kcenon::monitoring::token_bucket_limiter Class Reference

Token bucket rate limiter implementation. More...

#include <resource_manager.h>

Inheritance diagram for kcenon::monitoring::token_bucket_limiter:

Collaboration diagram for kcenon::monitoring::token_bucket_limiter:

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

Public Member Functions
	token_bucket_limiter (const std::string &name, double rate, size_t capacity, throttling_strategy=throttling_strategy::reject)
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	refill ()

Private Attributes
std::string	name_
double	rate_
size_t	capacity_
double	tokens_
clock::time_point	last_refill_
std::mutex	mutex_

Detailed Description

Token bucket rate limiter implementation.

Uses the token bucket algorithm for rate limiting. Tokens are added at a fixed rate and consumed by requests.

Definition at line 215 of file resource_manager.h.

Member Typedef Documentation

clock

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

Definition at line 217 of file resource_manager.h.

Constructor & Destructor Documentation

token_bucket_limiter()

kcenon::monitoring::token_bucket_limiter::token_bucket_limiter ( const std::string & name, double rate, size_t capacity, throttling_strategy = throttling_strategy::reject )

inline

Definition at line 219 of file resource_manager.h.

        : name_(name)
        , rate_(rate)
        , capacity_(capacity)
        , tokens_(static_cast<double>(capacity))
        , last_refill_(clock::now()) {}

Member Function Documentation

get_name()

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

inlineoverridevirtual

Get the name of this rate limiter.

Implements kcenon::monitoring::rate_limiter.

Definition at line 238 of file resource_manager.h.

                                               {
        return name_;
    }

References name_.

refill()

void kcenon::monitoring::token_bucket_limiter::refill ( )

inlineprivate

Definition at line 243 of file resource_manager.h.

                  {
        auto now = clock::now();
        auto elapsed = std::chrono::duration<double>(now - last_refill_).count();
        tokens_ = std::min(static_cast<double>(capacity_), tokens_ + elapsed * rate_);
        last_refill_ = now;
    }

References capacity_, last_refill_, rate_, and tokens_.

Referenced by try_acquire().

Here is the caller graph for this function:

try_acquire()

bool kcenon::monitoring::token_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 227 of file resource_manager.h.

                                                {
        std::lock_guard<std::mutex> lock(mutex_);
        refill();
 
        if (tokens_ >= static_cast<double>(count)) {
            tokens_ -= static_cast<double>(count);
            return true;
        }
        return false;
    }

References mutex_, refill(), and tokens_.

Here is the call graph for this function:

Member Data Documentation

capacity_

size_t kcenon::monitoring::token_bucket_limiter::capacity_

private

Definition at line 252 of file resource_manager.h.

Referenced by refill().

last_refill_

clock::time_point kcenon::monitoring::token_bucket_limiter::last_refill_

private

Definition at line 254 of file resource_manager.h.

Referenced by refill().

mutex_

std::mutex kcenon::monitoring::token_bucket_limiter::mutex_

mutableprivate

Definition at line 255 of file resource_manager.h.

Referenced by try_acquire().

name_

std::string kcenon::monitoring::token_bucket_limiter::name_

private

Definition at line 250 of file resource_manager.h.

Referenced by get_name().

rate_

double kcenon::monitoring::token_bucket_limiter::rate_

private

Definition at line 251 of file resource_manager.h.

Referenced by refill().

tokens_

double kcenon::monitoring::token_bucket_limiter::tokens_

private

Definition at line 253 of file resource_manager.h.

Referenced by refill(), and try_acquire().

---

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

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