Struct Item 

pub struct Item<T = usize> { /* private fields */ }

Queue item.

Items are stored in queues, and can have arbitrary associated data. An item has a specific deadline, which is the ordering property of the queue.

Items must only be considered for processing when their deadline has passed, which is exactly what Queue::take ensures. This allows to implement timers and intervals in an efficient manner. In case two items have the same deadline, order is undefined, but this doesn’t matter for us.

Note that mutable data needs to be stored outside of the queue, as items are immutable. The built-in Queue uses a Slab for this matter.

Implementations

impl<T> Item<T>

pub fn new(data: T) -> Self

Creates a queue item.

Examples

use zrx_store::queue::Item;

// Create queue item
let item = Item::new(42);

pub fn set_deadline(&mut self, deadline: Instant)

Updates the deadline of the queue item.

Examples

use std::time::Instant;
use zrx_store::queue::Item;

// Create queue item and set deadline
let mut item = Item::new(42);
item.set_deadline(Instant::now());

impl<T> Item<T>

pub fn deadline(&self) -> Instant

Returns the deadline.

pub fn data(&self) -> &T

Returns a reference to the associated data.

Trait Implementations

impl<T: Clone> Clone for Item<T>

fn clone(&self) -> Item<T>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T: Debug> Debug for Item<T>

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

Formats the value using the given formatter.

impl<T> Ord for Item<T>

where T: Eq,

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

Orders two queue items.

Examples

use zrx_store::queue::Item;

// Create and compare queue items
let a = Item::new(42);
let b = Item::new(84);
assert!(a <= b);

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.

impl<T> PartialEq for Item<T>

where T: PartialEq,

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

Compares two queue items for equality.

Note that two queue items are considered being equal if their associated data is equal. Deadlines are solely relevant for ordering.

Examples

use zrx_store::queue::Item;

// Create and compare queue items
let a = Item::new(42);
let b = Item::new(42);
assert_eq!(a, b);

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<T> PartialOrd for Item<T>

where T: Eq,

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

Orders two queue items.

Examples

use zrx_store::queue::Item;

// Create and compare queue items
let a = Item::new(42);
let b = Item::new(84);
assert!(a <= b);

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<T> Eq for Item<T>

where T: Eq,