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

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

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/*
 * Copyright  2014 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.BatchWritable;
import co.cask.cdap.common.logging.LoggingContextAccessor;
import co.cask.cdap.internal.app.runtime.batch.BasicMapReduceContext;
import co.cask.cdap.internal.app.runtime.batch.MapReduceContextProvider;
import com.google.common.base.Throwables;
import org.apache.hadoop.mapreduce.RecordWriter;
import org.apache.hadoop.mapreduce.TaskAttemptContext;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;

final class DataSetRecordWriter<KEY, VALUE> extends RecordWriter<KEY, VALUE> {
    private static final Logger LOG = LoggerFactory.getLogger(DataSetRecordWriter.class);

    private final BatchWritable<KEY, VALUE> batchWritable;
    private final BasicMapReduceContext mrContext;
    private final MapReduceContextProvider mrContextProvider;

    public DataSetRecordWriter(final BatchWritable<KEY, VALUE> batchWritable,
            final MapReduceContextProvider mrContextProvider) {
        this.batchWritable = batchWritable;
        this.mrContextProvider = mrContextProvider;
        this.mrContext = mrContextProvider.get();

        // hack: making sure logging context is set on the thread that accesses the runtime context
        LoggingContextAccessor.setLoggingContext(mrContext.getLoggingContext());
    }

    @Override
    public void write(final KEY key, final VALUE value) throws IOException {
        batchWritable.write(key, value);
    }

    @Override
    public void close(final TaskAttemptContext context) throws IOException, InterruptedException {
        // transaction is not finished, but we want all operations to be dispatched (some could be buffered in memory by tx
        // agent)
        try {
            mrContext.flushOperations();
        } catch (Exception e) {
            LOG.error("Failed to flush operations at the end of reducer of " + mrContext.toString());
            throw Throwables.propagate(e);
        } finally {
            try {
                mrContext.close();
            } finally {
                mrContextProvider.stop();
            }
        }
    }
}