fix(map): rate limit station reverse geocoding

vehicle-map/server.py

@@ -38,12 +38,15 @@ STATION_GEOCODE_CACHE_SECONDS = int(os.getenv("STATION_GEOCODE_CACHE_SECONDS", "
 STATION_GEOCODE_CACHE_PATH = Path(os.getenv(
     "STATION_GEOCODE_CACHE_PATH", str(ROOT / ".station-geocode-cache.json")
 ))
+AMAP_REGEOCODE_MIN_INTERVAL_SECONDS = float(os.getenv("AMAP_REGEOCODE_MIN_INTERVAL_SECONDS", "0.25"))
 _cache_lock = threading.Lock()
 _cache = {}
 _cache_load_locks = {}
 _station_geocode_cache_lock = threading.Lock()
 _station_geocode_cache = None
 _station_geocode_cache_dirty = False
+_station_geocode_rate_lock = threading.Lock()
+_station_geocode_next_request_at = 0.0
 
 
 class ThreadingHTTPServer(ThreadingMixIn, HTTPServer):
@@ -142,8 +145,15 @@ def _persist_station_geocode_cache():
 
 
 def _reverse_geocode_station(longitude, latitude):
+    global _station_geocode_next_request_at
     if not AMAP_REGEOCODE_KEY:
         raise RuntimeError("AMAP_REGEOCODE_KEY is not configured")
+    with _station_geocode_rate_lock:
+        now = time.monotonic()
+        wait_seconds = max(0.0, _station_geocode_next_request_at - now)
+        _station_geocode_next_request_at = max(now, _station_geocode_next_request_at) + AMAP_REGEOCODE_MIN_INTERVAL_SECONDS
+    if wait_seconds:
+        time.sleep(wait_seconds)
     query = urlencode({
         "key": AMAP_REGEOCODE_KEY,
         "location": "{:.6f},{:.6f}".format(longitude, latitude),