2 * Copyright (c) 2018 Pantheon Technologies, s.r.o. 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.binding.api;
10 import com.google.common.util.concurrent.FluentFuture;
11 import java.util.Optional;
12 import org.eclipse.jdt.annotation.NonNull;
13 import org.opendaylight.mdsal.common.api.LogicalDatastoreType;
14 import org.opendaylight.mdsal.common.api.ReadFailedException;
15 import org.opendaylight.yangtools.yang.binding.DataObject;
16 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
19 * Read-like operations supported by {@link ReadTransaction} and {@link ReadWriteTransaction}. This interface defines
20 * the operations without a tie-in with lifecycle management.
22 public interface ReadOperations {
24 * Reads data from the provided logical data store located at the provided path.
27 * If the target is a subtree, then the whole subtree is read (and will be accessible from the returned data
30 * @param store Logical data store from which read should occur.
31 * @param path Path which uniquely identifies subtree which client want to read
32 * @return a FluentFuture containing the result of the read. The Future blocks until the commit operation is
33 * complete. Once complete:
35 * <li>If the data at the supplied path exists, the Future returns an Optional object containing the data.
37 * <li>If the data at the supplied path does not exist, the Future returns Optional.empty().</li>
38 * <li>If the read of the data fails, the Future will fail with a {@link ReadFailedException} or
39 * an exception derived from ReadFailedException.</li>
41 * @throws NullPointerException if any of the arguments is null
43 <T extends DataObject> @NonNull FluentFuture<Optional<T>> read(@NonNull LogicalDatastoreType store,
44 @NonNull InstanceIdentifier<T> path);