Add hook/event system

pull/9407/head
Pascal Kuthe 5 months ago committed by Blaž Hrastnik
parent 7d7ace551c
commit 13ed4f6c47

@ -1,3 +1,17 @@
# we use tokio_unstable to enable runtime::Handle::id so we can separate
# globals from multiple parallel tests. If that function ever does get removed
# its possible to replace (with some additional overhead and effort)
# Annoyingly build.rustflags doesn't work here because it gets overwritten
# if people have their own global target.<..> config (for example to enable mold)
# specifying flags this way is more robust as they get merged
# This still gets overwritten by RUST_FLAGS though, luckily it shouldn't be necessary
# to set those most of the time. If downstream does overwrite this its not a huge
# deal since it will only break tests anyway
[target."cfg(all())"]
rustflags = ["--cfg", "tokio_unstable", "-C", "target-feature=-crt-static"]
[alias]
xtask = "run --package xtask --"
integration-test = "test --features integration --profile integration --workspace --test integration"

6
Cargo.lock generated

@ -1102,6 +1102,12 @@ dependencies = [
name = "helix-event"
version = "23.10.0"
dependencies = [
"ahash",
"anyhow",
"futures-executor",
"hashbrown 0.14.3",
"log",
"once_cell",
"parking_lot",
"tokio",
]

@ -12,5 +12,18 @@ homepage.workspace = true
# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
[dependencies]
tokio = { version = "1", features = ["rt", "rt-multi-thread", "time", "sync", "parking_lot"] }
parking_lot = { version = "0.12", features = ["send_guard"] }
ahash = "0.8.3"
hashbrown = "0.14.0"
tokio = { version = "1", features = ["rt", "rt-multi-thread", "time", "sync", "parking_lot", "macros"] }
# the event registry is essentially read only but must be an rwlock so we can
# setup new events on initialization, hardware-lock-elision hugely benefits this case
# as it essentially makes the lock entirely free as long as there is no writes
parking_lot = { version = "0.12", features = ["hardware-lock-elision"] }
once_cell = "1.18"
anyhow = "1"
log = "0.4"
futures-executor = "0.3.28"
[features]
integration_test = []

@ -0,0 +1,19 @@
use std::future::Future;
pub use oneshot::channel as cancelation;
use tokio::sync::oneshot;
pub type CancelTx = oneshot::Sender<()>;
pub type CancelRx = oneshot::Receiver<()>;
pub async fn cancelable_future<T>(future: impl Future<Output = T>, cancel: CancelRx) -> Option<T> {
tokio::select! {
biased;
_ = cancel => {
None
}
res = future => {
Some(res)
}
}
}

@ -0,0 +1,67 @@
//! Utilities for declaring an async (usually debounced) hook
use std::time::Duration;
use futures_executor::block_on;
use tokio::sync::mpsc::{self, error::TrySendError, Sender};
use tokio::time::Instant;
/// Async hooks provide a convenient framework for implementing (debounced)
/// async event handlers. Most synchronous event hooks will likely need to
/// debounce their events, coordinate multiple different hooks and potentially
/// track some state. `AsyncHooks` facilitate these use cases by running as
/// a background tokio task that waits for events (usually an enum) to be
/// sent through a channel.
pub trait AsyncHook: Sync + Send + 'static + Sized {
type Event: Sync + Send + 'static;
/// Called immediately whenever an event is received, this function can
/// consume the event immediately or debounce it. In case of debouncing,
/// it can either define a new debounce timeout or continue the current one
fn handle_event(&mut self, event: Self::Event, timeout: Option<Instant>) -> Option<Instant>;
/// Called whenever the debounce timeline is reached
fn finish_debounce(&mut self);
fn spawn(self) -> mpsc::Sender<Self::Event> {
// the capacity doesn't matter too much here, unless the cpu is totally overwhelmed
// the cap will never be reached since we always immediately drain the channel
// so it should only be reached in case of total CPU overload.
// However, a bounded channel is much more efficient so it's nice to use here
let (tx, rx) = mpsc::channel(128);
tokio::spawn(run(self, rx));
tx
}
}
async fn run<Hook: AsyncHook>(mut hook: Hook, mut rx: mpsc::Receiver<Hook::Event>) {
let mut deadline = None;
loop {
let event = match deadline {
Some(deadline_) => {
let res = tokio::time::timeout_at(deadline_, rx.recv()).await;
match res {
Ok(event) => event,
Err(_) => {
hook.finish_debounce();
deadline = None;
continue;
}
}
}
None => rx.recv().await,
};
let Some(event) = event else {
break;
};
deadline = hook.handle_event(event, deadline);
}
}
pub fn send_blocking<T>(tx: &Sender<T>, data: T) {
// block_on has some overhead and in practice the channel should basically
// never be full anyway so first try sending without blocking
if let Err(TrySendError::Full(data)) = tx.try_send(data) {
// set a timeout so that we just drop a message instead of freezing the editor in the worst case
let _ = block_on(tx.send_timeout(data, Duration::from_millis(10)));
}
}

