GOSSIP-89 - Refactor gossip examples; common code in base class.

gossip-examples/src/main/java/org/apache/gossip/examples/RunStandardExamples.java

@@ -0,0 +1,105 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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.apache.gossip.examples;
+
+import java.io.IOException;
+
+public class RunStandardExamples {
+
+  private static boolean WILL_READ = true;
+
+  private static boolean WILL_NOT_READ = false;
+
+  public static void main(String[] args) {
+    if ((args.length < 1) || args[0].equals("-h") || args[0].equals("--help") || args.length < 2) {
+      System.out.print(usage());
+      return;
+    }
+    try {
+      int example = intFromString(args[0]);
+      int channel = intFromString(args[1]);
+      if ((example < 1) || (example > 4) || (channel < 0) || (channel > 2)) {
+        System.out.print(usage());
+        return;
+      }
+      runExaple(example, channel);
+    } catch (Exception e) {
+      System.out.print(usage());
+    }
+  }
+
+  private static void runExaple(int exampleNumber, int channel) throws IOException {
+    String[] args = stanardArgs(channel, new String[4]);
+    if (exampleNumber == 1) {
+      StandAloneNode example = new StandAloneNode(args);
+      example.exec(WILL_NOT_READ);
+    } else if (exampleNumber == 2) {
+      StandAloneNodeCrdtOrSet example = new StandAloneNodeCrdtOrSet(args);
+      example.exec(WILL_READ);
+    } else if (exampleNumber == 3) {
+      StandAlonePNCounter example = new StandAlonePNCounter(args);
+      example.exec(WILL_READ);
+    } else if (exampleNumber == 4) {
+      args = extendedArgs(channel, new String[6]);
+      StandAloneDatacenterAndRack example = new StandAloneDatacenterAndRack(args);
+      example.exec(WILL_READ);
+    }
+  }
+
+  private static String[] stanardArgs(int channel, String[] args) {
+    // see README.md for examples
+    args[0] = "udp://localhost:1000" + channel;
+    args[1] = "" + channel;
+    args[2] = "udp://localhost:10000";
+    args[3] = "0";
+    return args;
+  }
+
+  private static String[] extendedArgs(int channel, String[] args) {
+    args = stanardArgs(channel, args);
+    // see README.md for examples
+    if (channel == 0) {
+      args[4] = "1";
+      args[5] = "2";
+    }
+    if (channel == 1) {
+      args[4] = "1";
+      args[5] = "3";
+    }
+    if (channel == 2) {
+      args[4] = "2";
+      args[5] = "2";
+    }
+    return args;
+  }
+
+  private static int intFromString(String string) {
+    return Integer.parseInt(string);
+  }
+
+  private static String usage() {
+    return "Select and run (usually in a seperate terminal window) \n"
+            + "one of the the standard Examples,\n" + " 1. StandAloneNode\n"
+            + " 2. StandAloneNodeCrdtOrSet\n" + " 3. StandAlonePNCounter\n"
+            + " 4. StandAloneDatacenterAndRack\n" + "(See README.md in this modules)\n" + "\n"
+            + "Usage: mvn exec:java -Dexec.mainClass=org.apache.gossip.examples.RunStandardExamples  -Dexec.args=\"s c\"\n"
+            + "where...\n" + "  s - int - the example number from above\n"
+            + "  c - int - the channel number: 0, 1, or 2\n";
+  }
+
+}

gossip-examples/src/main/java/org/apache/gossip/examples/StandAloneDatacenterAndRack.java

@@ -18,8 +18,8 @@
 
 package org.apache.gossip.examples;
 
+import java.io.IOException;
 import java.net.URI;
-import java.net.UnknownHostException;
 import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Map;
@@ -30,12 +30,20 @@
 import org.apache.gossip.manager.GossipManager;
 import org.apache.gossip.manager.GossipManagerBuilder;
 
-public class StandAloneDatacenterAndRack {
+public class StandAloneDatacenterAndRack extends StandAloneExampleBase {
 
-  private static ExampleCommon common = new ExampleCommon();
+  public static void main(String[] args) throws InterruptedException, IOException {
+    StandAloneDatacenterAndRack example = new StandAloneDatacenterAndRack(args);
+    boolean willRead = true;
+    example.exec(willRead);
+  }
+
+  StandAloneDatacenterAndRack(String[] args) {
+    args = super.checkArgsForClearFlag(args);
+    initGossipManager(args);
+  }
 
