prom::prometheus_cpp::PrometheusCppAdapter Class Reference

Maps prom's metric types onto prometheus-cpp families and series. More...

#include <adapter.hpp>

Inheritance diagram for prom::prometheus_cpp::PrometheusCppAdapter:

Collaboration diagram for prom::prometheus_cpp::PrometheusCppAdapter:

Classes
class	Impl

Public Member Functions
	PrometheusCppAdapter ()
	Construct with a freshly-allocated, owned registry.
	PrometheusCppAdapter (std::shared_ptr< prometheus::Registry > registry)
	Construct around an externally-owned registry (shared), e.g.
	~PrometheusCppAdapter () override
prometheus::Registry &	registry () const noexcept
	The registry backing this adapter — hand it to a prometheus::Exposer or serialize it for a scrape response.
std::shared_ptr< prometheus::Registry >	registry_ptr () const noexcept
	Shared ownership of the backing registry.
std::string_view	backend_name () const noexcept override
	Stable identifier of the backend (e.g. "null", "prometheus-cpp").
prom::MetricHandle	register_metric (const prom::MetricMeta &meta) noexcept override
	Register a metric family.
prom::MetricHandle	resolve (const prom::MetricHandle &family, const prom::Labels &dynamic) noexcept override
	Resolve the labeled child of family for the given dynamic labels, creating it on first request.
void	inc (const prom::MetricHandle &handle, double amount) noexcept override
	Increase the series behind handle by amount (counter/gauge).
void	dec (const prom::MetricHandle &handle, double amount) noexcept override
	Decrease the series behind handle by amount (gauge).
void	set (const prom::MetricHandle &handle, double value) noexcept override
	Set the series behind handle to value (gauge/untyped).
void	observe (const prom::MetricHandle &handle, double value) noexcept override
	Record an observation against handle (histogram/summary).
void	set_info (const prom::MetricHandle &handle, std::span< const prom::Label > labels) noexcept override
	Replace the label set carried by an info metric.
void	set_state (const prom::MetricHandle &handle, std::string_view state, bool active) noexcept override
	Set the boolean value of one member of a state set.
Public Member Functions inherited from prom::Adapter
	Adapter ()=default
	Adapter (const Adapter &)=delete
Adapter &	operator= (const Adapter &)=delete
	Adapter (Adapter &&)=delete
Adapter &	operator= (Adapter &&)=delete
virtual	~Adapter ()=default
virtual void	set_unit (const MetricHandle &, const Unit &) noexcept
	Late unit inference hook.

Detailed Description

Maps prom's metric types onto prometheus-cpp families and series.

Owns (or shares) the underlying prometheus::Registry, which the host exposes via an exposer/scrape endpoint.

Mapping. Counter/Gauge/Histogram/Summary map to their direct prometheus-cpp equivalents. Untyped maps to a Gauge. Info maps to a <name> Gauge whose label set carries the payload at value 1. StateSet maps to a Gauge family with one series per state (labelled by the metric name), each 0 or 1.

Constructor & Destructor Documentation

PrometheusCppAdapter() [1/2]

prom::prometheus_cpp::PrometheusCppAdapter::PrometheusCppAdapter

(

)

Construct with a freshly-allocated, owned registry.

PrometheusCppAdapter() [2/2]

prom::prometheus_cpp::PrometheusCppAdapter::PrometheusCppAdapter ( std::shared_ptr< prometheus::Registry >  registry )

explicit

Construct around an externally-owned registry (shared), e.g.

one already wired to an exposer.

~PrometheusCppAdapter()

prom::prometheus_cpp::PrometheusCppAdapter::~PrometheusCppAdapter ( )

overridedefault

Member Function Documentation

backend_name()

std::string_view prom::prometheus_cpp::PrometheusCppAdapter::backend_name ( ) const

overridevirtualnoexcept

Stable identifier of the backend (e.g. "null", "prometheus-cpp").

Implements prom::Adapter.

dec()

void prom::prometheus_cpp::PrometheusCppAdapter::dec ( const prom::MetricHandle &  handle, double  amount  )

overridevirtualnoexcept

Decrease the series behind handle by amount (gauge).

Implements prom::Adapter.

inc()

void prom::prometheus_cpp::PrometheusCppAdapter::inc ( const prom::MetricHandle &  handle, double  amount  )

overridevirtualnoexcept

Increase the series behind handle by amount (counter/gauge).

Implements prom::Adapter.

observe()

void prom::prometheus_cpp::PrometheusCppAdapter::observe ( const prom::MetricHandle &  handle, double  value  )

overridevirtualnoexcept

Record an observation against handle (histogram/summary).

Implements prom::Adapter.

register_metric()

prom::MetricHandle prom::prometheus_cpp::PrometheusCppAdapter::register_metric ( const prom::MetricMeta &  meta )

overridevirtualnoexcept

Register a metric family.

Must return a non-null handle even on failure (fall back to an inert handle) so callers never have to null-check.

Implements prom::Adapter.

registry()

prometheus::Registry & prom::prometheus_cpp::PrometheusCppAdapter::registry ( ) const

noexcept

The registry backing this adapter — hand it to a prometheus::Exposer or serialize it for a scrape response.

registry_ptr()

std::shared_ptr<::prometheus::Registry > prom::prometheus_cpp::PrometheusCppAdapter::registry_ptr ( ) const

noexcept

Shared ownership of the backing registry.

resolve()

prom::MetricHandle prom::prometheus_cpp::PrometheusCppAdapter::resolve ( const prom::MetricHandle &  family, const prom::Labels &  dynamic  )

overridevirtualnoexcept

Resolve the labeled child of family for the given dynamic labels, creating it on first request.

The backend owns the child cache. Must return a non-null handle.

Implements prom::Adapter.

set()

void prom::prometheus_cpp::PrometheusCppAdapter::set ( const prom::MetricHandle &  handle, double  value  )

overridevirtualnoexcept

Set the series behind handle to value (gauge/untyped).

Implements prom::Adapter.

set_info()

void prom::prometheus_cpp::PrometheusCppAdapter::set_info ( const prom::MetricHandle &  handle, std::span< const prom::Label >  labels  )

overridevirtualnoexcept

Replace the label set carried by an info metric.

Implements prom::Adapter.

set_state()

void prom::prometheus_cpp::PrometheusCppAdapter::set_state ( const prom::MetricHandle &  handle, std::string_view  state, bool  active  )

overridevirtualnoexcept

Set the boolean value of one member of a state set.

Implements prom::Adapter.

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

• adapters/prometheus_cpp/include/prom/prometheus_cpp/adapter.hpp
• adapters/prometheus_cpp/src/adapter.cpp