2 * Copyright (c) 2017 Inocybe Technologies and others. All rights reserved.
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
8 package org.opendaylight.controller.cluster.datastore;
10 import static java.util.Objects.requireNonNull;
12 import akka.actor.ActorRef;
13 import akka.pattern.Patterns;
14 import akka.util.Timeout;
15 import com.google.common.base.Stopwatch;
16 import com.google.common.cache.Cache;
17 import com.google.common.cache.CacheBuilder;
18 import java.util.concurrent.TimeUnit;
19 import org.opendaylight.controller.cluster.datastore.messages.OnDemandShardState;
20 import org.opendaylight.controller.cluster.raft.client.messages.GetOnDemandRaftState;
21 import scala.concurrent.Await;
24 * Maintains a short-lived shared cache of OnDemandShardState.
26 * @author Thomas Pantelis
28 final class OnDemandShardStateCache {
29 private static final Cache<String, OnDemandShardState> ONDEMAND_SHARD_STATE_CACHE =
30 CacheBuilder.newBuilder().expireAfterWrite(2, TimeUnit.SECONDS).build();
32 private final ActorRef shardActor;
33 private final String shardName;
34 private volatile String stateRetrievalTime;
36 OnDemandShardStateCache(final String shardName, final ActorRef shardActor) {
37 this.shardName = requireNonNull(shardName);
38 this.shardActor = shardActor;
41 OnDemandShardState get() throws Exception {
42 if (shardActor == null) {
43 return OnDemandShardState.newBuilder().build();
46 return ONDEMAND_SHARD_STATE_CACHE.get(shardName, this::retrieveState);
49 String getStatRetrievaelTime() {
50 return stateRetrievalTime;
53 private OnDemandShardState retrieveState() throws Exception {
54 stateRetrievalTime = null;
55 Timeout timeout = new Timeout(10, TimeUnit.SECONDS);
56 Stopwatch timer = Stopwatch.createStarted();
58 OnDemandShardState state = (OnDemandShardState) Await.result(Patterns.ask(shardActor,
59 GetOnDemandRaftState.INSTANCE, timeout), timeout.duration());
61 stateRetrievalTime = timer.stop().toString();