Updaed websocket to perform batch updates

src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/controller/MotionSensorController.java

@@ -53,7 +53,7 @@ public class MotionSensorController {
         sensor.setDetected(detected);
         final MotionSensor toReturn = motionSensorService.save(sensor);
 
-        sensorSocketEndpoint.broadcast(sensor, motionSensorService.findUser(sensor.getId()));
+        sensorSocketEndpoint.queueDeviceUpdate(sensor, motionSensorService.findUser(sensor.getId()));
 
         return toReturn;
     }

src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/controller/SensorController.java

@@ -56,7 +56,7 @@ public class SensorController {
         sensor.setValue(value);
         final Sensor toReturn = sensorRepository.save(sensor);
 
-        sensorSocketEndpoint.broadcast(sensor, sensorRepository.findUser(sensor.getId()));
+        sensorSocketEndpoint.queueDeviceUpdate(sensor, sensorRepository.findUser(sensor.getId()));
 
         return toReturn;
     }

src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/scheduled/UpdateTasks.java

@@ -43,8 +43,7 @@ public class UpdateTasks {
                                         Sensor.TYPICAL_VALUES
                                                 .get(sensor.getSensor())
                                                 .multiply(
-                                                        new BigDecimal(
+                                                        BigDecimal.valueOf(0.9875 + Math.random() / 40))));
-                                                                0.9875 + Math.random() / 40))));
     }
 
     /**
@@ -72,6 +71,12 @@ public class UpdateTasks {
     public void smartPlugConsumptionFakeUpdate() {
         smartPlugRepository.updateTotalConsumption(SmartPlug.AVERAGE_CONSUMPTION_KW);
         final Collection<SmartPlug> c = smartPlugRepository.findByOn(true);
-        c.forEach(s -> sensorSocketEndpoint.broadcast(s, sensorRepository.findUser(s.getId())));
+        c.forEach(s -> sensorSocketEndpoint.queueDeviceUpdate(s, sensorRepository.findUser(s.getId())));
+    }
+
+    /** Sends device updates through sensor socket in batch every one second */
+    @Scheduled(fixedDelay = 1000)
+    public void socketFlush() {
+        sensorSocketEndpoint.flushDeviceUpdates();
     }
 }

src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/socket/SensorSocketEndpoint.java

@@ -3,6 +3,7 @@ package ch.usi.inf.sa4.sanmarinoes.smarthut.socket;
 
 import ch.usi.inf.sa4.sanmarinoes.smarthut.config.GsonConfig;
 import ch.usi.inf.sa4.sanmarinoes.smarthut.config.JWTTokenUtils;
+import ch.usi.inf.sa4.sanmarinoes.smarthut.models.Device;
 import ch.usi.inf.sa4.sanmarinoes.smarthut.models.User;
 import ch.usi.inf.sa4.sanmarinoes.smarthut.models.UserRepository;
 import com.google.common.collect.HashMultimap;
@@ -18,6 +19,7 @@ import com.google.gson.JsonObject;
 import io.jsonwebtoken.ExpiredJwtException;
 import org.hibernate.annotations.common.reflection.XProperty;
 import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.security.core.parameters.P;
 import org.springframework.stereotype.Component;
 
 /**
@@ -35,6 +37,8 @@ public class SensorSocketEndpoint extends Endpoint {
     private Multimap<User, Session> authorizedClients =
             Multimaps.synchronizedMultimap(HashMultimap.create());
 
+    private final Map<User, Map<Long, Device>> messages = new HashMap<>();
+
     @Autowired
     public SensorSocketEndpoint(UserRepository userRepository, JWTTokenUtils jwtTokenUtils) {
         this.jwtTokenUtils = jwtTokenUtils;
@@ -42,18 +46,43 @@ public class SensorSocketEndpoint extends Endpoint {
     }
 
     /**
-     * Given a message and a user, broadcasts that message in json to all associated clients and
+     * Queues a single device update for a certain user to be sent
-     * returns the number of successful transfers
+     * @param device the device update to be sent
+     * @param u the user the device belongs
+     */
+    public void queueDeviceUpdate(Device device, User u) {
+        synchronized (messages) {
+            messages.putIfAbsent(u, new HashMap<>());
+            messages.get(u).put(device.getId(), device);
+        }
+    }
+
+    /**
+     * Sends all device updates queued to be sent in a unique WebSocket message
+     */
+    public void flushDeviceUpdates() {
+        synchronized (messages) {
+            for (Map.Entry<User, Map<Long, Device>> batchForUser : messages.entrySet()) {
+                broadcast(batchForUser.getKey(), batchForUser.getValue().values());
+                batchForUser.getValue().clear();
+            }
+        }
+    }
+
+    /**
+     * Given a collection of messages and a user, broadcasts that message in json to all
+     * associated clients
      *
-     * @param message the message to send
+     * @param messages the message batch to send
      * @param u       the user to which to send the message
      */
-    public void broadcast(Object message, User u) {
+    private void broadcast(User u, Collection<?> messages) {
+        if (messages.isEmpty()) return;
         final HashSet<Session> sessions = new HashSet<>(authorizedClients.get(u));
         for (Session s : sessions) {
             try {
                 if (s.isOpen()) {
-                    s.getBasicRemote().sendText(gson.toJson(message));
+                    s.getBasicRemote().sendText(gson.toJson(messages));
                 } else {
                     authorizedClients.remove(u, s);
                 }