| /** |
| * 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.hcatalog.rcfile; |
| |
| import java.io.IOException; |
| |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.fs.Path; |
| import org.apache.hadoop.hive.ql.io.RCFile; |
| import org.apache.hadoop.hive.ql.io.RCFile.Reader; |
| import org.apache.hadoop.hive.serde2.columnar.BytesRefArrayWritable; |
| import org.apache.hadoop.io.LongWritable; |
| 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; |
| |
| public class RCFileMapReduceRecordReader<K extends LongWritable, V extends BytesRefArrayWritable> |
| extends RecordReader<LongWritable, BytesRefArrayWritable> { |
| |
| private Reader in; |
| private long start; |
| private long end; |
| private boolean more = true; |
| |
| // key and value objects are created once in initialize() and then reused |
| // for every getCurrentKey() and getCurrentValue() call. This is important |
| // since RCFile makes an assumption of this fact. |
| |
| private LongWritable key; |
| private BytesRefArrayWritable value; |
| |
| @Override |
| public void close() throws IOException { |
| in.close(); |
| } |
| |
| @Override |
| public LongWritable getCurrentKey() throws IOException, InterruptedException { |
| return key; |
| } |
| |
| @Override |
| public BytesRefArrayWritable getCurrentValue() throws IOException, InterruptedException { |
| return value; |
| } |
| |
| @Override |
| public float getProgress() throws IOException, InterruptedException { |
| if (end == start) { |
| return 0.0f; |
| } else { |
| return Math.min(1.0f, (in.getPosition() - start) / (float) (end - start)); |
| } |
| } |
| |
| @Override |
| public boolean nextKeyValue() throws IOException, InterruptedException { |
| |
| more = next(key); |
| if (more) { |
| in.getCurrentRow(value); |
| } |
| |
| return more; |
| } |
| |
| private boolean next(LongWritable key) throws IOException { |
| if (!more) { |
| return false; |
| } |
| |
| more = in.next(key); |
| if (!more) { |
| return false; |
| } |
| |
| if (in.lastSeenSyncPos() >= end) { |
| more = false; |
| return more; |
| } |
| return more; |
| } |
| |
| @Override |
| public void initialize(InputSplit split, TaskAttemptContext context) throws IOException, |
| InterruptedException { |
| |
| FileSplit fSplit = (FileSplit) split; |
| Path path = fSplit.getPath(); |
| Configuration conf = context.getConfiguration(); |
| this.in = new RCFile.Reader(path.getFileSystem(conf), path, conf); |
| this.end = fSplit.getStart() + fSplit.getLength(); |
| |
| if (fSplit.getStart() > in.getPosition()) { |
| in.sync(fSplit.getStart()); |
| } |
| |
| this.start = in.getPosition(); |
| more = start < end; |
| |
| key = new LongWritable(); |
| value = new BytesRefArrayWritable(); |
| } |
| } |