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 com.google.common.annotations.Beta;
11 import com.google.common.base.Preconditions;
12 import com.google.common.base.Verify;
13 import java.util.concurrent.atomic.AtomicLongFieldUpdater;
14 import org.opendaylight.controller.cluster.access.concepts.LocalHistoryIdentifier;
15 import org.opendaylight.controller.cluster.access.concepts.TransactionIdentifier;
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
28 public final class ClientLocalHistory extends AbstractClientHistory implements AutoCloseable {
30 private static final AtomicLongFieldUpdater<ClientLocalHistory> NEXT_TX_UPDATER =
31 AtomicLongFieldUpdater.newUpdater(ClientLocalHistory.class, "nextTx");
33 // Used via NEXT_TX_UPDATER
34 @SuppressWarnings("unused")
35 private volatile long nextTx = 0;
37 ClientLocalHistory(final DistributedDataStoreClientBehavior client, final LocalHistoryIdentifier historyId) {
38 super(client, historyId);
41 public ClientTransaction createTransaction() {
42 final State local = state();
43 Preconditions.checkState(local == State.IDLE, "Local history %s state is %s", this, local);
44 updateState(local, State.TX_OPEN);
46 return new ClientTransaction(this, new TransactionIdentifier(getIdentifier(),
47 NEXT_TX_UPDATER.getAndIncrement(this)));
52 final State local = state();
53 if (local != State.CLOSED) {
54 Preconditions.checkState(local == State.IDLE, "Local history %s has an open transaction", this);
55 updateState(local, State.CLOSED);
60 void onTransactionReady(final ClientTransaction transaction) {
61 final State local = state();
62 Verify.verify(local == State.TX_OPEN, "Local history %s is in unexpected state %s", this, local);
63 updateState(local, State.IDLE);
64 super.onTransactionReady(transaction);