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handle all the reads on the "main" watcher thread

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This commit is contained in:
Aleksey Kladov 2019-01-26 17:01:58 +03:00
parent 3ce531f95d
commit 012ea3fac6
1 changed files with 75 additions and 48 deletions
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123
crates/ra_vfs/src/io.rs
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@ -5,7 +5,7 @@ use std::{
sync::{mpsc, Arc},
time::Duration,
};
use crossbeam_channel::{Receiver, Sender};
use crossbeam_channel::{Receiver, Sender, unbounded, RecvError, select};
use relative_path::RelativePathBuf;
use thread_worker::WorkerHandle;
use walkdir::WalkDir;
@ -61,9 +61,25 @@ pub(crate) struct Worker {
impl Worker {
pub(crate) fn start(roots: Arc<Roots>) -> Worker {
let (worker, worker_handle) =
thread_worker::spawn("vfs", 128, move |input_receiver, output_sender| {
// This is a pretty elaborate setup of threads & channels! It is
// explained by the following concerns:
// * we need to burn a thread translating from notify's mpsc to
// crossbeam_channel.
// * we want to read all files from a single thread, to gurantee that
// we always get fresher versions and never go back in time.
// * we want to tear down everything neatly during shutdown.
let (worker, worker_handle) = thread_worker::spawn(
"vfs",
128,
// This are the channels we use to communicate with outside world.
// If `input_receiver` is closed we need to tear ourselves down.
// `output_sender` should not be closed unless the parent died.
move |input_receiver, output_sender| {
// These are `std` channels notify will send events to
let (notify_sender, notify_receiver) = mpsc::channel();
// These are the corresponding crossbeam channels
let (watcher_sender, watcher_receiver) = unbounded();
let watcher = notify::watcher(notify_sender, WATCHER_DELAY)
.map_err(|e| log::error!("failed to spawn notify {}", e))
.ok();
@ -72,18 +88,30 @@ impl Worker {
watcher: Arc::new(Mutex::new(watcher)),
sender: output_sender,
};
let thread = thread::spawn({
let ctx = ctx.clone();
move || {
let _ = notify_receiver
.into_iter()
// forward relevant events only
.try_for_each(|change| ctx.handle_debounced_event(change));
let thread = thread::spawn(move || {
let _ = notify_receiver
.into_iter()
// forward relevant events only
.for_each(|event| convert_notify_event(event, &watcher_sender));
});
loop {
select! {
// Received request from the caller. If this channel is
// closed, we should shutdown everything.
recv(input_receiver) -> t => match t {
Err(RecvError) => break,
Ok(Task::AddRoot { root, config }) => watch_root(&ctx, root, Arc::clone(&config)),
},
// Watcher send us changes. If **this** channel is
// closed, the watcher has died, which indicates a bug
// -- escalate!
recv(watcher_receiver) -> event => match event {
Err(RecvError) => panic!("watcher is dead"),
Ok((path, change)) => WatcherCtx::handle_change(&ctx, path, change).unwrap(),
},
}
});
let res1 = input_receiver.into_iter().try_for_each(|t| match t {
Task::AddRoot { root, config } => watch_root(&ctx, root, Arc::clone(&config)),
});
}
drop(ctx.watcher.lock().take());
drop(ctx);
let res2 = thread.join();
@ -91,9 +119,9 @@ impl Worker {
Ok(()) => log::info!("... Watcher terminated with ok"),
Err(_) => log::error!("... Watcher terminated with err"),
}
res1.unwrap();
res2.unwrap();
});
},
);
Worker {
worker,
worker_handle,
@ -114,7 +142,7 @@ impl Worker {
}
}
fn watch_root(woker: &WatcherCtx, root: VfsRoot, config: Arc<RootConfig>) -> Result<()> {
fn watch_root(woker: &WatcherCtx, root: VfsRoot, config: Arc<RootConfig>) {
let mut guard = woker.watcher.lock();
log::debug!("loading {} ...", config.root.as_path().display());
let files = watch_recursive(guard.as_mut(), config.root.as_path(), &*config)
@ -127,9 +155,9 @@ fn watch_root(woker: &WatcherCtx, root: VfsRoot, config: Arc<RootConfig>) -> Res
.collect();
woker
.sender
.send(TaskResult::BulkLoadRoot { root, files })?;
.send(TaskResult::BulkLoadRoot { root, files })
.unwrap();
log::debug!("... loaded {}", config.root.as_path().display());
Ok(())
}
#[derive(Clone)]
@ -139,38 +167,37 @@ struct WatcherCtx {
sender: Sender<TaskResult>,
}
impl WatcherCtx {
fn handle_debounced_event(&self, ev: DebouncedEvent) -> Result<()> {
match ev {
DebouncedEvent::NoticeWrite(_)
| DebouncedEvent::NoticeRemove(_)
| DebouncedEvent::Chmod(_) => {
// ignore
}
DebouncedEvent::Rescan => {
// TODO rescan all roots
}
DebouncedEvent::Create(path) => {
self.handle_change(path, ChangeKind::Create)?;
}
DebouncedEvent::Write(path) => {
self.handle_change(path, ChangeKind::Write)?;
}
DebouncedEvent::Remove(path) => {
self.handle_change(path, ChangeKind::Remove)?;
}
DebouncedEvent::Rename(src, dst) => {
self.handle_change(src, ChangeKind::Remove)?;
self.handle_change(dst, ChangeKind::Create)?;
}
DebouncedEvent::Error(err, path) => {
// TODO should we reload the file contents?
log::warn!("watcher error \"{}\", {:?}", err, path);
}
fn convert_notify_event(event: DebouncedEvent, sender: &Sender<(PathBuf, ChangeKind)>) {
match event {
DebouncedEvent::NoticeWrite(_)
| DebouncedEvent::NoticeRemove(_)
| DebouncedEvent::Chmod(_) => {
// ignore
}
DebouncedEvent::Rescan => {
// TODO rescan all roots
}
DebouncedEvent::Create(path) => {
sender.send((path, ChangeKind::Create)).unwrap();
}
DebouncedEvent::Write(path) => {
sender.send((path, ChangeKind::Write)).unwrap();
}
DebouncedEvent::Remove(path) => {
sender.send((path, ChangeKind::Remove)).unwrap();
}
DebouncedEvent::Rename(src, dst) => {
sender.send((src, ChangeKind::Remove)).unwrap();
sender.send((dst, ChangeKind::Create)).unwrap();
}
DebouncedEvent::Error(err, path) => {
// TODO should we reload the file contents?
log::warn!("watcher error \"{}\", {:?}", err, path);
}
Ok(())
}
}
impl WatcherCtx {
fn handle_change(&self, path: PathBuf, kind: ChangeKind) -> Result<()> {
let (root, rel_path) = match self.roots.find(&path) {
None => return Ok(()),