rclone/vendor/github.com/djherbis/times/ctime_windows.go
2019-02-10 20:55:16 +00:00

150 lines
3.3 KiB
Go

package times
import (
"os"
"syscall"
"time"
"unsafe"
)
// Stat returns the Timespec for the given filename.
func Stat(name string) (Timespec, error) {
ts, err := platformSpecficStat(name)
if err == nil {
return ts, err
}
return stat(name, os.Stat)
}
// Lstat returns the Timespec for the given filename, and does not follow Symlinks.
func Lstat(name string) (Timespec, error) {
ts, err := platformSpecficLstat(name)
if err == nil {
return ts, err
}
return stat(name, os.Lstat)
}
type timespecEx struct {
atime
mtime
ctime
btime
}
// StatFile finds a Windows Timespec with ChangeTime.
func StatFile(file *os.File) (Timespec, error) {
return statFile(syscall.Handle(file.Fd()))
}
func statFile(h syscall.Handle) (Timespec, error) {
var fileInfo fileBasicInfo
if err := getFileInformationByHandleEx(h, &fileInfo); err != nil {
return nil, err
}
var t timespecEx
t.atime.v = time.Unix(0, fileInfo.LastAccessTime.Nanoseconds())
t.mtime.v = time.Unix(0, fileInfo.LastWriteTime.Nanoseconds())
t.ctime.v = time.Unix(0, fileInfo.ChangeTime.Nanoseconds())
t.btime.v = time.Unix(0, fileInfo.CreationTime.Nanoseconds())
return t, nil
}
func platformSpecficLstat(name string) (Timespec, error) {
if findProcErr != nil {
return nil, findProcErr
}
isSym, err := isSymlink(name)
if err != nil {
return nil, err
}
var attrs = uint32(syscall.FILE_FLAG_BACKUP_SEMANTICS)
if isSym {
attrs |= syscall.FILE_FLAG_OPEN_REPARSE_POINT
}
return openHandleAndStat(name, attrs)
}
func isSymlink(name string) (bool, error) {
fi, err := os.Lstat(name)
if err != nil {
return false, err
}
return fi.Mode()&os.ModeSymlink != 0, nil
}
func platformSpecficStat(name string) (Timespec, error) {
if findProcErr != nil {
return nil, findProcErr
}
return openHandleAndStat(name, syscall.FILE_FLAG_BACKUP_SEMANTICS)
}
func openHandleAndStat(name string, attrs uint32) (Timespec, error) {
pathp, e := syscall.UTF16PtrFromString(name)
if e != nil {
return nil, e
}
h, e := syscall.CreateFile(pathp,
syscall.FILE_WRITE_ATTRIBUTES, syscall.FILE_SHARE_WRITE, nil,
syscall.OPEN_EXISTING, attrs, 0)
if e != nil {
return nil, e
}
defer syscall.Close(h)
return statFile(h)
}
var (
findProcErr error
procGetFileInformationByHandleEx *syscall.Proc
)
func init() {
var modkernel32 *syscall.DLL
if modkernel32, findProcErr = syscall.LoadDLL("kernel32.dll"); findProcErr == nil {
procGetFileInformationByHandleEx, findProcErr = modkernel32.FindProc("GetFileInformationByHandleEx")
}
}
// fileBasicInfo holds the C++ data for FileTimes.
//
// https://msdn.microsoft.com/en-us/library/windows/desktop/aa364217(v=vs.85).aspx
type fileBasicInfo struct {
CreationTime syscall.Filetime
LastAccessTime syscall.Filetime
LastWriteTime syscall.Filetime
ChangeTime syscall.Filetime
FileAttributes uint32
_ uint32 // padding
}
type fileInformationClass int
const (
fileBasicInfoClass fileInformationClass = iota
)
func getFileInformationByHandleEx(handle syscall.Handle, data *fileBasicInfo) (err error) {
if findProcErr != nil {
return findProcErr
}
r1, _, e1 := syscall.Syscall6(procGetFileInformationByHandleEx.Addr(), 4, uintptr(handle), uintptr(fileBasicInfoClass), uintptr(unsafe.Pointer(data)), unsafe.Sizeof(*data), 0, 0)
if r1 == 0 {
err = syscall.EINVAL
if e1 != 0 {
err = error(e1)
}
}
return
}