Struct ContextProbe 

pub struct ContextProbe {
    last_asked: HashMap<SessionSlot, Instant>,
}

The socket’s bound on asking, held for the life of the fold.

Fields

last_asked: HashMap<SessionSlot, Instant>

When the socket last asked for each seat’s reading.

Implementations

impl ContextProbe

pub fn admit( &mut self, slot: &SessionSlot, reading: impl FnOnce() -> ContextUsage, now: Instant, ) -> Result<(), Declined>

Whether the socket may ask for a fresh reading on slot, recording the ask when it may.

The reading arrives as a thunk because it is built under the session’s lock, and the interval can refuse the ask without it - so a fold that took the reading first would hold that lock once per finished turn, on the one task that serves every client.

pub fn force(&mut self, slot: &SessionSlot, now: Instant)

Record an ask made past both bounds, which is the one case they must not refuse: a compaction settled, so the held reading was taken from a transcript that no longer exists.

Both bounds read the reading they would be replacing, so without this a seat past the token gate refuses every ask and its number stands at the high value for the life of its occupant.

fn too_soon(&self, slot: &SessionSlot, now: Instant) -> bool

Whether slot was asked inside the interval, without building a reading to find out.

fn expire(&mut self, now: Instant)

Drop the seats whose last ask has aged out: the fold has no seat-closed signal to hang a removal on, and an entry older than the interval refuses nothing, so expiry is the whole of the bound.

Trait Implementations

impl Default for ContextProbe

fn default() -> Self

Returns the “default value” for a type.