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.io.InputOutputStreamFactory;
  22 import org.opendaylight.controller.cluster.raft.base.messages.CaptureSnapshotReply;
  23
  24 /**
  25  * This is an offload actor, which is given an isolated snapshot of the data tree. It performs the potentially
  26  * time-consuming operation of serializing the snapshot.
  27  *
  28  * @author Robert Varga
  29  */
  30 public final class ShardSnapshotActor extends AbstractUntypedActorWithMetering {
  31     // Internal message
  32     private static final class SerializeSnapshot {
  33         private final ShardDataTreeSnapshot snapshot;
  34         private final Optional<OutputStream> installSnapshotStream;
  35         private final ActorRef replyTo;
  36
  37         SerializeSnapshot(final ShardDataTreeSnapshot snapshot, final Optional<OutputStream> installSnapshotStream,
  38                 final ActorRef replyTo) {
  39             this.snapshot = requireNonNull(snapshot);
  40             this.installSnapshotStream = requireNonNull(installSnapshotStream);
  41             this.replyTo = requireNonNull(replyTo);
  42         }
  43
  44         ShardDataTreeSnapshot getSnapshot() {
  45             return snapshot;
  46         }
  47
  48         Optional<OutputStream> getInstallSnapshotStream() {
  49             return installSnapshotStream;
  50         }
  51
  52         ActorRef getReplyTo() {
  53             return replyTo;
  54         }
  55     }
  56
  57     //actor name override used for metering. This does not change the "real" actor name
  58     private static final String ACTOR_NAME_FOR_METERING = "shard-snapshot";
  59
  60     private final InputOutputStreamFactory streamFactory;
  61
  62     private ShardSnapshotActor(final InputOutputStreamFactory streamFactory) {
  63         super(ACTOR_NAME_FOR_METERING);
  64         this.streamFactory = requireNonNull(streamFactory);
  65     }
  66
  67     @Override
  68     protected void handleReceive(final Object message) {
  69         if (message instanceof SerializeSnapshot) {
  70             onSerializeSnapshot((SerializeSnapshot) message);
  71         } else {
  72             unknownMessage(message);
  73         }
  74     }
  75
  76     private void onSerializeSnapshot(final SerializeSnapshot request) {
  77         Optional<OutputStream> installSnapshotStream = request.getInstallSnapshotStream();
  78         if (installSnapshotStream.isPresent()) {
  79             try (ObjectOutputStream out = getOutputStream(installSnapshotStream.orElseThrow())) {
  80                 request.getSnapshot().serialize(out);
  81             } catch (IOException e) {
  82                 // TODO - we should communicate the failure in the CaptureSnapshotReply.
  83                 LOG.error("Error serializing snapshot", e);
  84             }
  85         }
  86
  87         request.getReplyTo().tell(new CaptureSnapshotReply(new ShardSnapshotState(request.getSnapshot()),
  88                 installSnapshotStream), ActorRef.noSender());
  89     }
  90
  91     private ObjectOutputStream getOutputStream(final OutputStream outputStream) throws IOException {
  92         return new ObjectOutputStream(streamFactory.wrapOutputStream(outputStream));
  93     }
  94
  95     /**
  96      * Sends a request to a ShardSnapshotActor to process a snapshot and send a CaptureSnapshotReply.
  97      *
  98      * @param snapshotActor the ShardSnapshotActor
  99      * @param snapshot the snapshot to process
 100      * @param installSnapshotStream Optional OutputStream that is present if the snapshot is to also be installed
 101      *        on a follower.
 102      * @param replyTo the actor to which to send the CaptureSnapshotReply
 103      */
 104     public static void requestSnapshot(final ActorRef snapshotActor, final ShardDataTreeSnapshot snapshot,
 105             final Optional<OutputStream> installSnapshotStream, final ActorRef replyTo) {
 106         snapshotActor.tell(new SerializeSnapshot(snapshot, installSnapshotStream, replyTo), ActorRef.noSender());
 107     }
 108
 109     public static Props props(final InputOutputStreamFactory streamFactory) {
 110         return Props.create(ShardSnapshotActor.class, streamFactory);
 111     }
 112 }