add chown method

afero.go

@@ -96,6 +96,9 @@ type Fs interface {
 
 	//Chtimes changes the access and modification times of the named file
 	Chtimes(name string, atime time.Time, mtime time.Time) error
+
+	// Chown changes uid and gid of the named file.
+	Chown(name string, uid, gid int) error
 }
 
 var (

basepath.go

@@ -177,4 +177,11 @@ func (b *BasePathFs) LstatIfPossible(name string) (os.FileInfo, bool, error) {
 	return fi, false, err
 }
 
+
+func (b *BasePathFs) Chown(name string, uid, gid int) (err error) {
+	if name, err = b.RealPath(name); err != nil {
+		return &os.PathError{Op: "chown", Path: name, Err: err}
+	}
+	return b.source.Chown(name, uid, gid)
+}
 // vim: ts=4 sw=4 noexpandtab nolist syn=go

cacheOnReadFs.go

@@ -288,3 +288,24 @@ func (u *CacheOnReadFs) Create(name string) (File, error) {
 	}
 	return &UnionFile{Base: bfh, Layer: lfh}, nil
 }
+
+func (u *CacheOnReadFs) Chown(name string, uid, gid int) error {
+	st, _, err := u.cacheStatus(name)
+	if err != nil {
+		return err
+	}
+	switch st {
+	case cacheLocal:
+	case cacheHit:
+		err = u.base.Chown(name, uid, gid)
+	case cacheStale, cacheMiss:
+		if err := u.copyToLayer(name); err != nil {
+			return err
+		}
+		err = u.base.Chown(name, uid, gid)
+	}
+	if err != nil {
+		return err
+	}
+	return u.layer.Chown(name, uid, gid)
+}

copyOnWriteFs.go

@@ -291,3 +291,16 @@ func (u *CopyOnWriteFs) MkdirAll(name string, perm os.FileMode) error {
 func (u *CopyOnWriteFs) Create(name string) (File, error) {
 	return u.OpenFile(name, os.O_CREATE|os.O_TRUNC|os.O_RDWR, 0666)
 }
+
+func (u *CopyOnWriteFs) Chown(name string, uid, gid int) error {
+	b, err := u.isBaseFile(name)
+	if err != nil {
+		return err
+	}
+	if b {
+		if err := u.copyToLayer(name); err != nil {
+			return err
+		}
+	}
+	return u.layer.Chown(name, uid, gid)
+}

mem/file.go

@@ -57,6 +57,8 @@ type FileData struct {
 	dir     bool
 	mode    os.FileMode
 	modtime time.Time
+	uid     int
+	gid     int
 }
 
 func (d *FileData) Name() string {
@@ -95,6 +97,18 @@ func setModTime(f *FileData, mtime time.Time) {
 	f.modtime = mtime
 }
 
+func SetUID(f *FileData, uid int) {
+	f.Lock()
+	f.uid = uid
+	f.Unlock()
+}
+
+func SetGID(f *FileData, gid int) {
+	f.Lock()
+	f.uid = gid
+	f.Unlock()
+}
+
 func GetFileInfo(f *FileData) *FileInfo {
 	return &FileInfo{f}
 }

memmap.go

@@ -358,6 +358,21 @@ func (m *MemMapFs) List() {
 	}
 }
 
+func (m *MemMapFs) Chown(name string, uid, gid int) error {
+	name = normalizePath(name)
+
+	m.mu.RLock()
+	f, ok := m.getData()[name]
+	m.mu.RUnlock()
+	if !ok {
+		return &os.PathError{Op: "chown", Path: name, Err: ErrFileNotFound}
+	}
+
+	mem.SetUID(f, uid)
+	mem.SetGID(f, gid)
+
+	return nil
+}
 // func debugMemMapList(fs Fs) {
 // 	if x, ok := fs.(*MemMapFs); ok {
 // 		x.List()

os.go

@@ -99,3 +99,7 @@ func (OsFs) LstatIfPossible(name string) (os.FileInfo, bool, error) {
 	fi, err := os.Lstat(name)
 	return fi, true, err
 }
+
+func (OsFs) Chown(name string, uid, gid int) error {
+	return os.Chown(name, uid, gid)
+}

readonlyfs.go

@@ -78,3 +78,7 @@ func (r *ReadOnlyFs) MkdirAll(n string, p os.FileMode) error {
 func (r *ReadOnlyFs) Create(n string) (File, error) {
 	return nil, syscall.EPERM
 }
+
+func (r *ReadOnlyFs) Chown(n string, uid, gid int) error {
+	return syscall.EPERM
+}

regexpfs.go

@@ -212,3 +212,10 @@ func (f *RegexpFile) Truncate(s int64) error {
 func (f *RegexpFile) WriteString(s string) (int, error) {
 	return f.f.WriteString(s)
 }
+
+func (r *RegexpFs) Chown(name string, uid, gid int) error {
+	if err := r.dirOrMatches(name); err != nil {
+		return err
+	}
+	return r.source.Chown(name, uid, gid)
+}

sftpfs/sftp.go

@@ -127,3 +127,7 @@ func (s Fs) Chmod(name string, mode os.FileMode) error {
 func (s Fs) Chtimes(name string, atime time.Time, mtime time.Time) error {
 	return s.client.Chtimes(name, atime, mtime)
 }
+
+func (s Fs) Chown(name string, uid, gid int) error {
+	return s.client.Chown(name, uid, gid)
+}