func (file *File) readdir(n int) ([]FileInfo, error) {
// If this file has no dirinfo, create one.
if file.dirinfo == nil {
file.dirinfo = new(dirInfo)
}
d := file.dirinfo
size := n
if size <= 0 {
size = 100
n = -1
}
fi := make([]FileInfo, 0, size) // Empty with room to grow.
for n != 0 {
// Refill the buffer if necessary.
if d.bufp >= d.nbuf {
nb, err := file.Read(d.buf[:])
// Update the buffer state before checking for errors.
d.bufp, d.nbuf = 0, nb
if err != nil {
if err == io.EOF {
break
}
return fi, &PathError{"readdir", file.name, err}
}
if nb < syscall.STATFIXLEN {
return fi, &PathError{"readdir", file.name, syscall.ErrShortStat}
}
}
// Get a record from the buffer.
b := d.buf[d.bufp:]
m := int(uint16(b[0])|uint16(b[1])<<8) + 2
if m < syscall.STATFIXLEN {
return fi, &PathError{"readdir", file.name, syscall.ErrShortStat}
}
dir, err := syscall.UnmarshalDir(b[:m])
if err != nil {
return fi, &PathError{"readdir", file.name, err}
}
fi = append(fi, fileInfoFromStat(dir))
d.bufp += m
n--
}
if n >= 0 && len(fi) == 0 {
return fi, io.EOF
}
return fi, nil
}
// arg is an open *File or a path string.
func dirstat(arg interface{}) (*syscall.Dir, error) {
var name string
var err error
size := syscall.STATFIXLEN + 16*4
for i := 0; i < 2; i++ {
buf := make([]byte, _BIT16SZ+size)
var n int
switch a := arg.(type) {
case *File:
name = a.name
n, err = syscall.Fstat(a.fd, buf)
case string:
name = a
n, err = syscall.Stat(a, buf)
default:
panic("phase error in dirstat")
}
if n < _BIT16SZ {
return nil, &PathError{"stat", name, err}
}
// Pull the real size out of the stat message.
size = int(uint16(buf[0]) | uint16(buf[1])<<8)
// 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 := syscall.UnmarshalDir(buf[:n])
if err != nil {
return nil, &PathError{"stat", name, err}
}
return d, nil
}
}
if err == nil {
err = syscall.ErrBadStat
}
return nil, &PathError{"stat", name, err}
}
// arg is an open *File or a path string.
func dirstat(arg interface{}) (*syscall.Dir, error) {
var name string
// This is big enough for most stat messages
// and rounded to a multiple of 128 bytes.
size := (syscall.STATFIXLEN + 16*4 + 128) &^ 128
for i := 0; i < 2; i++ {
buf := make([]byte, size)
var n int
var err error
switch a := arg.(type) {
case *File:
name = a.name
n, err = syscall.Fstat(a.fd, buf)
case string:
name = a
n, err = syscall.Stat(a, buf)
default:
panic("phase error in dirstat")
}
if err != nil {
return nil, &PathError{"stat", name, err}
}
if n < syscall.STATFIXLEN {
return nil, &PathError{"stat", name, syscall.ErrShortStat}
}
// Pull the real size out of the stat message.
size = int(uint16(buf[0]) | uint16(buf[1])<<8)
// 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 {
continue
}
d, err := syscall.UnmarshalDir(buf[:n])
if err != nil {
return nil, &PathError{"stat", name, err}
}
return d, nil
}
return nil, &PathError{"stat", name, syscall.ErrBadStat}
}