1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
//!
//! Abortable trigger, can be used to cancel (abort) an asynchronous task.
//!
use wasm_bindgen::prelude::*;
use std::sync::{
Arc,
atomic::{AtomicBool, Ordering},
};
/// Error emitted by [`Abortable`].
/// @category General
#[wasm_bindgen]
pub struct Aborted;
impl std::error::Error for Aborted {}
impl std::fmt::Debug for Aborted {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
write!(f, "task aborted")
}
}
impl std::fmt::Display for Aborted {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
write!(f, "task aborted")
}
}
///
/// Abortable trigger wraps an `Arc<AtomicBool>`, which can be cloned
/// to signal task terminating using an atomic bool.
///
/// ```text
/// let abortable = Abortable::default();
/// let result = my_task(abortable).await?;
/// // ... elsewhere
/// abortable.abort();
/// ```
///
/// @category General
#[derive(Default, Clone)]
#[wasm_bindgen]
pub struct Abortable(Arc<AtomicBool>);
#[wasm_bindgen]
impl Abortable {
/// Creates a new [`Abortable`] in the non-aborted state.
#[wasm_bindgen(constructor)]
pub fn new() -> Self {
Self(Arc::new(AtomicBool::new(false)))
}
/// Returns `true` if [`abort`](Self::abort) has been signalled.
#[wasm_bindgen(js_name=isAborted)]
pub fn is_aborted(&self) -> bool {
self.0.load(Ordering::SeqCst)
}
/// Signals abort, causing subsequent [`check`](Self::check) calls to fail.
pub fn abort(&self) {
self.0.store(true, Ordering::SeqCst);
}
/// Returns `Err(`[`Aborted`]`)` if abort has been signalled, otherwise `Ok(())`.
pub fn check(&self) -> Result<(), Aborted> {
if self.is_aborted() {
Err(Aborted)
} else {
Ok(())
}
}
/// Clears the abort signal, returning the trigger to its non-aborted state.
pub fn reset(&self) {
self.0.store(false, Ordering::SeqCst);
}
}
impl TryFrom<&JsValue> for Abortable {
type Error = JsValue;
fn try_from(value: &JsValue) -> Result<Self, Self::Error> {
use wasm_bindgen::convert::*;
let idx = IntoWasmAbi::into_abi(value);
#[link(wasm_import_module = "__wbindgen_placeholder__")]
#[cfg(all(
target_arch = "wasm32",
not(any(target_os = "emscripten", target_os = "wasi"))
))]
unsafe extern "C" {
fn __wbg_abortable_unwrap(ptr: u32) -> u32;
}
#[cfg(not(all(
target_arch = "wasm32",
not(any(target_os = "emscripten", target_os = "wasi"))
)))]
unsafe fn __wbg_abortable_unwrap(_: u32) -> u32 {
panic!("cannot convert from JsValue outside of the wasm target")
}
let ptr = unsafe { __wbg_abortable_unwrap(idx) };
if ptr == 0 {
wasm_bindgen::__rt::std::result::Result::Err(value.clone())
} else {
unsafe {
// wasm-bindgen 0.2.126 changed the exported-struct ABI from a
// bare u32 to `WasmPtr`; wrap the unwrapped pointer accordingly.
wasm_bindgen::__rt::std::result::Result::Ok(
<Self as FromWasmAbi>::from_abi(wasm_bindgen::__rt::WasmPtr::from_usize(
ptr as usize,
))
.clone(),
)
}
}
}
}