@ -0,0 +1,91 @@
//! rust dynamic dispatch is extremely limited so we have to build our
//! own vtable implementation. Otherwise implementing the event system would not be possible.
//! A nice bonus of this approach is that we can optimize the vtable a bit more. Normally
//! a dyn Trait fat pointer contains two pointers: A pointer to the data itself and a
//! pointer to a global (static) vtable entry which itself contains multiple other pointers
//! (the various functions of the trait, drop, size and align). That makes dynamic
//! dispatch pretty slow (double pointer indirections). However, we only have a single function
//! in the hook trait and don't need a drop implementation (event system is global anyway
//! and never dropped) so we can just store the entire vtable inline.
use anyhow::Result;
use std::ptr::{self, NonNull};
use crate::Event;
/// Opaque handle type that represents an erased type parameter.
///
/// If extern types were stable, this could be implemented as `extern { pub type Opaque; }` but
/// until then we can use this.
///
/// Care should be taken that we don't use a concrete instance of this. It should only be used
/// through a reference, so we can maintain something else's lifetime.
struct Opaque(());
pub(crate) struct ErasedHook {
data: NonNull<Opaque>,
call: unsafe fn(NonNull<Opaque>, NonNull<Opaque>, NonNull<Opaque>),
}
impl ErasedHook {
pub(crate) fn new_dynamic<H: Fn() -> Result<()> + 'static + Send + Sync>(
hook: H,
) -> ErasedHook {
unsafe fn call<F: Fn() -> Result<()> + 'static + Send + Sync>(
hook: NonNull<Opaque>,
_event: NonNull<Opaque>,
result: NonNull<Opaque>,
) {
let hook: NonNull<F> = hook.cast();
let result: NonNull<Result<()>> = result.cast();
let hook: &F = hook.as_ref();
let res = hook();
ptr::write(result.as_ptr(), res)
}
unsafe {
ErasedHook {
data: NonNull::new_unchecked(Box::into_raw(Box::new(hook)) as *mut Opaque),
call: call::<H>,
}
}
}
pub(crate) fn new<E: Event, F: Fn(&mut E) -> Result<()>>(hook: F) -> ErasedHook {
unsafe fn call<E: Event, F: Fn(&mut E) -> Result<()>>(
hook: NonNull<Opaque>,
event: NonNull<Opaque>,
result: NonNull<Opaque>,
) {
let hook: NonNull<F> = hook.cast();
let mut event: NonNull<E> = event.cast();
let result: NonNull<Result<()>> = result.cast();
let hook: &F = hook.as_ref();
let res = hook(event.as_mut());
ptr::write(result.as_ptr(), res)
}
unsafe {
ErasedHook {
data: NonNull::new_unchecked(Box::into_raw(Box::new(hook)) as *mut Opaque),
call: call::<E, F>,
}
}
}
pub(crate) unsafe fn call<E: Event>(&self, event: &mut E) -> Result<()> {
let mut res = Ok(());
unsafe {
(self.call)(
self.data,
NonNull::from(event).cast(),
NonNull::from(&mut res).cast(),
);
}
res
}
}
unsafe impl Sync for ErasedHook {}
unsafe impl Send for ErasedHook {}

