rclone/lib/file/mkdir_windows.go

78 lines
2.1 KiB
Go

//go:build windows
package file
import (
"os"
"path/filepath"
"syscall"
)
// MkdirAll creates a directory named path, along with any necessary parents.
//
// Improves os.MkdirAll by avoiding trying to create a folder `\\?` when the
// volume of a given extended length path does not exist, and `\\?\UNC` when
// a network host name does not exist.
//
// Based on source code from golang's os.MkdirAll
// (https://github.com/golang/go/blob/master/src/os/path.go)
func MkdirAll(path string, perm os.FileMode) error {
// Fast path: if we can tell whether path is a directory or file, stop with success or error.
dir, err := os.Stat(path)
if err == nil {
if dir.IsDir() {
return nil
}
return &os.PathError{
Op: "mkdir",
Path: path,
Err: syscall.ENOTDIR,
}
}
// Slow path: make sure parent exists and then call Mkdir for path.
i := len(path)
for i > 0 && os.IsPathSeparator(path[i-1]) { // Skip trailing path separator.
i--
}
if i > 0 {
path = path[:i]
if path == filepath.VolumeName(path) {
// Make reference to a drive's root directory include the trailing slash.
// In extended-length form without trailing slash ("\\?\C:"), os.Stat
// and os.Mkdir both fails. With trailing slash ("\\?\C:\") works,
// and regular paths with or without it ("C:" and "C:\") both works.
path = path + string(os.PathSeparator)
} else {
// See if there is a parent to be created first.
// Not when path refer to a drive's root directory, because we don't
// want to return noninformative error trying to create \\?.
j := i
for j > 0 && !os.IsPathSeparator(path[j-1]) { // Scan backward over element.
j--
}
if j > 1 {
if path[:j-1] != `\\?\UNC` && path[:j-1] != `\\?` {
// Create parent.
err = MkdirAll(path[:j-1], perm)
if err != nil {
return err
}
}
}
}
}
// Parent now exists; invoke Mkdir and use its result.
err = os.Mkdir(path, perm)
if err != nil {
// Handle arguments like "foo/." by
// double-checking that directory doesn't exist.
dir, err1 := os.Lstat(path)
if err1 == nil && dir.IsDir() {
return nil
}
return err
}
return nil
}