Struct BoundedRing 

pub struct BoundedRing { /* private fields */ }

A fixed-capacity byte ring. On overflow the oldest bytes are dropped (never blocks the writer) and counted so the consumer can surface backpressure.

Implementations

impl BoundedRing

pub fn new(capacity: usize) -> Self

pub fn extend(&mut self, data: &[u8])

Append data, dropping the oldest bytes if it would exceed capacity.

pub fn snapshot(&self) -> Vec<u8>

Copy the current contents out (oldest-to-newest).

pub fn len(&self) -> usize

pub fn is_empty(&self) -> bool

pub fn capacity(&self) -> usize

pub fn dropped_bytes(&self) -> u64

Total bytes dropped due to overflow over this ring’s lifetime.

pub fn total_written(&self) -> u64

Total bytes ever written to the ring (dropped + currently buffered). This is a monotonic cursor: a reader that remembers the next value from BoundedRing::read_since can ask for everything appended since, without the fragile two-snapshot diff a sliding window would otherwise require. Drive output streaming (Wave 4) rides on this.

pub fn read_since(&self, cursor: u64) -> ReadSince

Return everything appended after the absolute byte offset cursor.

next is the offset to pass on the following call. gap is true when cursor pointed at bytes the ring has since dropped (overflow), so the reader knows its stream skipped ahead and can surface a drop notice rather than silently splicing non-contiguous output. A cursor past the current tail (a reader ahead of the writer, or a stale-but-future value) yields no bytes and next == cursor.max(total).

Trait Implementations

impl Debug for BoundedRing

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

Formats the value using the given formatter.