Refactor position and event handlers

44 files changed, 466 insertions, 580 deletions

diff --git a/src/main/java/org/traccar/BaseDataHandler.java b/src/main/java/org/traccar/BaseDataHandler.java
deleted file mode 100644
index 48794b0d7..000000000
--- a/src/main/java/org/traccar/BaseDataHandler.java
+++ /dev/null
@@ -1,38 +0,0 @@
-/*
- * Copyright 2015 - 2018 Anton Tananaev (anton@traccar.org)
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.traccar;
-
-import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
-import org.traccar.model.Position;
-
-public abstract class BaseDataHandler extends ChannelInboundHandlerAdapter {
-
-    @Override
-    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
-        if (msg instanceof Position) {
-            Position position = handlePosition((Position) msg);
-            if (position != null) {
-                ctx.fireChannelRead(position);
-            }
-        } else {
-            super.channelRead(ctx, msg);
-        }
-    }
-
-    protected abstract Position handlePosition(Position position);
-
-}
diff --git a/src/main/java/org/traccar/BasePipelineFactory.java b/src/main/java/org/traccar/BasePipelineFactory.java
index ca4a4ae63..6d9431ad6 100644
--- a/src/main/java/org/traccar/BasePipelineFactory.java
+++ b/src/main/java/org/traccar/BasePipelineFactory.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2012 - 2023 Anton Tananaev (anton@traccar.org)
+ * Copyright 2012 - 2024 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -25,36 +25,13 @@ import io.netty.channel.ChannelPipeline;
 import io.netty.handler.timeout.IdleStateHandler;
 import org.traccar.config.Config;
 import org.traccar.config.Keys;
-import org.traccar.handler.AcknowledgementHandler;
-import org.traccar.handler.ComputedAttributesHandler;
-import org.traccar.handler.CopyAttributesHandler;
-import org.traccar.handler.DefaultDataHandler;
-import org.traccar.handler.DistanceHandler;
-import org.traccar.handler.EngineHoursHandler;
-import org.traccar.handler.FilterHandler;
-import org.traccar.handler.GeocoderHandler;
-import org.traccar.handler.GeofenceHandler;
-import org.traccar.handler.GeolocationHandler;
-import org.traccar.handler.HemisphereHandler;
-import org.traccar.handler.MotionHandler;
-import org.traccar.handler.NetworkForwarderHandler;
-import org.traccar.handler.NetworkMessageHandler;
-import org.traccar.handler.OpenChannelHandler;
-import org.traccar.handler.RemoteAddressHandler;
-import org.traccar.handler.SpeedLimitHandler;
-import org.traccar.handler.StandardLoggingHandler;
-import org.traccar.handler.TimeHandler;
-import org.traccar.handler.events.AlertEventHandler;
-import org.traccar.handler.events.BehaviorEventHandler;
-import org.traccar.handler.events.CommandResultEventHandler;
-import org.traccar.handler.events.DriverEventHandler;
-import org.traccar.handler.events.FuelEventHandler;
-import org.traccar.handler.events.GeofenceEventHandler;
-import org.traccar.handler.events.IgnitionEventHandler;
-import org.traccar.handler.events.MaintenanceEventHandler;
-import org.traccar.handler.events.MediaEventHandler;
-import org.traccar.handler.events.MotionEventHandler;
-import org.traccar.handler.events.OverspeedEventHandler;
+import org.traccar.handler.network.AcknowledgementHandler;
+import org.traccar.handler.network.MainEventHandler;
+import org.traccar.handler.network.NetworkForwarderHandler;
+import org.traccar.handler.network.NetworkMessageHandler;
+import org.traccar.handler.network.OpenChannelHandler;
+import org.traccar.handler.network.RemoteAddressHandler;
+import org.traccar.handler.network.StandardLoggingHandler;
 
 import java.util.Map;
 
@@ -83,15 +60,7 @@ public abstract class BasePipelineFactory extends ChannelInitializer<Channel> {
 
     protected abstract void addProtocolHandlers(PipelineBuilder pipeline);
 
-    @SafeVarargs
-    private void addHandlers(ChannelPipeline pipeline, Class<? extends ChannelHandler>... handlerClasses) {
-        for (Class<? extends ChannelHandler> handlerClass : handlerClasses) {
-            if (handlerClass != null) {
-                pipeline.addLast(injector.getInstance(handlerClass));
-            }
-        }
-    }
-
+    @SuppressWarnings("unchecked")
     public static <T extends ChannelHandler> T getHandler(ChannelPipeline pipeline, Class<T> clazz) {
         for (Map.Entry<String, ChannelHandler> handlerEntry : pipeline) {
             ChannelHandler handler = handlerEntry.getValue();
@@ -107,6 +76,11 @@ public abstract class BasePipelineFactory extends ChannelInitializer<Channel> {
         return null;
     }
 
+    private <T> T injectMembers(T object) {
+        injector.injectMembers(object);
+        return object;
+    }
+
     @Override
     protected void initChannel(Channel channel) {
         final ChannelPipeline pipeline = channel.pipeline();
@@ -119,15 +93,11 @@ public abstract class BasePipelineFactory extends ChannelInitializer<Channel> {
         pipeline.addLast(new OpenChannelHandler(connector));
         if (config.hasKey(Keys.SERVER_FORWARD)) {
             int port = config.getInteger(Keys.PROTOCOL_PORT.withPrefix(protocol));
-            var handler = new NetworkForwarderHandler(port);
-            injector.injectMembers(handler);
-            pipeline.addLast(handler);
+            pipeline.addLast(injectMembers(new NetworkForwarderHandler(port)));
         }
         pipeline.addLast(new NetworkMessageHandler());
-
-        var loggingHandler = new StandardLoggingHandler(protocol);
-        injector.injectMembers(loggingHandler);
-        pipeline.addLast(loggingHandler);
+        pipeline.addLast(new RemoteAddressHandler(config));
+        pipeline.addLast(injectMembers(new StandardLoggingHandler(protocol)));
 
         if (!connector.isDatagram() && !config.getBoolean(Keys.SERVER_INSTANT_ACKNOWLEDGEMENT)) {
             pipeline.addLast(new AcknowledgementHandler());
@@ -135,7 +105,7 @@ public abstract class BasePipelineFactory extends ChannelInitializer<Channel> {
 
         addProtocolHandlers(handler -> {
             if (handler instanceof BaseProtocolDecoder || handler instanceof BaseProtocolEncoder) {
-                injector.injectMembers(handler);
+                injectMembers(handler);
             } else {
                 if (handler instanceof ChannelInboundHandler) {
                     handler = new WrapperInboundHandler((ChannelInboundHandler) handler);
@@ -146,35 +116,8 @@ public abstract class BasePipelineFactory extends ChannelInitializer<Channel> {
             pipeline.addLast(handler);
         });
 
-        addHandlers(
-                pipeline,
-                TimeHandler.class,
-                GeolocationHandler.class,
-                HemisphereHandler.class,
-                DistanceHandler.class,
-                RemoteAddressHandler.class,
-                FilterHandler.class,
-                GeofenceHandler.class,
-                GeocoderHandler.class,
-                SpeedLimitHandler.class,
-                MotionHandler.class,
-                CopyAttributesHandler.class,
-                EngineHoursHandler.class,
-                ComputedAttributesHandler.class,
-                PositionForwardingHandler.class,
-                DefaultDataHandler.class,
-                MediaEventHandler.class,
-                CommandResultEventHandler.class,
-                OverspeedEventHandler.class,
-                BehaviorEventHandler.class,
-                FuelEventHandler.class,
-                MotionEventHandler.class,
-                GeofenceEventHandler.class,
-                AlertEventHandler.class,
-                IgnitionEventHandler.class,
-                MaintenanceEventHandler.class,
-                DriverEventHandler.class,
-                MainEventHandler.class);
+        pipeline.addLast(injector.getInstance(ProcessingHandler.class));
+        pipeline.addLast(injector.getInstance(MainEventHandler.class));
     }
 
 }
diff --git a/src/main/java/org/traccar/ExtendedObjectDecoder.java b/src/main/java/org/traccar/ExtendedObjectDecoder.java
index cddddcd80..9468e2fff 100644
--- a/src/main/java/org/traccar/ExtendedObjectDecoder.java
+++ b/src/main/java/org/traccar/ExtendedObjectDecoder.java
@@ -23,7 +23,7 @@ import io.netty.channel.ChannelInboundHandlerAdapter;
 import io.netty.util.ReferenceCountUtil;
 import org.traccar.config.Config;
 import org.traccar.config.Keys;
-import org.traccar.handler.AcknowledgementHandler;
+import org.traccar.handler.network.AcknowledgementHandler;
 import org.traccar.helper.DataConverter;
 import org.traccar.model.Position;
 
