001package org.eclipse.aether.named.redisson;
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 org.eclipse.aether.named.support.AdaptedSemaphoreNamedLock;
023import org.redisson.api.RSemaphore;
024
025import javax.inject.Named;
026import javax.inject.Singleton;
027import java.util.concurrent.ConcurrentHashMap;
028import java.util.concurrent.ConcurrentMap;
029import java.util.concurrent.TimeUnit;
030
031/**
032 * Provider of {@link RedissonSemaphoreNamedLockFactory} using Redisson and {@link org.redisson.api.RSemaphore}.
033 */
034@Singleton
035@Named( RedissonSemaphoreNamedLockFactory.NAME )
036public class RedissonSemaphoreNamedLockFactory
037    extends RedissonNamedLockFactorySupport
038{
039    public static final String NAME = "semaphore-redisson";
040
041    private final ConcurrentMap<String, RSemaphore> semaphores;
042
043    public RedissonSemaphoreNamedLockFactory()
044    {
045        this.semaphores = new ConcurrentHashMap<>();
046    }
047
048    @Override
049    protected AdaptedSemaphoreNamedLock createLock( final String name )
050    {
051        RSemaphore semaphore = semaphores.computeIfAbsent( name, k ->
052        {
053            RSemaphore result = redissonClient.getSemaphore( NAME_PREFIX + k );
054            result.trySetPermits( Integer.MAX_VALUE );
055            return result;
056        } );
057        return new AdaptedSemaphoreNamedLock( name, this, new RedissonSemaphore( semaphore ) );
058    }
059
060    @Override
061    protected void destroyLock( final String name )
062    {
063        RSemaphore semaphore = semaphores.remove( name );
064        if ( semaphore == null )
065        {
066            throw new IllegalStateException( "Semaphore expected but does not exist: " + name );
067        }
068        semaphore.delete();
069    }
070
071    private static final class RedissonSemaphore implements AdaptedSemaphoreNamedLock.AdaptedSemaphore
072    {
073        private final RSemaphore semaphore;
074
075        private RedissonSemaphore( final RSemaphore semaphore )
076        {
077            this.semaphore = semaphore;
078        }
079
080        @Override
081        public boolean tryAcquire( final int perms, final long time, final TimeUnit unit ) throws InterruptedException
082        {
083            return semaphore.tryAcquire( perms, time, unit );
084        }
085
086        @Override
087        public void release( final int perms )
088        {
089            semaphore.release( perms );
090        }
091    }
092}