Struct EventMetrics

pub struct EventMetrics { /* private fields */ }

A human- and machine-readable report about observed occurrences of a single event.

Part of a collected Report,

Implementations

impl EventMetrics

pub fn name(&self) -> &EventName

The name of the event associated with these metrics.

Example

use nm::{Event, Report};

thread_local! {
    static HTTP_REQUESTS: Event = Event::builder()
        .name("http_requests")
        .build();
}

HTTP_REQUESTS.with(|e| e.observe_once());
let report = Report::collect();

for event in report.events() {
    println!("Event name: {}", event.name());
}

pub fn count(&self) -> u64

Total number of occurrences that have been observed.

Example

use nm::{Event, Report};

thread_local! {
    static HTTP_REQUESTS: Event = Event::builder()
        .name("http_requests")
        .build();
}

HTTP_REQUESTS.with(|e| e.observe_once());
HTTP_REQUESTS.with(|e| e.observe_once());
let report = Report::collect();

for event in report.events() {
    println!("Total count: {}", event.count());
}

pub fn sum(&self) -> Magnitude

Sum of the magnitudes of all observed occurrences.

Example

use nm::{Event, Report};

thread_local! {
    static SENT_BYTES: Event = Event::builder()
        .name("sent_bytes")
        .build();
}

SENT_BYTES.with(|e| e.observe(1024));
SENT_BYTES.with(|e| e.observe(2048));
let report = Report::collect();

for event in report.events() {
    println!("Total bytes: {}", event.sum());
}

pub fn mean(&self) -> Magnitude

Mean magnitude of all observed occurrences.

If there are no observations, this will be zero.

Example

use nm::{Event, Report};

thread_local! {
    static RESPONSE_TIME: Event = Event::builder()
        .name("response_time_ms")
        .build();
}

RESPONSE_TIME.with(|e| e.observe(100));
RESPONSE_TIME.with(|e| e.observe(200));
let report = Report::collect();

for event in report.events() {
    println!("Average response time: {}ms", event.mean());
}

pub fn histogram(&self) -> Option<&Histogram>

The histogram of observed magnitudes (if configured).

None if the event was not configured to generate a histogram.

Example

use nm::{Event, Magnitude, Report};

const RESPONSE_TIME_BUCKETS_MS: &[Magnitude] = &[10, 50, 100, 500];

thread_local! {
    static HTTP_RESPONSE_TIME_MS: Event = Event::builder()
        .name("http_response_time_ms")
        .histogram(RESPONSE_TIME_BUCKETS_MS)
        .build();
}

HTTP_RESPONSE_TIME_MS.with(|e| e.observe(75));
let report = Report::collect();

for event in report.events() {
    if let Some(histogram) = event.histogram() {
        println!("Histogram for {}", event.name());
        for (bucket_upper_bound, count) in histogram.buckets() {
            println!("  ≤{}: {}", bucket_upper_bound, count);
        }
    }
}

Trait Implementations

impl Debug for EventMetrics

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for EventMetrics

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.