Struct ChildStopper 

pub struct ChildStopper { /* private fields */ }

A cancellation primitive with tree-structured parent-child relationships.

ChildStopper uses a unified clone model: clone to share, any clone can cancel. When cancelled, it does NOT affect its parent or siblings - only this node and any of its children.

Example

use almost_enough::{ChildStopper, Stop};

let parent = ChildStopper::new();
let child = parent.child();

// Clone to share across threads
let child_clone = child.clone();

// Any clone can cancel
child_clone.cancel();
assert!(child.should_stop());

// Parent is not affected
assert!(!parent.should_stop());

Performance

• Size: 8 bytes (one pointer)
• check(): ~5-20ns depending on tree depth (walks parent chain)
• Root nodes: no parent check, similar to Stopper

Implementations

impl ChildStopper

pub fn new() -> Self

Create a new root tree node (no parent).

This creates a tree root that can have children added via child().

Example

use almost_enough::{ChildStopper, Stop};

let root = ChildStopper::new();
let child = root.child();

root.cancel();
assert!(child.should_stop());

pub fn with_parent<T: Stop + 'static>(parent: T) -> Self

Create a new tree node with a parent.

The child will stop if either:

• cancel() is called on this node (or any clone)
• Any ancestor in the parent chain is cancelled

Example

use almost_enough::{Stopper, ChildStopper, Stop};

let root = Stopper::new();
let child = ChildStopper::with_parent(root.clone());

root.cancel();
assert!(child.should_stop());

pub fn child(&self) -> ChildStopper

Create a child of this tree node.

The child will stop if either this node or any ancestor is cancelled. Cancelling the child does NOT affect this node.

Example

use almost_enough::{ChildStopper, Stop};

let parent = ChildStopper::new();
let child = parent.child();
let grandchild = child.child();

child.cancel();
assert!(!parent.should_stop());  // Parent unaffected
assert!(child.should_stop());
assert!(grandchild.should_stop());  // Inherits from parent

pub fn cancel(&self)

Cancel this node (and all its children).

This does NOT affect the parent or siblings.

pub fn is_cancelled(&self) -> bool

Check if this node is cancelled (either directly or via ancestor).

Trait Implementations

impl Cancellable for ChildStopper

fn stop(&self)

Request stop/cancellation.

impl Clone for ChildStopper

fn clone(&self) -> ChildStopper

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ChildStopper

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

Formats the value using the given formatter.

impl Default for ChildStopper

fn default() -> Self

Returns the “default value” for a type.

impl Stop for ChildStopper

fn check(&self) -> Result<(), StopReason>

Check if the operation should stop.

fn should_stop(&self) -> bool

Returns true if the operation should stop.