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#[macro_use]
extern crate derive_more;
#[macro_use]
extern crate log;
extern crate notify;
extern crate parking_lot;
use std::collections::HashMap;
use std::fmt;
use std::fs::canonicalize;
use std::path::{Path, PathBuf};
use std::sync::mpsc::{channel, Receiver};
use std::sync::Arc;
use std::time::Duration;
use notify::{RecommendedWatcher, RecursiveMode, Watcher};
use parking_lot::Mutex;
pub use notify::DebouncedEvent as Event;
fn path_from_event(e: &Event) -> Option<PathBuf> {
match e {
&Event::NoticeWrite(ref p)
| &Event::NoticeRemove(ref p)
| &Event::Create(ref p)
| &Event::Write(ref p)
| &Event::Chmod(ref p)
| &Event::Remove(ref p)
| &Event::Rename(ref p, _) => Some(p.clone()),
&_ => None,
}
}
#[derive(Debug, From)]
pub enum Error {
Io(std::io::Error),
Notify(notify::Error),
}
impl fmt::Display for Error {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match self {
Error::Io(error) => error.fmt(f),
Error::Notify(error) => error.fmt(f),
}
}
}
impl std::error::Error for Error {
fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
match self {
Error::Io(error) => error.source(),
Error::Notify(error) => error.source(),
}
}
}
type HotwatchResult<T> = Result<T, Error>;
type Handler = Box<Fn(Event) + Send>;
type HandlerMapMutex = Arc<Mutex<HashMap<PathBuf, Handler>>>;
pub struct Hotwatch {
watcher: RecommendedWatcher,
handler_map_mutex: HandlerMapMutex,
}
impl Hotwatch {
pub fn new() -> HotwatchResult<Self> {
let (tx, rx) = channel();
let handler_map_mutex: Arc<Mutex<HashMap<_, _>>> = Default::default();
Hotwatch::run(handler_map_mutex.clone(), rx);
Watcher::new(tx, Duration::from_secs(2))
.map_err(Error::Notify)
.map(|watcher| Hotwatch {
watcher,
handler_map_mutex,
})
}
pub fn watch<P, F>(&mut self, path: P, handler: F) -> HotwatchResult<()>
where
P: AsRef<Path>,
F: 'static + Fn(Event) + Send,
{
let absolute_path = canonicalize(path)?;
let mut handlers = self.handler_map_mutex.lock();
self.watcher
.watch(Path::new(&absolute_path), RecursiveMode::Recursive)
.map_err(|err| match err {
notify::Error::Io(err) => Error::Io(err),
_ => Error::Notify(err),
})
.map(|_| {
(*handlers).insert(PathBuf::from(absolute_path), Box::new(handler));
debug!("HotwatchHandlers {:?}", handlers.keys());
})
}
fn run(handler_map_mutex: HandlerMapMutex, rx: Receiver<Event>) {
std::thread::spawn(move || loop {
match rx.recv() {
Ok(event) => {
debug!("HotwatchEvent {:?}", event);
let handlers = handler_map_mutex.lock();
if let Some(mut path) = path_from_event(&event) {
let mut handler = None;
let mut poppable = true;
while handler.is_none() && poppable {
debug!("HotwatchMatch {:?}", path);
handler = (*handlers).get(&path);
poppable = path.pop();
}
if let Some(handler) = handler {
handler(event);
}
}
}
Err(e) => {
error!("Receiver error: {:?}", e);
}
}
});
}
}