diff --git a/src/main/java/org/traccar/ProcessingHandler.java b/src/main/java/org/traccar/ProcessingHandler.java
new file mode 100644
index 000000000..7627c719b
--- /dev/null
+++ b/src/main/java/org/traccar/ProcessingHandler.java
@@ -0,0 +1,145 @@
+/*
+ * Copyright 2024 Anton Tananaev (anton@traccar.org)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.traccar;
+
+import com.google.inject.Injector;
+import io.netty.channel.ChannelHandler;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.channel.ChannelInboundHandlerAdapter;
+import jakarta.inject.Inject;
+import jakarta.inject.Singleton;
+import org.traccar.database.NotificationManager;
+import org.traccar.handler.BasePositionHandler;
+import org.traccar.handler.ComputedAttributesHandler;
+import org.traccar.handler.CopyAttributesHandler;
+import org.traccar.handler.DatabaseHandler;
+import org.traccar.handler.DistanceHandler;
+import org.traccar.handler.EngineHoursHandler;
+import org.traccar.handler.FilterHandler;
+import org.traccar.handler.GeocoderHandler;
+import org.traccar.handler.GeofenceHandler;
+import org.traccar.handler.GeolocationHandler;
+import org.traccar.handler.HemisphereHandler;
+import org.traccar.handler.MotionHandler;
+import org.traccar.handler.PositionForwardingHandler;
+import org.traccar.handler.SpeedLimitHandler;
+import org.traccar.handler.TimeHandler;
+import org.traccar.handler.events.AlertEventHandler;
+import org.traccar.handler.events.BaseEventHandler;
+import org.traccar.handler.events.BehaviorEventHandler;
+import org.traccar.handler.events.CommandResultEventHandler;
+import org.traccar.handler.events.DriverEventHandler;
+import org.traccar.handler.events.FuelEventHandler;
+import org.traccar.handler.events.GeofenceEventHandler;
+import org.traccar.handler.events.IgnitionEventHandler;
+import org.traccar.handler.events.MaintenanceEventHandler;
+import org.traccar.handler.events.MediaEventHandler;
+import org.traccar.handler.events.MotionEventHandler;
+import org.traccar.handler.events.OverspeedEventHandler;
+import org.traccar.handler.network.AcknowledgementHandler;
+import org.traccar.model.Position;
+
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+@Singleton
+@ChannelHandler.Sharable
+public class ProcessingHandler extends ChannelInboundHandlerAdapter {
+
+    private final NotificationManager notificationManager;
+    private final List<BasePositionHandler> positionHandlers;
+    private final List<BaseEventHandler> eventHandlers;
+
+    @Inject
+    public ProcessingHandler(Injector injector, NotificationManager notificationManager) {
+        this.notificationManager = notificationManager;
+
+        positionHandlers = Stream.of(
+                TimeHandler.class,
+                GeolocationHandler.class,
+                HemisphereHandler.class,
+                DistanceHandler.class,
+                FilterHandler.class,
+                GeofenceHandler.class,
+                GeocoderHandler.class,
+                SpeedLimitHandler.class,
+                MotionHandler.class,
+                EngineHoursHandler.class,
+                ComputedAttributesHandler.class,
+                CopyAttributesHandler.class,
+                PositionForwardingHandler.class,
+                DatabaseHandler.class)
+                .map((clazz) -> (BasePositionHandler) injector.getInstance(clazz))
+                .filter(Objects::nonNull)
+                .collect(Collectors.toUnmodifiableList());
+
+        eventHandlers = Stream.of(
+                MediaEventHandler.class,
+                CommandResultEventHandler.class,
+                OverspeedEventHandler.class,
+                BehaviorEventHandler.class,
+                FuelEventHandler.class,
+                MotionEventHandler.class,
+                GeofenceEventHandler.class,
+                AlertEventHandler.class,
+                IgnitionEventHandler.class,
+                MaintenanceEventHandler.class,
+                DriverEventHandler.class)
+                .map((clazz) -> (BaseEventHandler) injector.getInstance(clazz))
+                .filter(Objects::nonNull)
+                .collect(Collectors.toUnmodifiableList());
+    }
+
+    @Override
+    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
+        if (msg instanceof Position) {
+            processPositionHandlers(ctx, (Position) msg);
+        }
+        super.channelRead(ctx, msg);
+    }
+
+    private void processPositionHandlers(ChannelHandlerContext ctx, Position position) {
+        var iterator = positionHandlers.iterator();
+        iterator.next().handlePosition(position, new BasePositionHandler.Callback() {
+            @Override
+            public void processed(Position position) {
+                if (position != null) {
+                    if (iterator.hasNext()) {
+                        iterator.next().handlePosition(position, this);
+                    } else {
+                        processEventHandlers(ctx, position);
+                    }
+                } else {
+                    finishedProcessing(ctx, null);
+                }
+            }
+        });
+    }
+
+    private void processEventHandlers(ChannelHandlerContext ctx, Position position) {
+        eventHandlers.forEach(handler -> handler.analyzePosition(
+                position, (event) -> notificationManager.updateEvents(Map.of(event, position))));
+        finishedProcessing(ctx, position);
+    }
+
+    private void finishedProcessing(ChannelHandlerContext ctx, Position position) {
+        ctx.writeAndFlush(new AcknowledgementHandler.EventHandled(position));
+    }
+
+}
diff --git a/src/main/java/org/traccar/handler/BasePositionHandler.java b/src/main/java/org/traccar/handler/BasePositionHandler.java
new file mode 100644
index 000000000..2fee5c652
--- /dev/null
+++ b/src/main/java/org/traccar/handler/BasePositionHandler.java
@@ -0,0 +1,27 @@
+/*
+ * Copyright 2015 - 2024 Anton Tananaev (anton@traccar.org)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.traccar.handler;
+
+import org.traccar.model.Position;
+
+public abstract class BasePositionHandler {
+
+    public interface Callback {
+        void processed(Position position);
+    }
+
+    public abstract void handlePosition(Position position, Callback callback);
+}
diff --git a/src/main/java/org/traccar/handler/ComputedAttributesHandler.java b/src/main/java/org/traccar/handler/ComputedAttributesHandler.java
index 8b010ceae..8d6fb39c3 100644
--- a/src/main/java/org/traccar/handler/ComputedAttributesHandler.java
+++ b/src/main/java/org/traccar/handler/ComputedAttributesHandler.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 - 2023 Anton Tananaev (anton@traccar.org)
+ * Copyright 2017 - 2024 Anton Tananaev (anton@traccar.org)
  * Copyright 2017 Andrey Kunitsyn (andrey@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
@@ -16,26 +16,15 @@
  */
 package org.traccar.handler;
 
-import java.lang.reflect.InvocationTargetException;
-import java.lang.reflect.Method;
-import java.util.Arrays;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.HashSet;
-import java.util.Map;
-import java.util.Set;
-import java.util.List;
-
-import io.netty.channel.ChannelHandler;
-import org.apache.commons.jexl3.JexlFeatures;
-import org.apache.commons.jexl3.JexlEngine;
+import jakarta.inject.Inject;
 import org.apache.commons.jexl3.JexlBuilder;
-import org.apache.commons.jexl3.introspection.JexlSandbox;
+import org.apache.commons.jexl3.JexlEngine;
 import org.apache.commons.jexl3.JexlException;
+import org.apache.commons.jexl3.JexlFeatures;
 import org.apache.commons.jexl3.MapContext;
+import org.apache.commons.jexl3.introspection.JexlSandbox;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
-import org.traccar.BaseDataHandler;
 import org.traccar.config.Config;
 import org.traccar.config.Keys;
 import org.traccar.model.Attribute;
@@ -43,12 +32,17 @@ import org.traccar.model.Device;
 import org.traccar.model.Position;
 import org.traccar.session.cache.CacheManager;
 
-import jakarta.inject.Inject;
-import jakarta.inject.Singleton;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
 
-@Singleton
-@ChannelHandler.Sharable
-public class ComputedAttributesHandler extends BaseDataHandler {
+public class ComputedAttributesHandler extends BasePositionHandler {
 
     private static final Logger LOGGER = LoggerFactory.getLogger(ComputedAttributesHandler.class);
 
@@ -144,7 +138,7 @@ public class ComputedAttributesHandler extends BaseDataHandler {
     }
 
     @Override
-    protected Position handlePosition(Position position) {
+    public void handlePosition(Position position, Callback callback) {
         Collection<Attribute> attributes = cacheManager.getDeviceObjects(position.getDeviceId(), Attribute.class);
         for (Attribute attribute : attributes) {
             if (attribute.getAttribute() != null) {
@@ -202,7 +196,7 @@ public class ComputedAttributesHandler extends BaseDataHandler {
                 }
             }
         }
-        return position;
+        callback.processed(position);
     }
 
 }
diff --git a/src/main/java/org/traccar/handler/CopyAttributesHandler.java b/src/main/java/org/traccar/handler/CopyAttributesHandler.java
index 42b438e41..9c31bf56e 100644
--- a/src/main/java/org/traccar/handler/CopyAttributesHandler.java
+++ b/src/main/java/org/traccar/handler/CopyAttributesHandler.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016 - 2022 Anton Tananaev (anton@traccar.org)
+ * Copyright 2016 - 2024 Anton Tananaev (anton@traccar.org)
  * Copyright 2016 - 2017 Andrey Kunitsyn (andrey@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
@@ -16,20 +16,14 @@
  */
 package org.traccar.handler;
 
-import io.netty.channel.ChannelHandler;
-import org.traccar.BaseDataHandler;
+import jakarta.inject.Inject;
 import org.traccar.config.Config;
 import org.traccar.config.Keys;
 import org.traccar.helper.model.AttributeUtil;
 import org.traccar.model.Position;
 import org.traccar.session.cache.CacheManager;
 
-import jakarta.inject.Inject;
-import jakarta.inject.Singleton;
-
-@Singleton
-@ChannelHandler.Sharable
-public class CopyAttributesHandler extends BaseDataHandler {
+public class CopyAttributesHandler extends BasePositionHandler {
 
     private final boolean enabled;
     private final CacheManager cacheManager;
@@ -41,7 +35,7 @@ public class CopyAttributesHandler extends BaseDataHandler {
     }
 
     @Override
-    protected Position handlePosition(Position position) {
+    public void handlePosition(Position position, Callback callback) {
         if (enabled) {
             String attributesString = AttributeUtil.lookup(
                     cacheManager, Keys.PROCESSING_COPY_ATTRIBUTES, position.getDeviceId());
@@ -54,7 +48,7 @@ public class CopyAttributesHandler extends BaseDataHandler {
                 }
             }
         }
-        return position;
+        callback.processed(position);
     }
 
 }
diff --git a/src/main/java/org/traccar/handler/DefaultDataHandler.java b/src/main/java/org/traccar/handler/DatabaseHandler.java
index cca6dcd0a..b1f218a1e 100644
--- a/src/main/java/org/traccar/handler/DefaultDataHandler.java
+++ b/src/main/java/org/traccar/handler/DatabaseHandler.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2015 - 2022 Anton Tananaev (anton@traccar.org)
+ * Copyright 2015 - 2024 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,33 +15,27 @@
  */
 package org.traccar.handler;
 
-import io.netty.channel.ChannelHandler;
+import jakarta.inject.Inject;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
-import org.traccar.BaseDataHandler;
 import org.traccar.model.Position;
 import org.traccar.storage.Storage;
 import org.traccar.storage.query.Columns;
 import org.traccar.storage.query.Request;
 
-import jakarta.inject.Inject;
-import jakarta.inject.Singleton;
-
-@Singleton
-@ChannelHandler.Sharable
-public class DefaultDataHandler extends BaseDataHandler {
+public class DatabaseHandler extends BasePositionHandler {
 
-    private static final Logger LOGGER = LoggerFactory.getLogger(DefaultDataHandler.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(DatabaseHandler.class);
 
     private final Storage storage;
 
     @Inject
-    public DefaultDataHandler(Storage storage) {
+    public DatabaseHandler(Storage storage) {
         this.storage = storage;
     }
 
     @Override
-    protected Position handlePosition(Position position) {
+    public void handlePosition(Position position, Callback callback) {
 
         try {
             position.setId(storage.addObject(position, new Request(new Columns.Exclude("id"))));
@@ -49,7 +43,7 @@ public class DefaultDataHandler extends BaseDataHandler {
             LOGGER.warn("Failed to store position", error);
         }
 
-        return position;
+        callback.processed(position);
     }
 
 }
diff --git a/src/main/java/org/traccar/handler/DistanceHandler.java b/src/main/java/org/traccar/handler/DistanceHandler.java
index db8c73779..ee5d64894 100644
--- a/src/main/java/org/traccar/handler/DistanceHandler.java
+++ b/src/main/java/org/traccar/handler/DistanceHandler.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016 - 2023 Anton Tananaev (anton@traccar.org)
+ * Copyright 2016 - 2024 Anton Tananaev (anton@traccar.org)
  * Copyright 2015 Amila Silva
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
@@ -16,19 +16,14 @@
  */
 package org.traccar.handler;
 
