001package org.eclipse.aether.named.hazelcast;
002
003/*
004 * Licensed to the Apache Software Foundation (ASF) under one
005 * or more contributor license agreements.  See the NOTICE file
006 * distributed with this work for additional information
007 * regarding copyright ownership.  The ASF licenses this file
008 * to you under the Apache License, Version 2.0 (the
009 * "License"); you may not use this file except in compliance
010 * with the License.  You may obtain a copy of the License at
011 *
012 *  http://www.apache.org/licenses/LICENSE-2.0
013 *
014 * Unless required by applicable law or agreed to in writing,
015 * software distributed under the License is distributed on an
016 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
017 * KIND, either express or implied.  See the License for the
018 * specific language governing permissions and limitations
019 * under the License.
020 */
021
022import java.util.concurrent.ConcurrentHashMap;
023import java.util.concurrent.ConcurrentMap;
024import java.util.concurrent.TimeUnit;
025
026import com.hazelcast.core.HazelcastInstance;
027import com.hazelcast.cp.ISemaphore;
028import org.eclipse.aether.named.support.AdaptedSemaphoreNamedLock;
029import org.eclipse.aether.named.support.AdaptedSemaphoreNamedLock.AdaptedSemaphore;
030import org.eclipse.aether.named.support.NamedLockFactorySupport;
031
032import static java.util.Objects.requireNonNull;
033
034/**
035 * Factory of {@link AdaptedSemaphoreNamedLock} instances, using adapted Hazelcast {@link ISemaphore}. It delegates
036 * most the work to {@link HazelcastSemaphoreProvider} and this class just adapts the returned semaphore to named lock
037 * and caches {@link ISemaphore} instances, as recommended by Hazelcast.
038 */
039public class HazelcastSemaphoreNamedLockFactory
040        extends NamedLockFactorySupport
041{
042    protected final HazelcastInstance hazelcastInstance;
043
044    protected final boolean manageHazelcast;
045
046    private final HazelcastSemaphoreProvider hazelcastSemaphoreProvider;
047
048    private final ConcurrentMap<String, ISemaphore> semaphores;
049
050    public HazelcastSemaphoreNamedLockFactory(
051            final HazelcastInstance hazelcastInstance,
052            final boolean manageHazelcast,
053            final HazelcastSemaphoreProvider hazelcastSemaphoreProvider
054    )
055    {
056        this.hazelcastInstance = requireNonNull( hazelcastInstance );
057        this.manageHazelcast = manageHazelcast;
058        this.hazelcastSemaphoreProvider = requireNonNull( hazelcastSemaphoreProvider );
059        this.semaphores = new ConcurrentHashMap<>();
060    }
061
062    @Override
063    protected AdaptedSemaphoreNamedLock createLock( final String name )
064    {
065        ISemaphore semaphore = semaphores.computeIfAbsent( name,
066                k -> hazelcastSemaphoreProvider.acquireSemaphore( hazelcastInstance, name ) );
067        return new AdaptedSemaphoreNamedLock( name, this, new HazelcastSemaphore( semaphore ) );
068    }
069
070    @Override
071    protected void destroyLock( final String name )
072    {
073        hazelcastSemaphoreProvider.releaseSemaphore( hazelcastInstance, name, semaphores.remove( name ) );
074    }
075
076    @Override
077    public void shutdown()
078    {
079        if ( manageHazelcast )
080        {
081            hazelcastInstance.shutdown();
082        }
083    }
084
085    private static final class HazelcastSemaphore implements AdaptedSemaphore
086    {
087        private final ISemaphore semaphore;
088
089        private HazelcastSemaphore( final ISemaphore semaphore )
090        {
091            this.semaphore = semaphore;
092        }
093
094        @Override
095        public boolean tryAcquire( final int perms, final long time, final TimeUnit unit )
096                throws InterruptedException
097        {
098            return semaphore.tryAcquire( perms, time, unit );
099        }
100
101        @Override
102        public void release( final int perms )
103        {
104            semaphore.release( perms );
105        }
106    }
107}