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;
020
021import java.util.concurrent.ConcurrentHashMap;
022import java.util.function.Supplier;
023
024/**
025 * A simplistic repository cache backed by a thread-safe map. The simplistic nature of this cache makes it only suitable
026 * for use with short-lived repository system sessions where pruning of cache data is not required.
027 */
028public final class DefaultRepositoryCache implements RepositoryCache {
029
030    private final ConcurrentHashMap<Object, Object> cache = new ConcurrentHashMap<>(256);
031
032    public Object get(RepositorySystemSession session, Object key) {
033        return cache.get(key);
034    }
035
036    public void put(RepositorySystemSession session, Object key, Object data) {
037        if (data != null) {
038            cache.put(key, data);
039        } else {
040            cache.remove(key);
041        }
042    }
043
044    @Override
045    public Object computeIfAbsent(RepositorySystemSession session, Object key, Supplier<Object> supplier) {
046        return cache.computeIfAbsent(key, k -> supplier.get());
047    }
048}