cadi/aaf/src/main/java/org/onap/aaf/cadi/register/Registrar.java

   1 /**
   2  * ============LICENSE_START====================================================
   3  * org.onap.aaf
   4  * ===========================================================================
   5  * Copyright (c) 2018 AT&T Intellectual Property. All rights reserved.
   6  * ===========================================================================
   7  * Licensed under the Apache License, Version 2.0 (the "License");
   8  * you may not use this file except in compliance with the License.
   9  * You may obtain a copy of the License at
  10  *
  11  *      http://www.apache.org/licenses/LICENSE-2.0
  12  *
  13  * Unless required by applicable law or agreed to in writing, software
  14  * distributed under the License is distributed on an "AS IS" BASIS,
  15  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  16  * See the License for the specific language governing permissions and
  17  * limitations under the License.
  18  * ============LICENSE_END====================================================
  19  *
  20  */
  21
  22 package org.onap.aaf.cadi.register;
  23
  24 import java.util.Deque;
  25 import java.util.Iterator;
  26 import java.util.Timer;
  27 import java.util.TimerTask;
  28 import java.util.concurrent.ConcurrentLinkedDeque;
  29
  30 import org.onap.aaf.cadi.client.Result;
  31 import org.onap.aaf.misc.env.impl.BasicEnv;
  32
  33 public class Registrar<ENV extends BasicEnv> {
  34         private static final String REGISTRAR = "Registrar";
  35         private static final long INTERVAL = 15*60*1000L; // 15 mins
  36         private static final long START = 3000; // Start in 3 seconds
  37         private static final Object LOCK = new Object();
  38         private Deque<Registrant<ENV>> registrants;
  39         private Timer timer, erroringTimer;
  40
  41         public Registrar(final ENV env, boolean shutdownHook) {
  42                 registrants = new ConcurrentLinkedDeque<Registrant<ENV>>();
  43
  44                 erroringTimer = null;
  45                 timer = new Timer(REGISTRAR,true);
  46                 timer.schedule(new RegistrationTimerTask(env), START, INTERVAL);
  47
  48                 if(shutdownHook) {
  49                         Runtime.getRuntime().addShutdownHook(new Thread() {
  50                                 public void run() {
  51                                         close(env);
  52                                 }
  53                         });
  54                 }
  55         }
  56
  57         private class RegistrationTimerTask extends TimerTask {
  58                 private final ENV env;
  59                 public RegistrationTimerTask(ENV env) {
  60                         this.env = env;
  61                 }
  62                 @Override
  63                 public void run() {
  64                         for(Iterator<Registrant<ENV>> iter = registrants.iterator(); iter.hasNext();) {
  65                                 Registrant<ENV> reg = iter.next();
  66                                 Result<Void> rv = reg.update(env);
  67                                 synchronized(LOCK) {
  68                                         if(rv.isOK()) {
  69                                                 if(erroringTimer!=null) {
  70                                                         erroringTimer.cancel();
  71                                                         erroringTimer = null;
  72                                                 }
  73                                         } else {
  74                                                 // Account for different Registrations not being to same place
  75                                                 if(erroringTimer==null) {
  76                                                         erroringTimer =  new Timer(REGISTRAR + " error re-check ",true);
  77                                                         erroringTimer.schedule(new RegistrationTimerTask(env),20000,20000);
  78                                                 }
  79                                         }
  80                                 }
  81                         }
  82                 }
  83         }
  84
  85         public void register(Registrant<ENV> r) {
  86                 registrants.addLast(r);
  87         }
  88
  89         public void deregister(Registrant<ENV> r) {
  90                 registrants.remove(r);
  91         }
  92
  93         public void close(ENV env) {
  94                 timer.cancel();
  95
  96                 Registrant<ENV> r;
  97                 while(registrants.peek()!=null) {
  98                         r = registrants.pop();
  99                         r.cancel(env);
 100                 }
 101         }
 102 }