| /* |
| * 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; |
| } |
| |
| } |