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denoland-deno/cli/ops/fs_events.rs
2020-04-15 23:14:28 -04:00

125 lines
3.7 KiB
Rust

// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
use super::dispatch_json::{Deserialize, JsonOp, Value};
use crate::op_error::OpError;
use crate::state::State;
use deno_core::*;
use futures::future::poll_fn;
use futures::future::FutureExt;
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::Serialize;
use std::convert::From;
use std::path::PathBuf;
use tokio::sync::mpsc;
pub fn init(i: &mut Isolate, s: &State) {
i.register_op("op_fs_events_open", s.stateful_json_op(op_fs_events_open));
i.register_op("op_fs_events_poll", s.stateful_json_op(op_fs_events_poll));
}
struct FsEventsResource {
#[allow(unused)]
watcher: RecommendedWatcher,
receiver: mpsc::Receiver<Result<FsEvent, ErrBox>>,
}
/// 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,
}
}
}
pub fn op_fs_events_open(
state: &State,
args: Value,
_zero_copy: Option<ZeroCopyBuf>,
) -> Result<JsonOp, OpError> {
#[derive(Deserialize)]
struct OpenArgs {
recursive: bool,
paths: Vec<String>,
}
let args: OpenArgs = serde_json::from_value(args)?;
let (sender, receiver) = mpsc::channel::<Result<FsEvent, ErrBox>>(16);
let sender = std::sync::Mutex::new(sender);
let mut watcher: RecommendedWatcher =
Watcher::new_immediate(move |res: Result<NotifyEvent, NotifyError>| {
let res2 = res.map(FsEvent::from).map_err(ErrBox::from);
let mut sender = sender.lock().unwrap();
// Ignore result, if send failed it means that watcher was already closed,
// but not all messages have been flushed.
let _ = sender.try_send(res2);
})
.map_err(ErrBox::from)?;
let recursive_mode = if args.recursive {
RecursiveMode::Recursive
} else {
RecursiveMode::NonRecursive
};
for path in &args.paths {
state.check_read(&PathBuf::from(path))?;
watcher.watch(path, recursive_mode).map_err(ErrBox::from)?;
}
let resource = FsEventsResource { watcher, receiver };
let table = &mut state.borrow_mut().resource_table;
let rid = table.add("fsEvents", Box::new(resource));
Ok(JsonOp::Sync(json!(rid)))
}
pub fn op_fs_events_poll(
state: &State,
args: Value,
_zero_copy: Option<ZeroCopyBuf>,
) -> Result<JsonOp, OpError> {
#[derive(Deserialize)]
struct PollArgs {
rid: u32,
}
let PollArgs { rid } = serde_json::from_value(args)?;
let state = state.clone();
let f = poll_fn(move |cx| {
let resource_table = &mut state.borrow_mut().resource_table;
let watcher = resource_table
.get_mut::<FsEventsResource>(rid)
.ok_or_else(OpError::bad_resource_id)?;
watcher
.receiver
.poll_recv(cx)
.map(|maybe_result| match maybe_result {
Some(Ok(value)) => Ok(json!({ "value": value, "done": false })),
Some(Err(err)) => Err(OpError::from(err)),
None => Ok(json!({ "done": true })),
})
});
Ok(JsonOp::Async(f.boxed_local()))
}