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.controller.md.sal.dom.api;
10 import com.google.common.base.Optional;
11 import com.google.common.util.concurrent.CheckedFuture;
12 import org.opendaylight.controller.md.sal.common.api.data.AsyncReadTransaction;
13 import org.opendaylight.controller.md.sal.common.api.data.LogicalDatastoreType;
14 import org.opendaylight.controller.md.sal.common.api.data.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.
22 * For more information on usage and examples, please see the documentation in {@link AsyncReadTransaction}.
24 public interface DOMDataReadTransaction extends AsyncReadTransaction<YangInstanceIdentifier, NormalizedNode<?, ?>> {
27 * Reads data from provided logical data store located at the provided path.
30 * If the target is a subtree, then the whole subtree is read (and will be
31 * accessible from the returned data object).
34 * Logical data store from which read should occur.
36 * Path which uniquely identifies subtree which client want to
38 * @return a CheckFuture containing the result of the read. The Future blocks until the
39 * commit operation is complete. Once complete:
41 * <li>If the data at the supplied path exists, the Future returns an Optional object
42 * containing the data.</li>
43 * <li>If the data at the supplied path does not exist, the Future returns
44 * Optional#absent().</li>
45 * <li>If the read of the data fails, the Future will fail with a
46 * {@link ReadFailedException} or an exception derived from ReadFailedException.</li>
49 CheckedFuture<Optional<NormalizedNode<?,?>>, ReadFailedException> read(
50 LogicalDatastoreType store, YangInstanceIdentifier path);
54 * Checks if data is available in the logical data store located at provided path.
57 * Note: a successful result from this method makes no guarantee that a subsequent call to {@link #read}
58 * will succeed. It is possible that the data resides in a data store on a remote node and, if that
59 * node goes down or a network failure occurs, a subsequent read would fail. Another scenario is if
60 * the data is deleted in between the calls to <code>exists</code> and <code>read</code>
63 * Logical data store from which read should occur.
65 * Path which uniquely identifies subtree which client want to
67 * @return a CheckFuture containing the result of the check.
69 * <li>If the data at the supplied path exists, the Future returns a Boolean
70 * whose value is true, false otherwise</li>
71 * <li>If checking for the data fails, the Future will fail with a
72 * {@link ReadFailedException} or an exception derived from ReadFailedException.</li>
75 CheckedFuture<Boolean, ReadFailedException> exists(LogicalDatastoreType store, YangInstanceIdentifier path);