001/* 002 * Licensed to the Apache Software Foundation (ASF) under one 003 * or more contributor license agreements. See the NOTICE file 004 * distributed with this work for additional information 005 * regarding copyright ownership. The ASF licenses this file 006 * to you under the Apache License, Version 2.0 (the 007 * "License"); you may not use this file except in compliance 008 * with the License. You may obtain a copy of the License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, 013 * software distributed under the License is distributed on an 014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 015 * KIND, either express or implied. See the License for the 016 * specific language governing permissions and limitations 017 * under the License. 018 */ 019package org.eclipse.aether.internal.impl.synccontext.named; 020 021import java.util.Collection; 022 023import org.eclipse.aether.RepositorySystemSession; 024import org.eclipse.aether.artifact.Artifact; 025import org.eclipse.aether.metadata.Metadata; 026import org.eclipse.aether.named.NamedLockKey; 027 028/** 029 * Component mapping lock names to passed in artifacts and metadata as required. 030 */ 031public interface NameMapper { 032 /** 033 * Returns {@code true} if lock names returned by this lock name mapper are file system friendly, can be used 034 * as file names and paths. 035 * <p> 036 * <em>Note:</em> The fact that name mapper is "file system friendly" means ONLY that names it produces CAN be 037 * used as file names and paths. Still, it does not mean they will work with ANY file based locking, as for example 038 * {@link org.eclipse.aether.named.providers.FileLockNamedLockFactory} expects names as string encoded 039 * {@link java.net.URI}s. The only name mapper doing it is {@link BasedirNameMapper}. 040 * 041 * @since 1.9.0 042 */ 043 boolean isFileSystemFriendly(); 044 045 /** 046 * Creates (opaque) names for passed in artifacts and metadata. Returned collection has max size of sum of the 047 * passed in artifacts and metadata collections, or less. If an empty collection is returned, there will be no 048 * locking happening. Never returns {@code null}. The resulting collection MUST BE "stable" (always sorted by 049 * same criteria) to avoid deadlocks by acquiring locks in same order, essentially disregarding the order of 050 * the input collections. 051 * <p> 052 * There is no requirement of any kind of "parity" between input element count (sum of two collections, that is) 053 * and output collection size, just the returned upper size limit is defined (sum of the passed in two collections 054 * size). If returned collection is empty, no locking will happen, if single element, one lock will be used, if two 055 * then two named locks will be used etc. 056 * <p> 057 * Note: name mapper must not use same string for artifacts and metadata, so even the simplest possible 058 * implementation like {@link StaticNameMapper} uses two different static strings. 059 */ 060 Collection<NamedLockKey> nameLocks( 061 RepositorySystemSession session, 062 Collection<? extends Artifact> artifacts, 063 Collection<? extends Metadata> metadatas); 064}