org.apache.hadoop.tools.util

Class ThrottledInputStream

java.lang.Object

java.io.InputStream

org.apache.hadoop.tools.util.ThrottledInputStream

All Implemented Interfaces:

Closeable, AutoCloseable, org.apache.hadoop.fs.Seekable

public class ThrottledInputStream
extends InputStream
implements org.apache.hadoop.fs.Seekable

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.)

Constructor Summary

Constructors

Constructor and Description
ThrottledInputStream(InputStream rawStream)
ThrottledInputStream(InputStream rawStream, float maxBytesPerSec)

Method Summary

Modifier and Type	Method and Description
void	close()
long	getBytesPerSec() Getter for the read-rate from this stream, since creation.
long	getPos()
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)
void	seek(long pos)
boolean	seekToNewSource(long targetPos)
String	toString()

Methods inherited from class java.io.InputStream

available, mark, markSupported, reset, skip

Methods inherited from class java.lang.Object

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

Constructor Detail

ThrottledInputStream

public ThrottledInputStream(InputStream rawStream)

ThrottledInputStream

public ThrottledInputStream(InputStream rawStream,
                            float maxBytesPerSec)

Method Detail

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

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

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

seek

public void seek(long pos)
          throws IOException

Specified by:

seek in interface org.apache.hadoop.fs.Seekable

Throws:

IOException

getPos

public long getPos()
            throws IOException

Specified by:

getPos in interface org.apache.hadoop.fs.Seekable

Throws:

IOException

seekToNewSource

public boolean seekToNewSource(long targetPos)
                        throws IOException

Specified by:

seekToNewSource in interface org.apache.hadoop.fs.Seekable

Throws:

IOException