opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/databroker/ClientBackedReadTransaction.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.databroker;
   9
  10 import com.google.common.base.Optional;
  11 import com.google.common.util.concurrent.CheckedFuture;
  12 import com.google.common.util.concurrent.Futures;
  13 import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
  14 import javax.annotation.Nullable;
  15 import org.opendaylight.controller.cluster.databroker.actors.dds.ClientSnapshot;
  16 import org.opendaylight.mdsal.common.api.ReadFailedException;
  17 import org.opendaylight.mdsal.dom.spi.store.DOMStoreReadTransaction;
  18 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  19 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  20
  21 /**
  22  * An implementation of {@link DOMStoreReadTransaction} backed by a {@link ClientSnapshot}. Used for standalone
  23  * transactions.
  24  *
  25  * @author Robert Varga
  26  */
  27 final class ClientBackedReadTransaction extends ClientBackedTransaction<ClientSnapshot>
  28         implements DOMStoreReadTransaction {
  29     private static final AtomicReferenceFieldUpdater<ClientBackedReadTransaction, ClientBackedTransactionChain>
  30         PARENT_UPDATER = AtomicReferenceFieldUpdater.newUpdater(ClientBackedReadTransaction.class,
  31             ClientBackedTransactionChain.class, "parent");
  32
  33     @SuppressWarnings("unused")
  34     private volatile ClientBackedTransactionChain parent;
  35
  36     ClientBackedReadTransaction(final ClientSnapshot delegate, @Nullable final ClientBackedTransactionChain parent,
  37         @Nullable final Throwable allocationContext) {
  38         super(delegate, allocationContext);
  39         this.parent = parent;
  40     }
  41
  42     @Override
  43     public CheckedFuture<Optional<NormalizedNode<?, ?>>, ReadFailedException> read(final YangInstanceIdentifier path) {
  44         return Futures.makeChecked(delegate().read(path), ReadFailedException.MAPPER);
  45     }
  46
  47     @Override
  48     public CheckedFuture<Boolean, ReadFailedException> exists(final YangInstanceIdentifier path) {
  49         return Futures.makeChecked(delegate().exists(path), ReadFailedException.MAPPER);
  50     }
  51
  52     @Override
  53     public void close() {
  54         super.close();
  55
  56         final ClientBackedTransactionChain local = PARENT_UPDATER.getAndSet(this, null);
  57         if (local != null) {
  58             local.snapshotClosed(delegate());
  59         }
  60     }
  61 }