Struct TokenBucket 

pub struct TokenBucket { /* private fields */ }

Strict-admission token bucket with atomic-CAS acquire semantics.

Cache-line aligned to prevent false sharing in concurrent admission pipelines.

Implementations

impl TokenBucket

pub fn new(capacity: u32, refill_per_second: f64) -> Self

Build a new bucket.

• capacity — maximum tokens the bucket can hold (burst size).
• refill_per_second — sustained refill rate, tokens per second.

The bucket starts full (tokens = capacity). refill_per_second of 0.0 produces a static-capacity bucket (no refill); negative or non-finite values are coerced to 0.0.

pub fn capacity(&self) -> u32

Bucket capacity in whole tokens.

pub fn refill_per_second(&self) -> f64

Refill rate in tokens per second (reconstructed from internal fixed-point storage; subject to small rounding).

pub fn available(&self) -> u32

Current available tokens (approximate snapshot — observation has no retry semantics; treat as advisory).

pub fn try_acquire(&self, n: u32) -> Result<()>

Attempt to acquire n tokens. Returns Ok(()) on success, or Err(MetricsError::WouldBlock) when fewer than n tokens are available even after refill.

n == 0 always succeeds without modifying state.

pub fn acquire(&self, n: u32) -> bool

Acquire-or-don’t variant that swallows the error and returns a bool.

pub fn reset(&self)

Reset the bucket to full capacity.

Trait Implementations

impl Debug for TokenBucket

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

Formats the value using the given formatter.