Time_based_metric Class Reference

Class that encodes how much time we waited for something. More...

#include <time_based_metric.h>

Inheritance diagram for Time_based_metric:

Public Member Functions
	Time_based_metric (bool manual_counting=false)
	Constructor that allows you to define counting as being manual. More...
Time_based_metric &	operator= (const Time_based_metric &other)
	Copy assignment operator. More...
Time_based_metric &	operator= (const Time_based_metric_interface &other)
	Assignment operator for the interface. More...
	Time_based_metric (const Time_based_metric &)=delete
	Deleted copy constructor, move constructor, move assignment operator. More...
	Time_based_metric (Time_based_metric &&)=delete
Time_based_metric &	operator= (Time_based_metric &&)=delete
	~Time_based_metric () override=default
	Default destuctor. More...
void	reset () override
	Resets the counter and summed time to 0. More...
int64_t	get_time () const override
	Returns the time waited across all executions of the start/stop methods. More...
void	increment_counter () override
	Increment the counter. More...
int64_t	get_count () const override
	Returns the number of time we waited on give spot. More...
Public Member Functions inherited from Time_based_metric_interface
virtual	~Time_based_metric_interface ()=default
auto	time_scope ()
	Start the timer, and return an object that will stop the timer when it is deleted. More...

Protected Member Functions
void	start_timer () override
	Starts the timer. More...
void	stop_timer () override
	Stops the timer. More...

Static Private Member Functions
static int64_t	now ()
	Helper to get current time. More...

Private Attributes
std::atomic< int64_t >	m_time {0}
	The total nanoseconds of all completed waits, minus the absolute start time of an ongoing wait, if any. More...
std::atomic< int64_t >	m_count {0}
	The number of times we waited. More...
bool	m_manual_counting {false}
	If false, the counter is incremented automatically by start_time, and the caller must not invoke increment_counter. More...

Detailed Description

Class that encodes how much time we waited for something.

Constructor & Destructor Documentation

Time_based_metric() [1/3]

Time_based_metric::Time_based_metric ( bool  manual_counting = false )

explicit

Constructor that allows you to define counting as being manual.

Parameters

manual_counting

shall count be automatic on start_timer or not (default false)

Time_based_metric() [2/3]

Time_based_metric::Time_based_metric ( const Time_based_metric &  )

delete

Deleted copy constructor, move constructor, move assignment operator.

Time_based_metric() [3/3]

Time_based_metric::Time_based_metric ( Time_based_metric &&  )

delete

~Time_based_metric()

Time_based_metric::~Time_based_metric ( )

overridedefault

Default destuctor.

Member Function Documentation

get_count()

int64_t Time_based_metric::get_count ( ) const

overridevirtual

Returns the number of time we waited on give spot.

Returns

the number of times waited

Implements Time_based_metric_interface.

get_time()

int64_t Time_based_metric::get_time ( ) const

overridevirtual

Returns the time waited across all executions of the start/stop methods.

Returns

The total time waited

Implements Time_based_metric_interface.

increment_counter()

void Time_based_metric::increment_counter ( )

overridevirtual

Increment the counter.

This is only allowed if the constructor was called using manual_counting=1. Otherwise, an assertion is raised.

Implements Time_based_metric_interface.

now()

int64_t Time_based_metric::now ( )

staticprivate

Helper to get current time.

Returns

Current time since the epoch for steady_clock, in nanoseconds.

operator=() [1/3]

Time_based_metric & Time_based_metric::operator=

(

const Time_based_metric &

other

)

Copy assignment operator.

Parameters

other

the object that is copied

Returns

this object

operator=() [2/3]

Time_based_metric & Time_based_metric::operator=

(

const Time_based_metric_interface &

other

)

Assignment operator for the interface.

Parameters

other

the object that is copied

Returns

this object

operator=() [3/3]

Time_based_metric & Time_based_metric::operator= ( Time_based_metric &&  )

delete

reset()

void Time_based_metric::reset ( )

overridevirtual

Resets the counter and summed time to 0.

Implements Time_based_metric_interface.

start_timer()

void Time_based_metric::start_timer ( )

overrideprotectedvirtual

Starts the timer.

Implements Time_based_metric_interface.

stop_timer()

void Time_based_metric::stop_timer ( )

overrideprotectedvirtual

Stops the timer.

Implements Time_based_metric_interface.

Member Data Documentation

m_count

std::atomic<int64_t> Time_based_metric::m_count {0}

private

The number of times we waited.

m_manual_counting

bool Time_based_metric::m_manual_counting {false}

private

If false, the counter is incremented automatically by start_time, and the caller must not invoke increment_counter.

If true, the counter is not incremented by start_time, so the caller has to invoke increment_counter.

m_time

std::atomic<int64_t> Time_based_metric::m_time {0}

private

The total nanoseconds of all completed waits, minus the absolute start time of an ongoing wait, if any.

If there is no ongoing wait, this is nonnegative and is the correct metric. If there is an ongoing wait, this is negative, and the correct value is given by adding the current time to it: result = sum_of_completed_waits + current_time - start_of_current_wait

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

• sql/changestreams/apply/metrics/time_based_metric.h
• sql/changestreams/apply/metrics/time_based_metric.cc