co.cask.cdap.internal.app.runtime.batch.dataset.DataSetInputSplit.java Source code

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Here is the source code for co.cask.cdap.internal.app.runtime.batch.dataset.DataSetInputSplit.java

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/*
 * Copyright  2014-2016 Cask Data, Inc.
 *
 * Licensed 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 co.cask.cdap.internal.app.runtime.batch.dataset;

import co.cask.cdap.api.data.batch.Split;
import co.cask.cdap.api.dataset.Dataset;
import com.google.common.base.Throwables;
import com.google.gson.Gson;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.Writable;
import org.apache.hadoop.mapreduce.InputSplit;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;

/**
 * Class for {@link InputSplit} of a {@link Dataset}.
 *
 * @see InputSplit
 */
public class DataSetInputSplit extends InputSplit implements Writable {
    private Split split;

    public DataSetInputSplit() {
    }

    public DataSetInputSplit(final Split split) {
        this.split = split;
    }

    public Split getSplit() {
        return split;
    }

    @Override
    public long getLength() throws IOException, InterruptedException {
        return split.getLength();
    }

    @Override
    public String[] getLocations() throws IOException, InterruptedException {
        // By default splits locations are not provided (todo: fix)
        return new String[0];
    }

    @Override
    public void write(final DataOutput out) throws IOException {
        Text.writeString(out, split.getClass().getName());
        String ser = new Gson().toJson(split);
        Text.writeString(out, ser);
    }

    @SuppressWarnings("unchecked")
    @Override
    public void readFields(final DataInput in) throws IOException {
        try {
            ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
            if (classLoader == null) {
                classLoader = getClass().getClassLoader();
            }
            Class<? extends Split> splitClass = (Class<Split>) classLoader.loadClass(Text.readString(in));
            split = new Gson().fromJson(Text.readString(in), splitClass);
        } catch (ClassNotFoundException e) {
            throw Throwables.propagate(e);
        }
    }
}