0
0
Fork 0
mirror of https://github.com/denoland/deno.git synced 2024-10-29 08:58:01 -04:00
denoland-deno/runtime/ops/fs_events.rs
David Sherret 7fc0e8ec8c
chore: use parking_lot for synchronization primitives to align with tokio (#11289)
parking_lot is already transitively used in tokio via the "full" cargo feature
2021-07-06 23:48:01 -04:00

151 lines
3.9 KiB
Rust

// Copyright 2018-2021 the Deno authors. All rights reserved. MIT license.
use crate::permissions::Permissions;
use deno_core::error::bad_resource_id;
use deno_core::error::AnyError;
use deno_core::parking_lot::Mutex;
use deno_core::AsyncRefCell;
use deno_core::CancelFuture;
use deno_core::CancelHandle;
use deno_core::OpState;
use deno_core::RcRef;
use deno_core::Resource;
use deno_core::ResourceId;
use deno_core::op_async;
use deno_core::op_sync;
use deno_core::Extension;
use notify::event::Event as NotifyEvent;
use notify::Error as NotifyError;
use notify::EventKind;
use notify::RecommendedWatcher;
use notify::RecursiveMode;
use notify::Watcher;
use serde::Deserialize;
use serde::Serialize;
use std::borrow::Cow;
use std::cell::RefCell;
use std::convert::From;
use std::path::PathBuf;
use std::rc::Rc;
use tokio::sync::mpsc;
pub fn init() -> Extension {
Extension::builder()
.ops(vec![
("op_fs_events_open", op_sync(op_fs_events_open)),
("op_fs_events_poll", op_async(op_fs_events_poll)),
])
.build()
}
struct FsEventsResource {
#[allow(unused)]
watcher: RecommendedWatcher,
receiver: AsyncRefCell<mpsc::Receiver<Result<FsEvent, AnyError>>>,
cancel: CancelHandle,
}
impl Resource for FsEventsResource {
fn name(&self) -> Cow<str> {
"fsEvents".into()
}
fn close(self: Rc<Self>) {
self.cancel.cancel();
}
}
/// Represents a file system event.
///
/// We do not use the event directly from the notify crate. We flatten
/// the structure into this simpler structure. We want to only make it more
/// complex as needed.
///
/// Feel free to expand this struct as long as you can add tests to demonstrate
/// the complexity.
#[derive(Serialize, Debug)]
struct FsEvent {
kind: String,
paths: Vec<PathBuf>,
}
impl From<NotifyEvent> for FsEvent {
fn from(e: NotifyEvent) -> Self {
let kind = match e.kind {
EventKind::Any => "any",
EventKind::Access(_) => "access",
EventKind::Create(_) => "create",
EventKind::Modify(_) => "modify",
EventKind::Remove(_) => "remove",
EventKind::Other => todo!(), // What's this for? Leaving it out for now.
}
.to_string();
FsEvent {
kind,
paths: e.paths,
}
}
}
#[derive(Deserialize)]
pub struct OpenArgs {
recursive: bool,
paths: Vec<String>,
}
fn op_fs_events_open(
state: &mut OpState,
args: OpenArgs,
_: (),
) -> Result<ResourceId, AnyError> {
let (sender, receiver) = mpsc::channel::<Result<FsEvent, AnyError>>(16);
let sender = Mutex::new(sender);
let mut watcher: RecommendedWatcher =
Watcher::new_immediate(move |res: Result<NotifyEvent, NotifyError>| {
let res2 = res.map(FsEvent::from).map_err(AnyError::from);
let sender = sender.lock();
// Ignore result, if send failed it means that watcher was already closed,
// but not all messages have been flushed.
let _ = sender.try_send(res2);
})?;
let recursive_mode = if args.recursive {
RecursiveMode::Recursive
} else {
RecursiveMode::NonRecursive
};
for path in &args.paths {
state
.borrow_mut::<Permissions>()
.read
.check(&PathBuf::from(path))?;
watcher.watch(path, recursive_mode)?;
}
let resource = FsEventsResource {
watcher,
receiver: AsyncRefCell::new(receiver),
cancel: Default::default(),
};
let rid = state.resource_table.add(resource);
Ok(rid)
}
async fn op_fs_events_poll(
state: Rc<RefCell<OpState>>,
rid: ResourceId,
_: (),
) -> Result<Option<FsEvent>, AnyError> {
let resource = state
.borrow()
.resource_table
.get::<FsEventsResource>(rid)
.ok_or_else(bad_resource_id)?;
let mut receiver = RcRef::map(&resource, |r| &r.receiver).borrow_mut().await;
let cancel = RcRef::map(resource, |r| &r.cancel);
let maybe_result = receiver.recv().or_cancel(cancel).await?;
match maybe_result {
Some(Ok(value)) => Ok(Some(value)),
Some(Err(err)) => Err(err),
None => Ok(None),
}
}