[Serve] Optimize DeploymentStateManager.get_deployment_statuses

python/ray/serve/_private/application_state.py

@@ -500,13 +500,12 @@ def _determine_app_status(self) -> Tuple[ApplicationStatus, str]:
         # Get the lowest rank, i.e. highest priority, deployment status info object
         # The deployment status info with highest priority determines the corresponding
         # application status to set.
-        lowest_rank_status = min(
-            self.get_deployments_statuses(), key=lambda info: info.rank
-        )
+        deployment_statuses = self.get_deployments_statuses()
+        lowest_rank_status = min(deployment_statuses, key=lambda info: info.rank)
         if lowest_rank_status.status == DeploymentStatus.UNHEALTHY:
             unhealthy_deployment_names = [
                 s.name
-                for s in self.get_deployments_statuses()
+                for s in deployment_statuses
                 if s.status == DeploymentStatus.UNHEALTHY
             ]
             status_msg = f"The deployments {unhealthy_deployment_names} are UNHEALTHY."

python/ray/serve/_private/deployment_state.py

@@ -2564,13 +2564,25 @@ def get_deployment_details(self, id: DeploymentID) -> Optional[DeploymentDetails
             )
 
     def get_deployment_statuses(
-        self, ids: List[DeploymentID] = None
+        self, ids: Optional[List[DeploymentID]] = None
     ) -> List[DeploymentStatusInfo]:
-        statuses = []
-        for id, state in self._deployment_states.items():
-            if not ids or id in ids:
-                statuses.append(state.curr_status_info)
-        return statuses
+        """
+        Return the statuses of the deployments with the given `ids`.
+        If `ids` is `None`, returns the status of all deployments.
+        """
+        if ids is None:
+            # fast path for returning all deployments,
+            # avoids checking `if ids is None` in a loop
+            return [
+                state.curr_status_info for state in self._deployment_states.values()
+            ]
+        else:
+            statuses = []
+            for id in ids:
+                state = self._deployment_states.get(id)
+                if state is not None:
+                    statuses.append(state.curr_status_info)
+            return statuses
 
     def get_alive_replica_actor_ids(self) -> Set[str]:
         alive_replica_actor_ids = set()