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1   package org.eclipse.aether.internal.impl.synccontext.named;
2   
3   /*
4    * Licensed to the Apache Software Foundation (ASF) under one
5    * or more contributor license agreements.  See the NOTICE file
6    * distributed with this work for additional information
7    * regarding copyright ownership.  The ASF licenses this file
8    * to you under the Apache License, Version 2.0 (the
9    * "License"); you may not use this file except in compliance
10   * with the License.  You may obtain a copy of the License at
11   *
12   *  http://www.apache.org/licenses/LICENSE-2.0
13   *
14   * Unless required by applicable law or agreed to in writing,
15   * software distributed under the License is distributed on an
16   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17   * KIND, either express or implied.  See the License for the
18   * specific language governing permissions and limitations
19   * under the License.
20   */
21  
22  import java.util.Collection;
23  
24  import org.eclipse.aether.RepositorySystemSession;
25  import org.eclipse.aether.artifact.Artifact;
26  import org.eclipse.aether.metadata.Metadata;
27  
28  /**
29   * Component mapping lock names to passed in artifacts and metadata as required.
30   */
31  public interface NameMapper
32  {
33      /**
34       * Returns {@code true} if lock names returned by this lock name mapper are file system friendly, can be used
35       * as file names and paths.
36       *
37       * @since 1.9.0
38       */
39      boolean isFileSystemFriendly();
40  
41      /**
42       * Creates (opaque) names for passed in artifacts and metadata. Returned collection has max size of sum of the
43       * passed in artifacts and metadata collections, or less. If an empty collection is returned, there will be no
44       * locking happening. Never returns {@code null}. The resulting collection MUST BE "stable" (always sorted by
45       * same criteria) to avoid deadlocks by acquiring locks in same order, essentially disregarding the order of
46       * the input collections.
47       * <p>
48       * There is no requirement of any kind of "parity" between input element count (sum of two collections, that is)
49       * and output collection size, just the returned upper size limit is defined (sum of the passed in two collections
50       * size). If returned collection is empty, no locking will happen, if single element, one lock will be used, if two
51       * then two named locks will be used etc.
52       */
53      Collection<String> nameLocks( RepositorySystemSession session,
54                                    Collection<? extends Artifact> artifacts,
55                                    Collection<? extends Metadata> metadatas );
56  }