@ -1,8 +1,203 @@
//! `helix-event` contains systems that allow (often async) communication between
//! different editor components without strongly coupling them. Currently this
//! crate only contains some smaller facilities but the intend is to add more
//! functionality in the future ( like a generic hook system)
//! different editor components without strongly coupling them. Specifically
//! it allows defining synchronous hooks that run when certain editor events
//! occur.
//!
//! The core of the event system are hook callbacks and the [`Event`] trait. A
//! hook is essentially just a closure `Fn(event: &mut impl Event) -> Result<()>`
//! that gets called every time an appropriate event is dispatched. The implementation
//! details of the [`Event`] trait are considered private. The [`events`] macro is
//! provided which automatically declares event types. Similarly the `register_hook`
//! macro should be used to (safely) declare event hooks.
//!
//! Hooks run synchronously which can be advantageous since they can modify the
//! current editor state right away (for example to immediately hide the completion
//! popup). However, they can not contain their own state without locking since
//! they only receive immutable references. For handler that want to track state, do
//! expensive background computations or debouncing an [`AsyncHook`] is preferable.
//! Async hooks are based around a channels that receive events specific to
//! that `AsyncHook` (usually an enum). These events can be sent by synchronous
//! hooks. Due to some limitations around tokio channels the [`send_blocking`]
//! function exported in this crate should be used instead of the builtin
//! `blocking_send`.
//!
//! In addition to the core event system, this crate contains some message queues
//! that allow transfer of data back to the main event loop from async hooks and
//! hooks that may not have access to all application data (for example in helix-view).
//! This include the ability to control rendering ([`lock_frame`], [`request_redraw`]) and
//! display status messages ([`status`]).
//!
//! Hooks declared in helix-term can furthermore dispatch synchronous jobs to be run on the
//! main loop (including access to the compositor). Ideally that queue will be moved
//! to helix-view in the future if we manage to detach the compositor from its rendering backend.
use anyhow::Result;
pub use cancel::{cancelable_future, cancelation, CancelRx, CancelTx};
pub use debounce::{send_blocking, AsyncHook};
pub use redraw::{lock_frame, redraw_requested, request_redraw, start_frame, RenderLockGuard};
pub use registry::Event;
mod cancel;
mod debounce;
mod hook;
mod redraw;
mod registry;
#[doc(hidden)]
pub mod runtime;
pub mod status;
#[cfg(test)]
mod test;
pub fn register_event<E: Event + 'static>() {
registry::with_mut(|registry| registry.register_event::<E>())
}
/// Registers a hook that will be called when an event of type `E` is dispatched.
/// This function should usually not be used directly, use the [`register_hook`]
/// macro instead.
///
///
/// # Safety
///
/// `hook` must be totally generic over all lifetime parameters of `E`. For
/// example if `E` was a known type `Foo<'a, 'b>`, then the correct trait bound
/// would be `F: for<'a, 'b, 'c> Fn(&'a mut Foo<'b, 'c>)`, but there is no way to
/// express that kind of constraint for a generic type with the Rust type system
/// as of this writing.
pub unsafe fn register_hook_raw<E: Event>(
hook: impl Fn(&mut E) -> Result<()> + 'static + Send + Sync,
) {
registry::with_mut(|registry| registry.register_hook(hook))
}
/// Register a hook solely by event name
pub fn register_dynamic_hook(
hook: impl Fn() -> Result<()> + 'static + Send + Sync,
id: &str,
) -> Result<()> {
registry::with_mut(|reg| reg.register_dynamic_hook(hook, id))
}
pub fn dispatch(e: impl Event) {
registry::with(|registry| registry.dispatch(e));
}
/// Macro to declare events
///
/// # Examples
///
/// ``` no-compile
/// events! {
/// FileWrite(&Path)
/// ViewScrolled{ view: View, new_pos: ViewOffset }
/// DocumentChanged<'a> { old_doc: &'a Rope, doc: &'a mut Document, changes: &'a ChangeSet }
/// }
///
/// fn init() {
/// register_event::<FileWrite>();
/// register_event::<ViewScrolled>();
/// register_event::<DocumentChanged>();
/// }
///
/// fn save(path: &Path, content: &str){
/// std::fs::write(path, content);
/// dispatch(FileWrite(path));
/// }
/// ```
#[macro_export]
macro_rules! events {
($name: ident<$($lt: lifetime),*> { $($data:ident : $data_ty:ty),* } $($rem:tt)*) => {
pub struct $name<$($lt),*> { $(pub $data: $data_ty),* }
unsafe impl<$($lt),*> $crate::Event for $name<$($lt),*> {
const ID: &'static str = stringify!($name);
const LIFETIMES: usize = $crate::events!(@sum $(1, $lt),*);
type Static = $crate::events!(@replace_lt $name, $('static, $lt),*);
}
$crate::events!{ $($rem)* }
};
($name: ident { $($data:ident : $data_ty:ty),* } $($rem:tt)*) => {
pub struct $name { $(pub $data: $data_ty),* }
unsafe impl $crate::Event for $name {
const ID: &'static str = stringify!($name);
const LIFETIMES: usize = 0;
type Static = Self;
}
$crate::events!{ $($rem)* }
};
() => {};
(@replace_lt $name: ident, $($lt1: lifetime, $lt2: lifetime),* ) => {$name<$($lt1),*>};
(@sum $($val: expr, $lt1: lifetime),* ) => {0 $(+ $val)*};
}
/// Safely register statically typed event hooks
#[macro_export]
macro_rules! register_hook {
// Safety: this is safe because we fully control the type of the event here and
// ensure all lifetime arguments are fully generic and the correct number of lifetime arguments
// is present
(move |$event:ident: &mut $event_ty: ident<$($lt: lifetime),*>| $body: expr) => {
let val = move |$event: &mut $event_ty<$($lt),*>| $body;
unsafe {
// Lifetimes are a bit of a pain. We want to allow events being
// non-static. Lifetimes don't actually exist at runtime so its
// fine to essentially transmute the lifetimes as long as we can
// prove soundness. The hook must therefore accept any combination
// of lifetimes. In other words fn(&'_ mut Event<'_, '_>) is ok
// but examples like fn(&'_ mut Event<'_, 'static>) or fn<'a>(&'a
// mut Event<'a, 'a>) are not. To make this safe we use a macro to
// forbid the user from specifying lifetimes manually (all lifetimes
// specified are always function generics and passed to the event so
// lifetimes can't be used multiple times and using 'static causes a
// syntax error).
//
// There is one soundness hole tough: Type Aliases allow
// "accidentally" creating these problems. For example:
//
// type Event2 = Event<'static>.
// type Event2<'a> = Event<'a, a>.
//
// These cases can be caught by counting the number of lifetimes
// parameters at the parameter declaration site and then at the hook
// declaration site. By asserting the number of lifetime parameters
// are equal we can catch all bad type aliases under one assumption:
// There are no unused lifetime parameters. Introducing a static
// would reduce the number of arguments of the alias by one in the
// above example Event2 has zero lifetime arguments while the original
// event has one lifetime argument. Similar logic applies to using
// a lifetime argument multiple times. The ASSERT below performs a
// a compile time assertion to ensure exactly this property.
//
// With unused lifetime arguments it is still one way to cause unsound code:
//
// type Event2<'a, 'b> = Event<'a, 'a>;
//
// However, this case will always emit a compiler warning/cause CI
// failures so a user would have to introduce #[allow(unused)] which
// is easily caught in review (and a very theoretical case anyway).
// If we want to be pedantic we can simply compile helix with
// forbid(unused). All of this is just a safety net to prevent
// very theoretical misuse. This won't come up in real code (and is
// easily caught in review).
#[allow(unused)]
const ASSERT: () = {
if <$event_ty as $crate::Event>::LIFETIMES != 0 + $crate::events!(@sum $(1, $lt),*){
panic!("invalid type alias");
}
};
$crate::register_hook_raw::<$crate::events!(@replace_lt $event_ty, $('static, $lt),*)>(val);
}
};
(move |$event:ident: &mut $event_ty: ident| $body: expr) => {
let val = move |$event: &mut $event_ty| $body;
unsafe {
#[allow(unused)]
const ASSERT: () = {
if <$event_ty as $crate::Event>::LIFETIMES != 0{
panic!("invalid type alias");
}
};
$crate::register_hook_raw::<$event_ty>(val);
}
};
}

