Struct LabeledGauge 

pub struct LabeledGauge<L: LabelEnum> { /* private fields */ }

A gauge indexed by an enum label, providing O(1) dimensional metrics.

Each label variant has its own gauge for independent point-in-time values.

Example

use fast_telemetry::{LabeledGauge, LabelEnum};

#[derive(Copy, Clone, Debug)]
enum CacheType { Memory, Disk, Network }

impl LabelEnum for CacheType {
    const CARDINALITY: usize = 3;
    const LABEL_NAME: &'static str = "cache_type";

    fn as_index(self) -> usize { self as usize }
    fn from_index(index: usize) -> Self {
        match index {
            0 => Self::Memory, 1 => Self::Disk, _ => Self::Network,
        }
    }
    fn variant_name(self) -> &'static str {
        match self {
            Self::Memory => "memory", Self::Disk => "disk", Self::Network => "network",
        }
    }
}

let gauge: LabeledGauge<CacheType> = LabeledGauge::new();
gauge.set(CacheType::Memory, 1024);
gauge.set(CacheType::Disk, 4096);

// Iteration for export
for (label, value) in gauge.iter() {
    println!("{}={}: {}", CacheType::LABEL_NAME, label.variant_name(), value);
}

Implementations

impl<L: LabelEnum> LabeledGauge<L>

pub fn new() -> Self

Create a new labeled gauge with all values initialized to zero.

pub fn set(&self, label: L, value: i64)

Set the gauge value for the given label.

pub fn get(&self, label: L) -> i64

Get the current gauge value for a specific label.

pub fn iter(&self) -> impl Iterator<Item = (L, i64)> + '_

Iterate over all label/value pairs.

Used for Prometheus export.

Trait Implementations

impl<L: LabelEnum> ClickHouseExport for LabeledGauge<L>

fn export_clickhouse( &self, batch: &mut ClickHouseMetricBatch, name: &str, description: &str, time_unix_nano: u64, )

impl<L: LabelEnum> Default for LabeledGauge<L>

fn default() -> Self

Returns the “default value” for a type.

impl<L: LabelEnum> DogStatsDExport for LabeledGauge<L>

fn export_dogstatsd( &self, output: &mut String, name: &str, tags: &[(&str, &str)], )

Export this metric to the output string in DogStatsD format.

impl<L: LabelEnum> OtlpExport for LabeledGauge<L>

fn export_otlp( &self, metrics: &mut Vec<Metric>, name: &str, description: &str, time_unix_nano: u64, )

impl<L: LabelEnum> PrometheusExport for LabeledGauge<L>

fn export_prometheus(&self, output: &mut String, name: &str, help: &str)

Export this metric to the output string.