Merge pull request #282 from python-accelerator-middle-layer/fix-device-access-list

Fix device access list

Author: JeanLucPons

pyaml/control/abstract_impl.py

@@ -95,21 +95,21 @@ def _iter_devices_and_ranges(devs: DeviceAccess | DeviceAccessList):
       - DeviceAccessList: yields N items based on get_devices() and get_range() flattening
     """
     # Single device
-    if hasattr(devs, "get") and hasattr(devs, "get_range") and not hasattr(devs, "get_devices"):
+    if isinstance(devs, DeviceAccess):
         r = devs.get_range()
         if r is None:
             r = [None, None]
         return [(devs, [r[0], r[1]])]
 
-    # Device list (expects get_devices() + get_range() flat list)
-    devices = devs.get_devices()
-    flat = np.asarray(devs.get_range(), dtype=object).ravel()
-    if (flat.size % 2) != 0:
+    # get_range() return a flat list
+    flat = devs.get_range()
+    if (len(flat) % 2) != 0:
         raise ValueError(f"dev_range must have an even length, got {flat.size}")
 
+    # Reshape
     pairs = []
-    for i, d in enumerate(devices):
-        pairs.append((d, [flat[2 * i], flat[2 * i + 1]]))
+    for i in range(devs.len()):
+        pairs.append((devs.get_device_at(i), [flat[2 * i], flat[2 * i + 1]]))
     return pairs
 
 
@@ -196,7 +196,7 @@ def unit(self) -> str:
         return self._devs.unit()
 
     def nb_device(self) -> int:
-        return self._devs.__len__()
+        return self._devs.len()
 
 
 # ------------------------------------------------------------------------------

pyaml/control/deviceaccesslist.py

@@ -4,22 +4,27 @@
 import numpy.typing as npt
 
 from .deviceaccess import DeviceAccess
-from .readback_value import Value
 
 
-class DeviceAccessList(list[DeviceAccess], metaclass=ABCMeta):
+class DeviceAccessList(metaclass=ABCMeta):
     """
-    Abstract class providing access to a list of control system float variable
+    Abstract class providing access to a list of control system variales.
+    Internal structure depends on the backend and might not be trivially iterable.
     """
 
     @abstractmethod
     def add_devices(self, devices: DeviceAccess | list[DeviceAccess]):
-        """Add a DeviceAccess to this list"""
+        """Add a DeviceAccess (or a list) to this list"""
         pass
 
     @abstractmethod
-    def get_devices(self) -> DeviceAccess | list[DeviceAccess]:
-        """Get the DeviceAccess list"""
+    def get_device_at(self, index: int) -> DeviceAccess:
+        """Returns the device at the given index"""
+        pass
+
+    @abstractmethod
+    def len(self) -> int:
+        """Get the DeviceAccessList length"""
         pass
 
     @abstractmethod
@@ -56,7 +61,7 @@ def get_range(self) -> list[float]:
         Returns
         -------
         list[float]
-            List containing [min, max] values
+            List containing [min0, max0, min1, max1, ...] values
         """
         pass
 

tests/dummy_cs/tango-pyaml/tango/pyaml/controlsystem.py

@@ -85,8 +85,5 @@ def name(self) -> str:
     def get_aggregator(self) -> str | None:
         return MultiAttribute()
 
-    def vector_aggregator(self) -> str | None:
-        return self._cfg.vector_aggregator
-
     def __repr__(self):
         return repr(self._cfg).replace("ConfigModel", self.__class__.__name__)

tests/dummy_cs/tango-pyaml/tango/pyaml/multi_attribute.py

@@ -12,7 +12,7 @@
 
 class MultiAttribute(DeviceAccessList):
     def __init__(self):
-        super().__init__()
+        self._items = []
 
     def add_devices(self, devices: DeviceAccess | list[DeviceAccess]):
         if isinstance(devices, list):
@@ -23,54 +23,54 @@ def add_devices(self, devices: DeviceAccess | list[DeviceAccess]):
                         (tango.pyaml.attribute) but got
                         ({device.__class__.__name__})"""
                     )
-            super().extend(devices)
+            self._items.extend(devices)
         else:
             if not isinstance(devices, Attribute):
                 raise pyaml.PyAMLException(
                     f"""Device must be an instance of Attribute
                     (tango.pyaml.attribute) but got
                     ({devices.__class__.__name__})"""
                 )
-            super().append(devices)
+            self._items.append(devices)
 
-    def get_devices(self) -> DeviceAccess | list[DeviceAccess]:
-        if len(self) == 1:
-            return self[0]
-        else:
-            return self
+    def len(self) -> int:
+        return len(self._items)
+
+    def get_device_at(self, index: int) -> DeviceAccess:
+        return self._items[index]
 
     def set(self, value: npt.NDArray[np.float64]):
         print(f"MultiAttribute.set({len(value)} values)")
         global LAST_NB_WRITTEN
         LAST_NB_WRITTEN += len(value)
-        for idx, a in enumerate(self):
+        for idx, a in enumerate(self._items):
             a.set(value[idx])
 
     def set_and_wait(self, value: npt.NDArray[np.float64]):
         pass
 
     def get(self) -> npt.NDArray[np.float64]:
-        print(f"MultiAttribute.get({len(self)} values)")
-        return np.array([a.get() for a in self])
+        print(f"MultiAttribute.get({len(self._items)} values)")
+        return np.array([a.get() for a in self._items])
 
     def readback(self) -> np.array:
         return np.array([])
 
     def unit(self) -> list[str]:
-        return [a.unit() for a in self]
+        return [a.unit() for a in self._items]
 
     def get_last_nb_written(self) -> int:
         return self.__last_nb_written
 
     def get_range(self) -> list[float]:
         attr_range: list[float] = []
-        for device in self:
+        for device in self._items:
             attr_range.extend(device.get_range())
         return attr_range
 
     def check_device_availability(self) -> bool:
         available = False
-        for device in self:
+        for device in self._items:
             available = device.check_device_availability()
             if not available:
                 break