org.apache.sentry.api.generic.thrift.SentryGenericServiceClientFactory.java Source code

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Here is the source code for org.apache.sentry.api.generic.thrift.SentryGenericServiceClientFactory.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
 * <p>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p>
 * 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.apache.sentry.api.generic.thrift;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.security.UserGroupInformation;
import org.apache.sentry.core.common.transport.RetryClientInvocationHandler;
import org.apache.sentry.core.common.transport.SentryPolicyClientTransportConfig;
import org.apache.sentry.core.common.transport.SentryTransportFactory;
import org.apache.sentry.core.common.transport.SentryTransportPool;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.annotation.concurrent.ThreadSafe;
import java.lang.reflect.Proxy;
import java.util.concurrent.atomic.AtomicReference;

/**
 * Produces client connection for Sentry clients using Generic model.
 * Factory is [alost] a singleton. Tests can call {@link #factoryReset()} to destroy the
 * existing factory and create a new one. This may be needed because tests modify
 * configuration and start and stop servers.
 */
@ThreadSafe
public final class SentryGenericServiceClientFactory {
    private static final Logger LOGGER = LoggerFactory.getLogger(SentryGenericServiceClientFactory.class);

    // Used to implement a singleton
    private static final AtomicReference<SentryGenericServiceClientFactory> clientFactory = new AtomicReference<>();

    private final SentryPolicyClientTransportConfig transportConfig = new SentryPolicyClientTransportConfig();
    private final SentryTransportPool transportPool;
    private final Configuration conf;

    /**
     * Obtain an Generic policy client instance.
     * @param conf Configuration that should be used. Configuration is only used for the
     *             initial creation and ignored afterwords.
     */
    public static SentryGenericServiceClient create(Configuration conf) throws Exception {
        SentryGenericServiceClientFactory factory = clientFactory.get();
        if (factory != null) {
            return factory.create();
        }
        factory = new SentryGenericServiceClientFactory(conf);
        boolean ok = clientFactory.compareAndSet(null, factory);
        if (ok) {
            return factory.create();
        }
        factory.close();
        return clientFactory.get().create();
    }

    /**
     * Create a new factory instance and atach it to a connection pool instance.
     * @param conf Configuration
     */
    private SentryGenericServiceClientFactory(Configuration conf) {
        if (transportConfig.isKerberosEnabled(conf) && transportConfig.useUserGroupInformation(conf)) {
            LOGGER.info("Using UserGroupInformation authentication");
            UserGroupInformation.setConfiguration(conf);
        }

        this.conf = conf;

        transportPool = new SentryTransportPool(this.conf, transportConfig,
                new SentryTransportFactory(this.conf, transportConfig));
    }

    /**
     * Create a new client connection to the server for Generic model clients
     * @return client instance
     * @throws Exception if something goes wrong
     */
    @SuppressWarnings("squid:S00112")
    private SentryGenericServiceClient create() throws Exception {
        return (SentryGenericServiceClient) Proxy.newProxyInstance(
                SentryGenericServiceClientDefaultImpl.class.getClassLoader(),
                SentryGenericServiceClientDefaultImpl.class.getInterfaces(), new RetryClientInvocationHandler(conf,
                        new SentryGenericServiceClientDefaultImpl(conf, transportPool), transportConfig));
    }

    // Should only be used by tests.
    // Resets the factory and destroys any pooled connections
    public static void factoryReset() {
        LOGGER.debug("factory reset");
        SentryGenericServiceClientFactory factory = clientFactory.getAndSet(null);
        if (factory != null) {
            try {
                factory.transportPool.close();
            } catch (Exception e) {
                LOGGER.error("failed to close transport pool", e);
            }
        }
    }

    private void close() {
        try {
            transportPool.close();
        } catch (Exception e) {
            LOGGER.error("failed to close transport pool", e);
        }
    }
}