2 * Copyright (c) 2016 Cisco Systems, Inc. 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.databroker.actors.dds;
10 import akka.actor.ActorRef;
11 import com.google.common.annotations.Beta;
12 import com.google.common.base.Preconditions;
13 import java.util.concurrent.atomic.AtomicIntegerFieldUpdater;
14 import javax.annotation.concurrent.NotThreadSafe;
15 import org.opendaylight.controller.cluster.access.concepts.LocalHistoryIdentifier;
18 * Client-side view of a local history. This class tracks all state related to a particular history and routes
19 * frontend requests towards the backend.
21 * This interface is used by the world outside of the actor system and in the actor system it is manifested via
22 * its client actor. That requires some state transfer with {@link DistributedDataStoreClientBehavior}. In order to
23 * reduce request latency, all messages are carbon-copied (and enqueued first) to the client actor.
25 * @author Robert Varga
29 public final class ClientLocalHistory implements AutoCloseable {
30 private static final AtomicIntegerFieldUpdater<ClientLocalHistory> CLOSED_UPDATER =
31 AtomicIntegerFieldUpdater.newUpdater(ClientLocalHistory.class, "state");
32 private static final int IDLE_STATE = 0;
33 private static final int CLOSED_STATE = 1;
35 private final LocalHistoryIdentifier historyId;
36 private final ActorRef backendActor;
37 private final ActorRef clientActor;
39 private volatile int state = IDLE_STATE;
41 ClientLocalHistory(final DistributedDataStoreClientBehavior client, final long historyId,
42 final ActorRef backendActor) {
43 this.clientActor = client.self();
44 this.backendActor = Preconditions.checkNotNull(backendActor);
45 this.historyId = new LocalHistoryIdentifier(client.getIdentifier(), historyId);
48 private void checkNotClosed() {
49 Preconditions.checkState(state != CLOSED_STATE, "Local history %s has been closed", historyId);
54 if (CLOSED_UPDATER.compareAndSet(this, IDLE_STATE, CLOSED_STATE)) {
55 // FIXME: signal close to both client actor and backend actor
56 } else if (state != CLOSED_STATE) {
57 throw new IllegalStateException("Cannot close history with an open transaction");
61 // FIXME: add client requests related to a particular local history