longcontrol/update: optimize capnp (commaai#23382)

selfdrive/controls/lib/longcontrol.py

@@ -65,15 +65,16 @@ def update(self, active, CS, CP, long_plan, accel_limits):
     """Update longitudinal control. This updates the state machine and runs a PID loop"""
     # Interp control trajectory
     # TODO estimate car specific lag, use .15s for now
-    if len(long_plan.speeds) == CONTROL_N:
-      v_target_lower = interp(CP.longitudinalActuatorDelayLowerBound, T_IDXS[:CONTROL_N], long_plan.speeds)
-      a_target_lower = 2 * (v_target_lower - long_plan.speeds[0])/CP.longitudinalActuatorDelayLowerBound - long_plan.accels[0]
+    speeds = long_plan.speeds
+    if len(speeds) == CONTROL_N:
+      v_target_lower = interp(CP.longitudinalActuatorDelayLowerBound, T_IDXS[:CONTROL_N], speeds)
+      a_target_lower = 2 * (v_target_lower - speeds[0])/CP.longitudinalActuatorDelayLowerBound - long_plan.accels[0]
 
-      v_target_upper = interp(CP.longitudinalActuatorDelayUpperBound, T_IDXS[:CONTROL_N], long_plan.speeds)
-      a_target_upper = 2 * (v_target_upper - long_plan.speeds[0])/CP.longitudinalActuatorDelayUpperBound - long_plan.accels[0]
+      v_target_upper = interp(CP.longitudinalActuatorDelayUpperBound, T_IDXS[:CONTROL_N], speeds)
+      a_target_upper = 2 * (v_target_upper - speeds[0])/CP.longitudinalActuatorDelayUpperBound - long_plan.accels[0]
       a_target = min(a_target_lower, a_target_upper)
 
-      v_target_future = long_plan.speeds[-1]
+      v_target_future = speeds[-1]
     else:
       v_target_future = 0.0
       a_target = 0.0
@@ -96,7 +97,7 @@ def update(self, active, CS, CP, long_plan, accel_limits):
 
     # tracking objects and driving
     elif self.long_control_state == LongCtrlState.pid:
-      self.v_pid = long_plan.speeds[0]
+      self.v_pid = speeds[0]
 
       # Toyota starts braking more when it thinks you want to stop
       # Freeze the integrator so we don't accelerate to compensate, and don't allow positive acceleration