os: provide access to file LastAccessTime and CreationTime on windows

Fixes #4569.

R=bradfitz, rsc
CC=golang-dev
https://golang.org/cl/6972047

src/pkg/os/file_windows.go

@@ -223,10 +223,15 @@ func (file *File) readdir(n int) (fi []FileInfo, err error) {
 		}
 		f := &fileStat{
 			name: name,
-			size:    mkSize(d.FileSizeHigh, d.FileSizeLow),
-			modTime: mkModTime(d.LastWriteTime),
-			mode:    mkMode(d.FileAttributes),
-			sys:     mkSys(file.dirinfo.path+`\`+name, d.LastAccessTime, d.CreationTime),
+			sys: syscall.Win32FileAttributeData{
+				FileAttributes: d.FileAttributes,
+				CreationTime:   d.CreationTime,
+				LastAccessTime: d.LastAccessTime,
+				LastWriteTime:  d.LastWriteTime,
+				FileSizeHigh:   d.FileSizeHigh,
+				FileSizeLow:    d.FileSizeLow,
+			},
+			path: file.dirinfo.path + `\` + name,
 		}
 		n--
 		fi = append(fi, f)

src/pkg/os/stat_darwin.go

@@ -9,9 +9,9 @@ import (
 	"time"
 )
 
-func sameFile(sys1, sys2 interface{}) bool {
-	stat1 := sys1.(*syscall.Stat_t)
-	stat2 := sys2.(*syscall.Stat_t)
+func sameFile(fs1, fs2 *fileStat) bool {
+	stat1 := fs1.sys.(*syscall.Stat_t)
+	stat2 := fs2.sys.(*syscall.Stat_t)
 	return stat1.Dev == stat2.Dev && stat1.Ino == stat2.Ino
 }
 

src/pkg/os/stat_freebsd.go

@@ -9,9 +9,9 @@ import (
 	"time"
 )
 
-func sameFile(sys1, sys2 interface{}) bool {
-	stat1 := sys1.(*syscall.Stat_t)
-	stat2 := sys2.(*syscall.Stat_t)
+func sameFile(fs1, fs2 *fileStat) bool {
+	stat1 := fs1.sys.(*syscall.Stat_t)
+	stat2 := fs2.sys.(*syscall.Stat_t)
 	return stat1.Dev == stat2.Dev && stat1.Ino == stat2.Ino
 }
 

src/pkg/os/stat_linux.go

@@ -9,9 +9,9 @@ import (
 	"time"
 )
 
-func sameFile(sys1, sys2 interface{}) bool {
-	stat1 := sys1.(*syscall.Stat_t)
-	stat2 := sys2.(*syscall.Stat_t)
+func sameFile(fs1, fs2 *fileStat) bool {
+	stat1 := fs1.sys.(*syscall.Stat_t)
+	stat2 := fs2.sys.(*syscall.Stat_t)
 	return stat1.Dev == stat2.Dev && stat1.Ino == stat2.Ino
 }
 

src/pkg/os/stat_netbsd.go

@@ -9,9 +9,9 @@ import (
 	"time"
 )
 
-func sameFile(sys1, sys2 interface{}) bool {
-	stat1 := sys1.(*syscall.Stat_t)
-	stat2 := sys2.(*syscall.Stat_t)
+func sameFile(fs1, fs2 *fileStat) bool {
+	stat1 := fs1.sys.(*syscall.Stat_t)
+	stat2 := fs2.sys.(*syscall.Stat_t)
 	return stat1.Dev == stat2.Dev && stat1.Ino == stat2.Ino
 }
 

src/pkg/os/stat_openbsd.go

@@ -9,9 +9,9 @@ import (
 	"time"
 )
 
-func sameFile(sys1, sys2 interface{}) bool {
-	stat1 := sys1.(*syscall.Stat_t)
-	stat2 := sys2.(*syscall.Stat_t)
+func sameFile(fs1, fs2 *fileStat) bool {
+	stat1 := fs1.sys.(*syscall.Stat_t)
+	stat2 := fs2.sys.(*syscall.Stat_t)
 	return stat1.Dev == stat2.Dev && stat1.Ino == stat2.Ino
 }
 

src/pkg/os/stat_plan9.go

@@ -9,9 +9,9 @@ import (
 	"time"
 )
 
