org.springframework.integration.cluster.redis.ClusterStatusRepositoryImpl.java Source code

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Here is the source code for org.springframework.integration.cluster.redis.ClusterStatusRepositoryImpl.java

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/*
 * Copyright 2002-2011 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.springframework.integration.cluster.redis;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.dao.DuplicateKeyException;
import org.springframework.dao.EmptyResultDataAccessException;
import org.springframework.dao.OptimisticLockingFailureException;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.integration.cluster.ClusterStatus;
import org.springframework.integration.cluster.ClusterStatusRepository;

/**
 * @author Gary Russell
 *
 */
public class ClusterStatusRepositoryImpl implements ClusterStatusRepository {

    @SuppressWarnings("unused")
    private static final Log LOG = LogFactory.getLog(ClusterStatusRepositoryImpl.class);

    private final RedisTemplate<String, ClusterStatus> statusTemplate;

    private final String instanceInfo;

    private int timeout = 10000;

    private final DistributedLockHandler lockHandler;

    /**
     * @param lockTemplate
     * @param statusTemplate
     */
    public ClusterStatusRepositoryImpl(StringRedisTemplate lockTemplate,
            RedisTemplate<String, ClusterStatus> statusTemplate, String instanceInfo) {
        this.statusTemplate = statusTemplate;
        this.instanceInfo = instanceInfo;
        this.lockHandler = new DistributedLockHandler(lockTemplate, this.timeout);
    }

    public void create(ClusterStatus clusterStatus) {
        String applicationId = clusterStatus.getApplicationId();
        this.lockHandler.acquireLock(applicationId, this.instanceInfo);
        ClusterStatus status = statusTemplate.opsForValue().get(applicationId);
        if (status != null) {
            throw new DuplicateKeyException("Cluster status already exists for application " + applicationId);
        }
        statusTemplate.opsForValue().set(applicationId, clusterStatus);
        this.lockHandler.relinquishLock(applicationId, this.instanceInfo);
    }

    public ClusterStatus find(String applicationId) {
        ClusterStatus status = statusTemplate.opsForValue().get(applicationId);
        if (status == null) {
            throw new EmptyResultDataAccessException(1);
        }
        return status;
    }

    public ClusterStatus lock(String applicationId) {
        this.lockHandler.acquireLock(applicationId, this.instanceInfo);
        ClusterStatus status = statusTemplate.opsForValue().get(applicationId);
        if (status == null) {
            this.lockHandler.relinquishLock(applicationId, this.instanceInfo);
            throw new EmptyResultDataAccessException(1);
        }
        return find(applicationId);
    }

    public void updateLastProcessed(ClusterStatus clusterStatus) {
        String applicationId = clusterStatus.getApplicationId();
        if (this.lockHandler.checkIOwnLock(applicationId)) {
            statusTemplate.opsForValue().set(applicationId, clusterStatus);
        } else {
            throw new OptimisticLockingFailureException(
                    "Held lock for " + applicationId + " too long - unsafe to update protected key");
        }
    }

    public void updateUsurper(ClusterStatus clusterStatus) {
        updateLastProcessed(clusterStatus);
    }

    public void updateMaster(ClusterStatus clusterStatus) {
        updateLastProcessed(clusterStatus);
    }

    public int updateStatusAll(String applicationId, String status) {
        // TODO - maybe change locks to a set? What about cross-contention?
        // return 0;
        throw new UnsupportedOperationException();
    }

    public void unlock(String applicationId) {
        this.lockHandler.relinquishLock(applicationId, this.instanceInfo);
    }

}