org.apache.hadoop.mapred.lib
Class CombineFileSplit

java.lang.Object
  org.apache.hadoop.mapred.lib.CombineFileSplit

All Implemented Interfaces:

Writable, InputSplit

Direct Known Subclasses:

MultiFileSplit

public class CombineFileSplit
extends Object
implements InputSplit

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

CombineFileSplit()
default constructor

CombineFileSplit(CombineFileSplit old)
Copy constructor

CombineFileSplit(JobConf job, Path[] files, long[] lengths)

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

Method Summary

JobConf	getJob()
long	getLength() Get the total number of bytes in the data of the InputSplit.
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 startoffsets 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 java.lang.Object

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

Constructor Detail

CombineFileSplit

public CombineFileSplit()

default constructor

CombineFileSplit

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

CombineFileSplit

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

CombineFileSplit

public CombineFileSplit(CombineFileSplit old)
                 throws IOException

Copy constructor

Throws:

IOException

Method Detail

getJob

public JobConf getJob()

getLength

public long getLength()

Description copied from interface: InputSplit

Get the total number of bytes in the data of the InputSplit.

Specified by:

getLength in interface InputSplit

Returns:

the number of bytes in the input split.

getStartOffsets

public long[] getStartOffsets()

Returns an array containing the startoffsets 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 interface InputSplit

Returns:

list of hostnames where data of the InputSplit is located as an array of Strings.

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

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

toString

public String toString()

Overrides:

toString in class Object