folly::BasicTokenBucket< Clock > Class Template Reference

#include <TokenBucket.h>

Public Member Functions
	BasicTokenBucket (double genRate, double burstSize, double zeroTime=0) noexcept
	BasicTokenBucket (const BasicTokenBucket &other) noexcept=default
BasicTokenBucket &	operator= (const BasicTokenBucket &other) noexcept=default
void	reset (double genRate, double burstSize, double nowInSeconds=defaultClockNow()) noexcept
void	setCapacity (double tokens, double nowInSeconds) noexcept
bool	consume (double toConsume, double nowInSeconds=defaultClockNow())
double	consumeOrDrain (double toConsume, double nowInSeconds=defaultClockNow())
double	available (double nowInSeconds=defaultClockNow()) const
double	rate () const noexcept
double	burst () const noexcept

Static Public Member Functions
static double	defaultClockNow () noexcept(noexcept(Impl::defaultClockNow()))

Private Types
using	Impl = BasicDynamicTokenBucket< Clock >

Private Attributes
Impl	tokenBucket_
double	rate_
double	burstSize_

Detailed Description

template<typename Clock = std::chrono::steady_clock>
class folly::BasicTokenBucket< Clock >

Specialization of BasicDynamicTokenBucket with a fixed token generation rate and a fixed maximum burst size.

Definition at line 221 of file TokenBucket.h.

Member Typedef Documentation

template<typename Clock = std::chrono::steady_clock>

using folly::BasicTokenBucket< Clock >::Impl = BasicDynamicTokenBucket<Clock>

private

Definition at line 225 of file TokenBucket.h.

Constructor & Destructor Documentation

template<typename Clock = std::chrono::steady_clock>

folly::BasicTokenBucket< Clock >::BasicTokenBucket ( double  genRate, double  burstSize, double  zeroTime = 0  )

inlinenoexcept

Construct a token bucket with a specific maximum rate and burst size.

Parameters

genRate	Number of tokens to generate per second.
burstSize	Maximum burst size. Must be greater than 0.
zeroTime	Initial time at which to consider the token bucket starting to fill. Defaults to 0, so by default token bucket is "full" after construction.

Definition at line 237 of file TokenBucket.h.

References folly::pushmi::__adl::noexcept(), and folly::BasicDynamicTokenBucket< Clock >::operator=().

      : tokenBucket_(zeroTime), rate_(genRate), burstSize_(burstSize) {
    assert(rate_ > 0);
    assert(burstSize_ > 0);
  }

template<typename Clock = std::chrono::steady_clock>

folly::BasicTokenBucket< Clock >::BasicTokenBucket ( const BasicTokenBucket< Clock > &  other )

defaultnoexcept

Copy constructor.

Warning: not thread safe!

Member Function Documentation

template<typename Clock = std::chrono::steady_clock>

double folly::BasicTokenBucket< Clock >::available ( double  nowInSeconds = defaultClockNow() ) const

inline

Returns the number of tokens currently available.

Thread-safe (but returned value may immediately be outdated).

Definition at line 347 of file TokenBucket.h.

Referenced by TEST().

                                                                  {
    return tokenBucket_.available(rate_, burstSize_, nowInSeconds);
  }

template<typename Clock = std::chrono::steady_clock>

double folly::BasicTokenBucket< Clock >::burst ( ) const

inlinenoexcept

Returns the maximum burst size.

Thread-safe (but returned value may immediately be outdated).

Definition at line 365 of file TokenBucket.h.

                                {
    return burstSize_;
  }

template<typename Clock = std::chrono::steady_clock>

bool folly::BasicTokenBucket< Clock >::consume ( double  toConsume, double  nowInSeconds = defaultClockNow()  )

inline

Attempts to consume some number of tokens. Tokens are first added to the bucket based on the time elapsed since the last attempt to consume tokens. Note: Attempts to consume more tokens than the burst size will always fail.

Thread-safe.

Parameters

toConsume	The number of tokens to consume.
nowInSeconds	Current time in seconds. Should be monotonically increasing from the nowInSeconds specified in this token bucket's constructor.

Returns

True if the rate limit check passed, false otherwise.