@ -5,16 +5,20 @@ use std::future::Future;
use parking_lot::{RwLock, RwLockReadGuard};
use tokio::sync::Notify;
/// A `Notify` instance that can be used to (asynchronously) request
/// the editor the render a new frame.
static REDRAW_NOTIFY: Notify = Notify::const_new();
/// A `RwLock` that prevents the next frame from being
/// drawn until an exclusive (write) lock can be acquired.
/// This allows asynchsonous tasks to acquire `non-exclusive`
/// locks (read) to prevent the next frame from being drawn
/// until a certain computation has finished.
static RENDER_LOCK: RwLock<()> = RwLock::new(());
use crate::runtime_local;
runtime_local! {
/// A `Notify` instance that can be used to (asynchronously) request
/// the editor to render a new frame.
static REDRAW_NOTIFY: Notify = Notify::const_new();
/// A `RwLock` that prevents the next frame from being
/// drawn until an exclusive (write) lock can be acquired.
/// This allows asynchronous tasks to acquire `non-exclusive`
/// locks (read) to prevent the next frame from being drawn
/// until a certain computation has finished.
static RENDER_LOCK: RwLock<()> = RwLock::new(());
}
pub type RenderLockGuard = RwLockReadGuard<'static, ()>;

@ -0,0 +1,131 @@
//! A global registry where events are registered and can be
//! subscribed to by registering hooks. The registry identifies event
//! types using their type name so multiple event with the same type name
//! may not be registered (will cause a panic to ensure soundness)
use std::any::TypeId;
use anyhow::{bail, Result};
use hashbrown::hash_map::Entry;
use hashbrown::HashMap;
use parking_lot::RwLock;
use crate::hook::ErasedHook;
use crate::runtime_local;
pub struct Registry {
events: HashMap<&'static str, TypeId, ahash::RandomState>,
handlers: HashMap<&'static str, Vec<ErasedHook>, ahash::RandomState>,
}
impl Registry {
pub fn register_event<E: Event + 'static>(&mut self) {
let ty = TypeId::of::<E>();
assert_eq!(ty, TypeId::of::<E::Static>());
match self.events.entry(E::ID) {
Entry::Occupied(entry) => {
if entry.get() == &ty {
// don't warn during tests to avoid log spam
#[cfg(not(feature = "integration_test"))]
panic!("Event {} was registered multiple times", E::ID);
} else {
panic!("Multiple events with ID {} were registered", E::ID);
}
}
Entry::Vacant(ent) => {
ent.insert(ty);
self.handlers.insert(E::ID, Vec::new());
}
}
}
/// # Safety
///
/// `hook` must be totally generic over all lifetime parameters of `E`. For
/// example if `E` was a known type `Foo<'a, 'b> then the correct trait bound
/// would be `F: for<'a, 'b, 'c> Fn(&'a mut Foo<'b, 'c>)` but there is no way to
/// express that kind of constraint for a generic type with the rust type system
/// right now.
pub unsafe fn register_hook<E: Event>(
&mut self,
hook: impl Fn(&mut E) -> Result<()> + 'static + Send + Sync,
) {
// ensure event type ids match so we can rely on them always matching
let id = E::ID;
let Some(&event_id) = self.events.get(id) else {
panic!("Tried to register handler for unknown event {id}");
};
assert!(
TypeId::of::<E::Static>() == event_id,
"Tried to register invalid hook for event {id}"
);
let hook = ErasedHook::new(hook);
self.handlers.get_mut(id).unwrap().push(hook);
}
pub fn register_dynamic_hook(
&mut self,
hook: impl Fn() -> Result<()> + 'static + Send + Sync,
id: &str,
) -> Result<()> {
// ensure event type ids match so we can rely on them always matching
if self.events.get(id).is_none() {
bail!("Tried to register handler for unknown event {id}");
};
let hook = ErasedHook::new_dynamic(hook);
self.handlers.get_mut(id).unwrap().push(hook);
Ok(())
}
pub fn dispatch<E: Event>(&self, mut event: E) {
let Some(hooks) = self.handlers.get(E::ID) else {
log::error!("Dispatched unknown event {}", E::ID);
return;
};
let event_id = self.events[E::ID];
assert_eq!(
TypeId::of::<E::Static>(),
event_id,
"Tried to dispatch invalid event {}",
E::ID
);
for hook in hooks {
// safety: event type is the same
if let Err(err) = unsafe { hook.call(&mut event) } {
log::error!("{} hook failed: {err:#?}", E::ID);
crate::status::report_blocking(err);
}
}
}
}
runtime_local! {
static REGISTRY: RwLock<Registry> = RwLock::new(Registry {
// hardcoded random number is good enough here we don't care about DOS resistance
// and avoids the additional complexity of `Option<Registry>`
events: HashMap::with_hasher(ahash::RandomState::with_seeds(423, 9978, 38322, 3280080)),
handlers: HashMap::with_hasher(ahash::RandomState::with_seeds(423, 99078, 382322, 3282938)),
});
}
pub(crate) fn with<T>(f: impl FnOnce(&Registry) -> T) -> T {
f(&REGISTRY.read())
}
pub(crate) fn with_mut<T>(f: impl FnOnce(&mut Registry) -> T) -> T {
f(&mut REGISTRY.write())
}
/// # Safety
/// The number of specified lifetimes and the static type *must* be correct.
/// This is ensured automatically by the [`events`](crate::events)
/// macro.
pub unsafe trait Event: Sized {
/// Globally unique (case sensitive) string that identifies this type.
/// A good candidate is the events type name
const ID: &'static str;
const LIFETIMES: usize;
type Static: Event + 'static;
}

