1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 */
19 package org.eclipse.aether.spi.locking;
20
21 import java.util.Optional;
22
23 import org.eclipse.aether.RepositorySystemSession;
24
25 /**
26 * A factory to create {@link LockingInhibitor} instances, that are capable to augment Resolver locking subsystem and
27 * prevent locking to happen on certain resources.
28 * <p>
29 * <em>Warning: locking inhibition should be applied ONLY to resources that do not conflict on disk (i.e. local
30 * repository) and are NOT produced/written or altered in any way by Resolver, merely cached and read. Hence, despite
31 * artifact locking inhibition is given as option, it should never happen in fact, as aforementioned conditions
32 * never stand for them. On the other hand, good examples of resources may be needing locking inhibition are
33 * archetype catalogs and RRF prefix files, as both are metadata, hence their remotely fetched cache entries do not
34 * conflict locally, furthermore both are produced by remote entities only, and are just cached and read by Maven.</em>
35 *
36 * @since 2.0.14
37 */
38 public interface LockingInhibitorFactory {
39 /**
40 * May return a {@link LockingInhibitor} or just empty {@link Optional}, if for example disabled.
41 */
42 Optional<LockingInhibitor> newInstance(RepositorySystemSession session);
43 }