Struct EntryId 

pub struct EntryId { /* private fields */ }

A Redis Streams entry id: the <milliseconds>-<sequence> pair the server assigns to every entry.

Parsed on construction, so a value of this type is always a well-formed id and comparisons order entries the way the stream does. The <milliseconds> half alone is accepted too ("1700000000000" means 1700000000000-0), matching what Redis accepts on the wire.

Examples

use std::time::{Duration, SystemTime, UNIX_EPOCH};

use ruststream_fred::stream::prelude::*;
use serde::Deserialize;

#[derive(Deserialize)]
struct Quote {
    price: u64,
}

// The id's first half is the server clock at `XADD`, so a quote's age needs no field of its own.
#[subscriber(RedisStream::new("quotes").group("pricing"))]
async fn price(quote: &Quote, Ctx(id): Ctx<keys::EntryId>) -> HandlerOutcome {
    let added = UNIX_EPOCH + Duration::from_millis(id.milliseconds());
    let age = SystemTime::now().duration_since(added).unwrap_or_default();
    if age > Duration::from_secs(5) {
        tracing::warn!(%id, age_ms = age.as_millis(), "stale quote");
        return HandlerOutcome::drop();
    }
    tracing::info!(quote.price, "quote");
    HandlerOutcome::ack()
}

#[ruststream::app]
fn app() -> impl App {
    RustStream::new(AppInfo::new("orders", "0.1.0")).with_broker(
        RedisBroker::standalone("redis://localhost:6379"),
        |b| {
            b.include(price);
        },
    )
}

Implementations

impl EntryId

pub const ZERO: Self

The lowest id the stream can express, below every real entry (Redis rejects 0-0 as an entry id, so nothing can sit at it).

pub const fn new(milliseconds: u64, sequence: u64) -> Self

Builds an id from its two halves.

pub const fn milliseconds(&self) -> u64

The <milliseconds> half: the entry’s server-side timestamp.

pub const fn sequence(&self) -> u64

The <sequence> half: the counter distinguishing entries added within one millisecond.

pub const fn previous(&self) -> Self

The id immediately below this one, saturating at ZERO.

Sequence numbers are dense within a millisecond, so the predecessor of <ms>-0 is <ms - 1>-<u64::MAX>. Used to turn “resume at this entry” into the exclusive cursor XGROUP SETID takes.

Trait Implementations

impl Clone for EntryId

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for EntryId

impl Debug for EntryId

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

Formats the value using the given formatter.

impl Display for EntryId

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

Formats the value using the given formatter.

impl Eq for EntryId

impl FromStr for EntryId

type Err = RedisError

The associated error which can be returned from parsing.

fn from_str(raw: &str) -> Result<Self, Self::Err>

Parses a string s to return a value of this type.

impl Hash for EntryId

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 Ord for EntryId

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

fn clamp_to<R>(self, range: R) -> Self

where Self: Sized, R: ClampBounds<Self>,

🔬This is a nightly-only experimental API. (clamp_to)

Restrict a value to a certain range.

impl PartialEq for EntryId

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

Equality operator ==.

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

Inequality operator !=.

impl PartialOrd for EntryId

fn partial_cmp(&self, other: &Self) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

Tests less than (for self and other) and is used by the < operator.

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

Tests less than or equal to (for self and other) and is used by the <= operator.

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

Tests greater than (for self and other) and is used by the > operator.

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

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl StructuralPartialEq for EntryId