Struct QueueConfig 

#[non_exhaustive]
pub struct QueueConfig {
    pub depth_bytes: usize,
    pub depth_objects: usize,
    pub max_hold: Option<Duration>,
    pub overflow: Overflow,
    pub on_expiry: Expiry,
}

The per-stream queue policy: how deep, how long, and what happens at each limit.

#[non_exhaustive] with a Default — see the module doc.

The Default is hand-written, not derived: a derived one would give depth_bytes == 0 and depth_objects == 0, which ShapeProfile::try_new rejects as ShapeError::EmptyQueue — so QueueConfig::default() would be a value that cannot be used, and the ..Default::default() idiom this type is built for would fail on every profile that did not restate both depths.

That hand-written Default is also what the written form defaults every key to, so a scenario file may omit queue entirely or name only the one knob it cares about. It is the one config in this module where the derived default would be the unusable value and the written default is therefore worth having.

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

depth_bytes: usize

Bytes one stream’s queue may hold. Defaults to 1 MiB, matching EgressConfig::max_pending_bytes.

depth_objects: usize

Objects one stream’s queue may hold. Defaults to 256 — a limit the byte depth does not imply, since a queue of small objects reaches neither.

max_hold: Option<Duration>

Deadline for a queued object, per class. None inherits EgressConfig::max_hold, which is 30 s.

Pin this explicitly in any fixture that relies on a class not delivering: under the default Expiry::Deliver a starved class still delivers at max_hold, so an unnamed 30 s is a margin the test inherited rather than chose.

overflow: Overflow

What happens when the queue is full.

on_expiry: Expiry

What happens when a queued object outlives max_hold.

Trait Implementations

impl Clone for QueueConfig

fn clone(&self) -> QueueConfig

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for QueueConfig

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

Formats the value using the given formatter.

impl Default for QueueConfig

fn default() -> Self

Returns the “default value” for a type.

impl Eq for QueueConfig

impl PartialEq for QueueConfig

fn eq(&self, other: &QueueConfig) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for QueueConfig