org.apache.avro.mapred.AvroTextOutputFormat.java Source code

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Here is the source code for org.apache.avro.mapred.AvroTextOutputFormat.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.avro.mapred;

import static org.apache.avro.mapred.AvroOutputFormat.EXT;

import java.io.IOException;
import java.nio.ByteBuffer;

import org.apache.avro.Schema;
import org.apache.avro.file.DataFileWriter;
import org.apache.avro.reflect.ReflectDatumWriter;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.FileOutputFormat;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.RecordWriter;
import org.apache.hadoop.mapred.Reporter;
import org.apache.hadoop.util.Progressable;

/** The equivalent of {@link org.apache.hadoop.mapred.TextOutputFormat} for
 * writing to Avro Data Files with a <code>"bytes"</code> schema. */
public class AvroTextOutputFormat<K, V> extends FileOutputFormat<K, V> {

    private static final String UTF8 = "UTF-8";

    @Override
    public RecordWriter<K, V> getRecordWriter(FileSystem ignore, JobConf job, String name, Progressable prog)
            throws IOException {

        Schema schema = Schema.create(Schema.Type.BYTES);

        final byte[] keyValueSeparator = job.get("mapreduce.output.textoutputformat.separator", "\t")
                .getBytes(UTF8);

        final DataFileWriter<ByteBuffer> writer = new DataFileWriter<ByteBuffer>(
                new ReflectDatumWriter<ByteBuffer>());

        AvroOutputFormat.configureDataFileWriter(writer, job);

        Path path = FileOutputFormat.getTaskOutputPath(job, name + EXT);
        writer.create(schema, path.getFileSystem(job).create(path));

        return new AvroTextRecordWriter(writer, keyValueSeparator);
    }

    class AvroTextRecordWriter implements RecordWriter<K, V> {
        private final DataFileWriter<ByteBuffer> writer;
        private final byte[] keyValueSeparator;

        public AvroTextRecordWriter(DataFileWriter<ByteBuffer> writer, byte[] keyValueSeparator) {
            this.writer = writer;
            this.keyValueSeparator = keyValueSeparator;
        }

        public void write(K key, V value) throws IOException {
            boolean nullKey = key == null || key instanceof NullWritable;
            boolean nullValue = value == null || value instanceof NullWritable;
            if (nullKey && nullValue) {
                return;
            } else if (!nullKey && nullValue) {
                writer.append(toByteBuffer(key));
            } else if (nullKey && !nullValue) {
                writer.append(toByteBuffer(value));
            } else {
                writer.append(toByteBuffer(key, keyValueSeparator, value));
            }
        }

        public void close(Reporter reporter) throws IOException {
            writer.close();
        }

        private ByteBuffer toByteBuffer(Object o) throws IOException {
            if (o instanceof Text) {
                Text to = (Text) o;
                return ByteBuffer.wrap(to.getBytes(), 0, to.getLength());
            } else {
                return ByteBuffer.wrap(o.toString().getBytes(UTF8));
            }
        }

        private ByteBuffer toByteBuffer(Object key, byte[] sep, Object value) throws IOException {
            byte[] keyBytes, valBytes;
            int keyLength, valLength;
            if (key instanceof Text) {
                Text tkey = (Text) key;
                keyBytes = tkey.getBytes();
                keyLength = tkey.getLength();
            } else {
                keyBytes = key.toString().getBytes(UTF8);
                keyLength = keyBytes.length;
            }
            if (value instanceof Text) {
                Text tval = (Text) value;
                valBytes = tval.getBytes();
                valLength = tval.getLength();
            } else {
                valBytes = value.toString().getBytes(UTF8);
                valLength = valBytes.length;
            }
            ByteBuffer buf = ByteBuffer.allocate(keyLength + sep.length + valLength);
            buf.put(keyBytes, 0, keyLength);
            buf.put(sep);
            buf.put(valBytes, 0, valLength);
            buf.rewind();
            return buf;
        }

    }

}