mirror of https://github.com/restic/restic.git
80 lines
2.2 KiB
Go
80 lines
2.2 KiB
Go
package fs
|
|
|
|
import (
|
|
"math/rand"
|
|
"os"
|
|
"path/filepath"
|
|
"strconv"
|
|
"strings"
|
|
"time"
|
|
|
|
"golang.org/x/sys/windows"
|
|
)
|
|
|
|
// fixpath returns an absolute path on windows, so restic can open long file
|
|
// names.
|
|
func fixpath(name string) string {
|
|
abspath, err := filepath.Abs(name)
|
|
if err == nil {
|
|
// Check if \\?\UNC\ already exist
|
|
if strings.HasPrefix(abspath, `\\?\UNC\`) {
|
|
return abspath
|
|
}
|
|
// Check if \\?\ already exist
|
|
if strings.HasPrefix(abspath, `\\?\`) {
|
|
return abspath
|
|
}
|
|
// Check if path starts with \\
|
|
if strings.HasPrefix(abspath, `\\`) {
|
|
return strings.Replace(abspath, `\\`, `\\?\UNC\`, 1)
|
|
}
|
|
// Normal path
|
|
return `\\?\` + abspath
|
|
}
|
|
return name
|
|
}
|
|
|
|
// TempFile creates a temporary file which is marked as delete-on-close
|
|
func TempFile(dir, prefix string) (f *os.File, err error) {
|
|
// slightly modified implementation of ioutil.TempFile(dir, prefix) to allow us to add
|
|
// the FILE_ATTRIBUTE_TEMPORARY | FILE_FLAG_DELETE_ON_CLOSE flags.
|
|
// These provide two large benefits:
|
|
// FILE_ATTRIBUTE_TEMPORARY tells Windows to keep the file in memory only if possible
|
|
// which reduces the amount of unnecessary disk writes.
|
|
// FILE_FLAG_DELETE_ON_CLOSE instructs Windows to automatically delete the file once
|
|
// all file descriptors are closed.
|
|
|
|
if dir == "" {
|
|
dir = os.TempDir()
|
|
}
|
|
|
|
access := uint32(windows.GENERIC_READ | windows.GENERIC_WRITE)
|
|
creation := uint32(windows.CREATE_NEW)
|
|
share := uint32(0) // prevent other processes from accessing the file
|
|
flags := uint32(windows.FILE_ATTRIBUTE_TEMPORARY | windows.FILE_FLAG_DELETE_ON_CLOSE)
|
|
|
|
rnd := rand.New(rand.NewSource(time.Now().UnixNano()))
|
|
for i := 0; i < 10000; i++ {
|
|
randSuffix := strconv.Itoa(int(1e9 + rnd.Intn(1e9)%1e9))[1:]
|
|
path := filepath.Join(dir, prefix+randSuffix)
|
|
|
|
ptr, err := windows.UTF16PtrFromString(path)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
h, err := windows.CreateFile(ptr, access, share, nil, creation, flags, 0)
|
|
if os.IsExist(err) {
|
|
continue
|
|
}
|
|
return os.NewFile(uintptr(h), path), err
|
|
}
|
|
|
|
// Proper error handling is still to do
|
|
return nil, os.ErrExist
|
|
}
|
|
|
|
// Chmod changes the mode of the named file to mode.
|
|
func Chmod(name string, mode os.FileMode) error {
|
|
return os.Chmod(fixpath(name), mode)
|
|
}
|