Library: Prometheus
Package: Core
Header: Poco/Prometheus/Gauge.h
Description
A generic gauge supporting labels.
To create a Gauge with labels and register it with the default Registry:
Gauge sampleGauge("sample_gauge"s, {
.help = "A sample gauge"s,
.labelNames = {"label1"s, "label2"s}
});
To increment a Gauge (with labels):
sampleGauge.labels({"value1"s, "value2"}).inc();
To create a Gauge without labels and register it with the default Registry:
Gauge simpleGauge("simple_gauge"s);
simpleGauge.help("A simple gauge"s);
To set the value of a Gauge (without labels):
simpleGauge.set(42);
Inheritance
Direct Base Classes: LabeledMetricImpl < GaugeSample >
All Base Classes: LabeledMetricImpl < GaugeSample >
Member Summary
Member Functions: createSample, dec, exportTo, help, inc, labelNames, set, setToCurrentTime, value, writeSample
Nested Classes
struct Params
Constructors
Gauge
explicit Gauge(
const std::string & name
);
Creates a Gauge with the given name and registers it with the default registry.
Gauge
Gauge(
const std::string & name,
const Params & params
);
Creates a Gauge with the given name and params and registers it with the default registry.
Gauge
Gauge(
const std::string & name,
Registry * pRegistry
);
Creates a Gauge with the given name and registers it with the given registry (if not nullptr).
Gauge
Gauge(
const std::string & name,
const Params & params,
Registry * pRegistry
);
Creates a Gauge with the given name and params, and registers it with the given registry (if not nullptr).
Destructor
~Gauge
~Gauge() = default;
Destroys the Gauge.
Member Functions
dec 
void dec(
double v = 1.0
);
Decrements the Gauge's current value.
Can only be used if no labels have been defined.
exportTo
void exportTo(
Exporter & exporter
) const override;
help
Gauge & help(
const std::string & text
);
inc
void inc(
double v = 1.0
);
Increments the Gauge's current value.
Can only be used if no labels have been defined.
labelNames
Gauge & labelNames(
const std::vector < std::string > & labelNames
);
set
void set(
double v
);
Sets the Gauge's current value.
Can only be used if no labels have been defined.
set
void set(
Poco::Clock::ClockVal v
);
Sets the Gauge's current value to the given Clock value, converted to seconds.
Can only be used if no labels have been defined.
setToCurrentTime
void setToCurrentTime();
Sets the Gauge's current value to the current epoch time (seconds since midnight January 1st 1970).
value
double value() const;
Returns the Gauge's current value.
Can only be used if no labels have been defined.
createSample 
std::unique_ptr < GaugeSample > createSample() const override;
writeSample
void writeSample(
Exporter & exporter,
const std::vector < std::string > & labelValues,
const GaugeSample & sample
) const override;