os: make Readdir & Readdirnames return os.EOF at end
Fixes #678
R=rsc, r, alex.brainman, bsiegert, jdpoirier
CC=golang-dev
https://golang.org/cl/4536058
diff --git a/src/pkg/os/dir_unix.go b/src/pkg/os/dir_unix.go
index f5b8223..9c54383 100644
--- a/src/pkg/os/dir_unix.go
+++ b/src/pkg/os/dir_unix.go
@@ -12,30 +12,40 @@
blockSize = 4096
)
-// Readdirnames reads the contents of the directory associated with file and
-// returns an array of up to count names, in directory order. Subsequent
-// calls on the same file will yield further names.
-// A negative count means to read until EOF.
-// Readdirnames returns the array and an Error, if any.
-func (file *File) Readdirnames(count int) (names []string, err Error) {
+// Readdirnames reads and returns a slice of names from the directory f.
+//
+// If n > 0, Readdirnames returns at most n names. In this case, if
+// Readdirnames returns an empty slice, it will return a non-nil error
+// explaining why. At the end of a directory, the error is os.EOF.
+//
+// If n <= 0, Readdirnames returns all the names from the directory in
+// a single slice. In this case, if Readdirnames succeeds (reads all
+// the way to the end of the directory), it returns the slice and a
+// nil os.Error. If it encounters an error before the end of the
+// directory, Readdirnames returns the names read until that point and
+// a non-nil error.
+func (f *File) Readdirnames(n int) (names []string, err Error) {
// If this file has no dirinfo, create one.
- if file.dirinfo == nil {
- file.dirinfo = new(dirInfo)
+ if f.dirinfo == nil {
+ f.dirinfo = new(dirInfo)
// The buffer must be at least a block long.
- file.dirinfo.buf = make([]byte, blockSize)
+ f.dirinfo.buf = make([]byte, blockSize)
}
- d := file.dirinfo
- size := count
+ d := f.dirinfo
+ wantAll := n < 0
+
+ size := n
if size < 0 {
size = 100
}
+
names = make([]string, 0, size) // Empty with room to grow.
- for count != 0 {
+ for n != 0 {
// Refill the buffer if necessary
if d.bufp >= d.nbuf {
d.bufp = 0
var errno int
- d.nbuf, errno = syscall.ReadDirent(file.fd, d.buf)
+ d.nbuf, errno = syscall.ReadDirent(f.fd, d.buf)
if errno != 0 {
return names, NewSyscallError("readdirent", errno)
}
@@ -46,9 +56,12 @@
// Drain the buffer
var nb, nc int
- nb, nc, names = syscall.ParseDirent(d.buf[d.bufp:d.nbuf], count, names)
+ nb, nc, names = syscall.ParseDirent(d.buf[d.bufp:d.nbuf], n, names)
d.bufp += nb
- count -= nc
+ n -= nc
+ }
+ if !wantAll && len(names) == 0 {
+ return names, EOF
}
return names, nil
}
diff --git a/src/pkg/os/dir_windows.go b/src/pkg/os/dir_windows.go
index 0d8267b..5a12d00 100644
--- a/src/pkg/os/dir_windows.go
+++ b/src/pkg/os/dir_windows.go
@@ -4,14 +4,16 @@
package os
-func (file *File) Readdirnames(count int) (names []string, err Error) {
- fis, e := file.Readdir(count)
- if e != nil {
- return nil, e
+func (file *File) Readdirnames(n int) (names []string, err Error) {
+ fis, err := file.Readdir(n)
+ // If n > 0 and we get an error, we return now.
+ // If n < 0, we return whatever we got + any error.
+ if n > 0 && e != nil {
+ return nil, err
}
names = make([]string, len(fis))
for i, fi := range fis {
names[i] = fi.Name
}
- return names, nil
+ return names, err
}
diff --git a/src/pkg/os/file_unix.go b/src/pkg/os/file_unix.go
index 2fb28df..c65c5b3 100644
--- a/src/pkg/os/file_unix.go
+++ b/src/pkg/os/file_unix.go
@@ -70,19 +70,29 @@
// Readdir reads the contents of the directory associated with file and
// returns an array of up to count FileInfo structures, as would be returned
-// by Lstat, in directory order. Subsequent calls on the same file will yield
+// by Lstat, in directory order. Subsequent calls on the same file will yield
// further FileInfos.
-// A negative count means to read until EOF.
-// Readdir returns the array and an Error, if any.
-func (file *File) Readdir(count int) (fi []FileInfo, err Error) {
+//
+// If n > 0, Readdir returns at most n names. In this case, if
+// Readdirnames returns an empty slice, it will return a non-nil error
+// explaining why. At the end of a directory, the error is os.EOF.
