Package org.apache.hadoop.hbase.io.hadoopbackport

Class ThrottledInputStream

java.lang.Object

java.io.InputStream

org.apache.hadoop.hbase.io.hadoopbackport.ThrottledInputStream

All Implemented Interfaces:

Closeable, AutoCloseable

@Private
public class ThrottledInputStream
extends InputStream

The ThrottleInputStream provides bandwidth throttling on a specified InputStream. It is implemented as a wrapper on top of another InputStream instance. The throttling works by examining the number of bytes read from the underlying InputStream from the beginning, and sleep()ing for a time interval if the byte-transfer is found exceed the specified tolerable maximum. (Thus, while the read-rate might exceed the maximum for a given short interval, the average tends towards the specified maximum, overall.)

Field Summary

Fields

Modifier and Type	Field	Description
private long	bytesRead
private final long	maxBytesPerSec
private final InputStream	rawStream
private final long	startTime
private long	totalSleepTime

Constructor Summary

Constructors

Constructor	Description
ThrottledInputStream(InputStream rawStream)
ThrottledInputStream(InputStream rawStream, long maxBytesPerSec)

Method Summary

Modifier and Type	Method	Description
private long	calSleepTimeMs()
(package private) static long	calSleepTimeMs(long bytesRead, long maxBytesPerSec, long elapsed)
void	close()
long	getBytesPerSec()	Getter for the read-rate from this stream, since creation.
long	getTotalBytesRead()	Getter for the number of bytes read from this stream, since creation.
long	getTotalSleepTime()	Getter the total time spent in sleep.
int	read()
int	read(byte[] b)
int	read(byte[] b, int off, int len)
int	read(long position, byte[] buffer, int offset, int length)	Read bytes starting from the specified position.
private void	throttle()
String	toString()

Methods inherited from class java.io.InputStream

available, mark, markSupported, nullInputStream, readAllBytes, readNBytes, readNBytes, reset, skip, skipNBytes, transferTo

Methods inherited from class java.lang.Object

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

Field Details

rawStream

private final InputStream rawStream

maxBytesPerSec

private final long maxBytesPerSec

startTime

private final long startTime

bytesRead

private long bytesRead

totalSleepTime

private long totalSleepTime

Constructor Details

ThrottledInputStream

public ThrottledInputStream(InputStream rawStream)

ThrottledInputStream

public ThrottledInputStream(InputStream rawStream,
 long maxBytesPerSec)

Method Details

close

public void close()
           throws IOException

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Overrides:

close in class InputStream

Throws:

IOException

read

public int read()
         throws IOException

Specified by:

read in class InputStream

Throws:

IOException

read

public int read(byte[] b)
         throws IOException

Overrides:

read in class InputStream

Throws:

IOException

read

public int read(byte[] b,
 int off,
 int len)
         throws IOException

Overrides:

read in class InputStream

Throws:

IOException

read

public int read(long position,
 byte[] buffer,
 int offset,
 int length)
         throws IOException

Read bytes starting from the specified position. This requires rawStream is an instance of PositionedReadable.

Returns:

the number of bytes read

Throws:

IOException

calSleepTimeMs

private long calSleepTimeMs()

calSleepTimeMs

static long calSleepTimeMs(long bytesRead,
 long maxBytesPerSec,
 long elapsed)

throttle

private void throttle()
               throws InterruptedIOException

Throws:

InterruptedIOException

getTotalBytesRead

public long getTotalBytesRead()

Getter for the number of bytes read from this stream, since creation.

Returns:

The number of bytes.

getBytesPerSec

public long getBytesPerSec()

Getter for the read-rate from this stream, since creation. Calculated as bytesRead/elapsedTimeSinceStart.

Returns:

Read rate, in bytes/sec.

getTotalSleepTime

public long getTotalSleepTime()

Getter the total time spent in sleep.

Returns:

Number of milliseconds spent in sleep.

toString

public String toString()

Overrides:

toString in class Object