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 akka.actor.ActorRef;
  11 import akka.actor.Props;
  12 import com.google.common.base.Preconditions;
  13 import java.io.IOException;
  14 import java.io.OutputStream;
  15 import java.util.Optional;
  16 import org.opendaylight.controller.cluster.common.actor.AbstractUntypedActorWithMetering;
  17 import org.opendaylight.controller.cluster.datastore.persisted.ShardDataTreeSnapshot;
  18 import org.opendaylight.controller.cluster.datastore.persisted.ShardSnapshotState;
  19 import org.opendaylight.controller.cluster.raft.base.messages.CaptureSnapshotReply;
  20 import org.slf4j.Logger;
  21 import org.slf4j.LoggerFactory;
  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     private static final Logger LOG = LoggerFactory.getLogger(ShardSnapshotActor.class);
  31
  32     // Internal message
  33     private static final class SerializeSnapshot {
  34         private final ShardDataTreeSnapshot snapshot;
  35         private final Optional<OutputStream> installSnapshotStream;
  36         private final ActorRef replyTo;
  37
  38         SerializeSnapshot(final ShardDataTreeSnapshot snapshot, final Optional<OutputStream> installSnapshotStream,
  39                 final ActorRef replyTo) {
  40             this.snapshot = Preconditions.checkNotNull(snapshot);
  41             this.installSnapshotStream = Preconditions.checkNotNull(installSnapshotStream);
  42             this.replyTo = Preconditions.checkNotNull(replyTo);
  43         }
  44
  45         ShardDataTreeSnapshot getSnapshot() {
  46             return snapshot;
  47         }
  48
  49         Optional<OutputStream> getInstallSnapshotStream() {
  50             return installSnapshotStream;
  51         }
  52
  53         ActorRef getReplyTo() {
  54             return replyTo;
  55         }
  56     }
  57
  58     //actor name override used for metering. This does not change the "real" actor name
  59     private static final String ACTOR_NAME_FOR_METERING = "shard-snapshot";
  60
  61     private ShardSnapshotActor() {
  62         super(ACTOR_NAME_FOR_METERING);
  63     }
  64
  65     @Override
  66     protected void handleReceive(final Object message) throws Exception {
  67         if (message instanceof SerializeSnapshot) {
  68             onSerializeSnapshot((SerializeSnapshot) message);
  69         } else {
  70             unknownMessage(message);
  71         }
  72     }
  73
  74     private void onSerializeSnapshot(SerializeSnapshot request) {
  75         Optional<OutputStream> installSnapshotStream = request.getInstallSnapshotStream();
  76         if (installSnapshotStream.isPresent()) {
  77             try {
  78                 request.getSnapshot().serialize(installSnapshotStream.get());
  79             } catch (IOException e) {
  80                 // TODO - we should communicate the failure in the CaptureSnapshotReply.
  81                 LOG.error("Error serializing snapshot", e);
  82             }
  83         }
  84
  85         request.getReplyTo().tell(new CaptureSnapshotReply(new ShardSnapshotState(request.getSnapshot()),
  86                 installSnapshotStream), ActorRef.noSender());
  87     }
  88
  89     /**
  90      * Sends a request to a ShardSnapshotActor to process a snapshot and send a CaptureSnapshotReply.
  91      *
  92      * @param snapshotActor the ShardSnapshotActor
  93      * @param snapshot the snapshot to process
  94      * @param installSnapshotStream Optional OutputStream that is present if the snapshot is to also be installed
  95      *        on a follower.
  96      * @param replyTo the actor to which to send the CaptureSnapshotReply
  97      */
  98     public static void requestSnapshot(final ActorRef snapshotActor, final ShardDataTreeSnapshot snapshot,
  99             final Optional<OutputStream> installSnapshotStream, final ActorRef replyTo) {
 100         snapshotActor.tell(new SerializeSnapshot(snapshot, installSnapshotStream, replyTo), ActorRef.noSender());
 101     }
 102
 103     public static Props props() {
 104         return Props.create(ShardSnapshotActor.class);
 105     }
 106 }