Package org.apache.hadoop.mapreduce.lib.input

Class CombineFileSplit

java.lang.Object

org.apache.hadoop.mapreduce.InputSplit

org.apache.hadoop.mapreduce.lib.input.CombineFileSplit

All Implemented Interfaces:

Writable

Direct Known Subclasses:

CombineFileSplit

@Public
@Stable
public class CombineFileSplit
extends InputSplit
implements Writable

A sub-collection of input files. Unlike FileSplit, CombineFileSplit class does not represent a split of a file, but a split of input files into smaller sets. A split may contain blocks from different file but all the blocks in the same split are probably local to some rack
CombineFileSplit can be used to implement RecordReader's, with reading one record per file.

See Also:

• FileSplit
• CombineFileInputFormat

Constructor Summary

Constructors

Constructor	Description
CombineFileSplit()	default constructor
CombineFileSplit(Path[] files, long[] lengths)
CombineFileSplit(Path[] files, long[] start, long[] lengths, String[] locations)
CombineFileSplit(CombineFileSplit old)	Copy constructor

Method Summary

Modifier and Type	Method	Description
long	getLength()	Get the size of the split, so that the input splits can be sorted by size.
long	getLength(int i)	Returns the length of the ith Path
long[]	getLengths()	Returns an array containing the lengths of the files in the split
String[]	getLocations()	Returns all the Paths where this input-split resides
int	getNumPaths()	Returns the number of Paths in the split
long	getOffset(int i)	Returns the start offset of the ith Path
Path	getPath(int i)	Returns the ith Path
Path[]	getPaths()	Returns all the Paths in the split
long[]	getStartOffsets()	Returns an array containing the start offsets of the files in the split
void	readFields(DataInput in)	Deserialize the fields of this object from in.
String	toString()
void	write(DataOutput out)	Serialize the fields of this object to out.

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

getLocationInfo

Methods inherited from class java.lang.Object

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

Constructor Details

CombineFileSplit

public CombineFileSplit()

default constructor

CombineFileSplit

public CombineFileSplit(Path[] files,
 long[] start,
 long[] lengths,
 String[] locations)

CombineFileSplit

public CombineFileSplit(Path[] files,
 long[] lengths)

CombineFileSplit

public CombineFileSplit(CombineFileSplit old)
                 throws IOException

Copy constructor

Throws:

IOException

Method Details

getLength

public long getLength()

Description copied from class: InputSplit

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

Specified by:

getLength in class InputSplit

Returns:

the number of bytes in the split

getStartOffsets

public long[] getStartOffsets()

Returns an array containing the start offsets of the files in the split

getLengths

public long[] getLengths()

Returns an array containing the lengths of the files in the split

getOffset

public long getOffset(int i)

Returns the start offset of the i^th Path

getLength

public long getLength(int i)

Returns the length of the i^th Path

getNumPaths

public int getNumPaths()

Returns the number of Paths in the split

getPath

public Path getPath(int i)

Returns the i^th Path

getPaths

public Path[] getPaths()

Returns all the Paths in the split

getLocations

public String[] getLocations()
                      throws IOException

Returns all the Paths where this input-split resides

Specified by:

getLocations in class InputSplit

Returns:

a new array of the node nodes.

Throws:

IOException

readFields

public void readFields(DataInput in)
                throws IOException

Description copied from interface: Writable

Deserialize the fields of this object from in.

For efficiency, implementations should attempt to re-use storage in the existing object where possible.

Specified by:

readFields in interface Writable

Parameters:

in - DataInput to deseriablize this object from.

Throws:

IOException - any other problem for readFields.

write

public void write(DataOutput out)
           throws IOException

Description copied from interface: Writable

Serialize the fields of this object to out.

Specified by:

write in interface Writable

Parameters:

out - DataOuput to serialize this object into.

Throws:

IOException - any other problem for write.

toString

public String toString()

Overrides:

toString in class Object