-import io.netty.channel.ChannelHandler;
 import jakarta.inject.Inject;
-import jakarta.inject.Singleton;
-import org.traccar.BaseDataHandler;
 import org.traccar.config.Config;
 import org.traccar.config.Keys;
 import org.traccar.helper.DistanceCalculator;
 import org.traccar.model.Position;
 import org.traccar.session.cache.CacheManager;
 
-@Singleton
-@ChannelHandler.Sharable
-public class DistanceHandler extends BaseDataHandler {
+public class DistanceHandler extends BasePositionHandler {
 
     private final CacheManager cacheManager;
 
@@ -45,7 +40,7 @@ public class DistanceHandler extends BaseDataHandler {
     }
 
     @Override
-    protected Position handlePosition(Position position) {
+    public void handlePosition(Position position, Callback callback) {
 
         double distance = 0.0;
         if (position.hasAttribute(Position.KEY_DISTANCE)) {
@@ -76,7 +71,7 @@ public class DistanceHandler extends BaseDataHandler {
         position.set(Position.KEY_DISTANCE, distance);
         position.set(Position.KEY_TOTAL_DISTANCE, totalDistance + distance);
 
-        return position;
+        callback.processed(position);
     }
 
 }
diff --git a/src/main/java/org/traccar/handler/EngineHoursHandler.java b/src/main/java/org/traccar/handler/EngineHoursHandler.java
index 621205b34..ed5f9b509 100644
--- a/src/main/java/org/traccar/handler/EngineHoursHandler.java
+++ b/src/main/java/org/traccar/handler/EngineHoursHandler.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2018 - 2022 Anton Tananaev (anton@traccar.org)
+ * Copyright 2018 - 2024 Anton Tananaev (anton@traccar.org)
  * Copyright 2018 Andrey Kunitsyn (andrey@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
@@ -16,17 +16,11 @@
  */
 package org.traccar.handler;
 
-import io.netty.channel.ChannelHandler;
-import org.traccar.BaseDataHandler;
+import jakarta.inject.Inject;
 import org.traccar.model.Position;
 import org.traccar.session.cache.CacheManager;
 
-import jakarta.inject.Inject;
-import jakarta.inject.Singleton;
-
-@Singleton
-@ChannelHandler.Sharable
-public class EngineHoursHandler extends BaseDataHandler {
+public class EngineHoursHandler extends BasePositionHandler {
 
     private final CacheManager cacheManager;
 
@@ -36,7 +30,7 @@ public class EngineHoursHandler extends BaseDataHandler {
     }
 
     @Override
-    protected Position handlePosition(Position position) {
+    public void handlePosition(Position position, Callback callback) {
         if (!position.hasAttribute(Position.KEY_HOURS)) {
             Position last = cacheManager.getPosition(position.getDeviceId());
             if (last != null) {
@@ -49,7 +43,7 @@ public class EngineHoursHandler extends BaseDataHandler {
                 }
             }
         }
-        return position;
+        callback.processed(position);
     }
 
 }
diff --git a/src/main/java/org/traccar/handler/FilterHandler.java b/src/main/java/org/traccar/handler/FilterHandler.java
index a15d3ffad..4cc6233d0 100644
--- a/src/main/java/org/traccar/handler/FilterHandler.java
+++ b/src/main/java/org/traccar/handler/FilterHandler.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2014 - 2023 Anton Tananaev (anton@traccar.org)
+ * Copyright 2014 - 2024 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,9 +15,7 @@
  */
 package org.traccar.handler;
 
-import io.netty.channel.ChannelHandler;
-import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import jakarta.inject.Inject;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.traccar.config.Config;
@@ -36,13 +34,9 @@ import org.traccar.storage.query.Condition;
 import org.traccar.storage.query.Order;
 import org.traccar.storage.query.Request;
 
-import jakarta.inject.Inject;
-import jakarta.inject.Singleton;
 import java.util.Date;
 
-@Singleton
-@ChannelHandler.Sharable
-public class FilterHandler extends ChannelInboundHandlerAdapter {
+public class FilterHandler extends BasePositionHandler {
 
     private static final Logger LOGGER = LoggerFactory.getLogger(FilterHandler.class);
 
@@ -277,16 +271,11 @@ public class FilterHandler extends ChannelInboundHandlerAdapter {
     }
 
     @Override
-    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
-        if (msg instanceof Position) {
-            Position position = (Position) msg;
-            if (enabled && filter(position)) {
-                ctx.writeAndFlush(new AcknowledgementHandler.EventHandled(position));
-            } else {
-                ctx.fireChannelRead(position);
-            }
+    public void handlePosition(Position position, Callback callback) {
+        if (enabled && filter(position)) {
+            callback.processed(null);
         } else {
-            super.channelRead(ctx, msg);
+            callback.processed(position);
         }
     }
 
diff --git a/src/main/java/org/traccar/handler/GeocoderHandler.java b/src/main/java/org/traccar/handler/GeocoderHandler.java
index e4f240a90..c62bcb6f8 100644
--- a/src/main/java/org/traccar/handler/GeocoderHandler.java
+++ b/src/main/java/org/traccar/handler/GeocoderHandler.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2012 - 2021 Anton Tananaev (anton@traccar.org)
+ * Copyright 2012 - 2024 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,9 +15,6 @@
  */
 package org.traccar.handler;
 
-import io.netty.channel.ChannelHandler;
-import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.traccar.config.Config;
@@ -26,8 +23,7 @@ import org.traccar.geocoder.Geocoder;
 import org.traccar.model.Position;
 import org.traccar.session.cache.CacheManager;
 
-@ChannelHandler.Sharable
-public class GeocoderHandler extends ChannelInboundHandlerAdapter {
+public class GeocoderHandler extends BasePositionHandler {
 
     private static final Logger LOGGER = LoggerFactory.getLogger(GeocoderHandler.class);
 
@@ -46,39 +42,38 @@ public class GeocoderHandler extends ChannelInboundHandlerAdapter {
     }
 
     @Override
-    public void channelRead(final ChannelHandlerContext ctx, Object message) {
-        if (message instanceof Position && !ignorePositions) {
-            final Position position = (Position) message;
-            if (processInvalidPositions || position.getValid()) {
-                if (reuseDistance != 0) {
-                    Position lastPosition = cacheManager.getPosition(position.getDeviceId());
-                    if (lastPosition != null && lastPosition.getAddress() != null
-                            && position.getDouble(Position.KEY_DISTANCE) <= reuseDistance) {
-                        position.setAddress(lastPosition.getAddress());
-                        ctx.fireChannelRead(position);
-                        return;
-                    }
+    public void handlePosition(Position position, Callback callback) {
+        if (!ignorePositions) {
+            callback.processed(position);
+        }
+
+        if (processInvalidPositions || position.getValid()) {
+            if (reuseDistance != 0) {
+                Position lastPosition = cacheManager.getPosition(position.getDeviceId());
+                if (lastPosition != null && lastPosition.getAddress() != null
+                        && position.getDouble(Position.KEY_DISTANCE) <= reuseDistance) {
+                    position.setAddress(lastPosition.getAddress());
+                    callback.processed(position);
+                    return;
                 }
+            }
 
-                geocoder.getAddress(position.getLatitude(), position.getLongitude(),
-                        new Geocoder.ReverseGeocoderCallback() {
-                    @Override
-                    public void onSuccess(String address) {
-                        position.setAddress(address);
-                        ctx.fireChannelRead(position);
-                    }
+            geocoder.getAddress(position.getLatitude(), position.getLongitude(),
+                    new Geocoder.ReverseGeocoderCallback() {
+                @Override
+                public void onSuccess(String address) {
+                    position.setAddress(address);
+                    callback.processed(position);
+                }
 
-                    @Override
-                    public void onFailure(Throwable e) {
-                        LOGGER.warn("Geocoding failed", e);
-                        ctx.fireChannelRead(position);
-                    }
-                });
-            } else {
-                ctx.fireChannelRead(position);
-            }
+                @Override
+                public void onFailure(Throwable e) {
+                    LOGGER.warn("Geocoding failed", e);
+                    callback.processed(position);
+                }
+            });
         } else {
-            ctx.fireChannelRead(message);
+            callback.processed(position);
         }
     }
 
diff --git a/src/main/java/org/traccar/handler/GeofenceHandler.java b/src/main/java/org/traccar/handler/GeofenceHandler.java
index 68bc6dbf0..33b46f058 100644
--- a/src/main/java/org/traccar/handler/GeofenceHandler.java
+++ b/src/main/java/org/traccar/handler/GeofenceHandler.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2023 Anton Tananaev (anton@traccar.org)
+ * Copyright 2023 - 2024 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,20 +15,15 @@
  */
 package org.traccar.handler;
 
-import io.netty.channel.ChannelHandler;
-import org.traccar.BaseDataHandler;
+import jakarta.inject.Inject;
 import org.traccar.config.Config;
 import org.traccar.helper.model.GeofenceUtil;
 import org.traccar.model.Position;
 import org.traccar.session.cache.CacheManager;
 
-import jakarta.inject.Inject;
-import jakarta.inject.Singleton;
 import java.util.List;
 
-@Singleton
-@ChannelHandler.Sharable
-public class GeofenceHandler extends BaseDataHandler {
+public class GeofenceHandler extends BasePositionHandler {
 
     private final Config config;
     private final CacheManager cacheManager;
@@ -40,13 +35,13 @@ public class GeofenceHandler extends BaseDataHandler {
     }
 
     @Override
-    protected Position handlePosition(Position position) {
+    public void handlePosition(Position position, Callback callback) {
 
         List<Long> geofenceIds = GeofenceUtil.getCurrentGeofences(config, cacheManager, position);
         if (!geofenceIds.isEmpty()) {
             position.setGeofenceIds(geofenceIds);
         }
-        return position;
+        callback.processed(position);
     }
 
 }
diff --git a/src/main/java/org/traccar/handler/GeolocationHandler.java b/src/main/java/org/traccar/handler/GeolocationHandler.java
index a54ea03e3..cb9c04808 100644
--- a/src/main/java/org/traccar/handler/GeolocationHandler.java
+++ b/src/main/java/org/traccar/handler/GeolocationHandler.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2015 - 2023 Anton Tananaev (anton@traccar.org)
+ * Copyright 2015 - 2024 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,9 +15,6 @@
  */
 package org.traccar.handler;
 
-import io.netty.channel.ChannelHandler;
-import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.traccar.config.Config;
@@ -27,8 +24,7 @@ import org.traccar.geolocation.GeolocationProvider;
 import org.traccar.model.Position;
 import org.traccar.session.cache.CacheManager;
 
-@ChannelHandler.Sharable
-public class GeolocationHandler extends ChannelInboundHandlerAdapter {
+public class GeolocationHandler extends BasePositionHandler {
 
     private static final Logger LOGGER = LoggerFactory.getLogger(GeolocationHandler.class);
 
