opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/sharding/LookupTask.java

   1 /*
   2  * Copyright (c) 2017 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8 package org.opendaylight.controller.cluster.sharding;
   9
  10 import static akka.actor.ActorRef.noSender;
  11
  12 import akka.actor.ActorRef;
  13 import akka.actor.Status;
  14 import org.eclipse.jdt.annotation.Nullable;
  15
  16 /**
  17  * Base class for lookup tasks. Lookup tasks are supposed to run repeatedly until successful lookup or maximum retries
  18  * are hit. This class is NOT thread-safe.
  19  */
  20 abstract class LookupTask implements Runnable {
  21     private final int maxRetries;
  22     private final ActorRef replyTo;
  23     private int retried = 0;
  24
  25     LookupTask(final ActorRef replyTo, final int maxRetries) {
  26         this.replyTo = replyTo;
  27         this.maxRetries = maxRetries;
  28     }
  29
  30     abstract void reschedule(int retries);
  31
  32     void tryReschedule(final @Nullable Throwable throwable) {
  33         if (retried <= maxRetries) {
  34             retried++;
  35             reschedule(retried);
  36         } else {
  37             fail(throwable);
  38         }
  39     }
  40
  41     void fail(final @Nullable Throwable throwable) {
  42         if (throwable == null) {
  43             replyTo.tell(new Status.Failure(
  44                     new DOMDataTreeShardCreationFailedException("Unable to find the backend shard."
  45                             + "Failing..")), noSender());
  46         } else {
  47             replyTo.tell(new Status.Failure(
  48                     new DOMDataTreeShardCreationFailedException("Unable to find the backend shard."
  49                             + "Failing..", throwable)), noSender());
  50         }
  51     }
  52 }