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.named.hazelcast;
020
021import java.util.concurrent.ConcurrentHashMap;
022import java.util.concurrent.ConcurrentMap;
023import java.util.concurrent.TimeUnit;
024
025import com.hazelcast.core.HazelcastInstance;
026import com.hazelcast.cp.ISemaphore;
027import org.eclipse.aether.named.NamedLock;
028import org.eclipse.aether.named.NamedLockKey;
029import org.eclipse.aether.named.support.AdaptedSemaphoreNamedLock;
030import org.eclipse.aether.named.support.AdaptedSemaphoreNamedLock.AdaptedSemaphore;
031import org.eclipse.aether.named.support.NamedLockFactorySupport;
032
033import static java.util.Objects.requireNonNull;
034
035/**
036 * Factory of {@link AdaptedSemaphoreNamedLock} instances, using adapted Hazelcast {@link ISemaphore}. It delegates
037 * most the work to {@link HazelcastSemaphoreProvider} and this class just adapts the returned semaphore to named lock
038 * and caches {@link ISemaphore} instances, as recommended by Hazelcast.
039 */
040public class HazelcastSemaphoreNamedLockFactory extends NamedLockFactorySupport {
041    protected final HazelcastInstance hazelcastInstance;
042
043    protected final boolean manageHazelcast;
044
045    private final HazelcastSemaphoreProvider hazelcastSemaphoreProvider;
046
047    private final ConcurrentMap<NamedLockKey, ISemaphore> semaphores;
048
049    public HazelcastSemaphoreNamedLockFactory(
050            final HazelcastInstance hazelcastInstance,
051            final boolean manageHazelcast,
052            final HazelcastSemaphoreProvider hazelcastSemaphoreProvider) {
053        this.hazelcastInstance = requireNonNull(hazelcastInstance);
054        this.manageHazelcast = manageHazelcast;
055        this.hazelcastSemaphoreProvider = requireNonNull(hazelcastSemaphoreProvider);
056        this.semaphores = new ConcurrentHashMap<>();
057    }
058
059    @Override
060    protected AdaptedSemaphoreNamedLock createLock(final NamedLockKey key) {
061        ISemaphore semaphore = semaphores.computeIfAbsent(
062                key, k -> hazelcastSemaphoreProvider.acquireSemaphore(hazelcastInstance, key));
063        return new AdaptedSemaphoreNamedLock(key, this, new HazelcastSemaphore(semaphore));
064    }
065
066    @Override
067    protected void destroyLock(final NamedLock namedLock) {
068        if (namedLock instanceof AdaptedSemaphoreNamedLock) {
069            final NamedLockKey key = namedLock.key();
070            hazelcastSemaphoreProvider.releaseSemaphore(hazelcastInstance, key, semaphores.remove(key));
071        }
072    }
073
074    @Override
075    protected void doShutdown() {
076        if (manageHazelcast) {
077            hazelcastInstance.shutdown();
078        }
079    }
080
081    private static final class HazelcastSemaphore implements AdaptedSemaphore {
082        private final ISemaphore semaphore;
083
084        private HazelcastSemaphore(final ISemaphore semaphore) {
085            this.semaphore = semaphore;
086        }
087
088        @Override
089        public boolean tryAcquire(final int perms, final long time, final TimeUnit unit) throws InterruptedException {
090            return semaphore.tryAcquire(perms, time, unit);
091        }
092
093        @Override
094        public void release(final int perms) {
095            semaphore.release(perms);
096        }
097    }
098}