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.internal.impl.synccontext.named;
20
21 import java.util.Collection;
22
23 import org.eclipse.aether.RepositorySystemSession;
24 import org.eclipse.aether.artifact.Artifact;
25 import org.eclipse.aether.metadata.Metadata;
26 import org.eclipse.aether.named.NamedLockKey;
27
28 /**
29 * Component mapping lock names to passed in artifacts and metadata as required.
30 */
31 public interface NameMapper {
32 /**
33 * Returns {@code true} if lock names returned by this lock name mapper are file system friendly, can be used
34 * as file names and paths.
35 * <p>
36 * <em>Note:</em> The fact that name mapper is "file system friendly" means ONLY that names it produces CAN be
37 * used as file names and paths. Still, it does not mean they will work with ANY file based locking, as for example
38 * {@link org.eclipse.aether.named.providers.FileLockNamedLockFactory} expects names as string encoded
39 * {@link java.net.URI}s. The only name mapper doing it is {@link BasedirNameMapper}.
40 *
41 * @since 1.9.0
42 */
43 boolean isFileSystemFriendly();
44
45 /**
46 * Creates (opaque) names for passed in artifacts and metadata. Returned collection has max size of sum of the
47 * passed in artifacts and metadata collections, or less. If an empty collection is returned, there will be no
48 * locking happening. Never returns {@code null}. The resulting collection MUST BE "stable" (always sorted by
49 * same criteria) to avoid deadlocks by acquiring locks in same order, essentially disregarding the order of
50 * the input collections.
51 * <p>
52 * There is no requirement of any kind of "parity" between input element count (sum of two collections, that is)
53 * and output collection size, just the returned upper size limit is defined (sum of the passed in two collections
54 * size). If returned collection is empty, no locking will happen, if single element, one lock will be used, if two
55 * then two named locks will be used etc.
56 * <p>
57 * Note: name mapper must not use same string for artifacts and metadata, so even the simplest possible
58 * implementation like {@link StaticNameMapper} uses two different static strings.
59 */
60 Collection<NamedLockKey> nameLocks(
61 RepositorySystemSession session,
62 Collection<? extends Artifact> artifacts,
63 Collection<? extends Metadata> metadatas);
64 }