mirror of
https://github.com/golang/go
synced 2024-11-25 23:07:58 -07:00
Make Readdirnames work properly on Linux.
Refactor so Readdir is portable code. R=rsc DELTA=192 (50 added, 130 deleted, 12 changed) OCL=24770 CL=24772
This commit is contained in:
Rob Pike
parent
651972b31f
commit
00b3d48f13
@ -64,63 +64,3 @@ func Readdirnames(fd *FD, count int) (names []string, err *os.Error) {
|
||||
}
|
||||
return names, nil
|
||||
}
|
||||
|
||||
// TODO(r): see comment in dir_amd64_linux.go
|
||||
|
||||
// Negative count means read until EOF.
|
||||
func Readdir(fd *FD, count int) (dirs []Dir, err *os.Error) {
|
||||
dirname := fd.name;
|
||||
if dirname == "" {
|
||||
dirname = ".";
|
||||
}
|
||||
dirname += "/";
|
||||
// Getdirentries needs the file offset - it's too hard for the kernel to remember
|
||||
// a number it already has written down.
|
||||
base, err1 := syscall.Seek(fd.fd, 0, 1);
|
||||
if err1 != 0 {
|
||||
return nil, os.ErrnoToError(err1)
|
||||
}
|
||||
// The buffer must be at least a block long.
|
||||
// TODO(r): use fstatfs to find fs block size.
|
||||
var buf = make([]byte, blockSize);
|
||||
dirs = make([]Dir, 0, 100); // TODO: could be smarter about size
|
||||
for {
|
||||
if count == 0 {
|
||||
break
|
||||
}
|
||||
ret, err2 := syscall.Getdirentries(fd.fd, &buf[0], int64(len(buf)), &base);
|
||||
if ret < 0 || err2 != 0 {
|
||||
return dirs, os.ErrnoToError(err2)
|
||||
}
|
||||
if ret == 0 {
|
||||
break
|
||||
}
|
||||
for w, i := uintptr(0),uintptr(0); i < uintptr(ret); i += w {
|
||||
if count == 0 {
|
||||
break
|
||||
}
|
||||
dirent := unsafe.Pointer((uintptr(unsafe.Pointer(&buf[0])) + i)).(*syscall.Dirent);
|
||||
w = uintptr(dirent.Reclen);
|
||||
if dirent.Ino == 0 {
|
||||
continue
|
||||
}
|
||||
count--;
|
||||
if len(dirs) == cap(dirs) {
|
||||
ndirs := make([]Dir, len(dirs), 2*len(dirs));
|
||||
for i := 0; i < len(dirs); i++ {
|
||||
ndirs[i] = dirs[i]
|
||||
}
|
||||
dirs = ndirs;
|
||||
}
|
||||
dirs = dirs[0:len(dirs)+1];
|
||||
filename := string(dirent.Name[0:dirent.Namlen]);
|
||||
dirp, err := Lstat(dirname + filename);
|
||||
if dirp == nil || err != nil {
|
||||
dirs[len(dirs)-1].Name = filename; // rest will be zeroed out
|
||||
} else {
|
||||
dirs[len(dirs)-1] = *dirp;
|
||||
}
|
||||
}
|
||||
}
|
||||
return dirs, nil;
|
||||
}
|
||||
|
||||
@ -10,6 +10,10 @@ import (
|
||||
"unsafe";
|
||||
)
|
||||
|
||||
const (
|
||||
blockSize = 4096 // TODO(r): use statfs
|
||||
)
|
||||
|
||||
func clen(n []byte) int {
|
||||
for i := 0; i < len(n); i++ {
|
||||
if n[i] == 0 {
|
||||
@ -21,28 +25,38 @@ func clen(n []byte) int {
|
||||
|
||||
// Negative count means read until EOF.
|
||||
func Readdirnames(fd *FD, count int) (names []string, err *os.Error) {
|
||||
// The buffer should be at least a block long.
|
||||
// TODO(r): use fstatfs to find fs block size.
|
||||
var buf = make([]syscall.Dirent, 8192/unsafe.Sizeof(*new(syscall.Dirent)));
|
||||
names = make([]string, 0, 100); // TODO: could be smarter about size
|
||||
for {
|
||||
if count == 0 {
|
||||
break
|
||||
}
|
||||
ret, err2 := syscall.Getdents(fd.fd, &buf[0], int64(len(buf) * unsafe.Sizeof(buf[0])));
|
||||
if ret < 0 || err2 != 0 {
|
||||
return names, os.ErrnoToError(err2)
|
||||
}
|
||||
if ret == 0 {
|
||||
break
|
||||
}
|
||||
for w, i := uintptr(0),uintptr(0); i < uintptr(ret); i += w {
|
||||
if count == 0 {
|
||||
break
|
||||
// If this fd has no dirinfo, create one.
|
||||
if fd.dirinfo == nil {
|
||||
fd.dirinfo = new(DirInfo);
|
||||
// The buffer must be at least a block long.
|
||||
// TODO(r): use fstatfs to find fs block size.
|
||||
fd.dirinfo.buf = make([]byte, blockSize);
|
||||
}
|
||||
d := fd.dirinfo;
|
||||
size := count;
|
||||
if size < 0 {
|
||||
size = 100
|
||||
}
|
||||
names = make([]string, 0, size); // Empty with room to grow.
