| /* |
| * 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 |
| * |
| * https://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.mapreduce; |
| |
| import java.io.IOException; |
| |
| import org.apache.avro.Schema; |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.fs.FileSystem; |
| import org.apache.hadoop.fs.Path; |
| import org.apache.avro.hadoop.io.AvroSequenceFile; |
| import org.apache.hadoop.io.SequenceFile; |
| 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.hadoop.mapreduce.lib.input.SequenceFileInputFormat; |
| |
| /** |
| * An input format for reading from AvroSequenceFiles (sequence files that |
| * support Avro data). |
| * |
| * @param <K> The input key type. |
| * @param <V> The input value type. |
| */ |
| public class AvroSequenceFileInputFormat<K, V> extends SequenceFileInputFormat<K, V> { |
| /** {@inheritDoc} */ |
| @Override |
| public RecordReader<K, V> createRecordReader(InputSplit inputSplit, TaskAttemptContext context) throws IOException { |
| return new AvroSequenceFileRecordReader(); |
| } |
| |
| /** |
| * Reads records from a SequenceFile that supports Avro data. |
| * |
| * <p> |
| * This class is based on Hadoop's SequenceFileRecordReader, modified to |
| * construct an AvroSequenceFile.Reader instead of a SequenceFile.Reader. |
| * </p> |
| */ |
| protected class AvroSequenceFileRecordReader extends RecordReader<K, V> { |
| private SequenceFile.Reader mReader; |
| private long mStart; |
| private long mEnd; |
| private boolean mHasMoreData; |
| private K mCurrentKey; |
| private V mCurrentValue; |
| |
| /** {@inheritDoc} */ |
| @Override |
| public void initialize(InputSplit split, TaskAttemptContext context) throws IOException, InterruptedException { |
| FileSplit fileSplit = (FileSplit) split; |
| Configuration conf = context.getConfiguration(); |
| Path path = fileSplit.getPath(); |
| FileSystem fs = path.getFileSystem(conf); |
| |
| // Configure the SequenceFile reader. |
| AvroSequenceFile.Reader.Options options = new AvroSequenceFile.Reader.Options().withFileSystem(fs) |
| .withInputPath(path).withConfiguration(conf); |
| Schema keySchema = AvroJob.getInputKeySchema(conf); |
| if (null != keySchema) { |
| options.withKeySchema(keySchema); |
| } |
| Schema valueSchema = AvroJob.getInputValueSchema(conf); |
| if (null != valueSchema) { |
| options.withValueSchema(valueSchema); |
| } |
| |
| mReader = new AvroSequenceFile.Reader(options); |
| mEnd = fileSplit.getStart() + fileSplit.getLength(); |
| |
| if (fileSplit.getStart() > mReader.getPosition()) { |
| // Sync to the beginning of the input split. |
| mReader.sync(fileSplit.getStart()); |
| } |
| |
| mStart = mReader.getPosition(); |
| mHasMoreData = mStart < mEnd; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| @SuppressWarnings("unchecked") |
| public boolean nextKeyValue() throws IOException, InterruptedException { |
| if (!mHasMoreData) { |
| return false; |
| } |
| long pos = mReader.getPosition(); |
| mCurrentKey = (K) mReader.next(mCurrentKey); |
| if (null == mCurrentKey || (pos >= mEnd && mReader.syncSeen())) { |
| mHasMoreData = false; |
| mCurrentKey = null; |
| mCurrentValue = null; |
| } else { |
| mCurrentValue = (V) mReader.getCurrentValue(mCurrentValue); |
| } |
| return mHasMoreData; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public K getCurrentKey() { |
| return mCurrentKey; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public V getCurrentValue() { |
| return mCurrentValue; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public float getProgress() throws IOException { |
| if (mEnd == mStart) { |
| return 0.0f; |
| } else { |
| return Math.min(1.0f, (mReader.getPosition() - mStart) / (float) (mEnd - mStart)); |
| } |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public synchronized void close() throws IOException { |
| mReader.close(); |
| } |
| } |
| } |