opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/actors/ShardSnapshotActor.java

   1 /*
   2  * Copyright (c) 2016 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.datastore.actors;
   9
  10 import static java.util.Objects.requireNonNull;
  11
  12 import akka.actor.ActorRef;
  13 import akka.actor.Props;
  14 import java.io.IOException;
  15 import java.io.ObjectOutputStream;
  16 import java.io.OutputStream;
  17 import java.util.Optional;
  18 import org.opendaylight.controller.cluster.common.actor.AbstractUntypedActorWithMetering;
  19 import org.opendaylight.controller.cluster.datastore.persisted.ShardDataTreeSnapshot;
  20 import org.opendaylight.controller.cluster.datastore.persisted.ShardSnapshotState;
  21 import org.opendaylight.controller.cluster.raft.base.messages.CaptureSnapshotReply;
  22
  23 /**
  24  * This is an offload actor, which is given an isolated snapshot of the data tree. It performs the potentially
  25  * time-consuming operation of serializing the snapshot.
  26  *
  27  * @author Robert Varga
  28  */
  29 public final class ShardSnapshotActor extends AbstractUntypedActorWithMetering {
  30     // Internal message
  31     private static final class SerializeSnapshot {
  32         private final ShardDataTreeSnapshot snapshot;
  33         private final Optional<OutputStream> installSnapshotStream;
  34         private final ActorRef replyTo;
  35
  36         SerializeSnapshot(final ShardDataTreeSnapshot snapshot, final Optional<OutputStream> installSnapshotStream,
  37                 final ActorRef replyTo) {
  38             this.snapshot = requireNonNull(snapshot);
  39             this.installSnapshotStream = requireNonNull(installSnapshotStream);
  40             this.replyTo = requireNonNull(replyTo);
  41         }
  42
  43         ShardDataTreeSnapshot getSnapshot() {
  44             return snapshot;
  45         }
  46
  47         Optional<OutputStream> getInstallSnapshotStream() {
  48             return installSnapshotStream;
  49         }
  50
  51         ActorRef getReplyTo() {
  52             return replyTo;
  53         }
  54     }
  55
  56     //actor name override used for metering. This does not change the "real" actor name
  57     private static final String ACTOR_NAME_FOR_METERING = "shard-snapshot";
  58
  59     private ShardSnapshotActor() {
  60         super(ACTOR_NAME_FOR_METERING);
  61     }
  62
  63     @Override
  64     protected void handleReceive(final Object message) {
  65         if (message instanceof SerializeSnapshot) {
  66             onSerializeSnapshot((SerializeSnapshot) message);
  67         } else {
  68             unknownMessage(message);
  69         }
  70     }
  71
  72     private void onSerializeSnapshot(final SerializeSnapshot request) {
  73         Optional<OutputStream> installSnapshotStream = request.getInstallSnapshotStream();
  74         if (installSnapshotStream.isPresent()) {
  75             try (ObjectOutputStream out = new ObjectOutputStream(installSnapshotStream.get())) {
  76                 request.getSnapshot().serialize(out);
  77             } catch (IOException e) {
  78                 // TODO - we should communicate the failure in the CaptureSnapshotReply.
  79                 LOG.error("Error serializing snapshot", e);
  80             }
  81         }
  82
  83         request.getReplyTo().tell(new CaptureSnapshotReply(new ShardSnapshotState(request.getSnapshot()),
  84                 installSnapshotStream), ActorRef.noSender());
  85     }
  86
  87     /**
  88      * Sends a request to a ShardSnapshotActor to process a snapshot and send a CaptureSnapshotReply.
  89      *
  90      * @param snapshotActor the ShardSnapshotActor
  91      * @param snapshot the snapshot to process
  92      * @param installSnapshotStream Optional OutputStream that is present if the snapshot is to also be installed
  93      *        on a follower.
  94      * @param replyTo the actor to which to send the CaptureSnapshotReply
  95      */
  96     public static void requestSnapshot(final ActorRef snapshotActor, final ShardDataTreeSnapshot snapshot,
  97             final Optional<OutputStream> installSnapshotStream, final ActorRef replyTo) {
  98         snapshotActor.tell(new SerializeSnapshot(snapshot, installSnapshotStream, replyTo), ActorRef.noSender());
  99     }
 100
 101     public static Props props() {
 102         return Props.create(ShardSnapshotActor.class);
 103     }
 104 }