Struct SubscriptionCount 

#[non_exhaustive]
pub struct SubscriptionCount {
    pub active: usize,
    pub started: usize,
}

How many of the service’s subscriptions are consuming, as a HealthProbe reports it.

A subscription counts once, whatever its worker count. It is active from the moment its dispatch loop starts until the loop ends: on shutdown, or when its stream ends while the service runs (see SubscriptionEnd). Whether a service with fewer active subscriptions than it started is healthy is the service’s own call.

Examples

use ruststream::memory::prelude::*;
use ruststream::runtime::{HealthProbe, RustStreamError, SubscriptionCount};
use serde::Deserialize;

#[derive(Deserialize)]
struct Order {
    id: u64,
}

#[subscriber("orders")]
async fn accept(order: &Order) -> HandlerOutcome {
    tracing::info!(order.id, "accepted");
    HandlerOutcome::ack()
}

/// Healthy while the service runs and every subscription it started still reads its queue.
fn healthy(health: &HealthProbe) -> bool {
    let SubscriptionCount {
        active, started, ..
    } = health.subscriptions();
    health.is_running() && active == started
}

pub async fn run() -> Result<(), RustStreamError> {
    let app = RustStream::new(AppInfo::new("orders", "0.1.0")).with_broker(
        MemoryBroker::new(),
        |b| {
            b.include(accept);
        },
    );
    let running = app.start().await?;
    tracing::info!(healthy = healthy(&running.health()), "service started");
    running.shutdown().await
}

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

active: usize

The subscriptions whose dispatch loop is running.

started: usize

The subscriptions the service started.

Trait Implementations

impl Clone for SubscriptionCount

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for SubscriptionCount

impl Debug for SubscriptionCount

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

Formats the value using the given formatter.

impl Default for SubscriptionCount

fn default() -> Self

Returns the “default value” for a type.

impl Eq for SubscriptionCount

impl PartialEq for SubscriptionCount

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for SubscriptionCount