@@ -51,46 +47,41 @@ public class GeolocationHandler extends ChannelInboundHandlerAdapter {
     }
 
     @Override
-    public void channelRead(final ChannelHandlerContext ctx, Object message) {
-        if (message instanceof Position) {
-            final Position position = (Position) message;
-            if ((position.getOutdated() || processInvalidPositions && !position.getValid())
-                    && position.getNetwork() != null
-                    && (!requireWifi || position.getNetwork().getWifiAccessPoints() != null)) {
-                if (reuse) {
-                    Position lastPosition = cacheManager.getPosition(position.getDeviceId());
-                    if (lastPosition != null && position.getNetwork().equals(lastPosition.getNetwork())) {
-                        updatePosition(
-                                position, lastPosition.getLatitude(), lastPosition.getLongitude(),
-                                lastPosition.getAccuracy());
-                        ctx.fireChannelRead(position);
-                        return;
-                    }
+    public void handlePosition(Position position, Callback callback) {
+        if ((position.getOutdated() || processInvalidPositions && !position.getValid())
+                && position.getNetwork() != null
+                && (!requireWifi || position.getNetwork().getWifiAccessPoints() != null)) {
+            if (reuse) {
+                Position lastPosition = cacheManager.getPosition(position.getDeviceId());
+                if (lastPosition != null && position.getNetwork().equals(lastPosition.getNetwork())) {
+                    updatePosition(
+                            position, lastPosition.getLatitude(), lastPosition.getLongitude(),
+                            lastPosition.getAccuracy());
+                    callback.processed(position);
+                    return;
                 }
+            }
 
-                if (statisticsManager != null) {
-                    statisticsManager.registerGeolocationRequest();
-                }
+            if (statisticsManager != null) {
+                statisticsManager.registerGeolocationRequest();
+            }
 
-                geolocationProvider.getLocation(position.getNetwork(),
-                        new GeolocationProvider.LocationProviderCallback() {
-                    @Override
-                    public void onSuccess(double latitude, double longitude, double accuracy) {
-                        updatePosition(position, latitude, longitude, accuracy);
-                        ctx.fireChannelRead(position);
-                    }
+            geolocationProvider.getLocation(position.getNetwork(),
+                    new GeolocationProvider.LocationProviderCallback() {
+                @Override
+                public void onSuccess(double latitude, double longitude, double accuracy) {
+                    updatePosition(position, latitude, longitude, accuracy);
+                    callback.processed(position);
+                }
 
-                    @Override
-                    public void onFailure(Throwable e) {
-                        LOGGER.warn("Geolocation network error", e);
-                        ctx.fireChannelRead(position);
-                    }
-                });
-            } else {
-                ctx.fireChannelRead(position);
-            }
+                @Override
+                public void onFailure(Throwable e) {
+                    LOGGER.warn("Geolocation network error", e);
+                    callback.processed(position);
+                }
+            });
         } else {
-            ctx.fireChannelRead(message);
+            callback.processed(position);
         }
     }
 
diff --git a/src/main/java/org/traccar/handler/HemisphereHandler.java b/src/main/java/org/traccar/handler/HemisphereHandler.java
index 294e449db..6b64177e4 100644
--- a/src/main/java/org/traccar/handler/HemisphereHandler.java
+++ b/src/main/java/org/traccar/handler/HemisphereHandler.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016 - 2022 Anton Tananaev (anton@traccar.org)
+ * Copyright 2016 - 2024 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,18 +15,12 @@
  */
 package org.traccar.handler;
 
-import io.netty.channel.ChannelHandler;
-import org.traccar.BaseDataHandler;
+import jakarta.inject.Inject;
 import org.traccar.config.Config;
 import org.traccar.config.Keys;
 import org.traccar.model.Position;
 
-import jakarta.inject.Inject;
-import jakarta.inject.Singleton;
-
-@Singleton
-@ChannelHandler.Sharable
-public class HemisphereHandler extends BaseDataHandler {
+public class HemisphereHandler extends BasePositionHandler {
 
     private int latitudeFactor;
     private int longitudeFactor;
@@ -52,14 +46,14 @@ public class HemisphereHandler extends BaseDataHandler {
     }
 
     @Override
-    protected Position handlePosition(Position position) {
+    public void handlePosition(Position position, Callback callback) {
         if (latitudeFactor != 0) {
             position.setLatitude(Math.abs(position.getLatitude()) * latitudeFactor);
         }
         if (longitudeFactor != 0) {
             position.setLongitude(Math.abs(position.getLongitude()) * longitudeFactor);
         }
-        return position;
+        callback.processed(position);
     }
 
 }
diff --git a/src/main/java/org/traccar/handler/MotionHandler.java b/src/main/java/org/traccar/handler/MotionHandler.java
index 68a31a16a..bb7ff2a65 100644
--- a/src/main/java/org/traccar/handler/MotionHandler.java
+++ b/src/main/java/org/traccar/handler/MotionHandler.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 - 2023 Anton Tananaev (anton@traccar.org)
+ * Copyright 2017 - 2024 Anton Tananaev (anton@traccar.org)
  * Copyright 2017 Andrey Kunitsyn (andrey@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
@@ -16,19 +16,13 @@
  */
 package org.traccar.handler;
 
-import io.netty.channel.ChannelHandler;
-import org.traccar.BaseDataHandler;
+import jakarta.inject.Inject;
 import org.traccar.config.Keys;
 import org.traccar.helper.model.AttributeUtil;
 import org.traccar.model.Position;
 import org.traccar.session.cache.CacheManager;
 
-import jakarta.inject.Inject;
-import jakarta.inject.Singleton;
-
-@Singleton
-@ChannelHandler.Sharable
-public class MotionHandler extends BaseDataHandler {
+public class MotionHandler extends BasePositionHandler {
 
     private final CacheManager cacheManager;
 
@@ -38,13 +32,13 @@ public class MotionHandler extends BaseDataHandler {
     }
 
     @Override
-    protected Position handlePosition(Position position) {
+    public void handlePosition(Position position, Callback callback) {
         if (!position.hasAttribute(Position.KEY_MOTION)) {
             double threshold = AttributeUtil.lookup(
                     cacheManager, Keys.EVENT_MOTION_SPEED_THRESHOLD, position.getDeviceId());
             position.set(Position.KEY_MOTION, position.getSpeed() > threshold);
         }
-        return position;
+        callback.processed(position);
     }
 
 }
diff --git a/src/main/java/org/traccar/PositionForwardingHandler.java b/src/main/java/org/traccar/handler/PositionForwardingHandler.java
index a79b01367..be62fff37 100644
--- a/src/main/java/org/traccar/PositionForwardingHandler.java
+++ b/src/main/java/org/traccar/handler/PositionForwardingHandler.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2015 - 2022 Anton Tananaev (anton@traccar.org)
+ * Copyright 2015 - 2024 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -13,12 +13,13 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.traccar;
+package org.traccar.handler;
 
-import io.netty.channel.ChannelHandler;
 import io.netty.util.Timeout;
 import io.netty.util.Timer;
 import io.netty.util.TimerTask;
+import jakarta.annotation.Nullable;
+import jakarta.inject.Inject;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.traccar.config.Config;
@@ -30,15 +31,10 @@ import org.traccar.model.Device;
 import org.traccar.model.Position;
 import org.traccar.session.cache.CacheManager;
 
-import jakarta.annotation.Nullable;
-import jakarta.inject.Inject;
-import jakarta.inject.Singleton;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicInteger;
 
-@Singleton
-@ChannelHandler.Sharable
-public class PositionForwardingHandler extends BaseDataHandler {
+public class PositionForwardingHandler extends BasePositionHandler {
 
     private static final Logger LOGGER = LoggerFactory.getLogger(PositionForwardingHandler.class);
 
@@ -128,14 +124,14 @@ public class PositionForwardingHandler extends BaseDataHandler {
     }
 
     @Override
-    protected Position handlePosition(Position position) {
+    public void handlePosition(Position position, Callback callback) {
         if (positionForwarder != null) {
             PositionData positionData = new PositionData();
             positionData.setPosition(position);
             positionData.setDevice(cacheManager.getObject(Device.class, position.getDeviceId()));
             new AsyncRequestAndCallback(positionData).send();
         }
-        return position;
+        callback.processed(position);
     }
 
 }
diff --git a/src/main/java/org/traccar/handler/SpeedLimitHandler.java b/src/main/java/org/traccar/handler/SpeedLimitHandler.java
index 6edb6e912..604c10ca7 100644
--- a/src/main/java/org/traccar/handler/SpeedLimitHandler.java
+++ b/src/main/java/org/traccar/handler/SpeedLimitHandler.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2020 - 2022 Anton Tananaev (anton@traccar.org)
+ * Copyright 2020 - 2024 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,20 +15,13 @@
  */
 package org.traccar.handler;
 
-import io.netty.channel.ChannelHandler;
-import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
+import jakarta.inject.Inject;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.traccar.model.Position;
 import org.traccar.speedlimit.SpeedLimitProvider;
 
-import jakarta.inject.Inject;
-import jakarta.inject.Singleton;
-
-@Singleton
-@ChannelHandler.Sharable
-public class SpeedLimitHandler extends ChannelInboundHandlerAdapter {
+public class SpeedLimitHandler extends BasePositionHandler {
 
     private static final Logger LOGGER = LoggerFactory.getLogger(SpeedLimitHandler.class);
 
@@ -40,26 +33,22 @@ public class SpeedLimitHandler extends ChannelInboundHandlerAdapter {
     }
 
     @Override
-    public void channelRead(final ChannelHandlerContext ctx, Object message) {
-        if (message instanceof Position) {
-            final Position position = (Position) message;
-            speedLimitProvider.getSpeedLimit(position.getLatitude(), position.getLongitude(),
-                    new SpeedLimitProvider.SpeedLimitProviderCallback() {
-                @Override
-                public void onSuccess(double speedLimit) {
-                    position.set(Position.KEY_SPEED_LIMIT, speedLimit);
-                    ctx.fireChannelRead(position);
-                }
-
-                @Override
-                public void onFailure(Throwable e) {
-                    LOGGER.warn("Speed limit provider failed", e);
-                    ctx.fireChannelRead(position);
-                }
-            });
-        } else {
-            ctx.fireChannelRead(message);
-        }
+    public void handlePosition(Position position, Callback callback) {
+
+        speedLimitProvider.getSpeedLimit(position.getLatitude(), position.getLongitude(),
+                new SpeedLimitProvider.SpeedLimitProviderCallback() {
+            @Override
+            public void onSuccess(double speedLimit) {
+                position.set(Position.KEY_SPEED_LIMIT, speedLimit);
+                callback.processed(position);
+            }
+
+            @Override
+            public void onFailure(Throwable e) {
+                LOGGER.warn("Speed limit provider failed", e);
+                callback.processed(position);
+            }
+        });
     }
 
