route api: try and bundle requests

this limits the responsiveness to 3 seconds but that's fine
it's still fast if there is lots of routes to look up on page load for
example

html/planeObject.js

@@ -3006,7 +3006,17 @@ function routeDoLookup() {
         g.route_check_checking = null;
         return;
     }
+    if (g.route_check_checking.length < 10 && currentTime - g.route_last_lookup < 3.5) {
+        // only do lookups every 3 seconds if we don't have many routes to check
+        if (debugRoute) {
+            console.log('delaying route check, trying to bundle request for 3 seconds');
+        }
+        return;
+    }
+
     g.route_check_in_flight = true;
+    g.route_last_lookup = currentTime;
+
     if (debugRoute) {
         console.log(`${currentTime}: g.route_check_checking:`, g.route_check_checking);
     }

html/script.js

@@ -11,6 +11,7 @@ g.route_cache = [];
 g.route_check_todo = {};
 g.route_check_in_flight = false;
 g.route_next_lookup = 0;
+g.route_last_lookup = 0;
 
 g.mapOrientation = mapOrientation;
 
@@ -5739,7 +5740,7 @@ function checkMovement() {
         return;
     }
 
-    let currentTime = new Date().getTime()/1000;
+    let currentTime = Date.now()/1000;
     if (currentTime > g.route_next_lookup && !g.route_check_in_flight) {
         // check if it's time to send a batch of request to the API server
         g.route_next_lookup = currentTime + 1;