Definition at line 318 of file TokenBucket.h.

Referenced by doTokenBucketTest(), TEST(), and TEST_P().

                                                                          {
    return tokenBucket_.consume(toConsume, rate_, burstSize_, nowInSeconds);
  }

template<typename Clock = std::chrono::steady_clock>

double folly::BasicTokenBucket< Clock >::consumeOrDrain ( double  toConsume, double  nowInSeconds = defaultClockNow()  )

inline

Similar to consume, but always consumes some number of tokens. If the bucket contains enough tokens - consumes toConsume tokens. Otherwise the bucket is drained.

Thread-safe.

Parameters

toConsume	The number of tokens to consume.
nowInSeconds	Current time in seconds. Should be monotonically increasing from the nowInSeconds specified in this token bucket's constructor.

Returns

number of tokens that were consumed.

Definition at line 335 of file TokenBucket.h.

                                               {
    return tokenBucket_.consumeOrDrain(
        toConsume, rate_, burstSize_, nowInSeconds);
  }

template<typename Clock = std::chrono::steady_clock>

static double folly::BasicTokenBucket< Clock >::defaultClockNow ( )

inlinestaticnoexcept

Returns the current time in seconds since Epoch.

Definition at line 263 of file TokenBucket.h.

                                                                            {
    return Impl::defaultClockNow();
  }

template<typename Clock = std::chrono::steady_clock>

BasicTokenBucket& folly::BasicTokenBucket< Clock >::operator= ( const BasicTokenBucket< Clock > &  other )

defaultnoexcept

Copy-assignment operator.

Warning: not thread safe!

template<typename Clock = std::chrono::steady_clock>

double folly::BasicTokenBucket< Clock >::rate ( ) const

inlinenoexcept

Returns the number of tokens generated per second.

Thread-safe (but returned value may immediately be outdated).

Definition at line 356 of file TokenBucket.h.

                               {
    return rate_;
  }

template<typename Clock = std::chrono::steady_clock>

void folly::BasicTokenBucket< Clock >::reset ( double  genRate, double  burstSize, double  nowInSeconds = defaultClockNow()  )

inlinenoexcept

Change rate and burst size.

Warning: not thread safe!

Parameters

genRate	Number of tokens to generate per second.
burstSize	Maximum burst size. Must be greater than 0.
nowInSeconds	Current time in seconds. Should be monotonically increasing from the nowInSeconds specified in this token bucket's constructor.

Definition at line 278 of file TokenBucket.h.

References folly::BasicDynamicTokenBucket< Clock >::available().

Referenced by folly::BasicTokenBucket< Clock >::setCapacity().

                                                        {
    assert(genRate > 0);
    assert(burstSize > 0);
    const double availTokens = available(nowInSeconds);
    rate_ = genRate;
    burstSize_ = burstSize;
    setCapacity(availTokens, nowInSeconds);
  }

template<typename Clock = std::chrono::steady_clock>

void folly::BasicTokenBucket< Clock >::setCapacity ( double  tokens, double  nowInSeconds  )

inlinenoexcept

Change number of tokens in bucket.

Warning: not thread safe!

Parameters

tokens	Desired number of tokens in bucket after the call.
nowInSeconds	Current time in seconds. Should be monotonically increasing from the nowInSeconds specified in this token bucket's constructor.

Definition at line 300 of file TokenBucket.h.

References folly::BasicTokenBucket< Clock >::reset(), and tokens.

                                                                {
    tokenBucket_.reset(nowInSeconds - tokens / rate_);
  }

Member Data Documentation

template<typename Clock = std::chrono::steady_clock>

double folly::BasicTokenBucket< Clock >::burstSize_

private

Definition at line 372 of file TokenBucket.h.

template<typename Clock = std::chrono::steady_clock>

double folly::BasicTokenBucket< Clock >::rate_

private

Definition at line 371 of file TokenBucket.h.

template<typename Clock = std::chrono::steady_clock>

Impl folly::BasicTokenBucket< Clock >::tokenBucket_

private

Definition at line 370 of file TokenBucket.h.

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The documentation for this class was generated from the following file:

• proxygen/folly/folly/TokenBucket.h