Struct ShapeTag 

struct ShapeTag {
    class: Class,
    expires_at: Instant,
    starved_noted: bool,
}

What the shaper attached to one queued unit, on a shaped stream.

None on every unit of every unshaped stream, which is what makes “a session with no ShapeProfile adds nothing to this path” a fact the type carries rather than a claim a reviewer checks.

Fields

class: Class

The row this unit’s bytes are charged to, and the bucket it draws from. Resolved per unit at admission — never per stream, because object_id and every_nth are legal class selectors and a stream-sticky class would evaluate them on object 0 alone.

expires_at: Instant

The instant this unit goes out anyway: arrived_at plus the profile’s max_hold, or the engine’s when the profile inherits it.

Under the default Expiry::Deliver that is a clamp, not a drop — so a starved class is late, never silently lossy, and “delivers zero bytes” is always a statement about a sampling window.

starved_noted: bool

Whether this unit has already been counted against starved_behind_other_class. Once per unit, not once per wake.

Trait Implementations

impl Clone for ShapeTag

fn clone(&self) -> ShapeTag

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for ShapeTag

impl Debug for ShapeTag

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

Formats the value using the given formatter.