#include <metrics.h>

Inheritance diagram for impala::SimpleMetric< T, metric_kind >:

Collaboration diagram for impala::SimpleMetric< T, metric_kind >:

Public Member Functions
	SimpleMetric (const std::string &key, const TUnit::type unit, const T &initial_value, const std::string &description="")

	SimpleMetric (const std::string &key, const TUnit::type unit, const std::string &description="")

virtual	~SimpleMetric ()

T	value ()
	Returns the current value, updating it if necessary. Thread-safe. More...

void	set_value (const T &value)
	Sets the current value. Thread-safe. More...

void	Increment (const T &delta)
	Adds 'delta' to the current value atomically. More...

virtual void	ToJson (rapidjson::Document document, rapidjson::Value val)
	name, value, human_readable, description More...

virtual std::string	ToHumanReadable ()

virtual void	ToLegacyJson (rapidjson::Document *document)
	This method is kept for backwards-compatibility with CM5.0. More...

const TUnit::type	unit () const

const TMetricKind::type	kind () const

const std::string &	key () const

const std::string &	description () const

Protected Member Functions
virtual void	CalculateValue ()

void	AddStandardFields (rapidjson::Document document, rapidjson::Value val)

Protected Attributes
const TUnit::type	unit_
	Units of this metric. More...

boost::mutex	lock_
	Guards access to value_. More...

T	value_
	The current value of the metric. More...

const std::string	key_
	Unique key identifying this metric. More...

const std::string	description_

Detailed Description

template<typename T, TMetricKind::type metric_kind = TMetricKind::GAUGE>
class impala::SimpleMetric< T, metric_kind >

A SimpleMetric has a value which is a simple primitive type: e.g. integers, strings and floats. It is parameterised not only by the type of its value, but by both the unit (e.g. bytes/s), drawn from TUnit and the 'kind' of the metric itself. The kind can be one of: 'gauge', which may increase or decrease over time, a 'counter' which is increasing only over time, or a 'property' which is not numeric. SimpleMetrics return their current value through the value() method. Access to value() is thread-safe. TODO: We can use type traits to select a more efficient lock-free implementation of value() etc. where it is safe to do so.

Definition at line 104 of file metrics.h.

Constructor & Destructor Documentation

template<typename T , TMetricKind::type metric_kind = TMetricKind::GAUGE>

impala::SimpleMetric< T, metric_kind >::SimpleMetric	(	const std::string &	key,
		const TUnit::type	unit,
		const T &	initial_value,
		const std::string &	description = `""`
	)

inline

Definition at line 106 of file metrics.h.

template<typename T , TMetricKind::type metric_kind = TMetricKind::GAUGE>

impala::SimpleMetric< T, metric_kind >::SimpleMetric	(	const std::string &	key,
		const TUnit::type	unit,
		const std::string &	description = `""`
	)

inline

Definition at line 111 of file metrics.h.

template<typename T , TMetricKind::type metric_kind = TMetricKind::GAUGE>

virtual impala::SimpleMetric< T, metric_kind >::~SimpleMetric ( )

inlinevirtual

Definition at line 115 of file metrics.h.

Member Function Documentation

void Metric::AddStandardFields	(	rapidjson::Document *	document,
		rapidjson::Value *	val
	)

protectedinherited

Convenience method to add standard fields (name, description, human readable string) to 'val'.

Definition at line 46 of file metrics.cc.

References impala::name.

Referenced by impala::SetMetric< std::string >::ToJson(), impala::StatsMetric< double >::ToJson(), and impala::SimpleMetric< T, metric_kind >::ToJson().

template<typename T , TMetricKind::type metric_kind = TMetricKind::GAUGE>

virtual void impala::SimpleMetric< T, metric_kind >::CalculateValue ( )

inlineprotectedvirtual

Called to compute value_ if necessary during calls to value(). The more natural approach would be to have virtual T value(), but that's not possible in C++. TODO: Should be cheap to have a blank implementation, but if required we can cause the compiler to avoid calling this entirely through a compile-time constant.

Definition at line 175 of file metrics.h.

Referenced by impala::SimpleMetric< T, metric_kind >::value().

const std::string& impala::Metric::description ( ) const

inlineinherited

Definition at line 72 of file metrics.h.

References impala::Metric::description_.

template<typename T , TMetricKind::type metric_kind = TMetricKind::GAUGE>

void impala::SimpleMetric< T, metric_kind >::Increment ( const T & delta )

inline

Adds 'delta' to the current value atomically.

Definition at line 131 of file metrics.h.

References impala::Metric::key(), impala::SimpleMetric< T, metric_kind >::kind(), impala::SimpleMetric< T, metric_kind >::lock_, and impala::SimpleMetric< T, metric_kind >::value_.

const std::string& impala::Metric::key ( ) const

inlineinherited

Definition at line 71 of file metrics.h.

References impala::Metric::key_.

Referenced by impala::SimpleMetric< T, metric_kind >::Increment().

template<typename T , TMetricKind::type metric_kind = TMetricKind::GAUGE>

const TMetricKind::type impala::SimpleMetric< T, metric_kind >::kind ( ) const

inline

Definition at line 167 of file metrics.h.

Referenced by impala::SimpleMetric< T, metric_kind >::Increment(), and impala::SimpleMetric< T, metric_kind >::ToJson().

template<typename T , TMetricKind::type metric_kind = TMetricKind::GAUGE>

void impala::SimpleMetric< T, metric_kind >::set_value ( const T & value )

inline

Sets the current value. Thread-safe.

