gerrit.onap Code Review - sdc.git/blob

   1 /*
   2  * Copyright © 2016-2018 European Support Limited
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *      http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 package org.openecomp.sdcrests.item.rest.services.catalog.notification;
  18
  19 import java.util.Collection;
  20 import java.util.concurrent.Callable;
  21 import java.util.concurrent.Executors;
  22 import java.util.concurrent.ScheduledExecutorService;
  23 import java.util.concurrent.TimeUnit;
  24 import java.util.function.BiFunction;
  25 import org.openecomp.sdc.logging.api.Logger;
  26 import org.openecomp.sdc.logging.api.LoggerFactory;
  27 import org.openecomp.sdc.logging.api.LoggingContext;
  28 import org.openecomp.sdcrests.item.types.ItemAction;
  29
  30 /**
  31  * Asynchronously runs a notification task.
  32  *
  33  * @author evitaliy
  34  * @since 22 Nov 2018
  35  */
  36 public class AsyncNotifier implements Notifier {
  37
  38     private static final ScheduledExecutorService EXECUTOR_SERVICE = Executors.newScheduledThreadPool(1);
  39
  40     private static final int DEFAULT_NUM_OF_RETRIES = 2;
  41     private static final long DEFAULT_INTERVAL = 5000;
  42
  43     private final BiFunction<Collection<String>, ItemAction, Callable<NextAction>> taskProducer;
  44
  45     AsyncNotifier(BiFunction<Collection<String>, ItemAction, Callable<NextAction>> taskProducer) {
  46         this.taskProducer = taskProducer;
  47     }
  48
  49     @Override
  50     public void execute(Collection<String> itemIds, ItemAction action) {
  51
  52         Callable<AsyncNotifier.NextAction> worker = taskProducer.apply(itemIds, action);
  53
  54         RetryingTask retryingTask =
  55                 new RetryingTask(worker, DEFAULT_NUM_OF_RETRIES, DEFAULT_INTERVAL, EXECUTOR_SERVICE);
  56
  57         EXECUTOR_SERVICE.submit(LoggingContext.copyToCallable(retryingTask));
  58     }
  59
  60     public enum NextAction {
  61         RETRY, DONE
  62     }
  63
  64     static class RetryingTask implements Callable<Void> {
  65
  66         private static final Logger LOGGER = LoggerFactory.getLogger(RetryingTask.class);
  67
  68         private final Callable<AsyncNotifier.NextAction> worker;
  69         private final long delay;
  70         private final ScheduledExecutorService scheduler;
  71         private volatile int retries;
  72
  73         RetryingTask(Callable<AsyncNotifier.NextAction> worker, int numOfRetries, long delay,
  74                 ScheduledExecutorService scheduler) {
  75
  76             this.worker = worker;
  77             this.retries = numOfRetries;
  78             this.delay = delay;
  79             this.scheduler = scheduler;
  80         }
  81
  82         @Override
  83         public synchronized Void call() throws Exception {
  84
  85             NextAction next = worker.call();
  86             if (next == NextAction.DONE) {
  87                 LOGGER.debug("Task successful: {}. Not going to retry", worker);
  88                 return null;
  89             }
  90
  91             retries--;
  92             if (retries == 0) {
  93                 LOGGER.warn("Exhausted number of retries for task {}, exiting", worker);
  94                 return null;
  95             }
  96
  97             scheduler.schedule(this, delay, TimeUnit.MILLISECONDS);
  98             return null;
  99         }
 100     }
 101 }