gobblin.runtime.locks.AbstractJobLockFactoryManager.java Source code

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Here is the source code for gobblin.runtime.locks.AbstractJobLockFactoryManager.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 gobblin.runtime.locks;

import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;

import org.slf4j.Logger;

import com.google.common.base.Optional;
import com.google.common.cache.Cache;
import com.google.common.cache.CacheBuilder;
import com.typesafe.config.Config;

/**
 * A default base implementation for {@link JobLockFactoryManager} implementations. It maintains a
 * cache from a factory configuration to factory instance.
 */
public abstract class AbstractJobLockFactoryManager<T extends JobLock, F extends JobLockFactory<T>>
        implements JobLockFactoryManager<T, F> {
    private final Cache<Config, F> _factoryCache;

    protected AbstractJobLockFactoryManager(Cache<Config, F> factoryCache) {
        _factoryCache = factoryCache;
    }

    public AbstractJobLockFactoryManager() {
        this(CacheBuilder.newBuilder().<Config, F>build());
    }

    /** Extracts the factory-specific configuration from the system configuration. The extracted
     * object should uniquely identify the factory instance. */
    protected abstract Config getFactoryConfig(Config sysConfig);

    /** Creates a new factory instance using the specified factory and system configs. */
    protected abstract F createFactoryInstance(final Optional<Logger> log, final Config sysConfig,
            final Config factoryConfig);

    /** {@inheritDoc} */
    @Override
    public F getJobLockFactory(final Config sysConfig, final Optional<Logger> log) {
        final Config factoryConfig = getFactoryConfig(sysConfig);
        try {
            return _factoryCache.get(factoryConfig, new Callable<F>() {
                @Override
                public F call() throws Exception {
                    return createFactoryInstance(log, sysConfig, factoryConfig);
                }
            });
        } catch (ExecutionException e) {
            throw new RuntimeException("Unable to create a job lock factory: " + e, e);
        }
    }

}