Struct ScientificEncoder 

pub struct ScientificEncoder;

A Prometheus text-format encoder that renders counter values in scientific notation ({:.10E}) and appends a trailing comma after the last label.

This matches the output format produced by Kafka’s JMX-to-Prometheus exporters, making it useful for dashboards that expect that convention.

Example

use prometheus::Opts;
use prometheus::core::Collector;
use prometheus_extensions::{AggregateCounter, ScientificEncoder};

let counter = AggregateCounter::new(
    Opts::new("bytes_in", "Bytes received"),
    &["topic"],
).unwrap();
counter.with_label_values(&["events"]).inc_by(4.6384186519e10);

let families = counter.collect();
let encoder = ScientificEncoder::new();
let mut buf = Vec::new();
encoder.encode(&families, &mut buf).unwrap();

let output = String::from_utf8(buf).unwrap();
assert!(output.contains("bytes_in{topic=\"events\",}"));
assert!(output.contains("E10"));

Implementations

impl ScientificEncoder

pub fn new() -> Self

Create a new encoder.

pub fn encode<W: Write>( &self, metric_families: &[MetricFamily], writer: &mut W, ) -> Result<(), Error>

Encode metric_families into the Prometheus text exposition format with scientific-notation counter values.

Trait Implementations

impl Default for ScientificEncoder

fn default() -> ScientificEncoder

Returns the “default value” for a type.