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