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.NonNullByDefault;
11 import org.opendaylight.yangtools.concepts.Registration;
12 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
15 * Data Broker which provides data transaction and data change listener functionality using {@link NormalizedNode}.
18 * All operations on the data tree are performed via one of the transactions:
20 * <li>Read-Only - allocated using {@link #newReadOnlyTransaction()}
21 * <li>Write-Only - allocated using {@link #newWriteOnlyTransaction()}
25 * These transactions provide a stable isolated view of data tree, which is guaranteed to be not
26 * affected by other concurrent transactions, until transaction is committed.
29 * For a detailed explanation of how transaction are isolated and how transaction-local changes are
30 * committed to global data tree, see {@link DOMDataTreeReadTransaction}, {@link DOMDataTreeWriteTransaction}
31 * and {@link DOMDataTreeWriteTransaction#commit()}.
35 * It is strongly recommended to use the type of transaction, which provides only the minimal
36 * capabilities you need. This allows for optimizations at the data broker / data store level. For
37 * example, implementations may optimize the transaction for reading if they know ahead of time that
38 * you only need to read data - such as not keeping additional meta-data, which may be required for
42 * <b>Implementation Note:</b> This interface is not intended to be implemented by users of MD-SAL,
43 * but only to be consumed by them.
46 public interface DOMDataBroker extends DOMService<DOMDataBroker, DOMDataBroker.Extension>, DOMTransactionFactory {
48 * Type capture of a {@link DOMService.Extension} applicable to {@link DOMDataBroker} implementations.
50 interface Extension extends DOMService.Extension<DOMDataBroker, Extension> {
55 * Create a new transaction chain. The chain will be initialized to read from its backing datastore, with
56 * no outstanding transaction.
58 * @return A new transaction chain.
60 DOMTransactionChain createTransactionChain();
63 * Create a new transaction chain. The chain will be initialized to read from its backing datastore, with
64 * no outstanding transaction.
67 * Unlike {@link #createTransactionChain()}, the transaction chain returned by this method is allowed to merge
68 * individual transactions into larger chunks. When transactions are merged, the results must be indistinguishable
69 * from the result of all operations having been performed on a single transaction.
72 * When transactions are merged, {@link DOMTransactionChain#newReadOnlyTransaction()} may actually be backed by
73 * a read-write transaction, hence an additional restriction on API use is that multiple read-only transactions
74 * may not be open at the same time.
76 * @return A new transaction chain.
78 DOMTransactionChain createMergingTransactionChain();
81 * Optional support for allowing a {@link DOMDataTreeCommitCohort} to participate in the process of committing
82 * {@link DOMDataTreeWriteTransaction}s.
84 interface CommitCohortExtension extends Extension {
86 * Register commit cohort which will participate in three-phase commit protocols of
87 * {@link DOMDataTreeWriteTransaction} in data broker associated with this instance of extension.
89 * @param path Subtree path on which commit cohort operates.
90 * @param cohort A {@link DOMDataTreeCommitCohort}
91 * @return A {@link Registration}
92 * @throws NullPointerException if any argument is {@code null}
94 Registration registerCommitCohort(DOMDataTreeIdentifier path, DOMDataTreeCommitCohort cohort);