org.apache.crunch.io.orc.OrcFileWriter.java Source code

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Here is the source code for org.apache.crunch.io.orc.OrcFileWriter.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.crunch.io.orc;

import java.io.Closeable;
import java.io.IOException;

import org.apache.crunch.MapFn;
import org.apache.crunch.types.PType;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hive.ql.io.orc.OrcOutputFormat;
import org.apache.hadoop.hive.ql.io.orc.OrcSerde;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.OutputFormat;
import org.apache.hadoop.mapred.RecordWriter;
import org.apache.hadoop.mapred.Reporter;
import org.apache.hadoop.util.Progressable;

/**
 * A writer class which is corresponding to OrcFileReaderFactory. Mainly used
 * for test purpose
 *
 * @param <T>
 */
public class OrcFileWriter<T> implements Closeable {

    private RecordWriter<NullWritable, Object> writer;
    private MapFn<T, Object> mapFn;
    private final OrcSerde serde;

    static class NullProgress implements Progressable {
        @Override
        public void progress() {
        }
    }

    public OrcFileWriter(Configuration conf, Path path, PType<T> pType) throws IOException {
        JobConf jobConf = new JobConf(conf);
        OutputFormat outputFormat = new OrcOutputFormat();
        writer = outputFormat.getRecordWriter(null, jobConf, path.toString(), new NullProgress());

        mapFn = pType.getOutputMapFn();
        mapFn.initialize();

        serde = new OrcSerde();
    }

    public void write(T t) throws IOException {
        OrcWritable ow = (OrcWritable) mapFn.map(t);
        if (ow.get() == null) {
            throw new NullPointerException("Cannot write null records to orc file");
        }
        writer.write(NullWritable.get(), serde.serialize(ow.get(), ow.getObjectInspector()));
    }

    @Override
    public void close() throws IOException {
        writer.close(Reporter.NULL);
    }

}