os: conform to Go 1 API on Plan 9

R=golang-dev, r, bradfitz, r
CC=golang-dev
https://golang.org/cl/6117062

src/pkg/os/dir_plan9.go

@@ -48,7 +48,7 @@ func (file *File) readdir(n int) (fi []FileInfo, err error) {
 		if m < syscall.STATFIXLEN {
 			return result, &PathError{"readdir", file.name, errShortStat}
 		}
-		dir, e := UnmarshalDir(d.buf[d.bufp : d.bufp+int(m)])
+		dir, e := unmarshalDir(d.buf[d.bufp : d.bufp+int(m)])
 		if e != nil {
 			return result, &PathError{"readdir", file.name, e}
 		}
@@ -73,12 +73,12 @@ func (file *File) readdirnames(n int) (names []string, err error) {
 	return
 }
 
-type Dir struct {
+type dir struct {
 	// system-modified data
 	Type uint16 // server type
 	Dev  uint32 // server subtype
 	// file data
-	Qid    Qid    // unique id from server
+	Qid    qid    // unique id from server
 	Mode   uint32 // permissions
 	Atime  uint32 // last read time
 	Mtime  uint32 // last write time
@@ -89,16 +89,16 @@ type Dir struct {
 	Muid   string // last modifier name
 }
 
-type Qid struct {
+type qid struct {
 	Path uint64 // the file server's unique identification for the file
 	Vers uint32 // version number for given Path
 	Type uint8  // the type of the file (syscall.QTDIR for example)
 }
 
-var nullDir = Dir{
+var nullDir = dir{
 	^uint16(0),
 	^uint32(0),
-	Qid{^uint64(0), ^uint32(0), ^uint8(0)},
+	qid{^uint64(0), ^uint32(0), ^uint8(0)},
 	^uint32(0),
 	^uint32(0),
 	^uint32(0),
@@ -111,12 +111,12 @@ var nullDir = Dir{
 
 // Null assigns members of d with special "don't care" values indicating
 // they should not be written by syscall.Wstat. 
-func (d *Dir) Null() {
+func (d *dir) Null() {
 	*d = nullDir
 }
 
 // pdir appends a 9P Stat message based on the contents of Dir d to a byte slice b.
-func pdir(b []byte, d *Dir) []byte {
+func pdir(b []byte, d *dir) []byte {
 	n := len(b)
 	b = pbit16(b, 0) // length, filled in later	
 	b = pbit16(b, d.Type)
@@ -134,9 +134,9 @@ func pdir(b []byte, d *Dir) []byte {
 	return b
 }
 
-// UnmarshalDir reads a 9P Stat message from a 9P protocol message stored in b,
-// returning the corresponding Dir struct.
-func UnmarshalDir(b []byte) (d *Dir, err error) {
+// unmarshalDir reads a 9P Stat message from a 9P protocol message stored in b,
+// returning the corresponding dir struct.
+func unmarshalDir(b []byte) (d *dir, err error) {
 	n := uint16(0)
 	n, b = gbit16(b)
 
@@ -144,7 +144,7 @@ func UnmarshalDir(b []byte) (d *Dir, err error) {
 		return nil, errBadStat
 	}
 
-	d = new(Dir)
+	d = new(dir)
 	d.Type, b = gbit16(b)
 	d.Dev, b = gbit32(b)
 	d.Qid, b = gqid(b)
@@ -165,17 +165,17 @@ func UnmarshalDir(b []byte) (d *Dir, err error) {
 }
 
 // gqid reads the qid part of a 9P Stat message from a 9P protocol message stored in b,
-// returning the corresponding Qid struct and the remaining slice of b.
-func gqid(b []byte) (Qid, []byte) {
-	var q Qid
+// returning the corresponding qid struct and the remaining slice of b.
+func gqid(b []byte) (qid, []byte) {
+	var q qid
 	q.Path, b = gbit64(b)
 	q.Vers, b = gbit32(b)
 	q.Type, b = gbit8(b)
 	return q, b
 }
 
-// pqid appends a Qid struct q to a 9P message b.
-func pqid(b []byte, q Qid) []byte {
+// pqid appends a qid struct q to a 9P message b.
+func pqid(b []byte, q qid) []byte {
 	b = pbit64(b, q.Path)
 	b = pbit32(b, q.Vers)
 	b = pbit8(b, q.Type)

src/pkg/os/file_plan9.go

@@ -5,14 +5,11 @@
 package os
 
 import (
-	"errors"
 	"runtime"
 	"syscall"
 	"time"
 )
 
