opendaylight/md-sal/sal-dom-spi/src/main/java/org/opendaylight/controller/sal/core/spi/data/SnapshotBackedReadWriteTransaction.java

   1 /*
   2  * Copyright (c) 2014 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.sal.core.spi.data;
   9
  10 import static com.google.common.base.Preconditions.checkNotNull;
  11 import com.google.common.annotations.Beta;
  12 import com.google.common.base.Optional;
  13 import com.google.common.util.concurrent.CheckedFuture;
  14 import com.google.common.util.concurrent.Futures;
  15 import org.opendaylight.controller.md.sal.common.api.data.ReadFailedException;
  16 import org.opendaylight.controller.sal.core.spi.data.SnapshotBackedWriteTransaction.TransactionReadyPrototype;
  17 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  18 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  19 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeSnapshot;
  20 import org.slf4j.Logger;
  21 import org.slf4j.LoggerFactory;
  22
  23 /**
  24  * Implementation of Read-Write transaction which is backed by {@link DataTreeSnapshot}
  25  * and executed according to {@link TransactionReadyPrototype}.
  26  *
  27  * @param <T> identifier type
  28  */
  29 @Beta
  30 public final class SnapshotBackedReadWriteTransaction<T> extends SnapshotBackedWriteTransaction<T> implements DOMStoreReadWriteTransaction {
  31     private static final Logger LOG = LoggerFactory.getLogger(SnapshotBackedReadWriteTransaction.class);
  32
  33     SnapshotBackedReadWriteTransaction(final T identifier, final boolean debug,
  34             final DataTreeSnapshot snapshot, final TransactionReadyPrototype<T> readyImpl) {
  35         super(identifier, debug, snapshot, readyImpl);
  36     }
  37
  38     @Override
  39     public CheckedFuture<Optional<NormalizedNode<?,?>>, ReadFailedException> read(final YangInstanceIdentifier path) {
  40         LOG.debug("Tx: {} Read: {}", getIdentifier(), path);
  41         checkNotNull(path, "Path must not be null.");
  42
  43         final Optional<NormalizedNode<?, ?>> result;
  44         try {
  45             result = readSnapshotNode(path);
  46         } catch (Exception e) {
  47             LOG.error("Tx: {} Failed Read of {}", getIdentifier(), path, e);
  48             return Futures.immediateFailedCheckedFuture(new ReadFailedException("Read failed", e));
  49         }
  50
  51         if (result == null) {
  52             return Futures.immediateFailedCheckedFuture(new ReadFailedException("Transaction is closed"));
  53         } else {
  54             return Futures.immediateCheckedFuture(result);
  55         }
  56     }
  57
  58     @Override
  59     public CheckedFuture<Boolean, ReadFailedException> exists(final YangInstanceIdentifier path) {
  60         try {
  61             return Futures.immediateCheckedFuture(
  62                 read(path).checkedGet().isPresent());
  63         } catch (ReadFailedException e) {
  64             return Futures.immediateFailedCheckedFuture(e);
  65         }
  66     }
  67 }