org.apache.hadoop.mapred
Class MultiFileSplit

java.lang.Object
  extended by org.apache.hadoop.mapred.MultiFileSplit
All Implemented Interfaces:
Writable, InputSplit

public class MultiFileSplit
extends Object
implements InputSplit

A sub-collection of input files. Unlike FileSplit, MultiFileSplit class does not represent a split of a file, but a split of input files into smaller sets. The atomic unit of split is a file.
MultiFileSplit can be used to implement RecordReader's, with reading one record per file.

See Also:
FileSplit, MultiFileInputFormat

Constructor Summary
MultiFileSplit(JobConf job, Path[] files, long[] lengths)
           
 
Method Summary
 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()
          Get the list of hostnames where the input split is located.
 int getNumPaths()
          Returns the number of Paths in the split
 Path getPath(int i)
          Returns the ith Path
 Path[] getPaths()
          Returns all the Paths 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

MultiFileSplit

public MultiFileSplit(JobConf job,
                      Path[] files,
                      long[] lengths)
Method Detail

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.

getLengths

public long[] getLengths()
Returns an array containing the lengths of the files in the split


getLength

public long getLength(int i)
Returns the length of the ith Path


getNumPaths

public int getNumPaths()
Returns the number of Paths in the split


getPath

public Path getPath(int i)
Returns the ith Path


getPaths

public Path[] getPaths()
Returns all the Paths in the split


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

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


Copyright © 2008 The Apache Software Foundation