-var ErrPlan9 = errors.New("unimplemented on Plan 9")
-
 // File represents an open file descriptor.
 type File struct {
 	*file
@@ -137,8 +134,8 @@ func OpenFile(name string, flag int, perm FileMode) (file *File, err error) {
 
 // Close closes the File, rendering it unusable for I/O.
 // It returns an error, if any.
-func (file *File) Close() error {
-	return file.file.close()
+func (f *File) Close() error {
+	return f.file.close()
 }
 
 func (file *file) close() error {
@@ -159,8 +156,8 @@ func (file *file) close() error {
 }
 
 // Stat returns the FileInfo structure describing file.
-// It returns the FileInfo and an error, if any.
-func (f *File) Stat() (FileInfo, error) {
+// If there is an error, it will be of type *PathError.
+func (f *File) Stat() (fi FileInfo, err error) {
 	d, err := dirstat(f)
 	if err != nil {
 		return nil, err
@@ -170,8 +167,9 @@ func (f *File) Stat() (FileInfo, error) {
 
 // Truncate changes the size of the file.
 // It does not change the I/O offset.
+// If there is an error, it will be of type *PathError.
 func (f *File) Truncate(size int64) error {
-	var d Dir
+	var d dir
 	d.Null()
 
 	d.Length = uint64(size)
@@ -187,7 +185,7 @@ const chmodMask = uint32(syscall.DMAPPEND | syscall.DMEXCL | syscall.DMTMP | Mod
 // Chmod changes the mode of the file to mode.
 // If there is an error, it will be of type *PathError.
 func (f *File) Chmod(mode FileMode) error {
-	var d Dir
+	var d dir
 
 	odir, e := dirstat(f)
 	if e != nil {
@@ -209,7 +207,7 @@ func (f *File) Sync() (err error) {
 		return ErrInvalid
 	}
 
-	var d Dir
+	var d dir
 	d.Null()
 
 	if e := syscall.Fwstat(f.fd, pdir(nil, &d)); e != nil {
@@ -255,7 +253,7 @@ func (f *File) seek(offset int64, whence int) (ret int64, err error) {
 // If the file is a symbolic link, it changes the size of the link's target.
 // If there is an error, it will be of type *PathError.
 func Truncate(name string, size int64) error {
-	var d Dir
+	var d dir
 	d.Null()
 
 	d.Length = uint64(size)
@@ -277,7 +275,7 @@ func Remove(name string) error {
 
 // Rename renames a file.
 func Rename(oldname, newname string) error {
-	var d Dir
+	var d dir
 	d.Null()
 
 	d.Name = newname
@@ -289,9 +287,10 @@ func Rename(oldname, newname string) error {
 }
 
 // Chmod changes the mode of the named file to mode.
+// If the file is a symbolic link, it changes the mode of the link's target.
 // If there is an error, it will be of type *PathError.
 func Chmod(name string, mode FileMode) error {
-	var d Dir
+	var d dir
 
 	odir, e := dirstat(name)
 	if e != nil {
@@ -310,8 +309,9 @@ func Chmod(name string, mode FileMode) error {
 //
 // The underlying filesystem may truncate or round the values to a
 // less precise time unit.
+// If there is an error, it will be of type *PathError.
 func Chtimes(name string, atime time.Time, mtime time.Time) error {
-	var d Dir
+	var d dir
 	d.Null()
 
 	d.Atime = uint32(atime.Unix())
@@ -323,6 +323,8 @@ func Chtimes(name string, atime time.Time, mtime time.Time) error {
 	return nil
 }
 
+// Pipe returns a connected pair of Files; reads from r return bytes
+// written to w. It returns the files and an error, if any.
 func Pipe() (r *File, w *File, err error) {
 	var p [2]int
 
@@ -338,32 +340,42 @@ func Pipe() (r *File, w *File, err error) {
 
 // not supported on Plan 9
 
-// Link creates a hard link.
+// Link creates newname as a hard link to the oldname file.
 // If there is an error, it will be of type *LinkError.
 func Link(oldname, newname string) error {
-	return &LinkError{"link", oldname, newname, ErrPlan9}
+	return &LinkError{"link", oldname, newname, syscall.EPLAN9}
 }
 
 // Symlink creates newname as a symbolic link to oldname.
 // If there is an error, it will be of type *LinkError.
 func Symlink(oldname, newname string) error {
-	return &LinkError{"symlink", oldname, newname, ErrPlan9}
+	return &LinkError{"symlink", oldname, newname, syscall.EPLAN9}
 }
 
