Enum Class 

pub(crate) enum Class {
    Rule(usize),
    Default,
    Unshapeable,
}

Which row of ShapeStats a unit is charged to.

Copy, and an index rather than a name: the storage is a pre-sized Vec<ClassCounters> in configured order, so charging a unit is one relaxed fetch_add at a known offset and never a map lookup.

Variants

Rule(usize)

The rule at this index in ShapeProfile::classes.

Default

No rule claimed the unit.

This is the falsifiable signal that a rule did not fire: an author who expected a class to claim everything and reads ShapeStats::default_class.objects_delivered > 0 knows their rule did not fire, and the ShapeRuleUnmatchable impairment says why.

objects_delivered, not objects_dropped — the counter this doc used to name has a producer only under Overflow::DropTail, so under the default Overflow::Block it is permanently zero and an author following the instruction would read a zero and conclude their rule had fired. objects_delivered has a producer under every overflow policy. (The drop row is still the right one to read in a DropTail fixture, which is why a_datagram_rule_says_so_instead_of_matching_nothing asserts it.)

Unshapeable

There was nothing to classify: a subgroup stream header, an oversized object the framer could only pass through, a bypassed stream’s bytes. Such a unit still takes an ordering slot — it is bytes on a wire that has other bytes queued in front of it — but it charges no bucket, because no rule can name what no ObjectMeta describes. Distinct from Self::Default, which is a unit the rules did see and none of them claimed: conflating them would let my rule matched nothing and there was nothing for a rule to match report as one number.

Trait Implementations

impl Clone for Class

fn clone(&self) -> Class

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Class

impl Debug for Class

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

Formats the value using the given formatter.

impl Eq for Class

impl PartialEq for Class

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Class