-func sameFile(sys1, sys2 interface{}) bool {
-	a := sys1.(*syscall.Dir)
-	b := sys2.(*syscall.Dir)
+func sameFile(fs1, fs2 *fileStat) bool {
+	a := fs1.sys.(*syscall.Dir)
+	b := fs2.sys.(*syscall.Dir)
 	return a.Qid.Path == b.Qid.Path && a.Type == b.Type && a.Dev == b.Dev
 }
 

src/pkg/os/stat_windows.go

@@ -5,9 +5,7 @@
 package os
 
 import (
-	"sync"
 	"syscall"
-	"time"
 	"unsafe"
 )
 
@@ -22,7 +20,7 @@ func (file *File) Stat() (fi FileInfo, err error) {
 		return Stat(file.name)
 	}
 	if file.name == DevNull {
-		return statDevNull()
+		return &devNullStat, nil
 	}
 	var d syscall.ByHandleFileInformation
 	e := syscall.GetFileInformationByHandle(syscall.Handle(file.fd), &d)
@@ -31,10 +29,17 @@ func (file *File) Stat() (fi FileInfo, err error) {
 	}
 	return &fileStat{
 		name: basename(file.name),
-		size:    mkSize(d.FileSizeHigh, d.FileSizeLow),
-		modTime: mkModTime(d.LastWriteTime),
-		mode:    mkMode(d.FileAttributes),
-		sys:     mkSysFromFI(&d),
+		sys: syscall.Win32FileAttributeData{
+			FileAttributes: d.FileAttributes,
+			CreationTime:   d.CreationTime,
+			LastAccessTime: d.LastAccessTime,
+			LastWriteTime:  d.LastWriteTime,
+			FileSizeHigh:   d.FileSizeHigh,
+			FileSizeLow:    d.FileSizeLow,
+		},
+		vol:   d.VolumeSerialNumber,
+		idxhi: d.FileIndexHigh,
+		idxlo: d.FileIndexLow,
 	}, nil
 }
 
@@ -45,29 +50,23 @@ func Stat(name string) (fi FileInfo, err error) {
 		return nil, &PathError{"Stat", name, syscall.Errno(syscall.ERROR_PATH_NOT_FOUND)}
 	}
 	if name == DevNull {
-		return statDevNull()
+		return &devNullStat, nil
 	}
-	var d syscall.Win32FileAttributeData
+	fs := &fileStat{name: basename(name)}
 	namep, e := syscall.UTF16PtrFromString(name)
 	if e != nil {
 		return nil, &PathError{"Stat", name, e}
 	}
-	e = syscall.GetFileAttributesEx(namep, syscall.GetFileExInfoStandard, (*byte)(unsafe.Pointer(&d)))
+	e = syscall.GetFileAttributesEx(namep, syscall.GetFileExInfoStandard, (*byte)(unsafe.Pointer(&fs.sys)))
 	if e != nil {
 		return nil, &PathError{"GetFileAttributesEx", name, e}
 	}
-	path := name
-	if !isAbs(path) {
+	fs.path = name
+	if !isAbs(fs.path) {
 		cwd, _ := Getwd()
-		path = cwd + `\` + path
+		fs.path = cwd + `\` + fs.path
 	}
-	return &fileStat{
-		name:    basename(name),
-		size:    mkSize(d.FileSizeHigh, d.FileSizeLow),
-		modTime: mkModTime(d.LastWriteTime),
-		mode:    mkMode(d.FileAttributes),
-		sys:     mkSys(path, d.LastAccessTime, d.CreationTime),
-	}, nil
+	return fs, nil
 }
 
 // Lstat returns the FileInfo structure describing the named file.
@@ -79,22 +78,6 @@ func Lstat(name string) (fi FileInfo, err error) {
 	return Stat(name)
 }
 
