Chg: #85 - refactoring of MessageEngine classes

* MessageEngine is now an interface which does not handle delays
* the former MessageEngine class is now called DefaultMessageEngine. It:
  * does not handle delays
  * speeds-up former check on link existence
* a DelayMessageEngine has been re-created. It:
  * inherits from DefaultMessageEngine
  * better handles instantaneous delays
* AsyncMessageEngine and RandomMessageEngine implementation have been modified to benefit from DefaultMessageEngine's modifications
* test classes have been added to showcase all MessageEngines behaviors

Author: remikey

apps/examples/src/main/java/examples/fancy/canadairs/Main.java

@@ -1,13 +1,8 @@
 package examples.fancy.canadairs;
 
-import io.jbotsim.core.Link;
-import io.jbotsim.core.Node;
-import io.jbotsim.core.Topology;
-import io.jbotsim.core.LinkResolver;
+import io.jbotsim.core.*;
 import io.jbotsim.ui.JViewer;
 
-import io.jbotsim.core.Color;
-
 /**
  * Created by acasteig on 22/03/15.
  */
@@ -36,7 +31,9 @@ public static void createMap(Topology topology){
     public static void main(String[] args) {
         topology = new Topology(800,600);
         topology.setLinkResolver(new Main());
-        topology.getMessageEngine().setDelay(10);
+        DelayMessageEngine messageEngine = new DelayMessageEngine(topology);
+        messageEngine.setDelay(10);
+        topology.setMessageEngine(messageEngine);
         createMap(topology);
         topology.setTimeUnit(30);
         topology.setDefaultNodeModel(Fire.class);

apps/examples/src/main/java/examples/features/async/AsyncExampleFIFO.java

@@ -0,0 +1,76 @@
+/*
+ * Copyright 2008 - 2020, Arnaud Casteigts and the JBotSim contributors <contact@jbotsim.io>
+ *
+ *
+ * This file is part of JBotSim.
+ *
+ * JBotSim is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * JBotSim is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with JBotSim.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+package examples.features.messaging;
+
+import io.jbotsim.core.Message;
+import io.jbotsim.core.Node;
+import io.jbotsim.core.Topology;
+import io.jbotsim.ui.JViewer;
+import io.jbotsim.contrib.messaging.AsyncMessageEngine;
+import io.jbotsim.gen.basic.TopologyGenerators;
+
+
+public class AsyncMessageEngineFIFOExampleMain extends Node {
+
+    static int msg = 0;
+
+    @Override
+    public void onSelection() {
+        int nbMsg = 50;
+        for(int i = 0; i < nbMsg; i++)
+            sendMessage();
+    }
+
+    protected void sendMessage() {
+        MessageContent content = new MessageContent();
+        sendAll(new Message(content));
+        System.out.println("["+ getID() + " - " + content.messageNumber + "] emitted at " + content.sendTime);
+        msg++;
+    }
+
+    @Override
+    public void onMessage(Message message) {
+        MessageContent messageContent = (MessageContent)message.getContent();
+        int currentTime = getTime();
+        int deliveryDuration = (currentTime - messageContent.sendTime);
+        int messageNumber = messageContent.messageNumber;
+        System.out.println("["+ messageNumber +"] received at " + currentTime + ", deliveryDuration = " + deliveryDuration + " rounds");
+    }
+
+    public static void main(String[] args) {
+        Topology tp = new Topology();
+        tp.setTimeUnit(20);
+        AsyncMessageEngine messageEngine = new AsyncMessageEngine(tp);
+        messageEngine.setAverageDuration(20);
+//        messageEngine.setDebug(true);
+        tp.setMessageEngine(messageEngine);
+        tp.setDefaultNodeModel(AsyncMessageEngineFIFOExampleMain.class);
+        TopologyGenerators.generateLine(tp, 2);
+        new JViewer(tp);
+        tp.start();
+    }
+
+    private class MessageContent {
+        int messageNumber = msg;
+        int sendTime = getTime();
+    }
+}

apps/examples/src/main/java/examples/features/async/AsyncExampleGrid.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2008 - 2020, Arnaud Casteigts and the JBotSim contributors <contact@jbotsim.io>
+ *
+ *
+ * This file is part of JBotSim.
+ *
+ * JBotSim is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * JBotSim is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with JBotSim.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+package examples.features.messaging;
+
+import io.jbotsim.contrib.messaging.AsyncMessageEngine;
+import io.jbotsim.core.MessageEngine;
+import io.jbotsim.core.Topology;
+import io.jbotsim.gen.basic.TopologyGenerators;
+import io.jbotsim.ui.JViewer;
+
+public class AsyncMessageEngineNonFIFOExampleMain {
+
+
+    public static void main(String[] args) {
+        final Topology tp = new Topology();
+        tp.setTimeUnit(10);
+        tp.setDefaultNodeModel(GridMessagingNode.class);
+        TopologyGenerators.generateGrid(tp, 10,10);
+        new JViewer(tp);
+
+        MessageEngine messageEngine = new AsyncMessageEngine(tp, 10, AsyncMessageEngine.Type.NONFIFO);
+        tp.setMessageEngine(messageEngine);
+
+        tp.start();
+    }
+
+}

apps/examples/src/main/java/examples/features/async/Readme.md

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2008 - 2019, Arnaud Casteigts and the JBotSim contributors <contact@jbotsim.io>
+ *
+ *
+ * This file is part of JBotSim.
+ *
+ * JBotSim is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * JBotSim is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with JBotSim.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+package examples.features.messaging;
+
+import io.jbotsim.core.DelayMessageEngine;
+import io.jbotsim.core.Topology;
+import io.jbotsim.gen.basic.TopologyGenerators;
+import io.jbotsim.ui.JViewer;
+
+
+public class DelayMessageEngineExampleMain {
+
+    public static void main(String[] args) {
+        Topology tp = new Topology();
+        tp.setTimeUnit(10);
+        tp.setDefaultNodeModel(GridMessagingNode.class);
+        TopologyGenerators.generateGrid(tp, 10,10);
+        new JViewer(tp);
+
+        DelayMessageEngine messageEngine = new DelayMessageEngine(tp);
+        messageEngine.setDelay(10);
+        messageEngine.setDebug(false);
+        tp.setMessageEngine(messageEngine);
+
+        tp.start();
+    }
+}