org.apache.hadoop.mapred
Class FileSplit

java.lang.Object
  org.apache.hadoop.mapred.FileSplit

All Implemented Interfaces:

Writable, InputSplit

public class FileSplit
extends Object
implements InputSplit

A section of an input file. Returned by InputFormat.getSplits(JobConf, int) and passed to InputFormat.getRecordReader(InputSplit,JobConf,Reporter).

Constructor Summary

FileSplit(Path file, long start, long length, JobConf conf)
Deprecated.

FileSplit(Path file, long start, long length, String[] hosts)
Constructs a split with host information

Method Summary

long	getLength() The number of bytes in the file to process.
String[]	getLocations() Get the list of hostnames where the input split is located.
Path	getPath() The file containing this split's data.
long	getStart() The position of the first byte in the file to process.
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

FileSplit

@Deprecated
public FileSplit(Path file,
                            long start,
                            long length,
                            JobConf conf)

Deprecated.

Constructs a split.

Parameters:

file - the file name

start - the position of the first byte in the file to process

length - the number of bytes in the file to process

FileSplit

public FileSplit(Path file,
                 long start,
                 long length,
                 String[] hosts)

Constructs a split with host information

Parameters:

file - the file name

start - the position of the first byte in the file to process

length - the number of bytes in the file to process

hosts - the list of hosts containing the block, possibly null

Method Detail

getPath

public Path getPath()

The file containing this split's data.

getStart

public long getStart()

The position of the first byte in the file to process.

getLength

public long getLength()

The number of bytes in the file to process.

Specified by:

getLength in interface InputSplit

Returns:

the number of bytes in the input split.

toString

public String toString()

Overrides:

toString in class Object

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

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

getLocations

public String[] getLocations()
                      throws IOException

Description copied from interface: InputSplit

Get the list of hostnames where the input split is located.

Specified by:

getLocations in interface InputSplit

Returns:

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

Throws:

IOException