opendaylight/md-sal/sal-inmemory-datastore/src/main/java/org/opendaylight/controller/md/sal/dom/store/impl/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.md.sal.dom.store.impl;
   9
  10 import static com.google.common.base.Preconditions.checkNotNull;
  11 import com.google.common.base.Optional;
  12 import com.google.common.util.concurrent.CheckedFuture;
  13 import com.google.common.util.concurrent.Futures;
  14 import org.opendaylight.controller.md.sal.common.api.data.ReadFailedException;
  15 import org.opendaylight.controller.sal.core.spi.data.DOMStoreReadWriteTransaction;
  16 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  17 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  18 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeSnapshot;
  19 import org.slf4j.Logger;
  20 import org.slf4j.LoggerFactory;
  21
  22 /**
  23  * Implementation of Read-Write transaction which is backed by {@link DataTreeSnapshot}
  24  * and executed according to {@link TransactionReadyPrototype}.
  25  *
  26  */
  27 final class SnapshotBackedReadWriteTransaction extends SnapshotBackedWriteTransaction implements DOMStoreReadWriteTransaction {
  28     private static final Logger LOG = LoggerFactory.getLogger(SnapshotBackedReadWriteTransaction.class);
  29
  30     /**
  31      * Creates new read-write transaction.
  32      *
  33      * @param identifier transaction Identifier
  34      * @param snapshot Snapshot which will be modified.
  35      * @param readyImpl Implementation of ready method.
  36      */
  37     protected SnapshotBackedReadWriteTransaction(final Object identifier, final boolean debug,
  38             final DataTreeSnapshot snapshot, final TransactionReadyPrototype store) {
  39         super(identifier, debug, snapshot, store);
  40     }
  41
  42     @Override
  43     public CheckedFuture<Optional<NormalizedNode<?,?>>, ReadFailedException> read(final YangInstanceIdentifier path) {
  44         LOG.debug("Tx: {} Read: {}", getIdentifier(), path);
  45         checkNotNull(path, "Path must not be null.");
  46
  47         final Optional<NormalizedNode<?, ?>> result;
  48         try {
  49             result = readSnapshotNode(path);
  50         } catch (Exception e) {
  51             LOG.error("Tx: {} Failed Read of {}", getIdentifier(), path, e);
  52             return Futures.immediateFailedCheckedFuture(new ReadFailedException("Read failed", e));
  53         }
  54
  55         if (result == null) {
  56             return Futures.immediateFailedCheckedFuture(new ReadFailedException("Transaction is closed"));
  57         } else {
  58             return Futures.immediateCheckedFuture(result);
  59         }
  60     }
  61
  62     @Override
  63     public CheckedFuture<Boolean, ReadFailedException> exists(final YangInstanceIdentifier path) {
  64         try {
  65             return Futures.immediateCheckedFuture(
  66                 read(path).checkedGet().isPresent());
  67         } catch (ReadFailedException e) {
  68             return Futures.immediateFailedCheckedFuture(e);
  69         }
  70     }
  71 }