|
||||
for count != 0 {
|
||||
// Refill the buffer if necessary
|
||||
if d.bufp == d.nbuf {
|
||||
var errno int64;
|
||||
dbuf := unsafe.Pointer(&d.buf[0]).(*syscall.Dirent);
|
||||
d.nbuf, errno = syscall.Getdents(fd.fd, dbuf, int64(len(d.buf)));
|
||||
if d.nbuf < 0 {
|
||||
return names, os.ErrnoToError(errno)
|
||||
}
|
||||
dirent := unsafe.Pointer((uintptr(unsafe.Pointer(&buf[0])) + i)).(*syscall.Dirent);
|
||||
w = uintptr(dirent.Reclen);
|
||||
if dirent.Ino == 0 {
|
||||
if d.nbuf == 0 {
|
||||
break // EOF
|
||||
}
|
||||
d.bufp = 0;
|
||||
}
|
||||
// Drain the buffer
|
||||
for count != 0 && d.bufp < d.nbuf {
|
||||
dirent := unsafe.Pointer(&d.buf[d.bufp]).(*syscall.Dirent);
|
||||
d.bufp += int64(dirent.Reclen);
|
||||
if dirent.Ino == 0 { // File absent in directory.
|
||||
continue
|
||||
}
|
||||
count--;
|
||||
@ -59,64 +73,3 @@ func Readdirnames(fd *FD, count int) (names []string, err *os.Error) {
|
||||
}
|
||||
return names, nil;
|
||||
}
|
||||
|
||||
// TODO(r): Readdir duplicates a lot of Readdirnames. The other way would
|
||||
// be to have Readdir (which could then be portable) call Readdirnames and
|
||||
// then do the Stats. The existing design was chosen to avoid allocating a
|
||||
// throwaway names array, but the issue should be revisited once we have
|
||||
// a better handle on what that overhead is with a strong garbage collector.
|
||||
// Also, it's possible given the nature of the Unix kernel that interleaving
|
||||
// reads of the directory with stats (as done here) would work better than
|
||||
// one big read of the directory followed by a long run of Stat calls.
|
||||
|
||||
// Negative count means read until EOF.
|
||||
func Readdir(fd *FD, count int) (dirs []Dir, err *os.Error) {
|
||||
dirname := fd.name;
|
||||
if dirname == "" {
|
||||
dirname = ".";
|
||||
}
|
||||
dirname += "/";
|
||||
// The buffer must be at least a block long.
|
||||
// TODO(r): use fstatfs to find fs block size.
|
||||
var buf = make([]syscall.Dirent, 8192/unsafe.Sizeof(*new(syscall.Dirent)));
|
||||
dirs = make([]Dir, 0, 100); // TODO: could be smarter about size
|
||||
for {
|
||||
if count == 0 {
|
||||
break
|
||||
}
|
||||
ret, err2 := syscall.Getdents(fd.fd, &buf[0], int64(len(buf) * unsafe.Sizeof(buf[0])));
|
||||
if ret < 0 || err2 != 0 {
|
||||
return dirs, os.ErrnoToError(err2)
|
||||
}
|
||||
if ret == 0 {
|
||||
break
|
||||
}
|
||||
for w, i := uintptr(0),uintptr(0); i < uintptr(ret); i += w {
|
||||
if count == 0 {
|
||||
break
|
||||
}
|
||||
dirent := unsafe.Pointer((uintptr(unsafe.Pointer(&buf[0])) + i)).(*syscall.Dirent);
|
||||
w = uintptr(dirent.Reclen);
|
||||
if dirent.Ino == 0 {
|
||||
continue
|
||||
}
|
||||
count--;
|
||||
if len(dirs) == cap(dirs) {
|
||||
ndirs := make([]Dir, len(dirs), 2*len(dirs));
|
||||
for i := 0; i < len(dirs); i++ {
|
||||
ndirs[i] = dirs[i]
|
||||
}
|
||||
dirs = ndirs;
|
||||
}
|
||||
dirs = dirs[0:len(dirs)+1];
|
||||
filename := string(dirent.Name[0:clen(dirent.Name)]);
|
||||
dirp, err := Stat(dirname + filename);
|
||||
if dirp == nil || err != nil {
|
||||
dirs[len(dirs)-1].Name = filename; // rest will be zeroed out
|
||||
} else {
|
||||
dirs[len(dirs)-1] = *dirp;
|
||||
}
|
||||
}
|
||||
}
|
||||
return dirs, nil;
|
||||
}
|
||||
|
||||
@ -160,3 +160,30 @@ func Lstat(name string) (dir *Dir, err *Error) {
|
||||
}
|
||||
return dirFromStat(name, new(Dir), stat), nil
|
||||
}
|
||||
|
||||
// Non-portable function defined in operating-system-dependent file.
|
||||
func Readdirnames(fd *FD, count int) (names []string, err *os.Error)
|
||||
|
||||
// Negative count means read until EOF.
|
||||
func Readdir(fd *FD, count int) (dirs []Dir, err *os.Error) {
|
||||
dirname := fd.name;
|
||||
if dirname == "" {
|
||||
dirname = ".";
|
||||
}
|
||||
dirname += "/";
|
||||
names, err1 := Readdirnames(fd, count);
|
||||
if err1 != nil {
|
||||
return nil, err1
|
||||
}
|
||||
dirs = make([]Dir, len(names));
|
||||
for i, filename := range names {
|
||||
dirp, err := Stat(dirname + filename);
|
||||
if dirp == nil || err != nil {
|
||||
dirs[i].Name = filename // rest is already zeroed out
|
||||
} else {
|
||||
dirs[i] = *dirp
|
||||
}
|
||||
}
|
||||
return
|
||||
}
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user