Definition at line 125 of file metrics.h.

References impala::SimpleMetric< T, metric_kind >::lock_, impala::SimpleMetric< T, metric_kind >::value(), and impala::SimpleMetric< T, metric_kind >::value_.

template<typename T , TMetricKind::type metric_kind = TMetricKind::GAUGE>

virtual std::string impala::SimpleMetric< T, metric_kind >::ToHumanReadable ( )

inlinevirtual

Writes a human-readable representation of this metric to 'out'. This is the representation that is often displayed in webpages etc.

Implements impala::Metric.

Definition at line 156 of file metrics.h.

References impala::PrettyPrinter::Print(), impala::SimpleMetric< T, metric_kind >::unit(), and impala::SimpleMetric< T, metric_kind >::value().

template<typename T , TMetricKind::type metric_kind = TMetricKind::GAUGE>

virtual void impala::SimpleMetric< T, metric_kind >::ToJson	(	rapidjson::Document *	document,
		rapidjson::Value *	val
	)

inlinevirtual

name, value, human_readable, description

Builds a new Value into 'val', using (if required) the allocator from 'document'. Should set the following fields where appropriate:

Implements impala::Metric.

Definition at line 140 of file metrics.h.

References impala::Metric::AddStandardFields(), impala::SimpleMetric< T, metric_kind >::kind(), impala::PrintTMetricKind(), impala::PrintTUnit(), impala::ToJsonValue(), impala::SimpleMetric< T, metric_kind >::unit(), and impala::SimpleMetric< T, metric_kind >::value().

template<typename T , TMetricKind::type metric_kind = TMetricKind::GAUGE>

virtual void impala::SimpleMetric< T, metric_kind >::ToLegacyJson ( rapidjson::Document * document )

inlinevirtual

This method is kept for backwards-compatibility with CM5.0.

Adds a new json value directly to 'document' of the form: "name" : "human-readable-string"

Implements impala::Metric.

Definition at line 160 of file metrics.h.

References impala::Metric::key_, impala::ToJsonValue(), and impala::SimpleMetric< T, metric_kind >::value().

template<typename T , TMetricKind::type metric_kind = TMetricKind::GAUGE>

const TUnit::type impala::SimpleMetric< T, metric_kind >::unit ( ) const

inline

Definition at line 166 of file metrics.h.

References impala::SimpleMetric< T, metric_kind >::unit_.

Referenced by impala::SimpleMetric< T, metric_kind >::ToHumanReadable(), and impala::SimpleMetric< T, metric_kind >::ToJson().

template<typename T , TMetricKind::type metric_kind = TMetricKind::GAUGE>

T impala::SimpleMetric< T, metric_kind >::value ( )

inline

Returns the current value, updating it if necessary. Thread-safe.

Definition at line 118 of file metrics.h.

References impala::SimpleMetric< T, metric_kind >::CalculateValue(), impala::SimpleMetric< T, metric_kind >::lock_, and impala::SimpleMetric< T, metric_kind >::value_.

Referenced by impala::SimpleMetric< T, metric_kind >::set_value(), impala::SimpleMetric< T, metric_kind >::ToHumanReadable(), impala::SimpleMetric< T, metric_kind >::ToJson(), and impala::SimpleMetric< T, metric_kind >::ToLegacyJson().

Member Data Documentation

const std::string impala::Metric::description_

protectedinherited

Description of this metric. TODO: share one copy amongst metrics with the same description.

Definition at line 80 of file metrics.h.

Referenced by impala::Metric::description().

const std::string impala::Metric::key_

protectedinherited

Unique key identifying this metric.

Definition at line 76 of file metrics.h.

Referenced by impala::Metric::key(), impala::SetMetric< std::string >::ToLegacyJson(), impala::StatsMetric< double >::ToLegacyJson(), and impala::SimpleMetric< T, metric_kind >::ToLegacyJson().

template<typename T , TMetricKind::type metric_kind = TMetricKind::GAUGE>

boost::mutex impala::SimpleMetric< T, metric_kind >::lock_

protected

Guards access to value_.

Definition at line 181 of file metrics.h.

Referenced by impala::SimpleMetric< T, metric_kind >::Increment(), impala::SimpleMetric< T, metric_kind >::set_value(), and impala::SimpleMetric< T, metric_kind >::value().

template<typename T , TMetricKind::type metric_kind = TMetricKind::GAUGE>

const TUnit::type impala::SimpleMetric< T, metric_kind >::unit_

protected

Units of this metric.

Definition at line 178 of file metrics.h.

Referenced by impala::SimpleMetric< T, metric_kind >::unit().

template<typename T , TMetricKind::type metric_kind = TMetricKind::GAUGE>

T impala::SimpleMetric< T, metric_kind >::value_

protected

The current value of the metric.

Definition at line 184 of file metrics.h.

Referenced by impala::SimpleMetric< T, metric_kind >::Increment(), impala::SimpleMetric< T, metric_kind >::set_value(), and impala::SimpleMetric< T, metric_kind >::value().

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

be/src/util/metrics.h

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

template<typename T, TMetricKind::type metric_kind = TMetricKind::GAUGE> class impala::SimpleMetric< T, metric_kind >

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation

template<typename T, TMetricKind::type metric_kind = TMetricKind::GAUGE>
class impala::SimpleMetric< T, metric_kind >