| /** |
| * 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.mapreduce; |
| |
| import java.io.IOException; |
| |
| import org.apache.avro.mapreduce.AvroJob; |
| import org.apache.avro.reflect.ReflectData; |
| import org.apache.hadoop.mapreduce.InputSplit; |
| import org.apache.hadoop.mapreduce.RecordReader; |
| import org.apache.hadoop.mapreduce.TaskAttemptContext; |
| import org.apache.hadoop.mapreduce.lib.input.FileSplit; |
| import org.apache.trevni.avro.AvroColumnReader; |
| import org.apache.trevni.avro.HadoopInput; |
| |
| /** |
| * Abstract base class for <code>RecordReader</code>s that read Trevni container files. |
| * |
| * @param <K> The type of key the record reader should generate. |
| * @param <V> The type of value the record reader should generate. |
| * @param <T> The type of the entries within the Trevni container file being read. |
| */ |
| public abstract class AvroTrevniRecordReaderBase<K, V, T> extends RecordReader<K, V> { |
| |
| /** The Trevni file reader */ |
| private AvroColumnReader<T> reader; |
| |
| /** Number of rows in the Trevni file */ |
| private float rows; |
| |
| /** The current row number being read in */ |
| private long row; |
| |
| /** A reusable object to hold records of the Avro container file. */ |
| private T mCurrentRecord; |
| |
| /** {@inheritDoc} */ |
| @Override |
| public void initialize(InputSplit inputSplit, TaskAttemptContext context) |
| throws IOException, InterruptedException { |
| final FileSplit file = (FileSplit)inputSplit; |
| context.setStatus(file.toString()); |
| |
| final AvroColumnReader.Params params = |
| new AvroColumnReader.Params(new HadoopInput(file.getPath(), context.getConfiguration())); |
| params.setModel(ReflectData.get()); |
| |
| if (AvroJob.getInputKeySchema(context.getConfiguration()) != null) { |
| params.setSchema(AvroJob.getInputKeySchema(context.getConfiguration())); |
| } |
| |
| reader = new AvroColumnReader<T>(params); |
| rows = reader.getRowCount(); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public boolean nextKeyValue() throws IOException, InterruptedException { |
| if (!reader.hasNext()) |
| return false; |
| mCurrentRecord = reader.next(); |
| row++; |
| return true; |
| } |
| |
| /** |
| * Gets the current record read from the Trevni container file. |
| * |
| * <p>Calling <code>nextKeyValue()</code> moves this to the next record.</p> |
| * |
| * @return The current Trevni record (may be null if no record has been read). |
| */ |
| protected T getCurrentRecord() { |
| return mCurrentRecord; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public void close() throws IOException { |
| reader.close(); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public float getProgress() throws IOException, InterruptedException { |
| return row / rows; |
| } |
| } |