@ -0,0 +1,88 @@
//! The event system makes use of global to decouple different systems.
//! However, this can cause problems for the integration test system because
//! it runs multiple helix applications in parallel. Making the globals
//! thread-local does not work because a applications can/does have multiple
//! runtime threads. Instead this crate implements a similar notion to a thread
//! local but instead of being local to a single thread, the statics are local to
//! a single tokio-runtime. The implementation requires locking so it's not exactly efficient.
//!
//! Therefore this function is only enabled during integration tests and behaves like
//! a normal static otherwise. I would prefer this module to be fully private and to only
//! export the macro but the macro still need to construct these internals so it's marked
//! `doc(hidden)` instead
use std::ops::Deref;
#[cfg(not(feature = "integration_test"))]
pub struct RuntimeLocal<T: 'static> {
/// inner API used in the macro, not part of public API
#[doc(hidden)]
pub __data: T,
}
#[cfg(not(feature = "integration_test"))]
impl<T> Deref for RuntimeLocal<T> {
type Target = T;
fn deref(&self) -> &Self::Target {
&self.__data
}
}
#[cfg(not(feature = "integration_test"))]
#[macro_export]
macro_rules! runtime_local {
($($(#[$attr:meta])* $vis: vis static $name:ident: $ty: ty = $init: expr;)*) => {
$($(#[$attr])* $vis static $name: $crate::runtime::RuntimeLocal<$ty> = $crate::runtime::RuntimeLocal {
__data: $init
};)*
};
}
#[cfg(feature = "integration_test")]
pub struct RuntimeLocal<T: 'static> {
data:
parking_lot::RwLock<hashbrown::HashMap<tokio::runtime::Id, &'static T, ahash::RandomState>>,
init: fn() -> T,
}
#[cfg(feature = "integration_test")]
impl<T> RuntimeLocal<T> {
/// inner API used in the macro, not part of public API
#[doc(hidden)]
pub const fn __new(init: fn() -> T) -> Self {
Self {
data: parking_lot::RwLock::new(hashbrown::HashMap::with_hasher(
ahash::RandomState::with_seeds(423, 9978, 38322, 3280080),
)),
init,
}
}
}
#[cfg(feature = "integration_test")]
impl<T> Deref for RuntimeLocal<T> {
type Target = T;
fn deref(&self) -> &T {
let id = tokio::runtime::Handle::current().id();
let guard = self.data.read();
match guard.get(&id) {
Some(res) => res,
None => {
drop(guard);
let data = Box::leak(Box::new((self.init)()));
let mut guard = self.data.write();
guard.insert(id, data);
data
}
}
}
}
#[cfg(feature = "integration_test")]
#[macro_export]
macro_rules! runtime_local {
($($(#[$attr:meta])* $vis: vis static $name:ident: $ty: ty = $init: expr;)*) => {
$($(#[$attr])* $vis static $name: $crate::runtime::RuntimeLocal<$ty> = $crate::runtime::RuntimeLocal::__new(|| $init);)*
};
}

@ -0,0 +1,68 @@
//! A queue of async messages/errors that will be shown in the editor
use std::borrow::Cow;
use std::time::Duration;
use crate::{runtime_local, send_blocking};
use once_cell::sync::OnceCell;
use tokio::sync::mpsc::{Receiver, Sender};
/// Describes the severity level of a [`StatusMessage`].
#[derive(Debug, Clone, Copy, Eq, PartialEq, PartialOrd, Ord)]
pub enum Severity {
Hint,
Info,
Warning,
Error,
}
pub struct StatusMessage {
pub severity: Severity,
pub message: Cow<'static, str>,
}
impl From<anyhow::Error> for StatusMessage {
fn from(err: anyhow::Error) -> Self {
StatusMessage {
severity: Severity::Error,
message: err.to_string().into(),
}
}
}
impl From<&'static str> for StatusMessage {
fn from(msg: &'static str) -> Self {
StatusMessage {
severity: Severity::Info,
message: msg.into(),
}
}
}
runtime_local! {
static MESSAGES: OnceCell<Sender<StatusMessage>> = OnceCell::new();
}
pub async fn report(msg: impl Into<StatusMessage>) {
// if the error channel overflows just ignore it
let _ = MESSAGES
.wait()
.send_timeout(msg.into(), Duration::from_millis(10))
.await;
}
pub fn report_blocking(msg: impl Into<StatusMessage>) {
let messages = MESSAGES.wait();
send_blocking(messages, msg.into())
}
/// Must be called once during editor startup exactly once
/// before any of the messages in this module can be used
///
/// # Panics
/// If called multiple times
pub fn setup() -> Receiver<StatusMessage> {
let (tx, rx) = tokio::sync::mpsc::channel(128);
let _ = MESSAGES.set(tx);
rx
}

@ -0,0 +1,90 @@
use std::sync::atomic::{AtomicUsize, Ordering};
use std::sync::Arc;
use std::time::Duration;
use parking_lot::Mutex;
use crate::{dispatch, events, register_dynamic_hook, register_event, register_hook};
#[test]
fn smoke_test() {
events! {
Event1 { content: String }
Event2 { content: usize }
}
register_event::<Event1>();
register_event::<Event2>();
// setup hooks
let res1: Arc<Mutex<String>> = Arc::default();
let acc = Arc::clone(&res1);
register_hook!(move |event: &mut Event1| {
acc.lock().push_str(&event.content);
Ok(())
});
let res2: Arc<AtomicUsize> = Arc::default();
let acc = Arc::clone(&res2);
register_hook!(move |event: &mut Event2| {
acc.fetch_add(event.content, Ordering::Relaxed);
Ok(())
});
// triggers events
let thread = std::thread::spawn(|| {
for i in 0..1000 {
dispatch(Event2 { content: i });
}
});
std::thread::sleep(Duration::from_millis(1));
dispatch(Event1 {
content: "foo".to_owned(),
});
dispatch(Event2 { content: 42 });
dispatch(Event1 {
content: "bar".to_owned(),
});
dispatch(Event1 {
content: "hello world".to_owned(),
});
thread.join().unwrap();
// check output
assert_eq!(&**res1.lock(), "foobarhello world");
assert_eq!(
res2.load(Ordering::Relaxed),
42 + (0..1000usize).sum::<usize>()
);
}
#[test]
fn dynamic() {
events! {
Event3 {}
Event4 { count: usize }
};
register_event::<Event3>();
register_event::<Event4>();
let count = Arc::new(AtomicUsize::new(0));
let count1 = count.clone();
let count2 = count.clone();
register_dynamic_hook(
move || {
count1.fetch_add(2, Ordering::Relaxed);
Ok(())
},
"Event3",
)
.unwrap();
register_dynamic_hook(
move || {
count2.fetch_add(3, Ordering::Relaxed);
Ok(())
},
"Event4",
)
.unwrap();
dispatch(Event3 {});
dispatch(Event4 { count: 0 });
dispatch(Event3 {});
assert_eq!(count.load(Ordering::Relaxed), 7)
}