-  public static void main(String[] args) throws UnknownHostException, InterruptedException {
-    args = common.checkArgsForClearFlag(args);
+  void initGossipManager(String[] args) {
     GossipSettings s = new GossipSettings();
     s.setWindowSize(1000);
     s.setGossipInterval(100);
@@ -48,20 +56,17 @@ public static void main(String[] args) throws UnknownHostException, InterruptedE
     props.put(DatacenterRackAwareActiveGossiper.DATACENTER, args[4]);
     props.put(DatacenterRackAwareActiveGossiper.RACK, args[5]);
     GossipManager manager = GossipManagerBuilder.newBuilder().cluster("mycluster")
-            .uri(URI.create(args[0]))
-            .id(args[1])
-            .gossipSettings(s)
+            .uri(URI.create(args[0])).id(args[1]).gossipSettings(s)
             .gossipMembers(
                     Arrays.asList(new RemoteMember("mycluster", URI.create(args[2]), args[3])))
-            .properties(props)
-            .build();
+            .properties(props).build();
     manager.init();
-    while (true) {
-      common.optionallyClearTerminal();
-      System.out.println("Live: " + manager.getLiveMembers());
-      System.out.println("Dead: " + manager.getDeadMembers());
-      Thread.sleep(2000);
-    }
+    setGossipService(manager);
+  }
+
+  @Override
+  void printValues(GossipManager gossipService) {
+    return;
   }
 
 }

gossip-examples/src/main/java/org/apache/gossip/examples/StandAloneExampleBase.java

@@ -0,0 +1,162 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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.apache.gossip.examples;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.net.URI;
+import java.util.Collections;
+import java.util.List;
+
+import org.apache.gossip.GossipSettings;
+import org.apache.gossip.LocalMember;
+import org.apache.gossip.RemoteMember;
+import org.apache.gossip.manager.GossipManager;
+import org.apache.gossip.manager.GossipManagerBuilder;
+
+abstract class StandAloneExampleBase {
+  private String lastInput = "{none}";
+
+  private boolean clearTerminalScreen = true;
+
+  private GossipManager gossipService = null;
+
+  abstract void printValues(GossipManager gossipService);
+
+  boolean processReadLoopInput(String line) {
+    return true;
+  }
+
+  void exec(boolean willRead) throws IOException {
+    gossipService.init();
+    startMonitorLoop(gossipService);
+    if (willRead) {
+      startBlockingReadLoop();
+    }
+  }
+
+  /*
+   * Look for -s in args. If there, suppress terminal-clear on write results: shift args for
+   * positional args, if necessary
+   */
+  String[] checkArgsForClearFlag(String[] args) {
+    int pos = 0;
+    for (int i = 0; i < args.length; i++) {
+      if (args[i].equals("-s")) {
+        clearTerminalScreen = false;
+      } else {
+        // in the case of the -s flag, shift args
+        // down by one slot; this will end up with
+        // a duplicate entry in the last position of args,
+        // but this is ok, because it will be ignored
+        args[pos++] = args[i];
+      }
+    }
+    return args;
+  }
+
+  private void optionallyClearTerminal() {
+    if (clearTerminalScreen) {
+      System.out.print("\033[H\033[2J");
+      System.out.flush();
+    }
+  }
+
+  private void setLastInput(String input, boolean valid) {
+    lastInput = input;
+    if (!valid) {
+      lastInput += " (invalid)";
+    }
+  }
+
+  String getLastInput() {
+    return lastInput;
+  }
+
+  private void startMonitorLoop(GossipManager gossipService) {
+    new Thread(() -> {
+      while (true) {
+        optionallyClearTerminal();
+        printLiveMembers(gossipService);
+        printDeadMambers(gossipService);
+        printValues(gossipService);
+        try {
+          Thread.sleep(2000);
+        } catch (Exception ignore) {
+        }
+      }
+    }).start();
+  }
+
+  private void printLiveMembers(GossipManager gossipService) {
+    List<LocalMember> members = gossipService.getLiveMembers();
+    if (members.isEmpty()) {
+      System.out.println("Live: (none)");
+      return;
+    }
+    System.out.println("Live: " + members.get(0));
+    for (int i = 1; i < members.size(); i++) {
+      System.out.println("    : " + members.get(i));
+    }
+  }
+
+  private void printDeadMambers(GossipManager gossipService) {
+    List<LocalMember> members = gossipService.getDeadMembers();
+    if (members.isEmpty()) {
+      System.out.println("Dead: (none)");
+      return;
+    }
+    System.out.println("Dead: " + members.get(0));
+    for (int i = 1; i < members.size(); i++) {
+      System.out.println("    : " + members.get(i));
+    }
+  }
+
+  private void startBlockingReadLoop() throws IOException {
+    String line;
+    try (BufferedReader br = new BufferedReader(new InputStreamReader(System.in))) {
+      while ((line = br.readLine()) != null) {
+        System.out.println(line);
+        boolean valid = processReadLoopInput(line);
+        setLastInput(line, valid);
+      }
+    }
+  }
+
+  void initGossipManager(String[] args) {
+    GossipSettings s = new GossipSettings();
+    s.setWindowSize(1000);
+    s.setGossipInterval(100);
+    GossipManager gossipService = GossipManagerBuilder.newBuilder().cluster("mycluster")
+            .uri(URI.create(args[0])).id(args[1])
+            .gossipMembers(Collections
+                    .singletonList(new RemoteMember("mycluster", URI.create(args[2]), args[3])))
+            .gossipSettings(s).build();
+    setGossipService(gossipService);
+  }
+
+  void setGossipService(GossipManager gossipService) {
+    this.gossipService = gossipService;
+  }
+
+  GossipManager getGossipManager() {
+    return this.gossipService;
+  }
+
+}