watchers: move filesystem monitoring stuff in lib

No functional change. This will allow reuse in other parts of aerc.

Signed-off-by: Robin Jarry <robin@jarry.cc>
Tested-by: Koni Marti <koni.marti@gmail.com>

1 files changed, 82 insertions, 0 deletions

diff --git a/lib/watchers/fsevents.go b/lib/watchers/fsevents.go
new file mode 100644
index 00000000..905db2af
--- /dev/null
+++ b/lib/watchers/fsevents.go
@@ -0,0 +1,82 @@
+//go:build darwin
+// +build darwin
+
+package watchers
+
+import (
+	"time"
+
+	"git.sr.ht/~rjarry/aerc/log"
+	"github.com/fsnotify/fsevents"
+)
+
+func init() {
+	RegisterWatcherFactory(newDarwinWatcher)
+}
+
+type darwinWatcher struct {
+	ch        chan *FSEvent
+	w         *fsevents.EventStream
+	watcherCh chan []fsevents.Event
+}
+
+func newDarwinWatcher() (FSWatcher, error) {
+	watcher := &darwinWatcher{
+		watcherCh: make(chan []fsevents.Event),
+		ch:        make(chan *FSEvent),
+		w: &fsevents.EventStream{
+			Flags:   fsevents.FileEvents | fsevents.WatchRoot,
+			Latency: 500 * time.Millisecond,
+		},
+	}
+	return watcher, nil
+}
+
+func (w *darwinWatcher) watch() {
+	defer log.PanicHandler()
+	for events := range w.w.Events {
+		for _, ev := range events {
+			switch {
+			case ev.Flags&fsevents.ItemCreated > 0:
+				w.ch <- &FSEvent{
+					Operation: FSCreate,
+					Path:      ev.Path,
+				}
+			case ev.Flags&fsevents.ItemRenamed > 0:
+				w.ch <- &FSEvent{
+					Operation: FSRename,
+					Path:      ev.Path,
+				}
+			case ev.Flags&fsevents.ItemRemoved > 0:
+				w.ch <- &FSEvent{
+					Operation: FSRemove,
+					Path:      ev.Path,
+				}
+			}
+		}
+	}
+}
+
+func (w *darwinWatcher) Configure(root string) error {
+	dev, err := fsevents.DeviceForPath(root)
+	if err != nil {
+		return err
+	}
+	w.w.Device = dev
+	w.w.Paths = []string{root}
+	w.w.Start()
+	go w.watch()
+	return nil
+}
+
+func (w *darwinWatcher) Events() chan *FSEvent {
+	return w.ch
+}
+
+func (w *darwinWatcher) Add(p string) error {
+	return nil
+}
+
+func (w *darwinWatcher) Remove(p string) error {
+	return nil
+}