Struct open_metrics_client::metrics::family::Family[−][src]

pub struct Family<S, M, C = fn() -> M> { /* fields omitted */ }

Expand description

Representation of the OpenMetrics MetricFamily data type.

A Family is a set of metrics with the same name, help text and type, differentiated by their label values thus spanning a multidimensional space.

Generic over the label set

A Family is generic over the label type. For convenience one might choose a Vec<(String, String)>, for performance and/or type safety one might define a custom type.

Examples

`Family` with `Vec<(String, String)>` for convenience

let family = Family::<Vec<(String, String)>, Counter>::default();

// Record a single HTTP GET request.
family.get_or_create(&vec![("method".to_owned(), "GET".to_owned())]).inc();

`Family` with custom type for performance and/or type safety

Using Encode derive macro to generate Encode implementation.

#[derive(Clone, Hash, PartialEq, Eq, Encode)]
struct Labels {
  method: Method,
};

#[derive(Clone, Hash, PartialEq, Eq, Encode)]
enum Method {
  GET,
  PUT,
};

let family = Family::<Labels, Counter>::default();

// Record a single HTTP GET request.
family.get_or_create(&Labels { method: Method::GET }).inc();

Implementations

[src]

impl<S: Clone + Hash + Eq, M, C> Family<S, M, C>

[src]

pub fn new_with_constructor(constructor: C) -> Self

Create a metric family using a custom constructor to construct new metrics.

When calling Family::get_or_create a Family needs to be able to construct a new metric in case none exists for the given label set. In most cases, e.g. for Counter Family can just use the Default::default implementation for the metric type. For metric types such as Histogram one might want Family to construct a Histogram with custom buckets (see example below). For such case one can use this method. For more involved constructors see MetricConstructor.

Family::<Vec<(String, String)>, Histogram>::new_with_constructor(|| {
    Histogram::new(exponential_buckets(1.0, 2.0, 10))
});

[src]

impl<S: Clone + Hash + Eq, M, C: MetricConstructor<M>> Family<S, M, C>

[src]

pub fn get_or_create(
&self,
label_set: &S
) -> OwningRef<RwLockReadGuard<'_, HashMap<S, M>>, M>

Access a metric with the given label set, creating it if one does not yet exist.

let family = Family::<Vec<(String, String)>, Counter>::default();

// Will create the metric with label `method="GET"` on first call and
// return a reference.
family.get_or_create(&vec![("method".to_owned(), "GET".to_owned())]).inc();

// Will return a reference to the existing metric on all subsequent
// calls.
family.get_or_create(&vec![("method".to_owned(), "GET".to_owned())]).inc();