timespan in geojson

Ships/DB.cpp

@@ -372,32 +372,33 @@ std::string DB::getKML()
 
 std::string DB::getGeoJSON()
 {
-	std::lock_guard<std::mutex> lock(mtx);
-
-	std::string s = "{\"type\":\"FeatureCollection\",\"features\":[";
-	int ptr = first;
-	std::time_t tm = time(nullptr);
-
-	bool addcomma = false;
-	while (ptr != -1)
-	{
-		const Ship &ship = ships[ptr];
-		if (ship.mmsi != 0)
-		{
-			long int delta_time = (long int)tm - (long int)ship.last_signal;
-			if (delta_time > TIME_HISTORY)
-				break;
-
-			if (addcomma)
-				s += ",";
-			addcomma = ship.getGeoJSON(s);
-		}
-		ptr = ships[ptr].next;
-	}
-	s += "]}";
-	return s;
+    std::lock_guard<std::mutex> lock(mtx);
+
+    std::string s = "{\"type\":\"FeatureCollection\",\"time_span\":" + std::to_string(TIME_HISTORY) + ",\"features\":[";
+    int ptr = first;
+    std::time_t tm = time(nullptr);
+
+    bool addcomma = false;
+    while (ptr != -1)
+    {
+        const Ship &ship = ships[ptr];
+        if (ship.mmsi != 0)
+        {
+            long int delta_time = (long int)tm - (long int)ship.last_signal;
+            if (delta_time > TIME_HISTORY)
+                break;
+
+            if (addcomma)
+                s += ",";
+            addcomma = ship.getGeoJSON(s);
+        }
+        ptr = ships[ptr].next;
+    }
+    s += "]}";
+    return s;
 }
 
+
 // needs fix, content is defined locally and in getSinglePathJSON member content is used as helper
 std::string DB::getAllPathJSON()
 {