@ -15,7 +15,7 @@ homepage.workspace = true
[features]
default = ["git"]
unicode-lines = ["helix-core/unicode-lines"]
integration = []
integration = ["helix-event/integration_test"]
git = ["helix-vcs/git"]
[[bin]]

@ -1,6 +1,10 @@
use arc_swap::{access::Map, ArcSwap};
use futures_util::Stream;
use helix_core::{pos_at_coords, syntax, Selection};
use helix_core::{
chars::char_is_word,
diagnostic::{DiagnosticTag, NumberOrString},
pos_at_coords, syntax, Selection,
};
use helix_lsp::{
lsp::{self, notification::Notification},
util::lsp_range_to_range,
@ -24,6 +28,7 @@ use crate::{
commands::apply_workspace_edit,
compositor::{Compositor, Event},
config::Config,
handlers,
job::Jobs,
keymap::Keymaps,
ui::{self, overlay::overlaid},
@ -138,6 +143,7 @@ impl Application {
let area = terminal.size().expect("couldn't get terminal size");
let mut compositor = Compositor::new(area);
let config = Arc::new(ArcSwap::from_pointee(config));
let handlers = handlers::setup(config.clone());
let mut editor = Editor::new(
area,
theme_loader.clone(),
@ -145,6 +151,7 @@ impl Application {
Arc::new(Map::new(Arc::clone(&config), |config: &Config| {
&config.editor
})),
handlers,
);
let keys = Box::new(Map::new(Arc::clone(&config), |config: &Config| {
@ -321,10 +328,21 @@ impl Application {
Some(event) = input_stream.next() => {
self.handle_terminal_events(event).await;
}
Some(callback) = self.jobs.futures.next() => {
self.jobs.handle_callback(&mut self.editor, &mut self.compositor, callback);
Some(callback) = self.jobs.callbacks.recv() => {
self.jobs.handle_callback(&mut self.editor, &mut self.compositor, Ok(Some(callback)));
self.render().await;
}
Some(msg) = self.jobs.status_messages.recv() => {
let severity = match msg.severity{
helix_event::status::Severity::Hint => Severity::Hint,
helix_event::status::Severity::Info => Severity::Info,
helix_event::status::Severity::Warning => Severity::Warning,
helix_event::status::Severity::Error => Severity::Error,
};
// TODO: show multiple status messages at once to avoid clobbering
self.editor.status_msg = Some((msg.message, severity));
helix_event::request_redraw();
}
Some(callback) = self.jobs.wait_futures.next() => {
self.jobs.handle_callback(&mut self.editor, &mut self.compositor, callback);
self.render().await;

@ -88,7 +88,7 @@ pub struct Context<'a> {
pub count: Option<NonZeroUsize>,
pub editor: &'a mut Editor,
pub callback: Option<crate::compositor::Callback>,
pub callback: Vec<crate::compositor::Callback>,
pub on_next_key_callback: Option<OnKeyCallback>,
pub jobs: &'a mut Jobs,
}
@ -96,16 +96,18 @@ pub struct Context<'a> {
impl<'a> Context<'a> {
/// Push a new component onto the compositor.
pub fn push_layer(&mut self, component: Box<dyn Component>) {
self.callback = Some(Box::new(|compositor: &mut Compositor, _| {
compositor.push(component)
}));
self.callback
.push(Box::new(|compositor: &mut Compositor, _| {
compositor.push(component)
}));
}
/// Call `replace_or_push` on the Compositor
pub fn replace_or_push_layer<T: Component>(&mut self, id: &'static str, component: T) {
self.callback = Some(Box::new(move |compositor: &mut Compositor, _| {
compositor.replace_or_push(id, component);
}));
self.callback
.push(Box::new(move |compositor: &mut Compositor, _| {
compositor.replace_or_push(id, component);
}));
}
#[inline]
@ -2934,7 +2936,7 @@ pub fn command_palette(cx: &mut Context) {
let register = cx.register;
let count = cx.count;
cx.callback = Some(Box::new(
cx.callback.push(Box::new(
move |compositor: &mut Compositor, cx: &mut compositor::Context| {
let keymap = compositor.find::<ui::EditorView>().unwrap().keymaps.map()
[&cx.editor.mode]
@ -2954,7 +2956,7 @@ pub fn command_palette(cx: &mut Context) {
register,
count,
editor: cx.editor,
callback: None,
callback: Vec::new(),
on_next_key_callback: None,
jobs: cx.jobs,
};
@ -2982,7 +2984,7 @@ pub fn command_palette(cx: &mut Context) {
fn last_picker(cx: &mut Context) {
// TODO: last picker does not seem to work well with buffer_picker
cx.callback = Some(Box::new(|compositor, cx| {
cx.callback.push(Box::new(|compositor, cx| {
if let Some(picker) = compositor.last_picker.take() {
compositor.push(picker);
} else {
@ -3494,6 +3496,7 @@ fn hunk_range(hunk: Hunk, text: RopeSlice) -> Range {
}
pub mod insert {
use crate::events::PostInsertChar;
use super::*;
pub type Hook = fn(&Rope, &Selection, char) -> Option<Transaction>;
pub type PostHook = fn(&mut Context, char);
@ -3627,6 +3630,7 @@ pub mod insert {
for hook in &[language_server_completion, signature_help] {
hook(cx, c);
}
helix_event::dispatch(PostInsertChar { c, cx });
}
pub fn smart_tab(cx: &mut Context) {
@ -5820,7 +5824,7 @@ fn replay_macro(cx: &mut Context) {
cx.editor.macro_replaying.push(reg);
let count = cx.count();
cx.callback = Some(Box::new(move |compositor, cx| {
cx.callback.push(Box::new(move |compositor, cx| {
for _ in 0..count {
for &key in keys.iter() {
compositor.handle_event(&compositor::Event::Key(key), cx);

