org.apache.accumulo.core.client.mapreduce

Class AbstractInputFormat.AbstractRecordReader<K,V>

java.lang.Object

org.apache.hadoop.mapreduce.RecordReader<K,V>

org.apache.accumulo.core.client.mapreduce.AbstractInputFormat.AbstractRecordReader<K,V>

All Implemented Interfaces:

Closeable, AutoCloseable

Direct Known Subclasses:

InputFormatBase.RecordReaderBase

Enclosing class:

AbstractInputFormat<K,V>

protected abstract static class AbstractInputFormat.AbstractRecordReader<K,V>
extends org.apache.hadoop.mapreduce.RecordReader<K,V>

An abstract base class to be used to create RecordReader instances that convert from Accumulo Key/Value pairs to the user's K/V types. Subclasses must implement RecordReader.nextKeyValue() and use it to update the following variables:

• K currentK
• V currentV
• Key currentKey (used for progress reporting)
• int numKeysRead (used for progress reporting)

Field Summary

Fields

Modifier and Type	Field and Description
protected K	currentK The Key that should be returned to the client
protected Key	currentKey The Key that is used to determine progress in the current InputSplit.
protected V	currentV The Value that should be return to the client
protected long	numKeysRead
protected Iterator<Map.Entry<Key,Value>>	scannerIterator
protected RangeInputSplit	split

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractRecordReader()

Method Summary

Modifier and Type	Method and Description
void	close()
K	getCurrentKey()
V	getCurrentValue()
float	getProgress()
void	initialize(org.apache.hadoop.mapreduce.InputSplit inSplit, org.apache.hadoop.mapreduce.TaskAttemptContext attempt) Initialize a scanner over the given input split using this task attempt configuration.
protected abstract void	setupIterators(org.apache.hadoop.mapreduce.TaskAttemptContext context, Scanner scanner, String tableName, RangeInputSplit split) Configures the iterators on a scanner for the given table name.

Methods inherited from class org.apache.hadoop.mapreduce.RecordReader

nextKeyValue

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

numKeysRead

protected long numKeysRead

scannerIterator

protected Iterator<Map.Entry<Key,Value>> scannerIterator

split

protected RangeInputSplit split

currentK

protected K currentK

The Key that should be returned to the client

currentV

protected V currentV

The Value that should be return to the client

currentKey

protected Key currentKey

The Key that is used to determine progress in the current InputSplit. It is not returned to the client and is only used internally

Constructor Detail

AbstractRecordReader

protected AbstractRecordReader()

Method Detail

setupIterators

protected abstract void setupIterators(org.apache.hadoop.mapreduce.TaskAttemptContext context,
                                       Scanner scanner,
                                       String tableName,
                                       RangeInputSplit split)

Configures the iterators on a scanner for the given table name.

Parameters:

context - the Hadoop context for the configured job

scanner - the scanner for which to configure the iterators

tableName - the table name for which the scanner is configured

Since:

1.6.0

initialize

public void initialize(org.apache.hadoop.mapreduce.InputSplit inSplit,
                       org.apache.hadoop.mapreduce.TaskAttemptContext attempt)
                throws IOException

Initialize a scanner over the given input split using this task attempt configuration.

Specified by:

initialize in class org.apache.hadoop.mapreduce.RecordReader<K,V>

Throws:

IOException

close

public void close()

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Specified by:

close in class org.apache.hadoop.mapreduce.RecordReader<K,V>

getProgress

public float getProgress()
                  throws IOException

Specified by:

getProgress in class org.apache.hadoop.mapreduce.RecordReader<K,V>

Throws:

IOException

getCurrentKey

public K getCurrentKey()
                throws IOException,
                       InterruptedException

Specified by:

getCurrentKey in class org.apache.hadoop.mapreduce.RecordReader<K,V>

Throws:

IOException

InterruptedException

getCurrentValue

public V getCurrentValue()
                  throws IOException,
                         InterruptedException

Specified by:

getCurrentValue in class org.apache.hadoop.mapreduce.RecordReader<K,V>

Throws:

IOException

InterruptedException