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
   9 package org.opendaylight.controller.cluster.sharding;
  10
  11 import static akka.actor.ActorRef.noSender;
  12
  13 import akka.actor.ActorRef;
  14 import akka.actor.Status;
  15 import javax.annotation.Nullable;
  16 import javax.annotation.concurrent.NotThreadSafe;
  17
  18 /**
  19  * Base class for lookup tasks. Lookup tasks are supposed to run repeatedly
  20  * until successful lookup or maximum retries are hit.
  21  */
  22 @NotThreadSafe
  23 abstract class LookupTask implements Runnable {
  24     private final int maxRetries;
  25     private final ActorRef replyTo;
  26     private int retries = 0;
  27
  28     LookupTask(final ActorRef replyTo, final int maxRetries) {
  29         this.replyTo = replyTo;
  30         this.maxRetries = maxRetries;
  31     }
  32
  33     abstract void reschedule(int retries);
  34
  35     void tryReschedule(@Nullable final Throwable throwable) {
  36         if (retries <= maxRetries) {
  37             retries++;
  38             reschedule(retries);
  39         } else {
  40             fail(throwable);
  41         }
  42     }
  43
  44     void fail(@Nullable final Throwable throwable) {
  45         if (throwable == null) {
  46             replyTo.tell(new Status.Failure(
  47                     new DOMDataTreeShardCreationFailedException("Unable to find the backend shard."
  48                             + "Failing..")), noSender());
  49         } else {
  50             replyTo.tell(new Status.Failure(
  51                     new DOMDataTreeShardCreationFailedException("Unable to find the backend shard."
  52                             + "Failing..", throwable)), noSender());
  53         }
  54     }
  55 }