initial commit

watch_directory.go

@@ -0,0 +1,95 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"github.com/fsnotify/fsnotify"
+)
+
+func WatchDirectory(op fsnotify.Op, path string) (<-chan string, error) {
+	watcher, err := fsnotify.NewWatcher()
+	if err != nil {
+		panic(err) // TODO error handling
+	}
+
+	err = watcher.Add(path)
+	if err != nil {
+		return nil, err
+	}
+
+	files, err := os.ReadDir(path)
+	if err != nil {
+		return nil, err
+	}
+
+	ch := make(chan string, 10)
+
+	// close channel on app shutdown
+	go func() {
+		<-AppCtx.Done()
+		watcher.Close()
+	}()
+
+	AppExitWg.Add(1)
+	go func(watcher *fsnotify.Watcher, ch chan<- string) {
+		defer AppExitWg.Done()
+		defer watcher.Close()
+
+		for _, file := range files {
+			path := filepath.Join(path, file.Name())
+			if file.IsDir() {
+				//fmt.Println("watching directory", path)
+				watcher.Add(path)
+
+				if dirFiles, err := os.ReadDir(path); err == nil {
+					for _, dirFile := range dirFiles {
+						ch <- filepath.Join(path, dirFile.Name())
+					}
+				}
+			} else {
+				ch <- path
+			}
+		}
+
+		for {
+			select {
+			case event, ok := <-watcher.Events:
+				if !ok {
+					close(ch)
+					return
+				}
+
+				if fi, err := os.Stat(event.Name); err == nil && fi.IsDir() {
+					if event.Op&fsnotify.Create == fsnotify.Create {
+						//fmt.Println("watching directory", event.Name)
+						watcher.Add(event.Name)
+					}
+
+					// read dir immediately because directory files could simultanously with its parent directory
+					if dirFiles, err := os.ReadDir(event.Name); err == nil {
+						for _, dirFile := range dirFiles {
+							ch <- filepath.Join(event.Name, dirFile.Name())
+						}
+					}
+				} else if err != nil && event.Op&fsnotify.Remove == fsnotify.Remove {
+					//fmt.Println("stopped watching directory", event.Name)
+					watcher.Remove(event.Name)
+				}
+
+				if event.Op&op == op {
+					ch <- event.Name
+				}
+			case err, ok := <-watcher.Errors:
+				if ok {
+					fmt.Println(err, ok)
+				}
+				close(ch)
+				return
+			}
+		}
+	}(watcher, ch)
+
+	return ch, nil
+}