Extract function SyncParent to reuse in elastic agent (#36)

* extract function

* add import

* remove old

Author: narph

file/helper_aix.go

@@ -24,7 +24,6 @@ import (
 
 // SafeFileRotate safely rotates an existing file under path and replaces it with the tempfile
 func SafeFileRotate(path, tempfile string) error {
-	parent := filepath.Dir(path)
 
 	if e := os.Rename(tempfile, path); e != nil {
 		return e
@@ -35,6 +34,14 @@ func SafeFileRotate(path, tempfile string) error {
 	// contain the new file being rotated in.
 	// On AIX, fsync will fail if the file is opened in read-only mode,
 	// which is the case with os.Open.
+	return SyncParent(path)
+
+}
+
+// SyncParent fsyncs parent directory
+func SyncParent(path string) error {
+	parent := filepath.Dir(path)
+
 	f, err := os.OpenFile(parent, os.O_RDWR, 0)
 	if err != nil {
 		return nil // ignore error

file/helper_other.go

@@ -27,7 +27,6 @@ import (
 
 // SafeFileRotate safely rotates an existing file under path and replaces it with the tempfile
 func SafeFileRotate(path, tempfile string) error {
-	parent := filepath.Dir(path)
 
 	if e := os.Rename(tempfile, path); e != nil {
 		return e
@@ -36,6 +35,12 @@ func SafeFileRotate(path, tempfile string) error {
 	// best-effort fsync on parent directory. The fsync is required by some
 	// filesystems, so to update the parents directory metadata to actually
 	// contain the new file being rotated in.
+	return SyncParent(path)
+}
+
+// SyncParent fsyncs parent directory
+func SyncParent(path string) error {
+	parent := filepath.Dir(path)
 	f, err := os.Open(parent)
 
 	// nolint: nilerr // ignore error

file/helper_windows.go

@@ -41,11 +41,25 @@ func SafeFileRotate(path, tempfile string) error {
 		return e
 	}
 
+	// .old file will still exist if path file is already there, it should be removed
+	_ = os.Remove(old)
+
 	// sync all files
+	return SyncParent(path)
+}
+
+// SyncParent fsyncs parent directory
+func SyncParent(path string) error {
 	parent := filepath.Dir(path)
 	if f, err := os.OpenFile(parent, os.O_SYNC|os.O_RDWR, 0755); err == nil {
-		_ = f.Sync()
-		f.Close()
+		err := f.Sync()
+		if err != nil {
+			return err
+		}
+		err = f.Close()
+		if err != nil {
+			return err
+		}
 	}
 
 	return nil