perf: retain exact flow caches and compiled targets

tests/test_amesim_signal_components.py

@@ -100,6 +100,38 @@ class AmesimSignalComponentTests(unittest.TestCase):
         valve.res.signal = -0.5
         self.assertAlmostEqual(valve.opening, 0.0)
 
+    def test_pnvo001_exact_repeated_flow_characteristics_are_cached(self) -> None:
+        valve = AmesimPnvo001SignalOpening("valve_1", self.medium, opening0=0.25)
+        valve._one_way_flow_characteristics.cache_clear()
+
+        first = valve._one_way_flow_characteristics(
+            upstream_pressure=501000.0,
+            downstream_pressure=500000.0,
+            upstream_temperature=300.0,
+        )
+        after_first = valve._one_way_flow_characteristics.cache_info()
+        second = valve._one_way_flow_characteristics(
+            upstream_pressure=501000.0,
+            downstream_pressure=500000.0,
+            upstream_temperature=300.0,
+        )
+        after_second = valve._one_way_flow_characteristics.cache_info()
+        changed_pressure = valve._one_way_flow_characteristics(
+            upstream_pressure=502000.0,
+            downstream_pressure=500000.0,
+            upstream_temperature=300.0,
+        )
+        after_pressure_change = valve._one_way_flow_characteristics.cache_info()
+
+        self.assertEqual(first, second)
+        self.assertEqual(after_first.misses, 1)
+        self.assertEqual(after_second.hits, after_first.hits + 1)
+        self.assertNotEqual(changed_pressure, second)
+        self.assertEqual(
+            after_pressure_change.misses,
+            after_second.misses + 1,
+        )
+
     def test_signal_resolver_propagates_step_to_valve_input(self) -> None:
         network = SimulationNetwork("signal-smoke")
         step = AmesimStep0("step_1", self.medium, initial=0.0, final=0.75, time=0.1)