org.apache.hadoop.hdfs.security.token.delegation.DelegationTokenIdentifier.java Source code

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Here is the source code for org.apache.hadoop.hdfs.security.token.delegation.DelegationTokenIdentifier.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.security.token.delegation;

import java.io.ByteArrayInputStream;
import java.io.DataInputStream;
import java.io.IOException;
import java.util.Collections;
import java.util.Map;

import org.apache.commons.collections.map.LRUMap;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.hdfs.web.WebHdfsConstants;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.security.UserGroupInformation;
import org.apache.hadoop.security.token.Token;
import org.apache.hadoop.security.token.TokenIdentifier;
import org.apache.hadoop.security.token.delegation.AbstractDelegationTokenIdentifier;

import com.google.common.annotations.VisibleForTesting;

/**
 * A delegation token identifier that is specific to HDFS.
 */
@InterfaceAudience.Private
public class DelegationTokenIdentifier extends AbstractDelegationTokenIdentifier {
    public static final Text HDFS_DELEGATION_KIND = new Text("HDFS_DELEGATION_TOKEN");

    @SuppressWarnings("unchecked")
    private static Map<TokenIdentifier, UserGroupInformation> ugiCache = Collections
            .synchronizedMap(new LRUMap(64));

    @VisibleForTesting
    public void clearCache() {
        ugiCache.clear();
    }

    /**
     * Create an empty delegation token identifier for reading into.
     */
    public DelegationTokenIdentifier() {
    }

    /**
     * Create a new delegation token identifier
     * @param owner the effective username of the token owner
     * @param renewer the username of the renewer
     * @param realUser the real username of the token owner
     */
    public DelegationTokenIdentifier(Text owner, Text renewer, Text realUser) {
        super(owner, renewer, realUser);
    }

    @Override
    public Text getKind() {
        return HDFS_DELEGATION_KIND;
    }

    @Override
    public UserGroupInformation getUser() {
        UserGroupInformation ugi = ugiCache.get(this);
        if (ugi == null) {
            ugi = super.getUser();
            ugiCache.put(this, ugi);
        }
        return ugi;
    }

    @Override
    public String toString() {
        StringBuilder sbld = new StringBuilder();
        sbld.append("token for ").append(getUser().getShortUserName()).append(": ").append(super.toString());
        return sbld.toString();
    }

    /*
     * A frozen version of toString() to be used to be backward compatible.
     * When backward compatibility is not needed, use toString(), which provides
     * more info and is supposed to evolve, see HDFS-9732.
     * Don't change this method except for major revisions.
     *
     * NOTE:
     * Currently this method is used by CLI for backward compatibility.
     */
    @Override
    public String toStringStable() {
        StringBuilder sbld = new StringBuilder();
        sbld.append(getKind()).append(" token ").append(getSequenceNumber()).append(" for ")
                .append(getUser().getShortUserName()).append(" with renewer ").append(getRenewer());
        return sbld.toString();
    }

    /** @return a string representation of the token */
    public static String stringifyToken(final Token<?> token) throws IOException {
        DelegationTokenIdentifier ident = new DelegationTokenIdentifier();
        ByteArrayInputStream buf = new ByteArrayInputStream(token.getIdentifier());
        DataInputStream in = new DataInputStream(buf);
        ident.readFields(in);

        if (token.getService().getLength() > 0) {
            return ident + " on " + token.getService();
        } else {
            return ident.toString();
        }
    }

    public static class WebHdfsDelegationTokenIdentifier extends DelegationTokenIdentifier {
        public WebHdfsDelegationTokenIdentifier() {
            super();
        }

        @Override
        public Text getKind() {
            return WebHdfsConstants.WEBHDFS_TOKEN_KIND;
        }
    }

    public static class SWebHdfsDelegationTokenIdentifier extends WebHdfsDelegationTokenIdentifier {
        public SWebHdfsDelegationTokenIdentifier() {
            super();
        }

        @Override
        public Text getKind() {
            return WebHdfsConstants.SWEBHDFS_TOKEN_KIND;
        }
    }
}