com.cloudera.crunch.impl.mr.run.RTNodeSerializer.java Source code

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Here is the source code for com.cloudera.crunch.impl.mr.run.RTNodeSerializer.java

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/**
 * Copyright (c) 2011, Cloudera, Inc. All Rights Reserved.
 *
 * Cloudera, Inc. 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
 *
 * This software 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 com.cloudera.crunch.impl.mr.run;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.List;

import org.apache.commons.codec.binary.Base64;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;

import com.cloudera.crunch.impl.mr.plan.DoNode;
import com.google.common.collect.Lists;

public class RTNodeSerializer {

    private static final Log LOG = LogFactory.getLog(RTNodeSerializer.class);

    public void serialize(List<DoNode> nodes, Configuration conf, NodeContext context) throws IOException {
        List<RTNode> rtNodes = Lists.newArrayList();
        for (DoNode node : nodes) {
            rtNodes.add(node.toRTNode(true, conf, context));
        }
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        ObjectOutputStream oos = new ObjectOutputStream(baos);
        oos.writeObject(rtNodes);
        String serialized = Base64.encodeBase64String(baos.toByteArray());
        conf.set(context.getConfigurationKey(), serialized);
    }

    @SuppressWarnings("unchecked")
    public List<RTNode> deserialize(CrunchTaskContext context) throws IOException {
        String serializedString = context.getSerializedState();
        byte[] serialized = Base64.decodeBase64(serializedString);
        ObjectInputStream ois = new ObjectInputStream(new ByteArrayInputStream(serialized));
        List<RTNode> nodes = null;
        try {
            nodes = (List<RTNode>) ois.readObject();
        } catch (ClassNotFoundException e) {
            LOG.info("Crunch deserialization error", e);
            throw new CrunchRuntimeException(e);
        }
        if (nodes != null) {
            for (RTNode node : nodes) {
                node.initialize(context);
            }
        }
        return nodes;
    }

}