Package org.apache.hadoop.mapreduce

Class InputSplit

java.lang.Object

org.apache.hadoop.mapreduce.InputSplit

Direct Known Subclasses:

CombineFileSplit, CompositeInputSplit, FileSplit, FileSplit

@Public
@Stable
public abstract class InputSplit
extends Object

InputSplit represents the data to be processed by an individual Mapper.

Typically, it presents a byte-oriented view on the input and is the responsibility of RecordReader of the job to process this and present a record-oriented view.

See Also:

• InputFormat
• RecordReader

Constructor Summary

Constructors

Constructor	Description
InputSplit()

Method Summary

Modifier and Type	Method	Description
abstract long	getLength()	Get the size of the split, so that the input splits can be sorted by size.
SplitLocationInfo[]	getLocationInfo()	Gets info about which nodes the input split is stored on and how it is stored at each location.
abstract String[]	getLocations()	Get the list of nodes by name where the data for the split would be local.

Methods inherited from class java.lang.Object

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

Constructor Details

InputSplit

public InputSplit()

Method Details

getLength

public abstract long getLength()
                        throws IOException,
InterruptedException

Get the size of the split, so that the input splits can be sorted by size.

Returns:

the number of bytes in the split

Throws:

IOException

InterruptedException

getLocations

public abstract String[] getLocations()
                               throws IOException,
InterruptedException

Get the list of nodes by name where the data for the split would be local. The locations do not need to be serialized.

Returns:

a new array of the node nodes.

Throws:

IOException

InterruptedException

getLocationInfo

@Evolving
public SplitLocationInfo[] getLocationInfo()
                                    throws IOException

Gets info about which nodes the input split is stored on and how it is stored at each location.

Returns:

list of SplitLocationInfos describing how the split data is stored at each location. A null value indicates that all the locations have the data stored on disk.

Throws:

IOException