Package com.google.common.util.concurrent

Class SmoothRateLimiter

java.lang.Object

com.google.common.util.concurrent.RateLimiter

com.google.common.util.concurrent.SmoothRateLimiter

Direct Known Subclasses:

SmoothRateLimiter.SmoothBursty, SmoothRateLimiter.SmoothWarmingUp

abstract class SmoothRateLimiter
extends RateLimiter

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
(package private) static class	SmoothRateLimiter.SmoothBursty	This implements a "bursty" RateLimiter, where storedPermits are translated to zero throttling.
(package private) static class	SmoothRateLimiter.SmoothWarmingUp	This implements the following function where coldInterval = coldFactor * stableInterval.

Nested classes/interfaces inherited from class com.google.common.util.concurrent.RateLimiter

RateLimiter.SleepingStopwatch

Field Summary

Fields

Modifier and Type	Field	Description
(package private) double	maxPermits	The maximum number of stored permits.
private long	nextFreeTicketMicros	The time when the next request (no matter its size) will be granted.
(package private) double	stableIntervalMicros	The interval between two unit requests, at our stable rate.
(package private) double	storedPermits	The currently stored permits.

Constructor Summary

Constructors

Modifier	Constructor	Description
private	SmoothRateLimiter(RateLimiter.SleepingStopwatch stopwatch)

Method Summary

Modifier and Type	Method	Description
(package private) abstract double	coolDownIntervalMicros()	Returns the number of microseconds during cool down that we have to wait to get a new permit.
(package private) double	doGetRate()
(package private) abstract void	doSetRate(double permitsPerSecond, double stableIntervalMicros)
(package private) void	doSetRate(double permitsPerSecond, long nowMicros)
(package private) long	queryEarliestAvailable(long nowMicros)	Returns the earliest time that permits are available (with one caveat).
(package private) long	reserveEarliestAvailable(int requiredPermits, long nowMicros)	Reserves the requested number of permits and returns the time that those permits can be used (with one caveat).
(package private) void	resync(long nowMicros)	Updates storedPermits and nextFreeTicketMicros based on the current time.
(package private) abstract long	storedPermitsToWaitTime(double storedPermits, double permitsToTake)	Translates a specified portion of our currently stored permits which we want to spend/acquire, into a throttling time.

Methods inherited from class com.google.common.util.concurrent.RateLimiter

acquire, acquire, create, create, create, create, create, getRate, reserve, reserveAndGetWaitLength, setRate, toString, tryAcquire, tryAcquire, tryAcquire, tryAcquire, tryAcquire, tryAcquire

Methods inherited from class java.lang.Object

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

Field Detail

storedPermits

double storedPermits

The currently stored permits.

maxPermits

double maxPermits

The maximum number of stored permits.

stableIntervalMicros

double stableIntervalMicros

The interval between two unit requests, at our stable rate. E.g., a stable rate of 5 permits per second has a stable interval of 200ms.

nextFreeTicketMicros

private long nextFreeTicketMicros

The time when the next request (no matter its size) will be granted. After granting a request, this is pushed further in the future. Large requests push this further than small requests.

Constructor Detail

SmoothRateLimiter

private SmoothRateLimiter(RateLimiter.SleepingStopwatch stopwatch)

Method Detail

doSetRate

final void doSetRate(double permitsPerSecond,
                     long nowMicros)

Specified by:

doSetRate in class RateLimiter

doSetRate

abstract void doSetRate(double permitsPerSecond,
                        double stableIntervalMicros)

doGetRate

final double doGetRate()

Specified by:

doGetRate in class RateLimiter

queryEarliestAvailable

final long queryEarliestAvailable(long nowMicros)

Description copied from class: RateLimiter

Returns the earliest time that permits are available (with one caveat).

Specified by:

queryEarliestAvailable in class RateLimiter

Returns:

the time that permits are available, or, if permits are available immediately, an arbitrary past or present time

reserveEarliestAvailable

final long reserveEarliestAvailable(int requiredPermits,
                                    long nowMicros)

Description copied from class: RateLimiter

Reserves the requested number of permits and returns the time that those permits can be used (with one caveat).

Specified by:

reserveEarliestAvailable in class RateLimiter

Returns:

the time that the permits may be used, or, if the permits may be used immediately, an arbitrary past or present time

storedPermitsToWaitTime

abstract long storedPermitsToWaitTime(double storedPermits,
                                      double permitsToTake)

Translates a specified portion of our currently stored permits which we want to spend/acquire, into a throttling time. Conceptually, this evaluates the integral of the underlying function we use, for the range of [(storedPermits - permitsToTake), storedPermits].

This always holds: 0 <= permitsToTake <= storedPermits

coolDownIntervalMicros

abstract double coolDownIntervalMicros()

Returns the number of microseconds during cool down that we have to wait to get a new permit.

resync

void resync(long nowMicros)

Updates storedPermits and nextFreeTicketMicros based on the current time.