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mirror of https://github.com/golang/go synced 2024-11-26 07:07:57 -07:00

add Readdir: returns an array of Dir structures

R=rsc
DELTA=200  (176 added, 12 deleted, 12 changed)
OCL=24680
CL=24680
This commit is contained in:
Rob Pike 2009-02-09 11:24:35 -08:00
parent c8d59c1fb2
commit aba4c75408
3 changed files with 188 additions and 24 deletions

View File

@ -37,9 +37,9 @@ func Readdirnames(fd *FD, count int) (names []string, err *os.Error) {
if count == 0 {
break
}
dir := unsafe.Pointer((uintptr(unsafe.Pointer(&buf[0])) + i)).(*syscall.Dirent);
w = uintptr(dir.Reclen);
if dir.Ino == 0 {
dirent := unsafe.Pointer((uintptr(unsafe.Pointer(&buf[0])) + i)).(*syscall.Dirent);
w = uintptr(dirent.Reclen);
if dirent.Ino == 0 {
continue
}
count--;
@ -51,8 +51,68 @@ func Readdirnames(fd *FD, count int) (names []string, err *os.Error) {
names = nnames;
}
names = names[0:len(names)+1];
names[len(names)-1] = string(dir.Name[0:dir.Namlen]);
names[len(names)-1] = string(dirent.Name[0:dirent.Namlen]);
}
}
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, 8192);
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 := Stat(dirname + filename);
if dir == nil || err != nil {
dirs[len(dirs)-1].Name = filename; // rest will be zeroed out
} else {
dirs[len(dirs)-1] = *dirp;
}
}
}
return dirs, nil;
}

View File

@ -40,9 +40,9 @@ func Readdirnames(fd *FD, count int) (names []string, err *os.Error) {
if count == 0 {
break
}
dir := unsafe.Pointer((uintptr(unsafe.Pointer(&buf[0])) + i)).(*syscall.Dirent);
w = uintptr(dir.Reclen);
if dir.Ino == 0 {
dirent := unsafe.Pointer((uintptr(unsafe.Pointer(&buf[0])) + i)).(*syscall.Dirent);
w = uintptr(dirent.Reclen);
if dirent.Ino == 0 {
continue
}
count--;
@ -54,8 +54,69 @@ func Readdirnames(fd *FD, count int) (names []string, err *os.Error) {
names = nnames;
}
names = names[0:len(names)+1];
names[len(names)-1] = string(dir.Name[0:clen(dir.Name)]);
names[len(names)-1] = string(dirent.Name[0:clen(dirent.Name)]);
}
}
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;
}

View File

@ -10,6 +10,25 @@ import (
"testing";
)
var dot = []string{
"dir_amd64_darwin.go",
"dir_amd64_linux.go",
"os_env.go",
"os_error.go",
"os_file.go",
"os_test.go",
"os_time.go",
"os_types.go",
"stat_amd64_darwin.go",
"stat_amd64_linux.go"
}
var etc = []string{
"group",
"hosts",
"passwd",
}
func size(file string, t *testing.T) uint64 {
fd, err := Open(file, O_RDONLY, 0);
defer fd.Close();
@ -78,29 +97,17 @@ func TestLstat(t *testing.T) {
}
}
func TestReaddirnames(t *testing.T) {
fd, err := Open(".", O_RDONLY, 0);
func testReaddirnames(dir string, contents []string, t *testing.T) {
fd, err := Open(dir, O_RDONLY, 0);
defer fd.Close();
if err != nil {
t.Fatal("open . failed:", err);
t.Fatalf("open %q failed: %s\n", dir, err.String());
}
s, err2 := Readdirnames(fd, -1);
if err2 != nil {
t.Fatal("readdirnames . failed:", err);
}
a := []string{
"dir_amd64_darwin.go",
"dir_amd64_linux.go",
"os_env.go",
"os_error.go",
"os_file.go",
"os_test.go",
"os_time.go",
"os_types.go",
"stat_amd64_darwin.go",
"stat_amd64_linux.go"
};
for i, m := range a {
for i, m := range contents {
found := false;
for j, n := range s {
if m == n {
@ -115,3 +122,39 @@ func TestReaddirnames(t *testing.T) {
}
}
}
func testReaddir(dir string, contents []string, t *testing.T) {
fd, err := Open(dir, O_RDONLY, 0);
defer fd.Close();
if err != nil {
t.Fatalf("open %q failed: %s\n", dir, err.String());
}
s, err2 := Readdir(fd, -1);
if err2 != nil {
t.Fatal("readdir . failed:", err);
}
for i, m := range contents {
found := false;
for j, n := range s {
if m == n.Name {
if found {
t.Error("present twice:", m);
}
found = true
}
}
if !found {
t.Error("could not find", m);
}
}
}
func TestReaddirnames(t *testing.T) {
testReaddirnames(".", dot, t);
testReaddirnames("/etc", etc, t);
}
func TestReaddir(t *testing.T) {
testReaddir(".", dot, t);
testReaddir("/etc", etc, t);
}