 }
diff --git a/src/main/java/org/traccar/handler/TimeHandler.java b/src/main/java/org/traccar/handler/TimeHandler.java
index ef0c3445d..2e703c681 100644
--- a/src/main/java/org/traccar/handler/TimeHandler.java
+++ b/src/main/java/org/traccar/handler/TimeHandler.java
@@ -15,11 +15,7 @@
  */
 package org.traccar.handler;
 
-import io.netty.channel.ChannelHandler;
-import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ChannelInboundHandlerAdapter;
 import jakarta.inject.Inject;
-import jakarta.inject.Singleton;
 import org.traccar.config.Config;
 import org.traccar.config.Keys;
 import org.traccar.model.Position;
@@ -28,9 +24,7 @@ import java.util.Arrays;
 import java.util.HashSet;
 import java.util.Set;
 
-@Singleton
-@ChannelHandler.Sharable
-public class TimeHandler extends ChannelInboundHandlerAdapter {
+public class TimeHandler extends BasePositionHandler {
 
     private final boolean enabled;
     private final boolean useServerTime;
@@ -53,10 +47,9 @@ public class TimeHandler extends ChannelInboundHandlerAdapter {
     }
 
     @Override
-    public void channelRead(ChannelHandlerContext ctx, Object msg) {
+    public void handlePosition(Position position, Callback callback) {
 
-        if (enabled && msg instanceof Position) {
-            Position position = (Position) msg;
+        if (enabled) {
             if (protocols == null || protocols.contains(position.getProtocol())) {
                 if (useServerTime) {
                     position.setDeviceTime(position.getServerTime());
@@ -66,7 +59,7 @@ public class TimeHandler extends ChannelInboundHandlerAdapter {
                 }
             }
         }
-        ctx.fireChannelRead(msg);
+        callback.processed(position);
     }
 
 }
diff --git a/src/main/java/org/traccar/handler/events/AlertEventHandler.java b/src/main/java/org/traccar/handler/events/AlertEventHandler.java
index 531a0f957..ca580b60d 100644
--- a/src/main/java/org/traccar/handler/events/AlertEventHandler.java
+++ b/src/main/java/org/traccar/handler/events/AlertEventHandler.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016 - 2022 Anton Tananaev (anton@traccar.org)
+ * Copyright 2016 - 2024 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,21 +15,13 @@
  */
 package org.traccar.handler.events;
 
-import java.util.Collections;
-import java.util.Map;
-
-import io.netty.channel.ChannelHandler;
+import jakarta.inject.Inject;
 import org.traccar.config.Config;
 import org.traccar.config.Keys;
 import org.traccar.model.Event;
 import org.traccar.model.Position;
 import org.traccar.session.cache.CacheManager;
 
-import jakarta.inject.Inject;
-import jakarta.inject.Singleton;
-
-@Singleton
-@ChannelHandler.Sharable
 public class AlertEventHandler extends BaseEventHandler {
 
     private final CacheManager cacheManager;
@@ -42,7 +34,7 @@ public class AlertEventHandler extends BaseEventHandler {
     }
 
     @Override
-    protected Map<Event, Position> analyzePosition(Position position) {
+    public void analyzePosition(Position position, Callback callback) {
         Object alarm = position.getAttributes().get(Position.KEY_ALARM);
         if (alarm != null) {
             boolean ignoreAlert = false;
@@ -55,10 +47,9 @@ public class AlertEventHandler extends BaseEventHandler {
             if (!ignoreAlert) {
                 Event event = new Event(Event.TYPE_ALARM, position);
                 event.set(Position.KEY_ALARM, (String) alarm);
-                return Collections.singletonMap(event, position);
+                callback.eventDetected(event);
             }
         }
-        return null;
     }
 
 }
diff --git a/src/main/java/org/traccar/handler/events/BaseEventHandler.java b/src/main/java/org/traccar/handler/events/BaseEventHandler.java
index 4a4fb40ff..009c83145 100644
--- a/src/main/java/org/traccar/handler/events/BaseEventHandler.java
+++ b/src/main/java/org/traccar/handler/events/BaseEventHandler.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016 - 2022 Anton Tananaev (anton@traccar.org)
+ * Copyright 2016 - 2024 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,33 +15,17 @@
  */
 package org.traccar.handler.events;
 
-import java.util.Map;
-
-import org.traccar.BaseDataHandler;
-import org.traccar.database.NotificationManager;
 import org.traccar.model.Event;
 import org.traccar.model.Position;
 
-import jakarta.inject.Inject;
-
-public abstract class BaseEventHandler extends BaseDataHandler {
-
-    private NotificationManager notificationManager;
+public abstract class BaseEventHandler {
 
-    @Inject
-    public void setNotificationManager(NotificationManager notificationManager) {
-        this.notificationManager = notificationManager;
+    public interface Callback {
+        void eventDetected(Event event);
     }
 
-    @Override
-    protected Position handlePosition(Position position) {
-        Map<Event, Position> events = analyzePosition(position);
-        if (events != null && !events.isEmpty()) {
-            notificationManager.updateEvents(events);
-        }
-        return position;
-    }
-
-    protected abstract Map<Event, Position> analyzePosition(Position position);
-
+    /**
+     * Event handlers should be processed synchronously.
+     */
+    public abstract void analyzePosition(Position position, Callback callback);
 }
diff --git a/src/main/java/org/traccar/handler/events/BehaviorEventHandler.java b/src/main/java/org/traccar/handler/events/BehaviorEventHandler.java
index 08ae35fcd..d654e18ce 100644
--- a/src/main/java/org/traccar/handler/events/BehaviorEventHandler.java
+++ b/src/main/java/org/traccar/handler/events/BehaviorEventHandler.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2021 - 2022 Anton Tananaev (anton@traccar.org)
+ * Copyright 2021 - 2024 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,7 +15,7 @@
  */
 package org.traccar.handler.events;
 
-import io.netty.channel.ChannelHandler;
+import jakarta.inject.Inject;
 import org.traccar.config.Config;
 import org.traccar.config.Keys;
 import org.traccar.helper.UnitsConverter;
@@ -23,13 +23,6 @@ import org.traccar.model.Event;
 import org.traccar.model.Position;
 import org.traccar.session.cache.CacheManager;
 
-import jakarta.inject.Inject;
-import jakarta.inject.Singleton;
-import java.util.Collections;
-import java.util.Map;
-
-@Singleton
-@ChannelHandler.Sharable
 public class BehaviorEventHandler extends BaseEventHandler {
 
     private final double accelerationThreshold;
@@ -45,7 +38,7 @@ public class BehaviorEventHandler extends BaseEventHandler {
     }
 
     @Override
-    protected Map<Event, Position> analyzePosition(Position position) {
+    public void analyzePosition(Position position, Callback callback) {
 
         Position lastPosition = cacheManager.getPosition(position.getDeviceId());
         if (lastPosition != null && position.getFixTime().equals(lastPosition.getFixTime())) {
@@ -54,14 +47,13 @@ public class BehaviorEventHandler extends BaseEventHandler {
             if (accelerationThreshold != 0 && acceleration >= accelerationThreshold) {
                 Event event = new Event(Event.TYPE_ALARM, position);
                 event.set(Position.KEY_ALARM, Position.ALARM_ACCELERATION);
-                return Collections.singletonMap(event, position);
+                callback.eventDetected(event);
             } else if (brakingThreshold != 0 && acceleration <= -brakingThreshold) {
                 Event event = new Event(Event.TYPE_ALARM, position);
                 event.set(Position.KEY_ALARM, Position.ALARM_BRAKING);
-                return Collections.singletonMap(event, position);
+                callback.eventDetected(event);
             }
         }
-        return null;
     }
 
 }
diff --git a/src/main/java/org/traccar/handler/events/CommandResultEventHandler.java b/src/main/java/org/traccar/handler/events/CommandResultEventHandler.java
index b70f8f33b..b98807b23 100644
--- a/src/main/java/org/traccar/handler/events/CommandResultEventHandler.java
+++ b/src/main/java/org/traccar/handler/events/CommandResultEventHandler.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016 - 2022 Anton Tananaev (anton@traccar.org)
+ * Copyright 2016 - 2024 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,18 +15,10 @@
  */
 package org.traccar.handler.events;
 
-import java.util.Collections;
-import java.util.Map;
-
-import io.netty.channel.ChannelHandler;
+import jakarta.inject.Inject;
 import org.traccar.model.Event;
 import org.traccar.model.Position;
 
-import jakarta.inject.Inject;
-import jakarta.inject.Singleton;
-
-@Singleton
-@ChannelHandler.Sharable
 public class CommandResultEventHandler extends BaseEventHandler {
 
     @Inject
@@ -34,14 +26,13 @@ public class CommandResultEventHandler extends BaseEventHandler {
     }
 
     @Override
-    protected Map<Event, Position> analyzePosition(Position position) {
+    public void analyzePosition(Position position, Callback callback) {
         Object commandResult = position.getAttributes().get(Position.KEY_RESULT);
         if (commandResult != null) {
             Event event = new Event(Event.TYPE_COMMAND_RESULT, position);
             event.set(Position.KEY_RESULT, (String) commandResult);
-            return Collections.singletonMap(event, position);
+            callback.eventDetected(event);
         }
-        return null;
     }
 
 }
diff --git a/src/main/java/org/traccar/handler/events/DriverEventHandler.java b/src/main/java/org/traccar/handler/events/DriverEventHandler.java
index b68327983..31f8d2b4b 100644
--- a/src/main/java/org/traccar/handler/events/DriverEventHandler.java
+++ b/src/main/java/org/traccar/handler/events/DriverEventHandler.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 - 2022 Anton Tananaev (anton@traccar.org)
+ * Copyright 2017 - 2024 Anton Tananaev (anton@traccar.org)
  * Copyright 2017 Andrey Kunitsyn (andrey@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
@@ -16,19 +16,12 @@
  */
 package org.traccar.handler.events;
 
-import io.netty.channel.ChannelHandler;
+import jakarta.inject.Inject;
 import org.traccar.helper.model.PositionUtil;
 import org.traccar.model.Event;
 import org.traccar.model.Position;
 import org.traccar.session.cache.CacheManager;
 
-import jakarta.inject.Inject;
-import jakarta.inject.Singleton;
-import java.util.Collections;
-import java.util.Map;
-
-@Singleton
-@ChannelHandler.Sharable
 public class DriverEventHandler extends BaseEventHandler {
 
     private final CacheManager cacheManager;
@@ -39,9 +32,9 @@ public class DriverEventHandler extends BaseEventHandler {
     }
 
