Struct EventBuffer 

pub struct EventBuffer { /* private fields */ }

A bounded, FIFO event buffer.

When the buffer is at capacity and a new event is pushed, the oldest event is evicted and returned. This mirrors the JS _eventBuffer behavior in SyncEngine where old events are shifted when the buffer exceeds _eventBufferSize.

Examples

use stateset_sync::{EventBuffer, SyncEvent};
use serde_json::json;

let mut buffer = EventBuffer::new(2);
buffer.push(SyncEvent::new("a", "x", "1", json!({})));
buffer.push(SyncEvent::new("b", "x", "2", json!({})));

// Third push evicts the oldest event
let evicted = buffer.push(SyncEvent::new("c", "x", "3", json!({})));
assert!(evicted.is_some());
assert_eq!(evicted.unwrap().event_type, "a");
assert_eq!(buffer.len(), 2);

Implementations

impl EventBuffer

pub fn new(capacity: usize) -> Self

Create a new EventBuffer with the given capacity.

A capacity of 0 means the buffer will evict every event immediately.

pub fn push(&mut self, event: SyncEvent) -> Option<SyncEvent>

Push an event into the buffer.

If the buffer is at capacity, the oldest event is evicted and returned. Returns None if no eviction was needed.

pub fn drain_all(&mut self) -> Vec<SyncEvent>

Drain all events from the buffer, returning them in FIFO order.

pub fn len(&self) -> usize

Return the number of events in the buffer.

pub fn is_empty(&self) -> bool

Whether the buffer contains no events.

pub fn is_full(&self) -> bool

Whether the buffer is at capacity.

pub const fn capacity(&self) -> usize

Return the maximum capacity.

pub fn recent(&self, count: usize) -> Vec<&SyncEvent>

Peek at the most recent count events (from the back of the buffer).

pub fn clear(&mut self)

Clear the buffer.

Trait Implementations

impl Debug for EventBuffer

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

Formats the value using the given formatter.