Struct Attempt 

pub struct Attempt;

The delivery’s attempt, 1 for the first delivery: the row’s attempt as it stood before the claim; None for a table without one.

Retry backoff is the handler’s: it reads the attempt and answers with HandlerOutcome::retry_after(..).

Examples

use std::time::Duration;

use ruststream::prelude::*;
use ruststream_sqlx::keys::Attempt;

#[subscriber(InboxQueue::<Job>::new("charges"))]
async fn charge(request: &Charge, Ctx(attempt): Ctx<Attempt>) -> HandlerOutcome {
    if try_charge(request).await {
        return HandlerOutcome::ack();
    }
    // Doubling backoff: 1s, 2s, 4s, ...
    let exponent = u32::try_from(attempt.unwrap_or(1).min(16)).unwrap_or(16);
    HandlerOutcome::retry_after(Duration::from_secs(1 << (exponent - 1)))
}

Trait Implementations

impl Clone for Attempt

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl ContextField for Attempt

type Context = InboxContext

The per-delivery context type this key reads from.

type Value = Option<u64>

The owned value the key yields.

fn read(self, src: &InboxContext) -> Option<u64>

Reads this key’s field out of src. Named apart from Field::get so a key implementing both traits stays unambiguous to call.

impl Copy for Attempt

impl Debug for Attempt

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

Formats the value using the given formatter.

impl Default for Attempt

fn default() -> Self

Returns the “default value” for a type.

impl Eq for Attempt

impl Hash for Attempt

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for Attempt

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Attempt