1use notify::EventKind;
  2use parking_lot::Mutex;
  3use std::sync::{Arc, OnceLock};
  4use util::ResultExt;
  5
  6use crate::{PathEvent, PathEventKind, Watcher};
  7
  8pub struct FsWatcher {
  9    tx: smol::channel::Sender<()>,
 10    pending_path_events: Arc<Mutex<Vec<PathEvent>>>,
 11}
 12
 13impl FsWatcher {
 14    pub fn new(
 15        tx: smol::channel::Sender<()>,
 16        pending_path_events: Arc<Mutex<Vec<PathEvent>>>,
 17    ) -> Self {
 18        Self {
 19            tx,
 20            pending_path_events,
 21        }
 22    }
 23}
 24
 25impl Watcher for FsWatcher {
 26    fn add(&self, path: &std::path::Path) -> gpui::Result<()> {
 27        let root_path = path.to_path_buf();
 28
 29        let tx = self.tx.clone();
 30        let pending_paths = self.pending_path_events.clone();
 31
 32        use notify::Watcher;
 33
 34        global({
 35            |g| {
 36                g.add(move |event: &notify::Event| {
 37                    let kind = match event.kind {
 38                        EventKind::Create(_) => Some(PathEventKind::Created),
 39                        EventKind::Modify(_) => Some(PathEventKind::Changed),
 40                        EventKind::Remove(_) => Some(PathEventKind::Removed),
 41                        _ => None,
 42                    };
 43                    let mut path_events = event
 44                        .paths
 45                        .iter()
 46                        .filter_map(|event_path| {
 47                            event_path.starts_with(&root_path).then(|| PathEvent {
 48                                path: event_path.clone(),
 49                                kind,
 50                            })
 51                        })
 52                        .collect::<Vec<_>>();
 53
 54                    if !path_events.is_empty() {
 55                        path_events.sort();
 56                        let mut pending_paths = pending_paths.lock();
 57                        if pending_paths.is_empty() {
 58                            tx.try_send(()).ok();
 59                        }
 60                        util::extend_sorted(
 61                            &mut *pending_paths,
 62                            path_events,
 63                            usize::MAX,
 64                            |a, b| a.path.cmp(&b.path),
 65                        );
 66                    }
 67                })
 68            }
 69        })?;
 70
 71        global(|g| {
 72            g.watcher
 73                .lock()
 74                .watch(path, notify::RecursiveMode::NonRecursive)
 75        })??;
 76
 77        Ok(())
 78    }
 79
 80    fn remove(&self, path: &std::path::Path) -> gpui::Result<()> {
 81        use notify::Watcher;
 82        Ok(global(|w| w.watcher.lock().unwatch(path))??)
 83    }
 84}
 85
 86pub struct GlobalWatcher {
 87    // two mutexes because calling watcher.add triggers an watcher.event, which needs watchers.
 88    #[cfg(target_os = "linux")]
 89    pub(super) watcher: Mutex<notify::INotifyWatcher>,
 90    #[cfg(target_os = "freebsd")]
 91    pub(super) watcher: Mutex<notify::KqueueWatcher>,
 92    #[cfg(target_os = "windows")]
 93    pub(super) watcher: Mutex<notify::ReadDirectoryChangesWatcher>,
 94    pub(super) watchers: Mutex<Vec<Box<dyn Fn(&notify::Event) + Send + Sync>>>,
 95}
 96
 97impl GlobalWatcher {
 98    pub(super) fn add(&self, cb: impl Fn(&notify::Event) + Send + Sync + 'static) {
 99        self.watchers.lock().push(Box::new(cb))
100    }
101}
102
103static FS_WATCHER_INSTANCE: OnceLock<anyhow::Result<GlobalWatcher, notify::Error>> =
104    OnceLock::new();
105
106fn handle_event(event: Result<notify::Event, notify::Error>) {
107    let Some(event) = event.log_err() else { return };
108    global::<()>(move |watcher| {
109        for f in watcher.watchers.lock().iter() {
110            f(&event)
111        }
112    })
113    .log_err();
114}
115
116pub fn global<T>(f: impl FnOnce(&GlobalWatcher) -> T) -> anyhow::Result<T> {
117    let result = FS_WATCHER_INSTANCE.get_or_init(|| {
118        notify::recommended_watcher(handle_event).map(|file_watcher| GlobalWatcher {
119            watcher: Mutex::new(file_watcher),
120            watchers: Default::default(),
121        })
122    });
123    match result {
124        Ok(g) => Ok(f(g)),
125        Err(e) => Err(anyhow::anyhow!("{}", e)),
126    }
127}