SHA dir refactoring: routines runner

shadirconcurrent/main.go

@@ -19,6 +19,16 @@ func sha256File(path string) (string, error) {
 	return fmt.Sprintf("SHA256 (%s) =  %x", path, h.Sum(nil)), nil
 }
 
+func runParallel(n uint, what func()) {
+	var wg sync.WaitGroup
+	for i := 0; i < int(n); i++ {
+		wg.Add(1)
+		what()
+		wg.Done()
+	}
+	wg.Wait()
+}
+
 func main() {
 	if len(os.Args) < 2 {
 		log.Fatalln("Usage shadir file")
@@ -26,10 +36,8 @@ func main() {
 
 	chan_hash, chan_path := make(chan string), make(chan string)
 
-	go func() { // 100 routines hashing
-		var wg sync.WaitGroup
-		for i := 0; i < 100; i++ {
-			wg.Add(1)
+	go func() {
+		runParallel(100, func() { // 100 routines hashing
 			for path := range chan_path {
 				if h, err := sha256File(path); err != nil {
 					log.Print("Error "+path, err)
@@ -37,9 +45,7 @@ func main() {
 					chan_hash <- h
 				}
 			}
-			wg.Done()
-		}
-		wg.Wait()
+		})
 		close(chan_hash)
 	}()