prom/include/prom_metric.h File Reference

Functions for retrieving metric samples from metrics given an ordered set of labels. More...

#include <math.h>
#include "prom_metric_sample.h"
#include "prom_metric_sample_histogram.h"

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Defines
#define	NaN   (0.0f / 0.0f)
Typedefs
typedef struct prom_metric	prom_metric_t
	A prometheus metric.
Functions
pms_t *	pms_from_labels (prom_metric_t *self, const char **label_values)
	Get a prom metric sample by label values.
pms_histogram_t *	pms_histogram_from_labels (prom_metric_t *self, const char **label_values)
	Get a prom histogram metric sample by label values.

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Detailed Description

Functions for retrieving metric samples from metrics given an ordered set of labels.

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Typedef Documentation

typedef struct prom_metric prom_metric_t

A prometheus metric.

Reference: https://prometheus.io/docs/concepts/data_model

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Function Documentation

pms_t* pms_from_labels	(	prom_metric_t *	self,
		const char **	label_values
	)

Get a prom metric sample by label values.

The order of label_values is significant.

You may use this function to cache metric samples to avoid sample lookup. Metric samples are stored in a hash map with O(1) lookups in average case. Nonethless, caching metric samples and updating them directly might be preferrable in performance-sensitive situations.

Parameters:

self	Metric to use for lookup.
label_values	label values associated with the metric sample being searched. The number of labels must match the value passed to label_key_count in the counter's constructor. If no label values are necessary, pass NULL. Otherwise, it may be convenient to pass this value as a literal.

Returns:

The sample found, NULL otherwise.

pms_histogram_t* pms_histogram_from_labels	(	prom_metric_t *	self,
		const char **	label_values
	)

Get a prom histogram metric sample by label values.

The order of label_values is significant.

You may use this function to cache metric samples to avoid sample lookup. Metric samples are stored in a hash map with O(1) lookups in average case. Nonethless, caching metric samples and updating them directly might be preferrable in performance-sensitive situations.

Parameters:

self	Metric to use for lookup.
label_values	label values associated with the metric sample being searched. The number of labels must match the value passed to label_key_count in the counter's constructor. If no label values are necessary, pass NULL. Otherwise, it may be convenient to pass this value as a literal.

Returns:

The histogram sample found, NULL otherwise.