Enum Overflow 

#[non_exhaustive]
pub enum Overflow {
    Block,
    DropTail,
    ResetStream {
        code: u64,
    },
}

What happens when a per-stream queue is full.

#[non_exhaustive], with Block as the Default: the only non-destructive answer is the one a caller gets without asking.

There is deliberately no DropHead. Dropping an already queued unit happens after the framer’s positional cursor has moved past it, so the elide fix-up can no longer be armed — and on drafts 14-19 object IDs are delta-encoded, so the result is not a gap but every successor decoding with a wrong absolute ID. Overflow::DropTail is sound for exactly the reason DropHead is not: it discards the arriving unit, at admission time, where the fix-up is still legal.

Written as "block", "drop-tail" or {"reset-stream": {"code": 1}}.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Block

Stop reading the source. Non-destructive. Default.

Per stream, and it does not reliably stall the peer: the transport’s own receive window absorbs megabytes first.

DropTail

Discard the arriving unit. Renumbers via the framer’s own elide fix-up, so absolute object IDs stay correct on drafts 14-19.

When an elide guard refuses the fix-up the unit is admitted anyway — the queue overshoots by one — and the refusal is reported. A shaper may not corrupt a stream to honour a depth limit.

ResetStream

Abandon the destination stream.

Fields

code: u64

The application error code to reset with.

Trait Implementations

impl Clone for Overflow

fn clone(&self) -> Overflow

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Overflow

impl Debug for Overflow

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

Formats the value using the given formatter.

impl Default for Overflow

fn default() -> Overflow

Returns the “default value” for a type.

impl Eq for Overflow

impl PartialEq for Overflow

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Overflow