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 org.eclipse.jdt.annotation.NonNull;
11 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
14 * Data Broker which provides data transaction and data change listener functionality using {@link NormalizedNode}.
17 * All operations on the data tree are performed via one of the transactions:
19 * <li>Read-Only - allocated using {@link #newReadOnlyTransaction()}
20 * <li>Write-Only - allocated using {@link #newWriteOnlyTransaction()}
24 * These transactions provide a stable isolated view of data tree, which is guaranteed to be not
25 * affected by other concurrent transactions, until transaction is committed.
28 * For a detailed explanation of how transaction are isolated and how transaction-local changes are
29 * committed to global data tree, see {@link DOMDataTreeReadTransaction}, {@link DOMDataTreeWriteTransaction}
30 * and {@link DOMDataTreeWriteTransaction#commit()}.
34 * It is strongly recommended to use the type of transaction, which provides only the minimal
35 * capabilities you need. This allows for optimizations at the data broker / data store level. For
36 * example, implementations may optimize the transaction for reading if they know ahead of time that
37 * you only need to read data - such as not keeping additional meta-data, which may be required for
41 * <b>Implementation Note:</b> This interface is not intended to be implemented by users of MD-SAL,
42 * but only to be consumed by them.
44 public interface DOMDataBroker extends DOMService<DOMDataBroker, DOMDataBroker.Extension>, DOMTransactionFactory {
46 * Type capture of a {@link DOMService.Extension} applicable to {@link DOMDataBroker} implementations.
48 interface Extension extends DOMService.Extension<DOMDataBroker, Extension> {
53 * Create a new transaction chain. The chain will be initialized to read from its backing datastore, with
54 * no outstanding transaction.
56 * @return A new transaction chain.
58 @NonNull DOMTransactionChain createTransactionChain();
61 * Create a new transaction chain. The chain will be initialized to read from its backing datastore, with
62 * no outstanding transaction.
65 * Unlike {@link #createTransactionChain()}, the transaction chain returned by this method is allowed to merge
66 * individual transactions into larger chunks. When transactions are merged, the results must be indistinguishable
67 * from the result of all operations having been performed on a single transaction.
70 * When transactions are merged, {@link DOMTransactionChain#newReadOnlyTransaction()} may actually be backed by
71 * a read-write transaction, hence an additional restriction on API use is that multiple read-only transactions
72 * may not be open at the same time.
74 * @return A new transaction chain.
76 @NonNull DOMTransactionChain createMergingTransactionChain();