Struct CounterSetBuffer 

pub struct CounterSetBuffer<'a> { /* private fields */ }

A local write buffer for a CounterSet.

Use one buffer per worker/thread when a hot path records several related counters per logical operation. The buffer accumulates deltas locally and flushes them to the backing CounterSet every flush_every completed operations, reducing shared atomic writes on very hot paths.

Individual updates are supported with CounterSetBuffer::inc and CounterSetBuffer::add. Call CounterSetBuffer::finish_op once after recording all updates for a logical operation. Full-group updates such as CounterSetBuffer::inc_all and CounterSetBuffer::add_values already finish the operation.

The buffer also flushes on drop, but long-lived services should still flush at request or task boundaries when they need prompt visibility to exporters.

use fast_telemetry::{CounterSet, CounterSetBuffer};

const REQUESTS: usize = 0;
const BYTES: usize = 1;
const ERRORS: usize = 2;

let counters = CounterSet::new(4, 3);
let mut buffer = CounterSetBuffer::new(&counters, 64);

buffer.inc(REQUESTS);
buffer.add(BYTES, 4096);
buffer.finish_op();

buffer.inc(REQUESTS);
buffer.inc(ERRORS);
buffer.finish_op();

buffer.flush();

assert_eq!(counters.sum(REQUESTS), 2);
assert_eq!(counters.sum(BYTES), 4096);
assert_eq!(counters.sum(ERRORS), 1);

Implementations

impl<'a> CounterSetBuffer<'a>

pub fn new(counters: &'a CounterSet, flush_every: usize) -> Self

Creates a local buffer for a grouped counter set.

pub fn inc(&mut self, counter_idx: usize)

Increments one buffered counter.

pub fn add(&mut self, counter_idx: usize, value: isize)

Adds a value to one buffered counter.

pub fn inc_all(&mut self)

Increments every buffered counter and marks one logical operation complete.

pub fn add_all(&mut self, value: isize)

Adds the same value to every buffered counter and marks one logical operation complete.

pub fn add_values(&mut self, values: &[isize])

Adds one value per buffered counter and marks one logical operation complete.

pub fn finish_op(&mut self)

Marks the current logical operation complete.

pub fn flush(&mut self)

Flushes buffered deltas to the backing grouped counter set.

Trait Implementations

impl Drop for CounterSetBuffer<'_>

fn drop(&mut self)

Executes the destructor for this type.

fn pin_drop(self: Pin<&mut Self>)

🔬This is a nightly-only experimental API. (pin_ergonomics)

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned.