Struct Queue

pub struct Queue<V: Copy + Default> { /* private fields */ }

A queue that exposes an idiomatic Rust interface to an underlying BPF queue.

Implementations

impl<V: Copy + Default> Queue<V>

pub fn with_capacity(entries: u32) -> Result<Self, Error>

Creates a new BPF queue with entries elements. A queue works as a FIFO container: push() inserts an element to the back and pop() consumes an element from the front.

Arguments

• entries - The maximum number of elements in the queue.

Example

use bpf_api::collections::Queue;

let queue = Queue::<u32>::with_capacity(10).expect("Failed to create queue");

pub fn pop(&self) -> Result<V, Error>

Retrieves and removes the next element in the queue, if it exists.

Example

use bpf_api::collections::Queue;

let queue = Queue::<u32>::with_capacity(10).expect("Failed to create queue");
assert!(matches!(queue.pop(), Err(_)));

pub fn front(&self) -> Result<V, Error>

Retrieves next element in the queue, if it exists. This does not remove the element.

Example

use bpf_api::collections::Queue;

let queue = Queue::<u32>::with_capacity(10).expect("Failed to create queue");
assert!(matches!(queue.front(), Err(_)));

pub fn push(&self, val: V) -> Result<(), Error>

Push a new element to the back of the queue.

Example

use bpf_api::collections::Queue;

let queue = Queue::<u32>::with_capacity(10).expect("Failed to create queue");
assert!(matches!(queue.push(100), Ok(_)));
assert!(matches!(queue.front(), Ok(100)));
assert!(matches!(queue.pop(), Ok(100)));
assert!(matches!(queue.pop(), Err(_)));

pub fn get_identifier(&self) -> u32

Retrieve the BPF identifier for this map. This is the underlying file descriptor that’s used in eBPF programs.

Example

use bpf_api::collections::Queue;

let queue = Queue::<u32>::with_capacity(10).expect("Failed to create queue");
queue.get_identifier();