@ -0,0 +1,20 @@
use helix_event::{events, register_event};
use helix_view::document::Mode;
use helix_view::events::{DocumentDidChange, SelectionDidChange};
use crate::commands;
use crate::keymap::MappableCommand;
events! {
OnModeSwitch<'a, 'cx> { old_mode: Mode, new_mode: Mode, cx: &'a mut commands::Context<'cx> }
PostInsertChar<'a, 'cx> { c: char, cx: &'a mut commands::Context<'cx> }
PostCommand<'a, 'cx> { command: & 'a MappableCommand, cx: &'a mut commands::Context<'cx> }
}
pub fn register() {
register_event::<OnModeSwitch>();
register_event::<PostInsertChar>();
register_event::<PostCommand>();
register_event::<DocumentDidChange>();
register_event::<SelectionDidChange>();
}

@ -0,0 +1,15 @@
use std::sync::Arc;
use arc_swap::ArcSwap;
use crate::config::Config;
use crate::events;
}
pub fn setup(config: Arc<ArcSwap<Config>>) -> Handlers {
events::register();
let handlers = Handlers {
};
handlers
}

@ -1,13 +1,37 @@
use helix_event::status::StatusMessage;
use helix_event::{runtime_local, send_blocking};
use helix_view::Editor;
use once_cell::sync::OnceCell;
use crate::compositor::Compositor;
use futures_util::future::{BoxFuture, Future, FutureExt};
use futures_util::stream::{FuturesUnordered, StreamExt};
use tokio::sync::mpsc::{channel, Receiver, Sender};
pub type EditorCompositorCallback = Box<dyn FnOnce(&mut Editor, &mut Compositor) + Send>;
pub type EditorCallback = Box<dyn FnOnce(&mut Editor) + Send>;
runtime_local! {
static JOB_QUEUE: OnceCell<Sender<Callback>> = OnceCell::new();
}
pub async fn dispatch_callback(job: Callback) {
let _ = JOB_QUEUE.wait().send(job).await;
}
pub async fn dispatch(job: impl FnOnce(&mut Editor, &mut Compositor) + Send + 'static) {
let _ = JOB_QUEUE
.wait()
.send(Callback::EditorCompositor(Box::new(job)))
.await;
}
pub fn dispatch_blocking(job: impl FnOnce(&mut Editor, &mut Compositor) + Send + 'static) {
let jobs = JOB_QUEUE.wait();
send_blocking(jobs, Callback::EditorCompositor(Box::new(job)))
}
pub enum Callback {
EditorCompositor(EditorCompositorCallback),
Editor(EditorCallback),
@ -21,11 +45,11 @@ pub struct Job {
pub wait: bool,
}
#[derive(Default)]
pub struct Jobs {
pub futures: FuturesUnordered<JobFuture>,
/// These are the ones that need to complete before we exit.
/// jobs that need to complete before we exit.
pub wait_futures: FuturesUnordered<JobFuture>,
pub callbacks: Receiver<Callback>,
pub status_messages: Receiver<StatusMessage>,
}
impl Job {
@ -52,8 +76,16 @@ impl Job {
}
impl Jobs {
#[allow(clippy::new_without_default)]
pub fn new() -> Self {
Self::default()
let (tx, rx) = channel(1024);
let _ = JOB_QUEUE.set(tx);
let status_messages = helix_event::status::setup();
Self {
wait_futures: FuturesUnordered::new(),
callbacks: rx,
status_messages,
}
}
pub fn spawn<F: Future<Output = anyhow::Result<()>> + Send + 'static>(&mut self, f: F) {
@ -85,18 +117,17 @@ impl Jobs {
}
}
pub async fn next_job(&mut self) -> Option<anyhow::Result<Option<Callback>>> {
tokio::select! {
event = self.futures.next() => { event }
event = self.wait_futures.next() => { event }
}
}
pub fn add(&self, j: Job) {
if j.wait {
self.wait_futures.push(j.future);
} else {
self.futures.push(j.future);
tokio::spawn(async move {
match j.future.await {
Ok(Some(cb)) => dispatch_callback(cb).await,
Ok(None) => (),
Err(err) => helix_event::status::report(err).await,
}
});
}
}

@ -6,13 +6,17 @@ pub mod args;
pub mod commands;
pub mod compositor;
pub mod config;
pub mod events;
pub mod health;
pub mod job;
pub mod keymap;
pub mod ui;
use std::path::Path;
use futures_util::Future;
mod handlers;
use ignore::DirEntry;
use url::Url;

