kcenon::monitoring::leaky_bucket_limiter Class Reference

Leaky bucket rate limiter implementation. More...

#include <resource_manager.h>

Inheritance diagram for kcenon::monitoring::leaky_bucket_limiter:

Collaboration diagram for kcenon::monitoring::leaky_bucket_limiter:

Public Types
using	clock = std::chrono::steady_clock

Public Member Functions
	leaky_bucket_limiter (const std::string &name, double rate, size_t capacity)
bool	try_acquire (size_t count=1) override
	Try to acquire tokens.
const std::string &	get_name () const override
	Get the name of this rate limiter.
Public Member Functions inherited from kcenon::monitoring::rate_limiter
virtual	~rate_limiter ()=default
template<typename Func >
auto	execute (Func &&func) -> decltype(func())
	Execute a function with rate limiting.

Private Member Functions
void	leak ()

Private Attributes
std::string	name_
double	rate_
size_t	capacity_
double	water_
clock::time_point	last_leak_
std::mutex	mutex_

Detailed Description

Leaky bucket rate limiter implementation.

Uses the leaky bucket algorithm for rate limiting. Requests fill the bucket and it leaks at a constant rate.

Definition at line 268 of file resource_manager.h.

Member Typedef Documentation

clock

using kcenon::monitoring::leaky_bucket_limiter::clock = std::chrono::steady_clock

Definition at line 270 of file resource_manager.h.

Constructor & Destructor Documentation

leaky_bucket_limiter()

kcenon::monitoring::leaky_bucket_limiter::leaky_bucket_limiter ( const std::string & name, double rate, size_t capacity )

inline

Definition at line 272 of file resource_manager.h.

        : name_(name)
        , rate_(rate)
        , capacity_(capacity)
        , water_(0.0)
        , last_leak_(clock::now()) {}

Member Function Documentation

get_name()

const std::string & kcenon::monitoring::leaky_bucket_limiter::get_name ( ) const

inlineoverridevirtual

Get the name of this rate limiter.

Implements kcenon::monitoring::rate_limiter.

Definition at line 290 of file resource_manager.h.

                                               {
        return name_;
    }

References name_.

leak()

void kcenon::monitoring::leaky_bucket_limiter::leak ( )

inlineprivate

Definition at line 295 of file resource_manager.h.

                {
        auto now = clock::now();
        auto elapsed = std::chrono::duration<double>(now - last_leak_).count();
        water_ = std::max(0.0, water_ - elapsed * rate_);
        last_leak_ = now;
    }

References last_leak_, rate_, and water_.

Referenced by try_acquire().

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try_acquire()

bool kcenon::monitoring::leaky_bucket_limiter::try_acquire ( size_t count = 1 )

inlineoverridevirtual

Try to acquire tokens.

Parameters

count

Number of tokens to acquire

Returns

true if tokens were acquired

Implements kcenon::monitoring::rate_limiter.

Definition at line 279 of file resource_manager.h.

                                                {
        std::lock_guard<std::mutex> lock(mutex_);
        leak();
 
        if (water_ + static_cast<double>(count) <= static_cast<double>(capacity_)) {
            water_ += static_cast<double>(count);
            return true;
        }
        return false;
    }

References capacity_, leak(), mutex_, and water_.

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Member Data Documentation

capacity_

size_t kcenon::monitoring::leaky_bucket_limiter::capacity_

private

Definition at line 304 of file resource_manager.h.

Referenced by try_acquire().

last_leak_

clock::time_point kcenon::monitoring::leaky_bucket_limiter::last_leak_

private

Definition at line 306 of file resource_manager.h.

Referenced by leak().

mutex_

std::mutex kcenon::monitoring::leaky_bucket_limiter::mutex_

mutableprivate

Definition at line 307 of file resource_manager.h.

Referenced by try_acquire().

name_

std::string kcenon::monitoring::leaky_bucket_limiter::name_

private

Definition at line 302 of file resource_manager.h.

Referenced by get_name().

rate_

double kcenon::monitoring::leaky_bucket_limiter::rate_

private

Definition at line 303 of file resource_manager.h.

Referenced by leak().

water_

double kcenon::monitoring::leaky_bucket_limiter::water_

private

Definition at line 305 of file resource_manager.h.

Referenced by leak(), and try_acquire().

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

• include/kcenon/monitoring/reliability/resource_manager.h