Use cache lifetime as polling interval (#452)

* Use cache lifetime as polling interval

* Renamed cache constant for clarity

Author: kjy5

src/ephys_link/bindings/mpm_binding.py

@@ -62,12 +62,11 @@ class MPMBinding(BaseBinding):
         "AN",
     )
 
-    # Server cache lifetime (60 FPS).
-    CACHE_LIFETIME = 1 / 60
+    # Server data update rate (30 FPS).
+    SERVER_DATA_UPDATE_RATE = 1 / 30
 
     # Movement polling preferences.
     UNCHANGED_COUNTER_LIMIT = 10
-    POLL_INTERVAL = 0.1
 
     # Speed preferences (mm/s to use coarse mode).
     COARSE_SPEED_THRESHOLD = 0.1
@@ -114,7 +113,7 @@ async def get_position(self, manipulator_id: str) -> Vector4:
         stage_z: float = manipulator_data["Stage_Z"]
 
         # Wait for the stage to stabilize.
-        await sleep(self.POLL_INTERVAL)
+        await sleep(self.SERVER_DATA_UPDATE_RATE)
 
         return Vector4(
             x=manipulator_data["Stage_X"],
@@ -182,7 +181,7 @@ async def set_position(self, manipulator_id: str, position: Vector4, speed: floa
             and unchanged_counter < self.UNCHANGED_COUNTER_LIMIT
         ):
             # Wait for a short time before checking again.
-            await sleep(self.POLL_INTERVAL)
+            await sleep(self.SERVER_DATA_UPDATE_RATE)
 
             # Update current position.
             current_position = await self.get_position(manipulator_id)
@@ -227,7 +226,7 @@ async def set_depth(self, manipulator_id: str, depth: float, speed: float) -> fl
             and unchanged_counter < self.UNCHANGED_COUNTER_LIMIT
         ):
             # Wait for a short time before checking again.
-            await sleep(self.POLL_INTERVAL)
+            await sleep(self.SERVER_DATA_UPDATE_RATE)
 
             # Get the current depth.
             current_depth = (await self.get_position(manipulator_id)).w
@@ -291,7 +290,7 @@ def unified_space_to_platform_space(self, unified_space: Vector4) -> Vector4:
     async def _query_data(self) -> dict[str, Any]:  # pyright: ignore [reportExplicitAny]
         try:
             # Update cache if it's expired.
-            if get_running_loop().time() - self.cache_time > self.CACHE_LIFETIME:
+            if get_running_loop().time() - self.cache_time > self.SERVER_DATA_UPDATE_RATE:
                 # noinspection PyTypeChecker
                 self.cache = (await get_running_loop().run_in_executor(None, get, self._url)).json()
                 self.cache_time = get_running_loop().time()