windows: implement Ftruncate using a single syscall on Windows

Ftruncate can be implemented on Windows using a single syscall. This
makes the implementation more efficient and less prone to races when
used in combination with other Seek calls.

Note that this is the x/sys counterpart for CL 618835.

Change-Id: Ie9be356bd953ccce85c0dd87a5dcc6ccf4fec464
Reviewed-on: https://go-review.googlesource.com/c/sys/+/621935
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Auto-Submit: Quim Muntal <quimmuntal@gmail.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
Reviewed-by: Damien Neil <dneil@google.com>
This commit is contained in:
qmuntal
2024-10-23 10:24:06 +02:00
committed by Gopher Robot
parent cff53d5a33
commit d045236a8d

View File

@@ -725,20 +725,12 @@ func DurationSinceBoot() time.Duration {
}
func Ftruncate(fd Handle, length int64) (err error) {
curoffset, e := Seek(fd, 0, 1)
if e != nil {
return e
type _FILE_END_OF_FILE_INFO struct {
EndOfFile int64
}
defer Seek(fd, curoffset, 0)
_, e = Seek(fd, length, 0)
if e != nil {
return e
}
e = SetEndOfFile(fd)
if e != nil {
return e
}
return nil
var info _FILE_END_OF_FILE_INFO
info.EndOfFile = length
return SetFileInformationByHandle(fd, FileEndOfFileInfo, (*byte)(unsafe.Pointer(&info)), uint32(unsafe.Sizeof(info)))
}
func Gettimeofday(tv *Timeval) (err error) {