     @Override
-    protected Map<Event, Position> analyzePosition(Position position) {
+    public void analyzePosition(Position position, Callback callback) {
         if (!PositionUtil.isLatest(cacheManager, position)) {
-            return null;
+            return;
         }
         String driverUniqueId = position.getString(Position.KEY_DRIVER_UNIQUE_ID);
         if (driverUniqueId != null) {
@@ -53,10 +46,9 @@ public class DriverEventHandler extends BaseEventHandler {
             if (!driverUniqueId.equals(oldDriverUniqueId)) {
                 Event event = new Event(Event.TYPE_DRIVER_CHANGED, position);
                 event.set(Position.KEY_DRIVER_UNIQUE_ID, driverUniqueId);
-                return Collections.singletonMap(event, position);
+                callback.eventDetected(event);
             }
         }
-        return null;
     }
 
 }
diff --git a/src/main/java/org/traccar/handler/events/FuelEventHandler.java b/src/main/java/org/traccar/handler/events/FuelEventHandler.java
index e5085ecc2..c5675f51d 100644
--- a/src/main/java/org/traccar/handler/events/FuelEventHandler.java
+++ b/src/main/java/org/traccar/handler/events/FuelEventHandler.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 - 2023 Anton Tananaev (anton@traccar.org)
+ * Copyright 2017 - 2024 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,7 +15,7 @@
  */
 package org.traccar.handler.events;
 
-import io.netty.channel.ChannelHandler;
+import jakarta.inject.Inject;
 import org.traccar.config.Keys;
 import org.traccar.helper.model.AttributeUtil;
 import org.traccar.helper.model.PositionUtil;
@@ -24,12 +24,6 @@ import org.traccar.model.Event;
 import org.traccar.model.Position;
 import org.traccar.session.cache.CacheManager;
 
-import jakarta.inject.Inject;
-import jakarta.inject.Singleton;
-import java.util.Map;
-
-@Singleton
-@ChannelHandler.Sharable
 public class FuelEventHandler extends BaseEventHandler {
 
     private final CacheManager cacheManager;
@@ -40,14 +34,14 @@ public class FuelEventHandler extends BaseEventHandler {
     }
 
     @Override
-    protected Map<Event, Position> analyzePosition(Position position) {
+    public void analyzePosition(Position position, Callback callback) {
 
         Device device = cacheManager.getObject(Device.class, position.getDeviceId());
         if (device == null) {
-            return null;
+            return;
         }
         if (!PositionUtil.isLatest(cacheManager, position)) {
-            return null;
+            return;
         }
 
         if (position.hasAttribute(Position.KEY_FUEL_LEVEL)) {
@@ -61,19 +55,17 @@ public class FuelEventHandler extends BaseEventHandler {
                     double threshold = AttributeUtil.lookup(
                             cacheManager, Keys.EVENT_FUEL_INCREASE_THRESHOLD, position.getDeviceId());
                     if (threshold > 0 && change >= threshold) {
-                        return Map.of(new Event(Event.TYPE_DEVICE_FUEL_INCREASE, position), position);
+                        callback.eventDetected(new Event(Event.TYPE_DEVICE_FUEL_INCREASE, position));
                     }
                 } else if (change < 0) {
                     double threshold = AttributeUtil.lookup(
                             cacheManager, Keys.EVENT_FUEL_DROP_THRESHOLD, position.getDeviceId());
                     if (threshold > 0 && Math.abs(change) >= threshold) {
-                        return Map.of(new Event(Event.TYPE_DEVICE_FUEL_DROP, position), position);
+                        callback.eventDetected(new Event(Event.TYPE_DEVICE_FUEL_DROP, position));
                     }
                 }
             }
         }
-
-        return null;
     }
 
 }
diff --git a/src/main/java/org/traccar/handler/events/GeofenceEventHandler.java b/src/main/java/org/traccar/handler/events/GeofenceEventHandler.java
index dbe2b8118..c8ecfb1ed 100644
--- a/src/main/java/org/traccar/handler/events/GeofenceEventHandler.java
+++ b/src/main/java/org/traccar/handler/events/GeofenceEventHandler.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016 - 2023 Anton Tananaev (anton@traccar.org)
+ * Copyright 2016 - 2024 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,7 +15,7 @@
  */
 package org.traccar.handler.events;
 
-import io.netty.channel.ChannelHandler;
+import jakarta.inject.Inject;
 import org.traccar.helper.model.PositionUtil;
 import org.traccar.model.Calendar;
 import org.traccar.model.Event;
@@ -23,15 +23,9 @@ import org.traccar.model.Geofence;
 import org.traccar.model.Position;
 import org.traccar.session.cache.CacheManager;
 
-import jakarta.inject.Inject;
-import jakarta.inject.Singleton;
 import java.util.ArrayList;
-import java.util.HashMap;
 import java.util.List;
-import java.util.Map;
 
-@Singleton
-@ChannelHandler.Sharable
 public class GeofenceEventHandler extends BaseEventHandler {
 
     private final CacheManager cacheManager;
@@ -42,9 +36,9 @@ public class GeofenceEventHandler extends BaseEventHandler {
     }
 
     @Override
-    protected Map<Event, Position> analyzePosition(Position position) {
+    public void analyzePosition(Position position, Callback callback) {
         if (!PositionUtil.isLatest(cacheManager, position)) {
-            return null;
+            return;
         }
 
         List<Long> oldGeofences = new ArrayList<>();
@@ -60,7 +54,6 @@ public class GeofenceEventHandler extends BaseEventHandler {
             oldGeofences.removeAll(position.getGeofenceIds());
         }
 
-        Map<Event, Position> events = new HashMap<>();
         for (long geofenceId : oldGeofences) {
             Geofence geofence = cacheManager.getObject(Geofence.class, geofenceId);
             if (geofence != null) {
@@ -69,7 +62,7 @@ public class GeofenceEventHandler extends BaseEventHandler {
                 if (calendar == null || calendar.checkMoment(position.getFixTime())) {
                     Event event = new Event(Event.TYPE_GEOFENCE_EXIT, position);
                     event.setGeofenceId(geofenceId);
-                    events.put(event, position);
+                    callback.eventDetected(event);
                 }
             }
         }
@@ -79,10 +72,8 @@ public class GeofenceEventHandler extends BaseEventHandler {
             if (calendar == null || calendar.checkMoment(position.getFixTime())) {
                 Event event = new Event(Event.TYPE_GEOFENCE_ENTER, position);
                 event.setGeofenceId(geofenceId);
-                events.put(event, position);
+                callback.eventDetected(event);
             }
         }
-        return events;
     }
-
 }
diff --git a/src/main/java/org/traccar/handler/events/IgnitionEventHandler.java b/src/main/java/org/traccar/handler/events/IgnitionEventHandler.java
index ba4159a42..bbf9fadd1 100644
--- a/src/main/java/org/traccar/handler/events/IgnitionEventHandler.java
+++ b/src/main/java/org/traccar/handler/events/IgnitionEventHandler.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016 - 2022 Anton Tananaev (anton@traccar.org)
+ * Copyright 2016 - 2024 Anton Tananaev (anton@traccar.org)
  * Copyright 2016 Andrey Kunitsyn (andrey@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
@@ -16,21 +16,13 @@
  */
 package org.traccar.handler.events;
 
-import java.util.Collections;
-import java.util.Map;
-
-import io.netty.channel.ChannelHandler;
+import jakarta.inject.Inject;
 import org.traccar.helper.model.PositionUtil;
 import org.traccar.model.Device;
 import org.traccar.model.Event;
 import org.traccar.model.Position;
 import org.traccar.session.cache.CacheManager;
 
-import jakarta.inject.Inject;
-import jakarta.inject.Singleton;
-
-@Singleton
-@ChannelHandler.Sharable
 public class IgnitionEventHandler extends BaseEventHandler {
 
     private final CacheManager cacheManager;
@@ -41,14 +33,12 @@ public class IgnitionEventHandler extends BaseEventHandler {
     }
 
     @Override
-    protected Map<Event, Position> analyzePosition(Position position) {
+    public void analyzePosition(Position position, Callback callback) {
         Device device = cacheManager.getObject(Device.class, position.getDeviceId());
         if (device == null || !PositionUtil.isLatest(cacheManager, position)) {
-            return null;
+            return;
         }
 
-        Map<Event, Position> result = null;
-
         if (position.hasAttribute(Position.KEY_IGNITION)) {
             boolean ignition = position.getBoolean(Position.KEY_IGNITION);
 
@@ -57,15 +47,12 @@ public class IgnitionEventHandler extends BaseEventHandler {
                 boolean oldIgnition = lastPosition.getBoolean(Position.KEY_IGNITION);
 
                 if (ignition && !oldIgnition) {
-                    result = Collections.singletonMap(
-                            new Event(Event.TYPE_IGNITION_ON, position), position);
+                    callback.eventDetected(new Event(Event.TYPE_IGNITION_ON, position));
                 } else if (!ignition && oldIgnition) {
-                    result = Collections.singletonMap(
-                            new Event(Event.TYPE_IGNITION_OFF, position), position);
+                    callback.eventDetected(new Event(Event.TYPE_IGNITION_OFF, position));
                 }
             }
         }
-        return result;
     }
 
 }
diff --git a/src/main/java/org/traccar/handler/events/MaintenanceEventHandler.java b/src/main/java/org/traccar/handler/events/MaintenanceEventHandler.java
index 2fa2e8869..573ad4ad6 100644
--- a/src/main/java/org/traccar/handler/events/MaintenanceEventHandler.java
+++ b/src/main/java/org/traccar/handler/events/MaintenanceEventHandler.java
@@ -16,20 +16,12 @@
  */
 package org.traccar.handler.events;
 
-import java.util.HashMap;
-import java.util.Map;
-
-import io.netty.channel.ChannelHandler;
+import jakarta.inject.Inject;
 import org.traccar.model.Event;
 import org.traccar.model.Maintenance;
 import org.traccar.model.Position;
 import org.traccar.session.cache.CacheManager;
 
-import jakarta.inject.Inject;
-import jakarta.inject.Singleton;
-
-@Singleton
-@ChannelHandler.Sharable
 public class MaintenanceEventHandler extends BaseEventHandler {
 
     private final CacheManager cacheManager;
@@ -40,13 +32,12 @@ public class MaintenanceEventHandler extends BaseEventHandler {
     }
 
     @Override
-    protected Map<Event, Position> analyzePosition(Position position) {
+    public void analyzePosition(Position position, Callback callback) {
         Position lastPosition = cacheManager.getPosition(position.getDeviceId());
         if (lastPosition == null || position.getFixTime().compareTo(lastPosition.getFixTime()) < 0) {
-            return null;
+            return;
         }
 
