Stowage/go
2
0
Fork 0
mirror of https://github.com/golang/go.git synced 2025-12-08 06:10:04 +00:00
Code Issues Projects Releases Packages Wiki Activity

syscall: make Seek use SetFilePointerEx on Windows, allowing large seek offsets

Browse source 
Fixes #21681
Updates #21728

Change-Id: I79cf4564c1355ecab891102d4215cbbffd8eb0ce
Reviewed-on: https://go-review.googlesource.com/82535
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This commit is contained in:
Brad Fitzpatrick 2017-12-06 18:20:26 +00:00
parent 9ce6b5c2ed
commit 7c46b62d0a
2 changed files with 39 additions and 11 deletions
Download patch file Download diff file Expand all files Collapse all files

18
src/os/os_test.go
View file

@ -1362,14 +1362,26 @@ func TestSeek(t *testing.T) {
{-1, io.SeekEnd, int64(len(data)) - 1}, {-1, io.SeekEnd, int64(len(data)) - 1},
{1 << 33, io.SeekStart, 1 << 33}, {1 << 33, io.SeekStart, 1 << 33},
{1 << 33, io.SeekEnd, 1<<33 + int64(len(data))}, {1 << 33, io.SeekEnd, 1<<33 + int64(len(data))},
// Issue 21681, Windows 4G-1, etc:
{1<<32 - 1, io.SeekStart, 1<<32 - 1},
{0, io.SeekCurrent, 1<<32 - 1},
{2<<32 - 1, io.SeekStart, 2<<32 - 1},
{0, io.SeekCurrent, 2<<32 - 1},
} }
for i, tt := range tests { for i, tt := range tests {
if runtime.GOOS == "nacl" && tt.out > 1<<30 {
t.Logf("skipping test case #%d on nacl; https://golang.org/issue/21728", i)
continue
}
off, err := f.Seek(tt.in, tt.whence) off, err := f.Seek(tt.in, tt.whence)
if off != tt.out || err != nil { if off != tt.out || err != nil {
if e, ok := err.(*PathError); ok && e.Err == syscall.EINVAL && tt.out > 1<<32 { if e, ok := err.(*PathError); ok && e.Err == syscall.EINVAL && tt.out > 1<<32 && runtime.GOOS == "linux" {
mounts, _ := ioutil.ReadFile("/proc/mounts")
if strings.Contains(string(mounts), "reiserfs") {
// Reiserfs rejects the big seeks. // Reiserfs rejects the big seeks.
// https://golang.org/issue/91 t.Skipf("skipping test known to fail on reiserfs; https://golang.org/issue/91")
break }
} }
t.Errorf("#%d: Seek(%v, %v) = %v, %v want %v, nil", i, tt.in, tt.whence, off, err, tt.out) t.Errorf("#%d: Seek(%v, %v) = %v, %v want %v, nil", i, tt.in, tt.whence, off, err, tt.out)
} }

30
src/syscall/syscall_windows.go
View file

@ -332,6 +332,27 @@ func Write(fd Handle, p []byte) (n int, err error) {
var ioSync int64 var ioSync int64
var procSetFilePointerEx = modkernel32.NewProc("SetFilePointerEx")
const ptrSize = unsafe.Sizeof(uintptr(0))
// setFilePointerEx calls SetFilePointerEx.
// See https://msdn.microsoft.com/en-us/library/windows/desktop/aa365542(v=vs.85).aspx
func setFilePointerEx(handle Handle, distToMove int64, newFilePointer *int64, whence uint32) error {
var e1 Errno
if ptrSize == 8 {
_, _, e1 = Syscall6(procSetFilePointerEx.Addr(), 4, uintptr(handle), uintptr(distToMove), uintptr(unsafe.Pointer(newFilePointer)), uintptr(whence), 0, 0)
} else {
// distToMove is a LARGE_INTEGER:
// https://msdn.microsoft.com/en-us/library/windows/desktop/aa383713(v=vs.85).aspx
_, _, e1 = Syscall6(procSetFilePointerEx.Addr(), 5, uintptr(handle), uintptr(distToMove), uintptr(distToMove>>32), uintptr(unsafe.Pointer(newFilePointer)), uintptr(whence), 0)
}
if e1 != 0 {
return errnoErr(e1)
}
return nil
}
func Seek(fd Handle, offset int64, whence int) (newoffset int64, err error) { func Seek(fd Handle, offset int64, whence int) (newoffset int64, err error) {
var w uint32 var w uint32
switch whence { switch whence {
@ -342,18 +363,13 @@ func Seek(fd Handle, offset int64, whence int) (newoffset int64, err error) {
case 2: case 2:
w = FILE_END w = FILE_END
} }
hi := int32(offset >> 32)
lo := int32(offset)
// use GetFileType to check pipe, pipe can't do seek // use GetFileType to check pipe, pipe can't do seek
ft, _ := GetFileType(fd) ft, _ := GetFileType(fd)
if ft == FILE_TYPE_PIPE { if ft == FILE_TYPE_PIPE {
return 0, ESPIPE return 0, ESPIPE
} }
rlo, e := SetFilePointer(fd, lo, &hi, w) err = setFilePointerEx(fd, offset, &newoffset, w)
if e != nil { return
return 0, e
}
return int64(hi)<<32 + int64(rlo), nil
} }
func Close(fd Handle) (err error) { func Close(fd Handle) (err error) {