Struct Hold 

pub struct Hold { /* private fields */ }

A deadline before which no request on a throttle may proceed.

A throttle’s buckets model the quota a venue publishes; a hold is what the server actually just said. They disagree more often than the tables suggest — Cloudflare’s error code: 1015 is an IP-scoped block with its own window, and it answers 429 no matter how many tokens the buckets still hold. So a 429 holds every request sharing the throttle, not just the one that saw it.

A hold only ever extends: several concurrent requests typically see the same 429 within a few milliseconds of each other, and taking the most recent value would let whichever response carried the smallest delay release all of them early. wait re-reads the deadline after waking, so a hold extended mid-wait is honoured in full.

A hold keeps time on a Runtime: it reads its deadline off the runtime’s clock and its waits sleep on the runtime. unbounded and with_ceiling take the target’s default runtime, unbounded_on and with_ceiling_on the one given. Every layer that waits and shares the hold keeps time on the hold’s runtime, so one throttle never mixes two clocks.

A clone shares the deadline. Every layer of one throttle holds a clone of one Hold, so replacing or resizing a layer keeps it.

Implementations

impl Hold

pub fn unbounded() -> Self

A hold with no ceiling, on the target’s default runtime: every extend is taken as asked.

pub fn unbounded_on(runtime: Arc<dyn Runtime>) -> Self

As unbounded, keeping time on runtime.

pub fn with_ceiling(ceiling: Duration) -> Self

A hold that clamps every extend to ceiling, so a server asking for longer holds for ceiling, on the target’s default runtime.

pub fn with_ceiling_on(ceiling: Duration, runtime: Arc<dyn Runtime>) -> Self

As with_ceiling, keeping time on runtime.

pub fn runtime(&self) -> &Arc<dyn Runtime>

The runtime this hold keeps time on, which every layer sharing the hold keeps time on too.

pub fn extend(&self, delay: Duration)

Hold every request for delay from now, clamped to the ceiling.

Extends a hold in force but never shortens one. A delay too large for the clock holds for thirty years rather than panicking.

pub async fn wait(&self)

Wait out the hold in force, if any.

pub fn is_held(&self) -> bool

Whether a hold is in force now.

Trait Implementations

impl Clone for Hold

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Hold

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

Formats the value using the given formatter.

impl Default for Hold

fn default() -> Self

Hold::unbounded.