watcher.go: Automatically watch added subdirectories

watcher.go

@@ -2,6 +2,8 @@ package main
 
 import (
 	"github.com/howeyc/fsnotify"
+	"os"
+	"path/filepath"
 )
 
 func StartWatching(watchDir string, fileUpdates chan *Event) {
@@ -10,39 +12,58 @@ func StartWatching(watchDir string, fileUpdates chan *Event) {
 		panic("Failed to create fsnotify watcher")
 	}
 
-	err = watcher.Watch(watchDir)
-	if err != nil {
-		panic("Failed to watch " + watchDir)
+	//function called by filepath.Walk to start watching a directory and all subdirectories
+	watchDirFn := func(path string, info os.FileInfo, err error) error {
+		if info.IsDir() {
+			err = watcher.Watch(path)
+			if err != nil {
+				panic("Failed to watch " + path)
+			}
+		}
+		return nil
 	}
 
-	for {
-		select {
-		case ev := <-watcher.Event:
-			event := new(Event)
-			if ev.IsCreate() || ev.IsModify() {
-				event.Type = UPDATE
-			} else if ev.IsDelete() || ev.IsRename() {
-				event.Type = DELETE
-			} else {
-				panic("Unknown fsnotify event type")
-			}
-
-			event.Path = ev.Name
-			if event.IsUpdate() {
-				event.Hash, err = HashFile(ev.Name)
-				if err != nil {
+	//processes all the fsnotify events into asink events
+	go func() {
+		for {
+			select {
+			case ev := <-watcher.Event:
+				//if a directory was created, begin recursively watching all its subdirectories
+				if fi, err := os.Stat(ev.Name); err == nil && fi.IsDir() {
+					if ev.IsCreate() {
+						filepath.Walk(ev.Name, watchDirFn)
+					}
 					continue
 				}
-			} else {
-				event.Hash = ""
+
+				event := new(Event)
+				if ev.IsCreate() || ev.IsModify() {
+					event.Type = UPDATE
+				} else if ev.IsDelete() || ev.IsRename() {
+					event.Type = DELETE
+				} else {
+					panic("Unknown fsnotify event type")
+				}
+
+				event.Path = ev.Name
+				if event.IsUpdate() {
+					event.Hash, err = HashFile(ev.Name)
+					if err != nil {
+						panic("file deleted already?")
+						continue
+					}
+				} else {
+					event.Hash = ""
+				}
+
+				fileUpdates <- event
+
+			case err := <-watcher.Error:
+				panic(err)
 			}
-
-			fileUpdates <- event
-
-			//TODO if creating a directory, start watching it (and then initiate a full scan of it so we're sure nothing slipped through the cracks)
-
-		case err := <-watcher.Error:
-			panic(err)
 		}
-	}
+	}()
+
+	//start watching the directory passed in
+	filepath.Walk(watchDir, watchDirFn)
 }