blob: 91b67d8d61d1fc0f23a4cf0fce2db8364401efa8 [file] [log] [blame]
// 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 (
"io"
"runtime"
"syscall"
"unsafe"
)
// Auxiliary information if the File describes a directory
type dirInfo struct {
dir uintptr // Pointer to DIR structure from dirent.h
}
func (d *dirInfo) close() {
if d.dir == 0 {
return
}
closedir(d.dir)
d.dir = 0
}
func (f *File) readdir(n int, mode readdirMode) (names []string, dirents []DirEntry, infos []FileInfo, err error) {
// If this file has no dirinfo, create one.
var d *dirInfo
for {
d = f.dirinfo.Load()
if d != nil {
break
}
dir, call, errno := f.pfd.OpenDir()
if errno != nil {
return nil, nil, nil, &PathError{Op: call, Path: f.name, Err: errno}
}
d = &dirInfo{dir: dir}
if f.dirinfo.CompareAndSwap(nil, d) {
break
}
// We lost the race: try again.
d.close()
}
size := n
if size <= 0 {
size = 100
n = -1
}
var dirent syscall.Dirent
var entptr *syscall.Dirent
for len(names)+len(dirents)+len(infos) < size || n == -1 {
if errno := readdir_r(d.dir, &dirent, &entptr); errno != 0 {
if errno == syscall.EINTR {
continue
}
return names, dirents, infos, &PathError{Op: "readdir", Path: f.name, Err: errno}
}
if entptr == nil { // EOF
break
}
// Darwin may return a zero inode when a directory entry has been
// deleted but not yet removed from the directory. The man page for
// getdirentries(2) states that programs are responsible for skipping
// those entries:
//
// Users of getdirentries() should skip entries with d_fileno = 0,
// as such entries represent files which have been deleted but not
// yet removed from the directory entry.
//
if dirent.Ino == 0 {
continue
}
name := (*[len(syscall.Dirent{}.Name)]byte)(unsafe.Pointer(&dirent.Name))[:]
for i, c := range name {
if c == 0 {
name = name[:i]
break
}
}
// Check for useless names before allocating a string.
if string(name) == "." || string(name) == ".." {
continue
}
if mode == readdirName {
names = append(names, string(name))
} else if mode == readdirDirEntry {
de, err := newUnixDirent(f.name, string(name), dtToType(dirent.Type))
if IsNotExist(err) {
// File disappeared between readdir and stat.
// Treat as if it didn't exist.
continue
}
if err != nil {
return nil, dirents, nil, err
}
dirents = append(dirents, de)
} else {
info, err := lstat(f.name + "/" + string(name))
if IsNotExist(err) {
// File disappeared between readdir + stat.
// Treat as if it didn't exist.
continue
}
if err != nil {
return nil, nil, infos, err
}
infos = append(infos, info)
}
runtime.KeepAlive(f)
}
if n > 0 && len(names)+len(dirents)+len(infos) == 0 {
return nil, nil, nil, io.EOF
}
return names, dirents, infos, nil
}
func dtToType(typ uint8) FileMode {
switch typ {
case syscall.DT_BLK:
return ModeDevice
case syscall.DT_CHR:
return ModeDevice | ModeCharDevice
case syscall.DT_DIR:
return ModeDir
case syscall.DT_FIFO:
return ModeNamedPipe
case syscall.DT_LNK:
return ModeSymlink
case syscall.DT_REG:
return 0
case syscall.DT_SOCK:
return ModeSocket
}
return ^FileMode(0)
}
// Implemented in syscall/syscall_darwin.go.
//go:linkname closedir syscall.closedir
func closedir(dir uintptr) (err error)
//go:linkname readdir_r syscall.readdir_r
func readdir_r(dir uintptr, entry *syscall.Dirent, result **syscall.Dirent) (res syscall.Errno)