org.apache.trevni.avro.AvroTrevniInputFormat.java Source code

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Here is the source code for org.apache.trevni.avro.AvroTrevniInputFormat.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.trevni.avro;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.FileInputFormat;
import org.apache.hadoop.mapred.InputSplit;
import org.apache.hadoop.mapred.FileSplit;
import org.apache.hadoop.mapred.Reporter;
import org.apache.hadoop.mapred.RecordReader;

import org.apache.avro.reflect.ReflectData;
import org.apache.avro.mapred.AvroJob;
import org.apache.avro.mapred.AvroWrapper;

/** An {@link org.apache.hadoop.mapred.InputFormat} for Trevni files.
 *
 * <p>A subset schema to be read may be specified with {@link
 * AvroJob#setInputSchema(Schema)}.
 */
public class AvroTrevniInputFormat<T> extends FileInputFormat<AvroWrapper<T>, NullWritable> {

    @Override
    protected boolean isSplitable(FileSystem fs, Path filename) {
        return false;
    }

    @Override
    protected FileStatus[] listStatus(JobConf job) throws IOException {
        List<FileStatus> result = new ArrayList<FileStatus>();
        job.setBoolean("mapred.input.dir.recursive", true);
        for (FileStatus file : super.listStatus(job))
            if (file.getPath().getName().endsWith(AvroTrevniOutputFormat.EXT))
                result.add(file);
        return result.toArray(new FileStatus[0]);
    }

    @Override
    public RecordReader<AvroWrapper<T>, NullWritable> getRecordReader(InputSplit split, final JobConf job,
            Reporter reporter) throws IOException {
        final FileSplit file = (FileSplit) split;
        reporter.setStatus(file.toString());

        final AvroColumnReader.Params params = new AvroColumnReader.Params(new HadoopInput(file.getPath(), job));
        params.setModel(ReflectData.get());
        if (job.get(AvroJob.INPUT_SCHEMA) != null)
            params.setSchema(AvroJob.getInputSchema(job));

        return new RecordReader<AvroWrapper<T>, NullWritable>() {
            private AvroColumnReader<T> reader = new AvroColumnReader<T>(params);
            private float rows = reader.getRowCount();
            private long row;

            public AvroWrapper<T> createKey() {
                return new AvroWrapper<T>(null);
            }

            public NullWritable createValue() {
                return NullWritable.get();
            }

            public boolean next(AvroWrapper<T> wrapper, NullWritable ignore) throws IOException {
                if (!reader.hasNext())
                    return false;
                wrapper.datum(reader.next());
                row++;
                return true;
            }

            public float getProgress() throws IOException {
                return row / rows;
            }

            public long getPos() throws IOException {
                return row;
            }

            public void close() throws IOException {
                reader.close();
            }

        };

    }

}