Accept None values in BatteryPool control methods

This allows lower priority actors to completely yield control, which
causes the algorithm to use the perferred power of the higher priority
actor as the target power.

Signed-off-by: Sahas Subramanian <[email protected]>

Author: shsms

src/frequenz/sdk/actor/_power_managing/_base_classes.py

@@ -78,7 +78,7 @@ class Proposal:
     """A proposal for a battery to be charged or discharged."""
 
     source_id: str
-    preferred_power: Power
+    preferred_power: Power | None
     bounds: tuple[Power, Power] | None
     battery_ids: frozenset[int]
     priority: int

src/frequenz/sdk/actor/_power_managing/_matryoshka.py

@@ -62,12 +62,13 @@ def _calc_target_power(
         for next_proposal in reversed(proposals):
             if upper_bound < lower_bound:
                 break
-            if next_proposal.preferred_power > upper_bound:
-                target_power = upper_bound
-            elif next_proposal.preferred_power < lower_bound:
-                target_power = lower_bound
-            else:
-                target_power = next_proposal.preferred_power
+            if next_proposal.preferred_power:
+                if next_proposal.preferred_power > upper_bound:
+                    target_power = upper_bound
+                elif next_proposal.preferred_power < lower_bound:
+                    target_power = lower_bound
+                else:
+                    target_power = next_proposal.preferred_power
             if next_proposal.bounds:
                 lower_bound = max(lower_bound, next_proposal.bounds[0])
                 upper_bound = min(upper_bound, next_proposal.bounds[1])

src/frequenz/sdk/timeseries/battery_pool/_battery_pool_wrapper.py

@@ -58,7 +58,7 @@ def __init__(self, battery_pool: BatteryPool, source_id: str | None, priority: i
 
     async def set_power(
         self,
-        preferred_power: Power,
+        preferred_power: Power | None,
         *,
         request_timeout: timedelta = timedelta(seconds=5.0),
         include_broken_batteries: bool = False,
@@ -103,7 +103,7 @@ async def set_power(
 
     async def charge(
         self,
-        power: Power,
+        power: Power | None,
         *,
         request_timeout: timedelta = timedelta(seconds=5.0),
         include_broken_batteries: bool = False,
@@ -130,7 +130,7 @@ async def charge(
         Raises:
             ValueError: If the given power is negative.
         """
-        if power < Power.zero():
+        if power and power < Power.zero():
             raise ValueError("Charge power must be positive.")
         await self._battery_pool._power_manager_requests_sender.send(
             _power_managing.Proposal(
@@ -146,7 +146,7 @@ async def charge(
 
     async def discharge(
         self,
-        power: Power,
+        power: Power | None,
         *,
         request_timeout: timedelta = timedelta(seconds=5.0),
         include_broken_batteries: bool = False,
@@ -173,7 +173,7 @@ async def discharge(
         Raises:
             ValueError: If the given power is negative.
         """
-        if power < Power.zero():
+        if power and power < Power.zero():
             raise ValueError("Discharge power must be positive.")
         await self._battery_pool._power_manager_requests_sender.send(
             _power_managing.Proposal(

tests/actor/_power_managing/test_matryoshka.py

@@ -28,7 +28,7 @@ async def test_matryoshka_algorithm() -> None:  # pylint: disable=too-many-state
 
     def test_tgt_power(
         priority: int,
-        power: float,
+        power: float | None,
         bounds: tuple[float, float] | None,
         expected: float | None,
     ) -> None:
@@ -39,7 +39,7 @@ def test_tgt_power(
             Proposal(
                 battery_ids=batteries,
                 source_id=f"actor-{priority}",
-                preferred_power=Power.from_watts(power),
+                preferred_power=None if power is None else Power.from_watts(power),
                 bounds=(Power.from_watts(bounds[0]), Power.from_watts(bounds[1]))
                 if bounds
                 else None,
@@ -52,11 +52,17 @@ def test_tgt_power(
         )
 
     def test_bounds(
-        priority: int, expected_power: float, expected_bounds: tuple[float, float]
+        priority: int,
+        expected_power: float | None,
+        expected_bounds: tuple[float, float],
     ) -> None:
         report = algorithm.get_status(batteries, priority, system_bounds, None)
-        assert report.target_power is not None and report.inclusion_bounds is not None
-        assert report.target_power.as_watts() == expected_power
+        if expected_power is None:
+            assert report.target_power is None
+        else:
+            assert report.target_power is not None
+            assert report.target_power.as_watts() == expected_power
+        assert report.inclusion_bounds is not None
         assert report.inclusion_bounds.lower.as_watts() == expected_bounds[0]
         assert report.inclusion_bounds.upper.as_watts() == expected_bounds[1]
 
@@ -142,3 +148,9 @@ def test_bounds(
 
     test_tgt_power(priority=1, power=200.0, bounds=(50, 200), expected=100.0)
     test_bounds(priority=1, expected_power=100.0, expected_bounds=(-100.0, 100.0))
+
+    test_tgt_power(priority=1, power=0.0, bounds=(-200, 200), expected=0.0)
+    test_bounds(priority=1, expected_power=0.0, expected_bounds=(-100.0, 100.0))
+
+    test_tgt_power(priority=1, power=None, bounds=(-200, 200), expected=50.0)
+    test_bounds(priority=1, expected_power=50.0, expected_bounds=(-100.0, 100.0))