edu.umn.cs.spatialHadoop.operations

Class Tail

java.lang.Object

edu.umn.cs.spatialHadoop.operations.Tail

public class Tail
extends java.lang.Object

Reads the last n lines of a text file

Author:

eldawy

Constructor Summary

Constructors

Constructor and Description
Tail()

Method Summary

Methods

Modifier and Type	Method and Description
static void	main(java.lang.String[] args)
static <T extends TextSerializable> long	tail(FileSystem fs, Path file, int n, T stockObject, ResultCollector<T> output) Reads a maximum of n non-empty lines from the end of the given file.
static <T extends TextSerializable> long	tail(FSDataInputStream in, int n, T stockObject, ResultCollector<T> output) Reads a maximum of n lines from the stream starting from its current position and going backward.

Methods inherited from class java.lang.Object

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

Constructor Detail

Tail

public Tail()

Method Detail

tail

public static <T extends TextSerializable> long tail(FSDataInputStream in,
                                     int n,
                                     T stockObject,
                                     ResultCollector<T> output)
                 throws java.io.IOException

Reads a maximum of n lines from the stream starting from its current position and going backward.

Parameters:

in - - An input stream. It'll be scanned from its current position backward till position 0

n - - Maximum number of lines to return

stockObject - - An object used to deserialize lines read. It can be set to null if output is also null. In this case, nothing is reported to the output.

output - - An output collector used to report lines read.

Returns:

- The position of the beginning of the earliest line read from buffer.

Throws:

java.io.IOException

tail

public static <T extends TextSerializable> long tail(FileSystem fs,
                                     Path file,
                                     int n,
                                     T stockObject,
                                     ResultCollector<T> output)
                 throws java.io.IOException

Reads a maximum of n non-empty lines from the end of the given file. The position of the earliest line read is returned

Parameters:

fs -

file -

n -

stockObject -

output -

Returns:

Throws:

java.io.IOException

main

public static void main(java.lang.String[] args)
                 throws java.io.IOException

Throws:

java.io.IOException