Struct Hook 

pub struct Hook<F: FnPtr> { /* private fields */ }

A mod’s link for one game function: its detour and the slot through which it reaches the rest of the chain.

Declared with detour! or #[hook], registered with Load::hook.

Examples

enshwick::detour! {
    /// Counts upgrades.
    static UPGRADE: unsafe extern "system" fn(ctx: *mut u64) = upgrade;
}

fn upgrade(next: enshwick::Next<unsafe extern "system" fn(*mut u64)>, ctx: *mut u64) {
    // SAFETY: the original takes the same context.
    unsafe { next.get()(ctx) }
}

assert_eq!(UPGRADE.name(), "UPGRADE");

Implementations

impl<F: FnPtr> Hook<F>

pub const fn new( name: &'static str, detour: F, priority: i32, flags: HookFlags, ) -> Self

A link whose entry point is detour; used by detour!.

Examples

See Hook.

pub const fn name(&self) -> &'static str

The name the link was declared with, used in log lines.

Examples

See Hook.

pub const fn entry(&self) -> F

The entry point the loader links into the chain: the detour with its panic guard, as the game calls it.

Examples

enshwick::detour! {
    static TICK: extern "system" fn() = tick;
}

fn tick(next: enshwick::Next<extern "system" fn()>) {
    next.get()();
}

let entry: extern "system" fn() = TICK.entry();

pub fn next(&'static self) -> Next<F>

The rest of the chain: the next link or the original function.

Examples

See Hook.

pub fn after_next<R>(&self, work: impl FnOnce() -> R) -> Option<R>

Runs work that a detour does after calling next, so that a panic in it turns the mod off without running the rest of the chain again.

A panic in the body falls through to the rest of the chain, which is right before next and wrong after it: the game’s function would run twice. Work after next belongs in here. A panic in work reports a fault, as a panic in the body does, and gives None; the detour then returns what next gave. The guard costs nothing until a panic.

Examples

use std::sync::atomic::{AtomicU32, Ordering};

static RAISED: AtomicU32 = AtomicU32::new(0);

enshwick::detour! {
    static RAISE: extern "system" fn(level: u32) -> u32 = raise;
}

fn raise(next: enshwick::Next<extern "system" fn(u32) -> u32>, level: u32) -> u32 {
    let raised = next.get()(level);
    let _counted = RAISE.after_next(|| RAISED.fetch_add(raised - level, Ordering::Relaxed));
    raised
}

Trait Implementations

impl<F: Debug + FnPtr> Debug for Hook<F>

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

Formats the value using the given formatter.