handle priorities in boat data

lib/boatData/GwBoatData.cpp

@@ -19,7 +19,7 @@ String GwBoatData::toJson() const {
         count++;
         elementSizes+=(*it)->getJsonSize();
     }
-    DynamicJsonDocument json(JSON_OBJECT_SIZE(count)+elementSizes);
+    DynamicJsonDocument json(JSON_OBJECT_SIZE(count)+elementSizes+4);
     for (it=values.begin() ; it != values.end();it++){
         (*it)->toJsonDoc(&json,minTime);
     }

lib/boatData/GwBoatData.h

@@ -14,8 +14,9 @@ class GwBoatItemBase{
         unsigned long lastSet=0;
         unsigned long invalidTime=INVALID_TIME;
         String name;
-        void uls(){
-            lastSet=millis();
+        void uls(unsigned long ts=0){
+            if (ts) lastSet=ts;
+            else lastSet=millis();
         }
     public:
         unsigned long getLastSet() const {return lastSet;}
@@ -35,7 +36,7 @@ class GwBoatItemBase{
             lastSet=0;
         }
         virtual void toJsonDoc(JsonDocument *doc, unsigned long minTime)=0;
-        virtual size_t getJsonSize(){return JSON_OBJECT_SIZE(4);}
+        virtual size_t getJsonSize(){return JSON_OBJECT_SIZE(5);}
         virtual int getLastSource()=0;
 };
 class GwBoatData;
@@ -56,10 +57,20 @@ template<class T> class GwBoatItem : public GwBoatItemBase{
             lastUpdateSource=-1;
         }
         virtual ~GwBoatItem(){}
-        void update(T nv, int source=-1){
+        bool update(T nv, int source=-1){
+            unsigned long now=millis();
+            if (isValid(now)){
+                //priority handling
+                //sources with lower ids will win
+                //and we will not overwrite their value
+                if (lastUpdateSource < source){
+                    return false;
+                }
+            }
             data=nv;
             lastUpdateSource=source;
-            uls();
+            uls(now);
+            return true;
         }
         T getData(bool useFormatter=false){
             if (! useFormatter || fmt == NULL) return data;

lib/nmea0183ton2k/NMEA0183DataToN2K.cpp

@@ -66,15 +66,13 @@ private:
     }
     bool updateDouble(GwBoatItem<double> *target,double v, int sourceId){
         if (v != NMEA0183DoubleNA){
-            target->update(v,sourceId);
-            return true;
+            return target->update(v,sourceId);
         }
         return false;
     }
     bool updateUint32(GwBoatItem<uint32_t> *target,uint32_t v, int sourceId){
         if (v != NMEA0183UInt32NA){
-            target->update(v,sourceId);
-            return true;
+            return target->update(v,sourceId);
         }
         return v;
     }

src/main.cpp

@@ -467,6 +467,7 @@ void loop() {
 
   //read channels
   socketServer.readMessages(&receiver);
+  receiver.id=USB_CHANNEL_ID;
   usbSerial.readMessages(&receiver);
 
   //handle message requests