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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331
use clonelet::clone;
use futures::{Future, FutureExt, StreamExt};
use futures_signals::{
signal::{Mutable, ReadOnlyMutable, Signal, SignalExt},
signal_vec::{MutableVec, MutableVecLockMut, SignalVec, SignalVecExt, VecDiff},
};
use silkenweb_macros::cfg_browser;
#[cfg_browser(false)]
/// Server only task tools.
pub mod server {
use std::{
pin::pin,
sync::Arc,
task::{Context, Poll, Wake},
};
use crossbeam::sync::{Parker, Unparker};
use futures::Future;
/// Synchronous version of [`run_tasks`][super::run_tasks].
///
/// This is only available on the server.
pub fn run_tasks_sync() {
super::arch::run_tasks_sync()
}
struct ThreadWaker(Unparker);
impl Wake for ThreadWaker {
fn wake(self: Arc<Self>) {
self.0.unpark();
}
}
/// Run a future to completion on the current thread.
///
/// This doesn't use the microtask executor, so it's safe to call
/// [run_tasks] from within the future. It's also safe to call `block_on`
/// recursively.
///
/// [run_tasks]: super::run_tasks
pub fn block_on<T>(fut: impl Future<Output = T>) -> T {
let mut fut = pin!(fut);
// Use a `Parker` instance rather than global `thread::park/unpark`, so no one
// else can steal our `unpark`s and they don't get confused with recursive
// `block_on` `unpark`s.
let parker = Parker::new();
// Make sure we create a new waker each call, rather than using a global, so
// recursive `block_on`s don't use the same waker.
let waker = Arc::new(ThreadWaker(parker.unparker().clone())).into();
let mut cx = Context::from_waker(&waker);
// Run the future to completion.
loop {
match fut.as_mut().poll(&mut cx) {
Poll::Ready(res) => return res,
Poll::Pending => parker.park(),
}
}
}
}
#[cfg_browser(false)]
mod arch {
use std::{cell::RefCell, future::Future};
use futures::{
executor::{LocalPool, LocalSpawner},
task::LocalSpawnExt,
};
use tokio::task_local;
pub struct Runtime {
executor: RefCell<LocalPool>,
spawner: LocalSpawner,
}
impl Default for Runtime {
fn default() -> Self {
let executor = RefCell::new(LocalPool::new());
let spawner = executor.borrow().spawner();
Self { executor, spawner }
}
}
task_local! {
pub static RUNTIME: Runtime;
}
fn with_runtime<R>(f: impl FnOnce(&Runtime) -> R) -> R {
match RUNTIME.try_with(f) {
Ok(r) => r,
Err(_) => panic!("Must be run from within `silkenweb_task::task::scope`"),
}
}
pub fn scope<Fut>(f: Fut) -> impl Future<Output = Fut::Output>
where
Fut: Future,
{
RUNTIME.scope(Runtime::default(), f)
}
pub fn sync_scope<F, R>(f: F) -> R
where
F: FnOnce() -> R,
{
RUNTIME.sync_scope(Runtime::default(), f)
}
pub async fn run_tasks() {
run_tasks_sync()
}
pub fn run_tasks_sync() {
with_runtime(|runtime| runtime.executor.borrow_mut().run_until_stalled())
}
pub fn spawn_local<F>(future: F)
where
F: Future<Output = ()> + 'static,
{
with_runtime(|runtime| runtime.spawner.spawn_local(future).unwrap())
}
}
#[cfg_browser(true)]
mod arch {
use std::future::Future;
use js_sys::Promise;
use wasm_bindgen::{JsValue, UnwrapThrowExt};
use wasm_bindgen_futures::JsFuture;
pub fn scope<Fut>(f: Fut) -> impl Future<Output = Fut::Output>
where
Fut: Future,
{
f
}
pub fn sync_scope<F, R>(f: F) -> R
where
F: FnOnce() -> R,
{
f()
}
// Microtasks are run in the order they were queued in Javascript, so we just
// put a task on the queue and `await` it.
pub async fn run_tasks() {
let wait_for_microtasks = Promise::resolve(&JsValue::NULL);
JsFuture::from(wait_for_microtasks).await.unwrap_throw();
}
pub fn spawn_local<F>(future: F)
where
F: Future<Output = ()> + 'static,
{
wasm_bindgen_futures::spawn_local(future)
}
}
/// Run futures on the microtask queue, until no more progress can be
/// made.
///
/// Don't call this from a future already on the microtask queue.
pub async fn run_tasks() {
arch::run_tasks().await
}
/// Run a future with a local task queue.
