dataclass
 from typing import Any
 
-from fastcs.attributes import AttributeIO, AttributeIORef, AttrRW, AttrW
+from fastcs.attributes import AttributeIO, AttributeIORef, AttrR, AttrRW, AttrW
 from fastcs.datatypes import DType_T
 from fastcs.logging import bind_logger
 
@@ -17,7 +17,9 @@ class ConfigFanAttributeIORef(AttributeIORef):
         attributes: A list of attributes to fan out to
     """
 
-    attributes: list[AttrW]
+    attributes: list[AttrRW]
+    _: KW_ONLY
+    update_period: float | None = 0.2
 
 
 class ConfigFanAttributeIO(AttributeIO[DType_T, ConfigFanAttributeIORef]):
@@ -32,5 +34,11 @@ async def send(self, attr: AttrW[DType_T, ConfigFanAttributeIORef], value: Any):
             ]
         )
 
-        if isinstance(attr, AttrRW):
-            await attr.update(value)
+    async def update(self, attr: AttrR[DType_T, ConfigFanAttributeIORef]):
+        values = [attribute.get() for attribute in attr.io_ref.attributes]
+
+        if attr.datatype.all_equal(values):
+            await attr.update(values[0])
+        else:
+            # TODO: Set an alarm - https://github.com/DiamondLightSource/FastCS/issues/286
+            await attr.update(attr.datatype.initial_value)

src/fastcs_odin/io/parameter_attribute_io.py

@@ -42,6 +42,13 @@ async def update(self, attr: AttrR[DType_T, ParameterTreeAttributeIORef]) -> Non
         if parameter not in response:
             raise ValueError(f"{parameter} not found in response:\n{response}")
 
+        self.log_event(
+            "Query for parameter",
+            uri=attr.io_ref.path,
+            response=response,
+            topic=attr,
+        )
+
         value = response.get(parameter)
         await attr.update(attr.datatype.validate(value))
 

tests/test_controllers.py

@@ -392,16 +392,28 @@ async def test_status_summary_updater_raise_exception_if_controller_not_found(
 
 @pytest.mark.asyncio
 async def test_config_fan_sender(mocker: MockerFixture):
-    attr1 = mocker.AsyncMock()
-    attr2 = mocker.AsyncMock()
+    attr1 = mocker.MagicMock()
+    attr1.put = (put1_mock := mocker.AsyncMock())
+    attr2 = mocker.MagicMock()
+    attr2.put = (put2_mock := mocker.AsyncMock())
 
     attr = AttrRW(Int(), ConfigFanAttributeIORef([attr1, attr2]))
     io = ConfigFanAttributeIO()
 
     await io.send(attr, 10)
-    attr1.put.assert_called_once_with(10, sync_setpoint=True)
-    attr2.put.assert_called_once_with(10, sync_setpoint=True)
-    assert attr.get() == 10
+    put1_mock.assert_called_once_with(10, sync_setpoint=True)
+    put2_mock.assert_called_once_with(10, sync_setpoint=True)
+
+    attr1.get.return_value = 10
+    attr2.get.return_value = 5
+
+    await io.update(attr)
+    assert attr.get() == 0  # attributes don't match -> default value
+
+    attr2.get.return_value = 10
+
+    await io.update(attr)
+    assert attr.get() == 10  # attributes match -> set value
 
 
 @pytest.mark.asyncio