Struct BackpressureController 

pub struct BackpressureController { /* private fields */ }

Backpressure controller for bounded pipeline channels.

Ensures producers block when consumers are overwhelmed, preventing memory explosion and maintaining system stability. Uses tokio semaphores for concurrency limiting.

Examples

use crawlkit_engine::BackpressureController;

let controller = BackpressureController::new(10);
let permit = controller.acquire().await.unwrap();
assert_eq!(controller.active_count(), 1);
drop(permit);
assert_eq!(controller.active_count(), 0);

Implementations

impl BackpressureController

pub fn new(max_concurrent: usize) -> Self

Create a new backpressure controller.

Arguments

• max_concurrent - Maximum concurrent tasks allowed

pub fn with_channel(max_concurrent: usize, channel_size: usize) -> Self

Create with bounded channel for additional backpressure.

pub async fn acquire(&self) -> Result<BackpressurePermit<'_>, BackpressureError>

Acquire a permit (blocks if at capacity).

Errors

Returns error if controller is shut down.

pub fn try_acquire(&self) -> Option<BackpressurePermit<'_>>

Try to acquire a permit without blocking.

pub fn active_count(&self) -> usize

Get number of active tasks.

pub fn is_at_capacity(&self) -> bool

Check if at capacity.

pub fn shutdown(&self)

Initiate graceful shutdown.

pub fn is_shut_down(&self) -> bool

Check if shut down.

Trait Implementations

impl Default for BackpressureController

fn default() -> Self

Returns the “default value” for a type.