///
/// On the server, this creates a [`tokio`] task local queue. You can put
/// futures on this queue with [`spawn_local`].
///
/// On the browser, this does nothing and returns the original future.
pub use arch::scope;
/// Synchronous version of [`scope`].
pub use arch::sync_scope;
/// Spawn a future on the microtask queue.
pub fn spawn_local<F>(future: F)
where
F: Future<Output = ()> + 'static,
{
arch::spawn_local(future)
}
/// [`Signal`] methods that require a task queue.
pub trait TaskSignal: Signal {
/// Convert `self` to a [`Mutable`].
///
/// This uses the microtask queue to spawn a future that drives the signal.
/// The resulting `Mutable` can be used to memoize the signal, allowing many
/// signals to be derived from it.
///
/// # Example
///
/// ```rust
/// # use futures_signals::signal::Mutable;
/// # use silkenweb_task::{sync_scope, server::run_tasks_sync, TaskSignal};
/// #
/// let source = Mutable::new(0);
/// let signal = source.signal();
///
/// // A scope isn't required on browser platforms
/// sync_scope(|| {
/// let copy = signal.to_mutable();
/// assert_eq!(copy.get(), 0);
/// source.set(1);
/// run_tasks_sync();
/// assert_eq!(copy.get(), 1);
/// });
/// ```
fn to_mutable(self) -> ReadOnlyMutable<Self::Item>;
/// Run `callback` on each signal value.
///
/// The future is spawned on the microtask queue. This is equivalent to
/// `spawn_local(sig.for_each(callback))`.
fn spawn_for_each<U, F>(self, callback: F)
where
U: Future<Output = ()> + 'static,
F: FnMut(Self::Item) -> U + 'static;
}
impl<Sig> TaskSignal for Sig
where
Sig: Signal + 'static,
{
fn to_mutable(self) -> ReadOnlyMutable<Self::Item> {
let mut s = Box::pin(self.to_stream());
let first_value = s
.next()
.now_or_never()
.expect("A `Signal`'s initial value must be `Ready` immediately")
.expect("`Signal`s must have an initial value");
let mutable = Mutable::new(first_value);
spawn_local({
clone!(mutable);
async move {
while let Some(value) = s.next().await {
mutable.set(value);
}
}
});
mutable.read_only()
}
fn spawn_for_each<U, F>(self, callback: F)
where
U: Future<Output = ()> + 'static,
F: FnMut(Self::Item) -> U + 'static,
{
spawn_local(self.for_each(callback));
}
}
/// [`SignalVec`] methods that require a task queue.
pub trait TaskSignalVec: SignalVec {
/// Convert `self` to a [`MutableVec`].
///
/// This uses the microtask queue to spawn a future that drives the signal.
/// The resulting `MutableVec` can be used to memoize the signal, allowing
/// many signals to be derived from it.
///
/// # Example
///
/// ```rust
/// # use futures_signals::signal_vec::MutableVec;
/// # use silkenweb_task::{sync_scope, server::run_tasks_sync, TaskSignalVec};
/// #
/// let source = MutableVec::new();
/// let signal = source.signal_vec();
///
/// // A scope isn't required on browser platforms
/// sync_scope(|| {
/// let copy = signal.to_mutable();
/// assert!(copy.lock_ref().is_empty());
/// source.lock_mut().push_cloned(1);
/// run_tasks_sync();
/// assert_eq!(*copy.lock_ref(), [1]);
/// });
/// ```
fn to_mutable(self) -> MutableVec<Self::Item>;
/// Run `callback` on each signal delta.
///
/// The future is spawned on the microtask queue. This is equivalent to
/// `spawn_local(sig.for_each(callback))`.
fn spawn_for_each<U, F>(self, callback: F)
where
U: Future<Output = ()> + 'static,
F: FnMut(VecDiff<Self::Item>) -> U + 'static;
}
impl<Sig> TaskSignalVec for Sig
where
Self::Item: Clone + 'static,
Sig: SignalVec + 'static,
{
fn to_mutable(self) -> MutableVec<Self::Item> {
let mv = MutableVec::new();
self.spawn_for_each({
clone!(mv);
move |diff| {
MutableVecLockMut::apply_vec_diff(&mut mv.lock_mut(), diff);
async {}
}
});
mv
}
fn spawn_for_each<U, F>(self, callback: F)
where
U: Future<Output = ()> + 'static,
F: FnMut(VecDiff<Self::Item>) -> U + 'static,
{
spawn_local(self.for_each(callback));
}
}