org.apache.hadoop.hbase.io.hfile

Class NanoTimer

java.lang.Object

org.apache.hadoop.hbase.io.hfile.NanoTimer

public class NanoTimer
extends Object

A nano-second timer.

Copied from hadoop-3315 tfile. Remove after tfile is committed and use the tfile version of this class instead.

Field Summary

Fields

Modifier and Type	Field and Description
private long	cumulate
private long	last
private boolean	started

Constructor Summary

Constructors

Constructor and Description
NanoTimer(boolean start) Constructor n * Start the timer upon construction.

Method Summary

Modifier and Type	Method and Description
boolean	isStarted() Checking whether the timer is started
static void	main(String[] args) Simple tester.
static String	nanoTimeToString(long t) A utility method to format a time duration in nano seconds into a human understandable stirng.
long	read() Read the timer.
private boolean	readable()
void	reset() Reset the timer.
void	start() Start the timer.
void	stop() Stop the timer.
String	toString() Format the elapsed time to a human understandable string.

Methods inherited from class java.lang.Object

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

Field Detail

last

private long last

started

private boolean started

cumulate

private long cumulate

Constructor Detail

NanoTimer

public NanoTimer(boolean start)

Constructor n * Start the timer upon construction.

Method Detail

start

public void start()

Start the timer. Note: No effect if timer is already started.

stop

public void stop()

Stop the timer. Note: No effect if timer is already stopped.

read

public long read()

Read the timer.

Returns:

the elapsed time in nano-seconds. Note: If the timer is never started before, -1 is returned.

reset

public void reset()

Reset the timer.

isStarted

public boolean isStarted()

Checking whether the timer is started

Returns:

true if timer is started.

toString

public String toString()

Format the elapsed time to a human understandable string. Note: If timer is never started, "ERR" will be returned.

Overrides:

toString in class Object

nanoTimeToString

public static String nanoTimeToString(long t)

A utility method to format a time duration in nano seconds into a human understandable stirng. n * Time duration in nano seconds.

Returns:

String representation.

readable

private boolean readable()

main

public static void main(String[] args)

Simple tester. n