+// Readlink returns the destination of the named symbolic link.
+// If there is an error, it will be of type *PathError.
 func Readlink(name string) (string, error) {
-	return "", ErrPlan9
+	return "", &PathError{"readlink", name, syscall.EPLAN9}
 }
 
+// Chown changes the numeric uid and gid of the named file.
+// If the file is a symbolic link, it changes the uid and gid of the link's target.
+// If there is an error, it will be of type *PathError.
 func Chown(name string, uid, gid int) error {
-	return ErrPlan9
+	return &PathError{"chown", name, syscall.EPLAN9}
 }
 
+// Lchown changes the numeric uid and gid of the named file.
+// If the file is a symbolic link, it changes the uid and gid of the link itself.
+// If there is an error, it will be of type *PathError.
 func Lchown(name string, uid, gid int) error {
-	return ErrPlan9
+	return &PathError{"lchown", name, syscall.EPLAN9}
 }
 
+// Chown changes the numeric uid and gid of the named file.
+// If there is an error, it will be of type *PathError.
 func (f *File) Chown(uid, gid int) error {
-	return ErrPlan9
+	return &PathError{"chown", f.name, syscall.EPLAN9}
 }
 
 // TempDir returns the default directory to use for temporary files.

src/pkg/os/path_plan9.go

@@ -5,8 +5,8 @@
 package os
 
 const (
-	PathSeparator     = '/' // OS-specific path separator
-	PathListSeparator = 0   // OS-specific path list separator
+	PathSeparator     = '/'    // OS-specific path separator
+	PathListSeparator = '\000' // OS-specific path list separator
 )
 
 // IsPathSeparator returns true if c is a directory separator character.

src/pkg/os/stat_plan9.go

@@ -10,12 +10,12 @@ import (
 )
 
 func sameFile(sys1, sys2 interface{}) bool {
-	a := sys1.(*Dir)
-	b := sys2.(*Dir)
+	a := sys1.(*dir)
+	b := sys2.(*dir)
 	return a.Qid.Path == b.Qid.Path && a.Type == b.Type && a.Dev == b.Dev
 }
 
-func fileInfoFromStat(d *Dir) FileInfo {
+func fileInfoFromStat(d *dir) FileInfo {
 	fs := &fileStat{
 		name:    d.Name,
 		size:    int64(d.Length),
@@ -39,7 +39,7 @@ func fileInfoFromStat(d *Dir) FileInfo {
 }
 
 // arg is an open *File or a path string. 
-func dirstat(arg interface{}) (d *Dir, err error) {
+func dirstat(arg interface{}) (d *dir, err error) {
 	var name string
 
 	// This is big enough for most stat messages
@@ -72,7 +72,7 @@ func dirstat(arg interface{}) (d *Dir, err error) {
 		// If the stat message is larger than our buffer we will
 		// go around the loop and allocate one that is big enough.
 		if size <= n {
-			d, err = UnmarshalDir(buf[:n])
+			d, err = unmarshalDir(buf[:n])
 			if err != nil {
 				return nil, &PathError{"stat", name, err}
 			}
@@ -82,9 +82,9 @@ func dirstat(arg interface{}) (d *Dir, err error) {
 	return nil, &PathError{"stat", name, errBadStat}
 }
 
-// Stat returns a FileInfo structure describing the named file.
+// Stat returns a FileInfo describing the named file.
 // If there is an error, it will be of type *PathError.
-func Stat(name string) (FileInfo, error) {
+func Stat(name string) (fi FileInfo, err error) {
 	d, err := dirstat(name)
 	if err != nil {
 		return nil, err
@@ -92,15 +92,15 @@ func Stat(name string) (FileInfo, error) {
 	return fileInfoFromStat(d), nil
 }
 
-// Lstat returns the FileInfo structure describing the named file.
-// If the file is a symbolic link (though Plan 9 does not have symbolic links), 
-// the returned FileInfo describes the symbolic link.  Lstat makes no attempt to follow the link.
+// Lstat returns a FileInfo describing the named file.
+// If the file is a symbolic link, the returned FileInfo
+// describes the symbolic link.  Lstat makes no attempt to follow the link.
 // If there is an error, it will be of type *PathError.
-func Lstat(name string) (FileInfo, error) {
+func Lstat(name string) (fi FileInfo, err error) {
 	return Stat(name)
 }
 
 // For testing.
 func atime(fi FileInfo) time.Time {
-	return time.Unix(int64(fi.Sys().(*Dir).Atime), 0)
+	return time.Unix(int64(fi.Sys().(*dir).Atime), 0)
 }