org.apache.hadoop.hdfs.KeyProviderCache.java Source code

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Here is the source code for org.apache.hadoop.hdfs.KeyProviderCache.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 org.apache.hadoop.hdfs;

import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.crypto.key.KeyProvider;

import com.google.common.annotations.VisibleForTesting;
import com.google.common.cache.Cache;
import com.google.common.cache.CacheBuilder;
import com.google.common.cache.RemovalListener;
import com.google.common.cache.RemovalNotification;

@InterfaceAudience.Private
public class KeyProviderCache {

    public static final Log LOG = LogFactory.getLog(KeyProviderCache.class);

    private final Cache<URI, KeyProvider> cache;

    public KeyProviderCache(long expiryMs) {
        cache = CacheBuilder.newBuilder().expireAfterAccess(expiryMs, TimeUnit.MILLISECONDS)
                .removalListener(new RemovalListener<URI, KeyProvider>() {
                    @Override
                    public void onRemoval(RemovalNotification<URI, KeyProvider> notification) {
                        try {
                            notification.getValue().close();
                        } catch (Throwable e) {
                            LOG.error("Error closing KeyProvider with uri [" + notification.getKey() + "]", e);
                            ;
                        }
                    }
                }).build();
    }

    public KeyProvider get(final Configuration conf) {
        URI kpURI = createKeyProviderURI(conf);
        if (kpURI == null) {
            return null;
        }
        try {
            return cache.get(kpURI, new Callable<KeyProvider>() {
                @Override
                public KeyProvider call() throws Exception {
                    return DFSUtil.createKeyProvider(conf);
                }
            });
        } catch (Exception e) {
            LOG.error("Could not create KeyProvider for DFSClient !!", e.getCause());
            return null;
        }
    }

    private URI createKeyProviderURI(Configuration conf) {
        final String providerUriStr = conf.getTrimmed(DFSConfigKeys.DFS_ENCRYPTION_KEY_PROVIDER_URI, "");
        // No provider set in conf
        if (providerUriStr.isEmpty()) {
            LOG.error("Could not find uri with key [" + DFSConfigKeys.DFS_ENCRYPTION_KEY_PROVIDER_URI
                    + "] to create a keyProvider !!");
            return null;
        }
        final URI providerUri;
        try {
            providerUri = new URI(providerUriStr);
        } catch (URISyntaxException e) {
            LOG.error("KeyProvider URI string is invalid [" + providerUriStr + "]!!", e.getCause());
            return null;
        }
        return providerUri;
    }

    @VisibleForTesting
    public void setKeyProvider(Configuration conf, KeyProvider keyProvider) throws IOException {
        URI uri = createKeyProviderURI(conf);
        cache.put(uri, keyProvider);
    }
}