Package org.apache.commons.io.input

Class ThrottledInputStream

java.lang.Object

java.io.InputStream

java.io.FilterInputStream

org.apache.commons.io.input.ProxyInputStream

org.apache.commons.io.input.CountingInputStream

org.apache.commons.io.input.ThrottledInputStream

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable

public final class ThrottledInputStream
extends CountingInputStream

Provides bandwidth throttling on an InputStream as a filter input stream. The throttling examines the number of bytes read from the underlying InputStream, and sleeps for a time interval if the byte-transfer is found to exceed the specified maximum rate. Thus, while the read-rate might exceed the maximum for a short interval, the average tends towards the specified maximum, overall.

To build an instance, call builder().

Inspired by Apache HBase's class of the same name.

Since:

2.16.0

See Also:

ThrottledInputStream.Builder

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	ThrottledInputStream.Builder	Builds a new ThrottledInputStream.

Nested classes/interfaces inherited from class org.apache.commons.io.input.ProxyInputStream

ProxyInputStream.AbstractBuilder<T,B extends AbstractStreamBuilder<T,B>>

Field Summary

Fields

Modifier and Type	Field	Description
private double	maxBytesPerSecond
private long	startTime
private java.time.Duration	totalSleepDuration

Fields inherited from class java.io.FilterInputStream

in

Constructor Summary

Constructors

Modifier	Constructor	Description
private	ThrottledInputStream(ThrottledInputStream.Builder builder)

Method Summary

Modifier and Type	Method	Description
protected void	beforeRead(int n)	Invoked by the read methods before the call is proxied.
static ThrottledInputStream.Builder	builder()	Constructs a new ThrottledInputStream.Builder.
private long	getBytesPerSecond()	Gets the read-rate from this stream, since creation.
(package private) double	getMaxBytesPerSecond()	Gets the maximum bytes per second.
(package private) long	getSleepMillis()	Gets the number of milliseconds to sleep to match to the maximum bytes per second.
(package private) java.time.Duration	getTotalSleepDuration()	Gets the total duration spent in sleep.
private void	throttle()
(package private) static long	toSleepMillis(long bytesRead, long elapsedMillis, double maxBytesPerSec)
java.lang.String	toString()

Methods inherited from class org.apache.commons.io.input.CountingInputStream

afterRead, getByteCount, getCount, resetByteCount, resetCount, skip

Methods inherited from class org.apache.commons.io.input.ProxyInputStream

available, checkOpen, close, handleIOException, isClosed, mark, markSupported, read, read, read, reset, setReference, unwrap

Methods inherited from class java.lang.Object

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

Field Detail

maxBytesPerSecond

private final double maxBytesPerSecond

startTime

private final long startTime

totalSleepDuration

private java.time.Duration totalSleepDuration

Constructor Detail

ThrottledInputStream

private ThrottledInputStream(ThrottledInputStream.Builder builder)
                      throws java.io.IOException

Throws:

java.io.IOException

Method Detail

builder

public static ThrottledInputStream.Builder builder()

Constructs a new ThrottledInputStream.Builder.

Returns:

a new ThrottledInputStream.Builder.

toSleepMillis

static long toSleepMillis(long bytesRead,
                          long elapsedMillis,
                          double maxBytesPerSec)

beforeRead

protected void beforeRead(int n)
                   throws java.io.IOException

Description copied from class: ProxyInputStream

Invoked by the read methods before the call is proxied. The number of bytes that the caller wanted to read (1 for the ProxyInputStream.read() method, buffer length for ProxyInputStream.read(byte[]), etc.) is given as an argument.

Subclasses can override this method to add common pre-processing functionality without having to override all the read methods. The default implementation does nothing.

Note this method is not called from ProxyInputStream.skip(long) or ProxyInputStream.reset(). You need to explicitly override those methods if you want to add pre-processing steps also to them.

Overrides:

beforeRead in class ProxyInputStream

Parameters:

n - number of bytes that the caller asked to be read.

Throws:

java.io.IOException - if the pre-processing fails in a subclass.

getBytesPerSecond

private long getBytesPerSecond()

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

Returns:

Read rate, in bytes/sec.

getMaxBytesPerSecond

double getMaxBytesPerSecond()

Gets the maximum bytes per second.

Package private for testing.

Returns:

The maximum bytes per second.

getSleepMillis

long getSleepMillis()

Gets the number of milliseconds to sleep to match to the maximum bytes per second.

Package private for testing.

Returns:

the number of milliseconds to sleep to match to the maximum bytes per second.

getTotalSleepDuration

java.time.Duration getTotalSleepDuration()

Gets the total duration spent in sleep.

Package private for testing

Returns:

Duration spent in sleep.

throttle

private void throttle()
               throws java.io.InterruptedIOException

Throws:

java.io.InterruptedIOException

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object