+//
+// If n <= 0, Readdir returns all the FileInfo from the directory in
+// a single slice. In this case, if Readdir succeeds (reads all
+// the way to the end of the directory), it returns the slice and a
+// nil os.Error. If it encounters an error before the end of the
+// directory, Readdir returns the FileInfo read until that point
+// and a non-nil error.
+func (file *File) Readdir(n int) (fi []FileInfo, err Error) {
dirname := file.name
if dirname == "" {
dirname = "."
}
dirname += "/"
- names, err1 := file.Readdirnames(count)
- if err1 != nil {
- return nil, err1
+ wantAll := n < 0
+ names, namesErr := file.Readdirnames(n)
+ if namesErr != nil && !wantAll {
+ return nil, namesErr
}
fi = make([]FileInfo, len(names))
for i, filename := range names {
@@ -93,6 +103,9 @@
fi[i] = *fip
}
}
+ if !wantAll && namesErr != EOF {
+ err = namesErr
+ }
return
}
diff --git a/src/pkg/os/file_windows.go b/src/pkg/os/file_windows.go
index 95f60b7..74ff3eb 100644
--- a/src/pkg/os/file_windows.go
+++ b/src/pkg/os/file_windows.go
@@ -124,11 +124,20 @@
// Readdir reads the contents of the directory associated with file and
// returns an array of up to count FileInfo structures, as would be returned
-// by Lstat, in directory order. Subsequent calls on the same file will yield
+// by Lstat, in directory order. Subsequent calls on the same file will yield
// further FileInfos.
-// A negative count means to read until EOF.
-// Readdir returns the array and an Error, if any.
-func (file *File) Readdir(count int) (fi []FileInfo, err Error) {
+//
+// If n > 0, Readdir returns at most n names. In this case, if
+// Readdirnames returns an empty slice, it will return a non-nil error
+// explaining why. At the end of a directory, the error is os.EOF.
+//
+// If n <= 0, Readdir returns all the FileInfo from the directory in
+// a single slice. In this case, if Readdir succeeds (reads all
+// the way to the end of the directory), it returns the slice and a
+// nil os.Error. If it encounters an error before the end of the
+// directory, Readdir returns the FileInfo read until that point
+// and a non-nil error.
+func (file *File) Readdir(n int) (fi []FileInfo, err Error) {
if file == nil || file.fd < 0 {
return nil, EINVAL
}
@@ -136,12 +145,13 @@
return nil, &PathError{"Readdir", file.name, ENOTDIR}
}
di := file.dirinfo
- size := count
+ wantAll := n < 0
+ size := n
if size < 0 {
size = 100
}
fi = make([]FileInfo, 0, size) // Empty with room to grow.
- for count != 0 {
+ for n != 0 {
if di.usefirststat {
di.usefirststat = false
} else {
@@ -150,7 +160,11 @@
if e == syscall.ERROR_NO_MORE_FILES {
break
} else {
- return nil, &PathError{"FindNextFile", file.name, Errno(e)}
+ err = &PathError{"FindNextFile", file.name, Errno(e)}
+ if !wantAll {
+ fi = nil
+ }
+ return
}
}
}
@@ -159,9 +173,12 @@
if f.Name == "." || f.Name == ".." { // Useless names
continue
}
- count--
+ n--
fi = append(fi, f)
}
+ if !wantAll && len(fi) == 0 {
+ return fi, EOF
+ }
return fi, nil
}
diff --git a/src/pkg/os/os_test.go b/src/pkg/os/os_test.go
index 65475c1..51ea818 100644
--- a/src/pkg/os/os_test.go
+++ b/src/pkg/os/os_test.go
@@ -236,11 +236,14 @@
count := 0
for {
d, err := file.Readdirnames(1)
+ if err == EOF {
+ break
+ }
if err != nil {
- t.Fatalf("readdir %q failed: %v", file.Name(), err)
+ t.Fatalf("readdirnames %q failed: %v", file.Name(), err)
}
if len(d) == 0 {
- break
+ t.Fatalf("readdirnames %q returned empty slice and no error")
}
names[count] = d[0]
count++
diff --git a/src/pkg/os/path.go b/src/pkg/os/path.go
index 0eb3ee5..5565aaa 100644
--- a/src/pkg/os/path.go
+++ b/src/pkg/os/path.go
@@ -95,6 +95,9 @@
err = err1
}
}
+ if err1 == EOF {
+ break
+ }
// If Readdirnames returned an error, use it.
if err == nil {
err = err1
