/**
* Copyright 2011 The Apache Software Foundation
*
* 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.hadoop.hbase.mapreduce;
import java.io.IOException;
import org.apache.hadoop.hbase.client.HTable;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import org.apache.hadoop.mapreduce.InputSplit;
import org.apache.hadoop.mapreduce.RecordReader;
import org.apache.hadoop.mapreduce.TaskAttemptContext;
/**
* Iterate over an HBase table data, return (ImmutableBytesWritable, Result)
* pairs.
*/
public class TableRecordReader
extends RecordReader<ImmutableBytesWritable, Result> {
private TableRecordReaderImpl recordReaderImpl = new TableRecordReaderImpl();
/**
* Restart from survivable exceptions by creating a new scanner.
*
* @param firstRow The first row to start at.
* @throws IOException When restarting fails.
*/
public void restart(byte[] firstRow) throws IOException {
this.recordReaderImpl.restart(firstRow);
}
/**
* Sets the HBase table.
*
* @param htable The {@link HTable} to scan.
*/
public void setHTable(HTable htable) {
this.recordReaderImpl.setHTable(htable);
}
/**
* Sets the scan defining the actual details like columns etc.
*
* @param scan The scan to set.
*/
public void setScan(Scan scan) {
this.recordReaderImpl.setScan(scan);
}
/**
* Closes the split.
*
* @see org.apache.hadoop.mapreduce.RecordReader#close()
*/
@Override
public void close() {
this.recordReaderImpl.close();
}
/**
* Returns the current key.
*
* @return The current key.
* @throws IOException
* @throws InterruptedException When the job is aborted.
* @see org.apache.hadoop.mapreduce.RecordReader#getCurrentKey()
*/
@Override
public ImmutableBytesWritable getCurrentKey() throws IOException,
InterruptedException {
return this.recordReaderImpl.getCurrentKey();
}
/**
* Returns the current value.
*
* @return The current value.
* @throws IOException When the value is faulty.
* @throws InterruptedException When the job is aborted.
* @see org.apache.hadoop.mapreduce.RecordReader#getCurrentValue()
*/
@Override
public Result getCurrentValue() throws IOException, InterruptedException {
return this.recordReaderImpl.getCurrentValue();
}
/**
* Initializes the reader.
*
* @param inputsplit The split to work with.
* @param context The current task context.
* @throws IOException When setting up the reader fails.
* @throws InterruptedException When the job is aborted.
* @see org.apache.hadoop.mapreduce.RecordReader#initialize(
* org.apache.hadoop.mapreduce.InputSplit,
* org.apache.hadoop.mapreduce.TaskAttemptContext)
*/
@Override
public void initialize(InputSplit inputsplit,
TaskAttemptContext context) throws IOException,
InterruptedException {
this.recordReaderImpl.initialize(inputsplit, context);
}
/**
* Positions the record reader to the next record.
*
* @return <code>true</code> if there was another record.
* @throws IOException When reading the record failed.
* @throws InterruptedException When the job was aborted.
* @see org.apache.hadoop.mapreduce.RecordReader#nextKeyValue()
*/
@Override
public boolean nextKeyValue() throws IOException, InterruptedException {
return this.recordReaderImpl.nextKeyValue();
}
/**
* The current progress of the record reader through its data.
*
* @return A number between 0.0 and 1.0, the fraction of the data read.
* @see org.apache.hadoop.mapreduce.RecordReader#getProgress()
*/
@Override
public float getProgress() {
return this.recordReaderImpl.getProgress();
}
}