// Copyright 2020 The Gitea Authors. All rights reserved.// SPDX-License-Identifier: MIT package util import (	"os"	"syscall"	"time") // Remove removes the named file or (empty) directory with at most 5 attempts.func Remove(name string) error {	var err error	for i := 0; i < 5; i++ {		err = os.Remove(name)		if err == nil {			break		}		unwrapped := err.(*os.PathError).Err		if unwrapped == syscall.EBUSY || unwrapped == syscall.ENOTEMPTY || unwrapped == syscall.EPERM || unwrapped == syscall.EMFILE || unwrapped == syscall.ENFILE {			// try again			<-time.After(100 * time.Millisecond)			continue		} 		if unwrapped == syscall.ENOENT {			// it's already gone			return nil		}	}	return err} // RemoveAll removes the named file or (empty) directory with at most 5 attempts.func RemoveAll(name string) error {	var err error	for i := 0; i < 5; i++ {		err = os.RemoveAll(name)		if err == nil {			break		}		unwrapped := err.(*os.PathError).Err		if unwrapped == syscall.EBUSY || unwrapped == syscall.ENOTEMPTY || unwrapped == syscall.EPERM || unwrapped == syscall.EMFILE || unwrapped == syscall.ENFILE {			// try again			<-time.After(100 * time.Millisecond)			continue		} 		if unwrapped == syscall.ENOENT {			// it's already gone			return nil		}	}	return err} // Rename renames (moves) oldpath to newpath with at most 5 attempts.func Rename(oldpath, newpath string) error {	var err error	for i := 0; i < 5; i++ {		err = os.Rename(oldpath, newpath)		if err == nil {			break		}		unwrapped := err.(*os.LinkError).Err		if unwrapped == syscall.EBUSY || unwrapped == syscall.ENOTEMPTY || unwrapped == syscall.EPERM || unwrapped == syscall.EMFILE || unwrapped == syscall.ENFILE {			// try again			<-time.After(100 * time.Millisecond)			continue		} 		if i == 0 && os.IsNotExist(err) {			return err		} 		if unwrapped == syscall.ENOENT {			// it's already gone			return nil		}	}	return err}