-        Map<Event, Position> events = new HashMap<>();
         for (Maintenance maintenance : cacheManager.getDeviceObjects(position.getDeviceId(), Maintenance.class)) {
             if (maintenance.getPeriod() != 0) {
                 double oldValue = getValue(lastPosition, maintenance.getType());
@@ -58,13 +49,11 @@ public class MaintenanceEventHandler extends BaseEventHandler {
                         Event event = new Event(Event.TYPE_MAINTENANCE, position);
                         event.setMaintenanceId(maintenance.getId());
                         event.set(maintenance.getType(), newValue);
-                        events.put(event, position);
+                        callback.eventDetected(event);
                     }
                 }
             }
         }
-
-        return events;
     }
 
     private double getValue(Position position, String type) {
diff --git a/src/main/java/org/traccar/handler/events/MediaEventHandler.java b/src/main/java/org/traccar/handler/events/MediaEventHandler.java
index 52d8e6961..2745296c4 100644
--- a/src/main/java/org/traccar/handler/events/MediaEventHandler.java
+++ b/src/main/java/org/traccar/handler/events/MediaEventHandler.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2022 Anton Tananaev (anton@traccar.org)
+ * Copyright 2022 - 2024 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,18 +15,12 @@
  */
 package org.traccar.handler.events;
 
-import io.netty.channel.ChannelHandler;
+import jakarta.inject.Inject;
 import org.traccar.model.Event;
 import org.traccar.model.Position;
 
-import jakarta.inject.Inject;
-import jakarta.inject.Singleton;
-import java.util.Map;
-import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
-@Singleton
-@ChannelHandler.Sharable
 public class MediaEventHandler extends BaseEventHandler {
 
     @Inject
@@ -34,8 +28,8 @@ public class MediaEventHandler extends BaseEventHandler {
     }
 
     @Override
-    protected Map<Event, Position> analyzePosition(Position position) {
-        return Stream.of(Position.KEY_IMAGE, Position.KEY_VIDEO, Position.KEY_AUDIO)
+    public void analyzePosition(Position position, Callback callback) {
+        Stream.of(Position.KEY_IMAGE, Position.KEY_VIDEO, Position.KEY_AUDIO)
                 .filter(position::hasAttribute)
                 .map(type -> {
                     Event event = new Event(Event.TYPE_MEDIA, position);
@@ -43,7 +37,7 @@ public class MediaEventHandler extends BaseEventHandler {
                     event.set("file", position.getString(type));
                     return event;
                 })
-                .collect(Collectors.toMap(event -> event, event -> position));
+                .forEach(callback::eventDetected);
     }
 
 }
diff --git a/src/main/java/org/traccar/handler/events/MotionEventHandler.java b/src/main/java/org/traccar/handler/events/MotionEventHandler.java
index 15902d6d4..41d68985b 100644
--- a/src/main/java/org/traccar/handler/events/MotionEventHandler.java
+++ b/src/main/java/org/traccar/handler/events/MotionEventHandler.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016 - 2023 Anton Tananaev (anton@traccar.org)
+ * Copyright 2016 - 2024 Anton Tananaev (anton@traccar.org)
  * Copyright 2017 Andrey Kunitsyn (andrey@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
@@ -16,14 +16,13 @@
  */
 package org.traccar.handler.events;
 
-import io.netty.channel.ChannelHandler;
+import jakarta.inject.Inject;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.traccar.config.Keys;
 import org.traccar.helper.model.AttributeUtil;
 import org.traccar.helper.model.PositionUtil;
 import org.traccar.model.Device;
-import org.traccar.model.Event;
 import org.traccar.model.Position;
 import org.traccar.reports.common.TripsConfig;
 import org.traccar.session.cache.CacheManager;
@@ -35,13 +34,6 @@ import org.traccar.storage.query.Columns;
 import org.traccar.storage.query.Condition;
 import org.traccar.storage.query.Request;
 
-import jakarta.inject.Inject;
-import jakarta.inject.Singleton;
-import java.util.Collections;
-import java.util.Map;
-
-@Singleton
-@ChannelHandler.Sharable
 public class MotionEventHandler extends BaseEventHandler {
 
     private static final Logger LOGGER = LoggerFactory.getLogger(MotionEventHandler.class);
@@ -56,17 +48,17 @@ public class MotionEventHandler extends BaseEventHandler {
     }
 
     @Override
-    protected Map<Event, Position> analyzePosition(Position position) {
+    public void analyzePosition(Position position, Callback callback) {
 
         long deviceId = position.getDeviceId();
         Device device = cacheManager.getObject(Device.class, deviceId);
         if (device == null || !PositionUtil.isLatest(cacheManager, position)) {
-            return null;
+            return;
         }
         boolean processInvalid = AttributeUtil.lookup(
                 cacheManager, Keys.EVENT_MOTION_PROCESS_INVALID_POSITIONS, deviceId);
         if (!processInvalid && !position.getValid()) {
-            return null;
+            return;
         }
 
         TripsConfig tripsConfig = new TripsConfig(new AttributeUtil.CacheProvider(cacheManager, deviceId));
@@ -82,7 +74,9 @@ public class MotionEventHandler extends BaseEventHandler {
                 LOGGER.warn("Update device motion error", e);
             }
         }
-        return state.getEvent() != null ? Collections.singletonMap(state.getEvent(), position) : null;
+        if (state.getEvent() != null) {
+            callback.eventDetected(state.getEvent());
+        }
     }
 
 }
diff --git a/src/main/java/org/traccar/handler/events/OverspeedEventHandler.java b/src/main/java/org/traccar/handler/events/OverspeedEventHandler.java
index 3bb5f713c..9598581e6 100644
--- a/src/main/java/org/traccar/handler/events/OverspeedEventHandler.java
+++ b/src/main/java/org/traccar/handler/events/OverspeedEventHandler.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016 - 2023 Anton Tananaev (anton@traccar.org)
+ * Copyright 2016 - 2024 Anton Tananaev (anton@traccar.org)
  * Copyright 2018 Andrey Kunitsyn (andrey@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
@@ -16,7 +16,7 @@
  */
 package org.traccar.handler.events;
 
-import io.netty.channel.ChannelHandler;
+import jakarta.inject.Inject;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.traccar.config.Config;
@@ -24,7 +24,6 @@ import org.traccar.config.Keys;
 import org.traccar.helper.model.AttributeUtil;
 import org.traccar.helper.model.PositionUtil;
 import org.traccar.model.Device;
-import org.traccar.model.Event;
 import org.traccar.model.Geofence;
 import org.traccar.model.Position;
 import org.traccar.session.cache.CacheManager;
@@ -36,13 +35,6 @@ import org.traccar.storage.query.Columns;
 import org.traccar.storage.query.Condition;
 import org.traccar.storage.query.Request;
 
-import jakarta.inject.Inject;
-import jakarta.inject.Singleton;
-import java.util.Collections;
-import java.util.Map;
-
-@Singleton
-@ChannelHandler.Sharable
 public class OverspeedEventHandler extends BaseEventHandler {
 
     private static final Logger LOGGER = LoggerFactory.getLogger(OverspeedEventHandler.class);
@@ -55,8 +47,7 @@ public class OverspeedEventHandler extends BaseEventHandler {
     private final double multiplier;
 
     @Inject
-    public OverspeedEventHandler(
-            Config config, CacheManager cacheManager, Storage storage) {
+    public OverspeedEventHandler(Config config, CacheManager cacheManager, Storage storage) {
         this.cacheManager = cacheManager;
         this.storage = storage;
         minimalDuration = config.getLong(Keys.EVENT_OVERSPEED_MINIMAL_DURATION) * 1000;
@@ -65,15 +56,15 @@ public class OverspeedEventHandler extends BaseEventHandler {
     }
 
     @Override
-    protected Map<Event, Position> analyzePosition(Position position) {
+    public void analyzePosition(Position position, Callback callback) {
 
         long deviceId = position.getDeviceId();
         Device device = cacheManager.getObject(Device.class, position.getDeviceId());
         if (device == null) {
-            return null;
+            return;
         }
         if (!PositionUtil.isLatest(cacheManager, position) || !position.getValid()) {
-            return null;
+            return;
         }
 
         double speedLimit = AttributeUtil.lookup(cacheManager, Keys.EVENT_OVERSPEED_LIMIT, deviceId);
@@ -105,7 +96,7 @@ public class OverspeedEventHandler extends BaseEventHandler {
         }
 
         if (speedLimit == 0) {
-            return null;
+            return;
         }
 
         OverspeedState state = OverspeedState.fromDevice(device);
@@ -120,7 +111,9 @@ public class OverspeedEventHandler extends BaseEventHandler {
                 LOGGER.warn("Update device overspeed error", e);
             }
         }
-        return state.getEvent() != null ? Collections.singletonMap(state.getEvent(), position) : null;
+        if (state.getEvent() != null) {
+            callback.eventDetected(state.getEvent());
+        }
     }
 
 }
diff --git a/src/main/java/org/traccar/handler/AcknowledgementHandler.java b/src/main/java/org/traccar/handler/network/AcknowledgementHandler.java
index 4c1085998..e87f5d34c 100644
--- a/src/main/java/org/traccar/handler/AcknowledgementHandler.java
+++ b/src/main/java/org/traccar/handler/network/AcknowledgementHandler.java
@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.traccar.handler;
+package org.traccar.handler.network;
 
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelOutboundHandlerAdapter;
diff --git a/src/main/java/org/traccar/MainEventHandler.java b/src/main/java/org/traccar/handler/network/MainEventHandler.java
index fb0171d63..901036d44 100644
--- a/src/main/java/org/traccar/MainEventHandler.java
+++ b/src/main/java/org/traccar/handler/network/MainEventHandler.java
@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.traccar;
+package org.traccar.handler.network;
 
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelHandler;
@@ -24,10 +24,11 @@ import io.netty.handler.codec.http.HttpRequestDecoder;
 import io.netty.handler.timeout.IdleStateEvent;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.traccar.BasePipelineFactory;
+import org.traccar.BaseProtocolDecoder;
 import org.traccar.config.Config;
 import org.traccar.config.Keys;
 import org.traccar.database.StatisticsManager;
-import org.traccar.handler.AcknowledgementHandler;
 import org.traccar.helper.DateUtil;
 import org.traccar.helper.NetworkUtil;
 import org.traccar.helper.model.PositionUtil;
diff --git a/src/main/java/org/traccar/handler/NetworkForwarderHandler.java b/src/main/java/org/traccar/handler/network/NetworkForwarderHandler.java
index 470e175ca..5f07ce355 100644
--- a/src/main/java/org/traccar/handler/NetworkForwarderHandler.java
+++ b/src/main/java/org/traccar/handler/network/NetworkForwarderHandler.java
@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.traccar.handler;
+package org.traccar.handler.network;
 
 import io.netty.buffer.ByteBuf;
 import io.netty.channel.ChannelHandlerContext;
diff --git a/src/main/java/org/traccar/handler/NetworkMessageHandler.java b/src/main/java/org/traccar/handler/network/NetworkMessageHandler.java
index b1d926bfa..c2fb9016a 100644
--- a/src/main/java/org/traccar/handler/NetworkMessageHandler.java
+++ b/src/main/java/org/traccar/handler/network/NetworkMessageHandler.java
@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.traccar.handler;
+package org.traccar.handler.network;
 
 import io.netty.buffer.ByteBuf;
 import io.netty.channel.ChannelDuplexHandler;
diff --git a/src/main/java/org/traccar/handler/OpenChannelHandler.java b/src/main/java/org/traccar/handler/network/OpenChannelHandler.java
index e416f35ae..21aaae676 100644
--- a/src/main/java/org/traccar/handler/OpenChannelHandler.java
+++ b/src/main/java/org/traccar/handler/network/OpenChannelHandler.java
@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.traccar.handler;
+package org.traccar.handler.network;
 
 import io.netty.channel.ChannelDuplexHandler;
 import io.netty.channel.ChannelHandlerContext;
diff --git a/src/main/java/org/traccar/handler/RemoteAddressHandler.java b/src/main/java/org/traccar/handler/network/RemoteAddressHandler.java
index 61ada5b91..d545ed799 100644
--- a/src/main/java/org/traccar/handler/RemoteAddressHandler.java
+++ b/src/main/java/org/traccar/handler/network/RemoteAddressHandler.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2015 - 2022 Anton Tananaev (anton@traccar.org)
+ * Copyright 2015 - 2024 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -13,20 +13,18 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.traccar.handler;
+package org.traccar.handler.network;
 
 import io.netty.channel.ChannelHandler;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelInboundHandlerAdapter;
+import jakarta.inject.Inject;
 import org.traccar.config.Config;
 import org.traccar.config.Keys;
 import org.traccar.model.Position;
 