-// statDevNull return FileInfo structure describing DevNull file ("NUL").
-// It creates invented data, since none of windows api will return
-// that information.
-func statDevNull() (fi FileInfo, err error) {
-	return &fileStat{
-		name: DevNull,
-		mode: ModeDevice | ModeCharDevice | 0666,
-		sys: &winSys{
-			// hopefully this will work for SameFile
-			vol:   0,
-			idxhi: 0,
-			idxlo: 0,
-		},
-	}, nil
-}
-
 // basename removes trailing slashes and the leading
 // directory name and drive letter from path name.
 func basename(name string) string {
@@ -172,95 +155,3 @@ func volumeName(path string) (v string) {
 	}
 	return ""
 }
-
-type winSys struct {
-	sync.Mutex
-	path              string
-	atime, ctime      syscall.Filetime
-	vol, idxhi, idxlo uint32
-}
-
-func mkSize(hi, lo uint32) int64 {
-	return int64(hi)<<32 + int64(lo)
-}
-
-func mkModTime(mtime syscall.Filetime) time.Time {
-	return time.Unix(0, mtime.Nanoseconds())
-}
-
-func mkMode(fa uint32) (m FileMode) {
-	if fa&syscall.FILE_ATTRIBUTE_DIRECTORY != 0 {
-		m |= ModeDir | 0111
-	}
-	if fa&syscall.FILE_ATTRIBUTE_READONLY != 0 {
-		m |= 0444
-	} else {
-		m |= 0666
-	}
-	return m
-}
-
-func mkSys(path string, atime, ctime syscall.Filetime) *winSys {
-	return &winSys{
-		path:  path,
-		atime: atime,
-		ctime: ctime,
-	}
-}
-
-func mkSysFromFI(i *syscall.ByHandleFileInformation) *winSys {
-	return &winSys{
-		atime: i.LastAccessTime,
-		ctime: i.CreationTime,
-		vol:   i.VolumeSerialNumber,
-		idxhi: i.FileIndexHigh,
-		idxlo: i.FileIndexLow,
-	}
-}
-
-func (s *winSys) loadFileId() error {
-	if s.path == "" {
-		// already done
-		return nil
-	}
-	s.Lock()
-	defer s.Unlock()
-	pathp, e := syscall.UTF16PtrFromString(s.path)
-	if e != nil {
-		return e
-	}
-	h, e := syscall.CreateFile(pathp, 0, 0, nil, syscall.OPEN_EXISTING, syscall.FILE_FLAG_BACKUP_SEMANTICS, 0)
-	if e != nil {
-		return e
-	}
-	defer syscall.CloseHandle(h)
-	var i syscall.ByHandleFileInformation
-	e = syscall.GetFileInformationByHandle(syscall.Handle(h), &i)
-	if e != nil {
-		return e
-	}
-	s.path = ""
-	s.vol = i.VolumeSerialNumber
-	s.idxhi = i.FileIndexHigh
-	s.idxlo = i.FileIndexLow
-	return nil
-}
-
-func sameFile(sys1, sys2 interface{}) bool {
-	s1 := sys1.(*winSys)
-	s2 := sys2.(*winSys)
-	e := s1.loadFileId()
-	if e != nil {
-		panic(e)
-	}
-	e = s2.loadFileId()
-	if e != nil {
-		panic(e)
-	}
-	return s1.vol == s2.vol && s1.idxhi == s2.idxhi && s1.idxlo == s2.idxlo
-}
-
-// For testing.
-func atime(fi FileInfo) time.Time {
-	return time.Unix(0, fi.Sys().(*winSys).atime.Nanoseconds())
-}

src/pkg/os/types.go

@@ -99,21 +99,8 @@ func (m FileMode) Perm() FileMode {
 	return m & ModePerm
 }
 
-// A fileStat is the implementation of FileInfo returned by Stat and Lstat.
-type fileStat struct {
-	name    string
-	size    int64
-	mode    FileMode
-	modTime time.Time
-	sys     interface{}
-}
-
 func (fs *fileStat) Name() string { return fs.name }
-func (fs *fileStat) Size() int64        { return fs.size }
-func (fs *fileStat) Mode() FileMode     { return fs.mode }
-func (fs *fileStat) ModTime() time.Time { return fs.modTime }
-func (fs *fileStat) IsDir() bool        { return fs.mode.IsDir() }
-func (fs *fileStat) Sys() interface{}   { return fs.sys }
+func (fs *fileStat) IsDir() bool  { return fs.Mode().IsDir() }
 
