Struct EventRing 

pub struct EventRing { /* private fields */ }

Bounded FIFO of ring items.

Implementations

impl EventRing

pub fn new() -> Self

pub fn with_capacity(cap: usize) -> Self

Build a ring with a specific capacity. cap == 0 is accepted and produces a drop-everything ring (tests may use this to confirm the bound is enforced at zero too); production callers should use DEFAULT_CAPACITY.

pub const fn capacity(&self) -> usize

Maximum number of items this ring retains.

pub fn len(&self) -> usize

Current number of retained items.

pub fn is_empty(&self) -> bool

true when no items have been recorded yet.

pub fn push_event(&mut self, event: EngineEvent)

Append a typed engine event. Drops the oldest item when at capacity so the push is O(1) and never allocates past cap.

pub fn push_event_at(&mut self, event: EngineEvent, ts: DateTime<Utc>)

Like Self::push_event with an explicit timestamp. Exists so snapshot tests can drive deterministic content for variants (Status, Positions, Risk, Regime) that do not carry a ts inside their typed payload. Never called by the runtime event loop — production writes always go through Self::push_event which takes the wall clock.

pub fn push_lagged(&mut self, skipped: u64)

Append a “broadcast channel lagged” marker. Reserved for the event loop’s RecvError::Lagged branch.

pub fn push_lagged_at(&mut self, skipped: u64, ts: DateTime<Utc>)

Deterministic sibling of Self::push_lagged for tests.

pub fn iter(&self) -> impl DoubleEndedIterator<Item = &RingItem>

Iterate newest-last (i.e. chronological order). Kept generic so callers can chain .rev() for newest-first rendering without paying for a materialized Vec.

pub fn tail(&self, n: usize) -> impl DoubleEndedIterator<Item = &RingItem>

Iterate the last n items in chronological order. When n exceeds Self::len the iterator yields every item — same as Self::iter. Used by the pane to render “last N rows” without allocating.

Trait Implementations

impl Debug for EventRing

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

Formats the value using the given formatter.

impl Default for EventRing

fn default() -> Self

Returns the “default value” for a type.