@ -2,6 +2,7 @@ use crate::{
commands::{self, OnKeyCallback},
compositor::{Component, Context, Event, EventResult},
job::{self, Callback},
events::{OnModeSwitch, PostCommand},
key,
keymap::{KeymapResult, Keymaps},
ui::{
@ -835,11 +836,18 @@ impl EditorView {
let mut execute_command = |command: &commands::MappableCommand| {
command.execute(cxt);
helix_event::dispatch(PostCommand { command, cx: cxt });
let current_mode = cxt.editor.mode();
match (last_mode, current_mode) {
(Mode::Normal, Mode::Insert) => {
// HAXX: if we just entered insert mode from normal, clear key buf
// and record the command that got us into this mode.
if current_mode != last_mode {
helix_event::dispatch(OnModeSwitch {
old_mode: last_mode,
new_mode: current_mode,
cx: cxt,
});
// how we entered insert mode is important, and we should track that so
// we can repeat the side effect.
@ -1004,7 +1012,7 @@ impl EditorView {
}
let area = completion.area(size, editor);
editor.last_completion = None;
editor.last_completion = Some(CompleteAction::Triggered);
self.last_insert.1.push(InsertEvent::TriggerCompletion);
// TODO : propagate required size on resize to completion too
@ -1265,7 +1273,7 @@ impl Component for EditorView {
editor: context.editor,
count: None,
register: None,
callback: None,
callback: Vec::new(),
on_next_key_callback: None,
jobs: context.jobs,
};
@ -1375,7 +1383,7 @@ impl Component for EditorView {
}
// appease borrowck
let callback = cx.callback.take();
let callbacks = take(&mut cx.callback);
// if the command consumed the last view, skip the render.
// on the next loop cycle the Application will then terminate.
@ -1394,6 +1402,16 @@ impl Component for EditorView {
if mode != Mode::Insert {
doc.append_changes_to_history(view);
}
let callback = if callbacks.is_empty() {
None
} else {
let callback: crate::compositor::Callback = Box::new(move |compositor, cx| {
for callback in callbacks {
callback(compositor, cx)
}
});
Some(callback)
};
EventResult::Consumed(callback)
}

@ -36,6 +36,7 @@ use helix_core::{
};
use crate::editor::Config;
use crate::events::{DocumentDidChange, SelectionDidChange};
use crate::{DocumentId, Editor, Theme, View, ViewId};
/// 8kB of buffer space for encoding and decoding `Rope`s.
@ -1096,6 +1097,10 @@ impl Document {
// TODO: use a transaction?
self.selections
.insert(view_id, selection.ensure_invariants(self.text().slice(..)));
helix_event::dispatch(SelectionDidChange {
doc: self,
view: view_id,
})
}
/// Find the origin selection of the text in a document, i.e. where
@ -1149,6 +1154,14 @@ impl Document {
let success = transaction.changes().apply(&mut self.text);
if success {
if emit_lsp_notification {
helix_event::dispatch(DocumentDidChange {
doc: self,
view: view_id,
old_text: &old_doc,
});
}
for selection in self.selections.values_mut() {
*selection = selection
.clone()
@ -1164,6 +1177,10 @@ impl Document {
view_id,
selection.clone().ensure_invariants(self.text.slice(..)),
);
helix_event::dispatch(SelectionDidChange {
doc: self,
view: view_id,
});
}
self.modified_since_accessed = true;
@ -1276,6 +1293,7 @@ impl Document {
}
if emit_lsp_notification {
// TODO: move to hook
// emit lsp notification
for language_server in self.language_servers() {
let notify = language_server.text_document_did_change(

@ -2,6 +2,7 @@ use crate::{
align_view,
document::{DocumentSavedEventFuture, DocumentSavedEventResult, Mode, SavePoint},
graphics::{CursorKind, Rect},
handlers::Handlers,
info::Info,
input::KeyEvent,
register::Registers,
@ -960,6 +961,7 @@ pub struct Editor {
/// field is set and any old requests are automatically
/// canceled as a result
pub completion_request_handle: Option<oneshot::Sender<()>>,
pub handlers: Handlers,
}
pub type Motion = Box<dyn Fn(&mut Editor)>;

@ -0,0 +1,9 @@
use helix_core::Rope;
use helix_event::events;
use crate::{Document, ViewId};
events! {
DocumentDidChange<'a> { doc: &'a mut Document, view: ViewId, old_text: &'a Rope }
SelectionDidChange<'a> { doc: &'a mut Document, view: ViewId }
}

@ -0,0 +1,12 @@
use std::sync::Arc;
use helix_event::send_blocking;
use tokio::sync::mpsc::Sender;
use crate::handlers::lsp::SignatureHelpInvoked;
use crate::Editor;
pub mod dap;
pub mod lsp;
pub struct Handlers {}

@ -1 +1,40 @@
use crate::{DocumentId, ViewId};
#[derive(Debug, Clone, Copy)]
pub struct CompletionTrigger {
/// The char position of the primary cursor when the
/// completion was triggered
pub trigger_pos: usize,
pub doc: DocumentId,
pub view: ViewId,
/// Whether the cause of the trigger was an automatic completion (any word
/// char for words longer than minimum word length).
/// This is false for trigger chars send by the LS
pub auto: bool,
}
pub enum CompletionEvent {
/// Auto completion was triggered by typing a word char
/// or a completion trigger
Trigger(CompletionTrigger),
/// A completion was manually requested (c-x)
Manual,
/// Some text was deleted and the cursor is now at `pos`
DeleteText { pos: usize },
/// Invalidate the current auto completion trigger
Cancel,
}
#[derive(Debug, PartialEq, Eq, Clone, Copy)]
pub enum SignatureHelpInvoked {
Automatic,
Manual,
}
pub enum SignatureHelpEvent {
Invoked,
Trigger,
ReTrigger,
Cancel,
RequestComplete { open: bool },
}

@ -1,17 +1,15 @@
#[macro_use]
pub mod macros;
pub mod base64;
pub mod clipboard;
pub mod document;
pub mod editor;
pub mod env;
pub mod events;
pub mod graphics;
pub mod gutter;
pub mod handlers {
pub mod dap;
pub mod lsp;
}
pub mod base64;
pub mod handlers;
pub mod info;
pub mod input;
pub mod keyboard;

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