 // SameFile reports whether fi1 and fi2 describe the same file.
 // For example, on Unix this means that the device and inode fields
@@ -127,5 +114,5 @@ func SameFile(fi1, fi2 FileInfo) bool {
 	if !ok1 || !ok2 {
 		return false
 	}
-	return sameFile(fs1.sys, fs2.sys)
+	return sameFile(fs1, fs2)
 }

src/pkg/os/types_notwin.go

@@ -0,0 +1,25 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build !windows
+
+package os
+
+import (
+	"time"
+)
+
+// A fileStat is the implementation of FileInfo returned by Stat and Lstat.
+type fileStat struct {
+	name    string
+	size    int64
+	mode    FileMode
+	modTime time.Time
+	sys     interface{}
+}
+
+func (fs *fileStat) Size() int64        { return fs.size }
+func (fs *fileStat) Mode() FileMode     { return fs.mode }
+func (fs *fileStat) ModTime() time.Time { return fs.modTime }
+func (fs *fileStat) Sys() interface{}   { return fs.sys }

src/pkg/os/types_windows.go

@@ -0,0 +1,104 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package os
+
+import (
+	"sync"
+	"syscall"
+	"time"
+)
+
+// A fileStat is the implementation of FileInfo returned by Stat and Lstat.
+type fileStat struct {
+	name string
+	sys  syscall.Win32FileAttributeData
+
+	// used to implement SameFile
+	sync.Mutex
+	path  string
+	vol   uint32
+	idxhi uint32
+	idxlo uint32
+}
+
+func (fs *fileStat) Size() int64 {
+	return int64(fs.sys.FileSizeHigh)<<32 + int64(fs.sys.FileSizeLow)
+}
+
+func (fs *fileStat) Mode() (m FileMode) {
+	if fs == &devNullStat {
+		return ModeDevice | ModeCharDevice | 0666
+	}
+	if fs.sys.FileAttributes&syscall.FILE_ATTRIBUTE_DIRECTORY != 0 {
+		m |= ModeDir | 0111
+	}
+	if fs.sys.FileAttributes&syscall.FILE_ATTRIBUTE_READONLY != 0 {
+		m |= 0444
+	} else {
+		m |= 0666
+	}
+	return m
+}
+
+func (fs *fileStat) ModTime() time.Time {
+	return time.Unix(0, fs.sys.LastWriteTime.Nanoseconds())
+}
+
+// Sys returns syscall.Win32FileAttributeData for file fs.
+func (fs *fileStat) Sys() interface{} { return &fs.sys }
+
+func (fs *fileStat) loadFileId() error {
+	fs.Lock()
+	defer fs.Unlock()
+	if fs.path == "" {
+		// already done
+		return nil
+	}
+	pathp, err := syscall.UTF16PtrFromString(fs.path)
+	if err != nil {
+		return err
+	}
+	h, err := syscall.CreateFile(pathp, 0, 0, nil, syscall.OPEN_EXISTING, syscall.FILE_FLAG_BACKUP_SEMANTICS, 0)
+	if err != nil {
+		return err
+	}
+	defer syscall.CloseHandle(h)
+	var i syscall.ByHandleFileInformation
+	err = syscall.GetFileInformationByHandle(syscall.Handle(h), &i)
+	if err != nil {
+		return err
+	}
+	fs.path = ""
+	fs.vol = i.VolumeSerialNumber
+	fs.idxhi = i.FileIndexHigh
+	fs.idxlo = i.FileIndexLow
+	return nil
+}
+
+// devNullStat is fileStat structure describing DevNull file ("NUL").
+var devNullStat = fileStat{
+	name: DevNull,
+	// hopefully this will work for SameFile
+	vol:   0,
+	idxhi: 0,
+	idxlo: 0,
+}
+
+func sameFile(fs1, fs2 *fileStat) bool {
+	e := fs1.loadFileId()
+	if e != nil {
+		return false
+	}
+	e = fs2.loadFileId()
+	if e != nil {
+		return false
+	}
+	return fs1.vol == fs2.vol && fs1.idxhi == fs2.idxhi && fs1.idxlo == fs2.idxlo
+}
+
+// For testing.
+func atime(fi FileInfo) time.Time {
+	return time.Unix(0, fi.Sys().(*syscall.Win32FileAttributeData).LastAccessTime.Nanoseconds())
+}