Cached value fallback strategy. More...

#include <error_boundary.h>

Inheritance diagram for kcenon::monitoring::cached_value_strategy< T >:

Collaboration diagram for kcenon::monitoring::cached_value_strategy< T >:

Public Member Functions
	cached_value_strategy (std::chrono::seconds ttl=std::chrono::seconds(60))

void	update_cache (const T &value)

common::Result< T >	get_fallback (const error_info &, degradation_level) override

Public Member Functions inherited from kcenon::monitoring::fallback_strategy_interface< T >
virtual	~fallback_strategy_interface ()=default

Private Attributes
std::chrono::seconds	ttl_

T	cached_value_

std::chrono::steady_clock::time_point	cache_time_

bool	has_value_

std::mutex	mutex_

Detailed Description

template<typename T>
class kcenon::monitoring::cached_value_strategy< T >

Cached value fallback strategy.

Definition at line 138 of file error_boundary.h.

Constructor & Destructor Documentation

◆ cached_value_strategy()

template<typename T >

kcenon::monitoring::cached_value_strategy< T >::cached_value_strategy ( std::chrono::seconds ttl = std::chrono::seconds(60) )

inlineexplicit

Definition at line 140 of file error_boundary.h.

141 : ttl_(ttl), has_value_(false) {}

kcenon::monitoring::cached_value_strategy::ttl_

std::chrono::seconds ttl_

Definition error_boundary.h:166

kcenon::monitoring::cached_value_strategy::has_value_

bool has_value_

Definition error_boundary.h:169

Member Function Documentation

◆ get_fallback()

template<typename T >

common::Result< T > kcenon::monitoring::cached_value_strategy< T >::get_fallback	(	const error_info &	,
		degradation_level	)

inlineoverridevirtual

Implements kcenon::monitoring::fallback_strategy_interface< T >.

Definition at line 150 of file error_boundary.h.

                                                                                    {
        std::lock_guard<std::mutex> lock(mutex_);
        if (!has_value_) {
            return common::Result<T>::err(error_info(monitoring_error_code::operation_failed, "No cached value available").to_common_error());
        }
 
        auto now = std::chrono::steady_clock::now();
        auto age = std::chrono::duration_cast<std::chrono::seconds>(now - cache_time_);
        if (age > ttl_) {
            return common::Result<T>::err(error_info(monitoring_error_code::operation_failed, "Cached value expired").to_common_error());
        }
 
        return common::ok(cached_value_);
    }

References kcenon::monitoring::cached_value_strategy< T >::cache_time_, kcenon::monitoring::cached_value_strategy< T >::cached_value_, kcenon::monitoring::cached_value_strategy< T >::has_value_, kcenon::monitoring::cached_value_strategy< T >::mutex_, kcenon::monitoring::operation_failed, and kcenon::monitoring::cached_value_strategy< T >::ttl_.

◆ update_cache()

template<typename T >

void kcenon::monitoring::cached_value_strategy< T >::update_cache ( const T & value )

inline

Definition at line 143 of file error_boundary.h.

                                      {
        std::lock_guard<std::mutex> lock(mutex_);
        cached_value_ = value;
        cache_time_ = std::chrono::steady_clock::now();
        has_value_ = true;
    }