-import jakarta.inject.Inject;
-import jakarta.inject.Singleton;
 import java.net.InetSocketAddress;
 
-@Singleton
 @ChannelHandler.Sharable
 public class RemoteAddressHandler extends ChannelInboundHandlerAdapter {
 
diff --git a/src/main/java/org/traccar/handler/StandardLoggingHandler.java b/src/main/java/org/traccar/handler/network/StandardLoggingHandler.java
index 513602dd8..dae93655d 100644
--- a/src/main/java/org/traccar/handler/StandardLoggingHandler.java
+++ b/src/main/java/org/traccar/handler/network/StandardLoggingHandler.java
@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.traccar.handler;
+package org.traccar.handler.network;
 
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.ByteBufUtil;
diff --git a/src/test/java/org/traccar/handler/DistanceHandlerTest.java b/src/test/java/org/traccar/handler/DistanceHandlerTest.java
index 7d2f1e2e3..04a27ad79 100644
--- a/src/test/java/org/traccar/handler/DistanceHandlerTest.java
+++ b/src/test/java/org/traccar/handler/DistanceHandlerTest.java
@@ -15,14 +15,15 @@ public class DistanceHandlerTest {
 
         DistanceHandler distanceHandler = new DistanceHandler(new Config(), mock(CacheManager.class));
 
-        Position position = distanceHandler.handlePosition(new Position());
+        Position position = new Position();
+        distanceHandler.handlePosition(position, p -> {});
 
         assertEquals(0.0, position.getAttributes().get(Position.KEY_DISTANCE));
         assertEquals(0.0, position.getAttributes().get(Position.KEY_TOTAL_DISTANCE));
 
         position.set(Position.KEY_DISTANCE, 100);
 
-        position = distanceHandler.handlePosition(position);
+        distanceHandler.handlePosition(position, p -> {});
 
         assertEquals(100.0, position.getAttributes().get(Position.KEY_DISTANCE));
         assertEquals(100.0, position.getAttributes().get(Position.KEY_TOTAL_DISTANCE));
diff --git a/src/test/java/org/traccar/handler/MotionHandlerTest.java b/src/test/java/org/traccar/handler/MotionHandlerTest.java
index 10cdf6a90..927c803d9 100644
--- a/src/test/java/org/traccar/handler/MotionHandlerTest.java
+++ b/src/test/java/org/traccar/handler/MotionHandlerTest.java
@@ -26,7 +26,8 @@ public class MotionHandlerTest {
 
         MotionHandler motionHandler = new MotionHandler(cacheManager);
 
-        Position position = motionHandler.handlePosition(new Position());
+        Position position = new Position();
+        motionHandler.handlePosition(position, p -> {});
 
         assertEquals(false, position.getAttributes().get(Position.KEY_MOTION));
 
diff --git a/src/test/java/org/traccar/handler/events/AlertEventHandlerTest.java b/src/test/java/org/traccar/handler/events/AlertEventHandlerTest.java
index 66dc55c85..7b1991553 100644
--- a/src/test/java/org/traccar/handler/events/AlertEventHandlerTest.java
+++ b/src/test/java/org/traccar/handler/events/AlertEventHandlerTest.java
@@ -7,10 +7,11 @@ import org.traccar.model.Event;
 import org.traccar.model.Position;
 import org.traccar.session.cache.CacheManager;
 
-import java.util.Map;
+import java.util.ArrayList;
+import java.util.List;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.mockito.Mockito.mock;
 
 public class AlertEventHandlerTest extends BaseTest {
@@ -22,9 +23,10 @@ public class AlertEventHandlerTest extends BaseTest {
         
         Position position = new Position();
         position.set(Position.KEY_ALARM, Position.ALARM_GENERAL);
-        Map<Event, Position> events = alertEventHandler.analyzePosition(position);
-        assertNotNull(events);
-        Event event = events.keySet().iterator().next();
+        List<Event> events = new ArrayList<>();
+        alertEventHandler.analyzePosition(position, events::add);
+        assertFalse(events.isEmpty());
+        Event event = events.iterator().next();
         assertEquals(Event.TYPE_ALARM, event.getType());
 
     }
diff --git a/src/test/java/org/traccar/handler/events/CommandResultEventHandlerTest.java b/src/test/java/org/traccar/handler/events/CommandResultEventHandlerTest.java
index bc24e42f5..58e198b7f 100644
--- a/src/test/java/org/traccar/handler/events/CommandResultEventHandlerTest.java
+++ b/src/test/java/org/traccar/handler/events/CommandResultEventHandlerTest.java
@@ -5,9 +5,12 @@ import org.traccar.BaseTest;
 import org.traccar.model.Event;
 import org.traccar.model.Position;
 
+import java.util.ArrayList;
+import java.util.List;
 import java.util.Map;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 
 public class CommandResultEventHandlerTest extends BaseTest {
@@ -19,9 +22,10 @@ public class CommandResultEventHandlerTest extends BaseTest {
         
         Position position = new Position();
         position.set(Position.KEY_RESULT, "Test Result");
-        Map<Event, Position> events = commandResultEventHandler.analyzePosition(position);
-        assertNotNull(events);
-        Event event = events.keySet().iterator().next();
+        List<Event> events = new ArrayList<>();
+        commandResultEventHandler.analyzePosition(position, events::add);
+        assertFalse(events.isEmpty());
+        Event event = events.iterator().next();
         assertEquals(Event.TYPE_COMMAND_RESULT, event.getType());
     }
 
diff --git a/src/test/java/org/traccar/handler/events/IgnitionEventHandlerTest.java b/src/test/java/org/traccar/handler/events/IgnitionEventHandlerTest.java
index 972932df4..61ff50efa 100644
--- a/src/test/java/org/traccar/handler/events/IgnitionEventHandlerTest.java
+++ b/src/test/java/org/traccar/handler/events/IgnitionEventHandlerTest.java
@@ -1,14 +1,11 @@
 package org.traccar.handler.events;
 
+import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
 import org.traccar.BaseTest;
-import org.traccar.model.Event;
 import org.traccar.model.Position;
 import org.traccar.session.cache.CacheManager;
 
-import java.util.Map;
-
-import static org.junit.jupiter.api.Assertions.assertNull;
 import static org.mockito.Mockito.mock;
 
 public class IgnitionEventHandlerTest extends BaseTest {
@@ -21,8 +18,7 @@ public class IgnitionEventHandlerTest extends BaseTest {
         Position position = new Position();
         position.set(Position.KEY_IGNITION, true);
         position.setValid(true);
-        Map<Event, Position> events = ignitionEventHandler.analyzePosition(position);
-        assertNull(events);
+        ignitionEventHandler.analyzePosition(position, Assertions::assertNull);
     }
 
 }
diff --git a/src/test/java/org/traccar/handler/events/MaintenanceEventHandlerTest.java b/src/test/java/org/traccar/handler/events/MaintenanceEventHandlerTest.java
index 661336d76..f0bd4a3f9 100644
--- a/src/test/java/org/traccar/handler/events/MaintenanceEventHandlerTest.java
+++ b/src/test/java/org/traccar/handler/events/MaintenanceEventHandlerTest.java
@@ -2,11 +2,14 @@ package org.traccar.handler.events;
 
 import org.junit.jupiter.api.Test;
 import org.traccar.BaseTest;
+import org.traccar.model.Event;
 import org.traccar.model.Maintenance;
 import org.traccar.model.Position;
 import org.traccar.session.cache.CacheManager;
 
+import java.util.ArrayList;
 import java.util.Date;
+import java.util.List;
 import java.util.Set;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
@@ -38,24 +41,30 @@ public class MaintenanceEventHandlerTest extends BaseTest {
         MaintenanceEventHandler eventHandler = new MaintenanceEventHandler(cacheManager);        
 
         when(maintenance.getStart()).thenReturn(10000.0);
-        when(maintenance.getPeriod()).thenReturn(2000.0);                
+        when(maintenance.getPeriod()).thenReturn(2000.0);
+
+        List<Event> events = new ArrayList<>();
  
         lastPosition.set(Position.KEY_TOTAL_DISTANCE, 1999);
-        position.set(Position.KEY_TOTAL_DISTANCE, 2001);        
-        assertTrue(eventHandler.analyzePosition(position).isEmpty());
+        position.set(Position.KEY_TOTAL_DISTANCE, 2001);
+        eventHandler.analyzePosition(position, events::add);
+        assertTrue(events.isEmpty());
 
         lastPosition.set(Position.KEY_TOTAL_DISTANCE, 3999);
-        position.set(Position.KEY_TOTAL_DISTANCE, 4001);        
-        assertTrue(eventHandler.analyzePosition(position).isEmpty());
+        position.set(Position.KEY_TOTAL_DISTANCE, 4001);
+        eventHandler.analyzePosition(position, events::add);
+        assertTrue(events.isEmpty());
 
         lastPosition.set(Position.KEY_TOTAL_DISTANCE, 9999);
         position.set(Position.KEY_TOTAL_DISTANCE, 10001);
-        assertEquals(1, eventHandler.analyzePosition(position).size());
+        eventHandler.analyzePosition(position, events::add);
+        assertEquals(1, events.size());
 
         lastPosition.set(Position.KEY_TOTAL_DISTANCE, 11999);
         position.set(Position.KEY_TOTAL_DISTANCE, 12001);
-        assertEquals(1, eventHandler.analyzePosition(position).size());
-        
+        eventHandler.analyzePosition(position, events::add);
+        assertEquals(2, events.size());
+
     }
 
 }