2 * Copyright (c) 2014 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.mdsal.dom.api;
10 import com.google.common.base.Optional;
11 import com.google.common.util.concurrent.CheckedFuture;
12 import org.opendaylight.mdsal.common.api.AsyncReadTransaction;
13 import org.opendaylight.mdsal.common.api.LogicalDatastoreType;
14 import org.opendaylight.mdsal.common.api.ReadFailedException;
15 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
16 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
19 * A transaction that provides read access to a logical data store.
21 * For more information on usage and examples, please see the documentation in {@link AsyncReadTransaction}.
23 public interface DOMDataTreeReadTransaction extends AsyncReadTransaction<YangInstanceIdentifier, NormalizedNode<?, ?>> {
26 * Reads data from provided logical data store located at the provided path.
28 * If the target is a subtree, then the whole subtree is read (and will be
29 * accessible from the returned data object).
32 * Logical data store from which read should occur.
34 * Path which uniquely identifies subtree which client want to
36 * @return a CheckFuture containing the result of the read. The Future blocks until the
37 * commit operation is complete. Once complete:
39 * <li>If the data at the supplied path exists, the Future returns an Optional object
40 * containing the data.</li>
41 * <li>If the data at the supplied path does not exist, the Future returns
42 * Optional#absent().</li>
43 * <li>If the read of the data fails, the Future will fail with a
44 * {@link ReadFailedException} or an exception derived from ReadFailedException.</li>
47 CheckedFuture<Optional<NormalizedNode<?,?>>, ReadFailedException> read(
48 LogicalDatastoreType store, YangInstanceIdentifier path);
51 * Checks if data is available in the logical data store located at provided path.
54 * Note: a successful result from this method makes no guarantee that a subsequent call to {@link #read}
55 * will succeed. It is possible that the data resides in a data store on a remote node and, if that
56 * node goes down or a network failure occurs, a subsequent read would fail. Another scenario is if
57 * the data is deleted in between the calls to <code>exists</code> and <code>read</code>
60 * Logical data store from which read should occur.
62 * Path which uniquely identifies subtree which client want to
64 * @return a CheckFuture containing the result of the check.
66 * <li>If the data at the supplied path exists, the Future returns a Boolean
67 * whose value is true, false otherwise</li>
68 * <li>If checking for the data fails, the Future will fail with a
69 * {@link ReadFailedException} or an exception derived from ReadFailedException.</li>
72 CheckedFuture<Boolean, ReadFailedException> exists(
73 LogicalDatastoreType store, YangInstanceIdentifier path);