From f74f50e046cbbb651586005c0ea73dfc8fe828c4 Mon Sep 17 00:00:00 2001 From: Yuval Pavel Zholkover Date: Wed, 1 Jun 2011 13:12:37 +1000 Subject: [PATCH] Make unix Readdir and windows Readdirnames return partially successful results on error. Make plan 9 Readdir & Readdirnames return os.EOF at end. Also fix typos in the unix and windows comments. R=golang-dev, fshahriar, bradfitz, rsc, r CC=golang-dev https://golang.org/cl/4557053 --- src/pkg/os/dir_plan9.go | 68 +++++++++++++++++++++++--------------- src/pkg/os/dir_windows.go | 5 --- src/pkg/os/file_unix.go | 15 +++------ src/pkg/os/file_windows.go | 6 ++-- 4 files changed, 49 insertions(+), 45 deletions(-) diff --git a/src/pkg/os/dir_plan9.go b/src/pkg/os/dir_plan9.go index 14decfce105..bbc2cb64726 100644 --- a/src/pkg/os/dir_plan9.go +++ b/src/pkg/os/dir_plan9.go @@ -9,35 +9,46 @@ import ( ) // Readdir reads the contents of the directory associated with file and -// returns an array of up to count FileInfo structures, 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) { +// returns an array of up to n FileInfo structures, as would be returned +// by Lstat, in directory order. Subsequent calls on the same file will yield +// further FileInfos. +// +// If n > 0, Readdir returns at most n FileInfo structures. 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 this file has no dirinfo, create one. if file.dirinfo == nil { file.dirinfo = new(dirInfo) } d := file.dirinfo - size := count - if size < 0 { + size := n + if size <= 0 { size = 100 + n = -1 } result := make([]FileInfo, 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 e Error d.nbuf, e = file.Read(d.buf[:]) if e != nil && e != EOF { - return nil, &PathError{"readdir", file.name, e} + return result, &PathError{"readdir", file.name, e} } if e == EOF { break } if d.nbuf < syscall.STATFIXLEN { - return nil, &PathError{"readdir", file.name, Eshortstat} + return result, &PathError{"readdir", file.name, Eshortstat} } } @@ -45,39 +56,44 @@ func (file *File) Readdir(count int) (fi []FileInfo, err Error) { m, _ := gbit16(d.buf[d.bufp:]) m += 2 if m < syscall.STATFIXLEN { - return nil, &PathError{"readdir", file.name, Eshortstat} + return result, &PathError{"readdir", file.name, Eshortstat} } dir, e := UnmarshalDir(d.buf[d.bufp : d.bufp+int(m)]) if e != nil { - return nil, &PathError{"readdir", file.name, e} + return result, &PathError{"readdir", file.name, e} } var f FileInfo fileInfoFromStat(&f, dir) result = append(result, f) d.bufp += int(m) - count-- + n-- + } + + if n >= 0 && len(result) == 0 { + return result, EOF } return result, nil } -// Readdirnames returns an array of up to count file names residing in the -// directory associated with file. A negative count will return all of them. -// Readdir returns the array and an Error, if any. -func (file *File) Readdirnames(count int) (names []string, err Error) { - fi, e := file.Readdir(count) - - if e != nil { - return []string{}, e - } - +// 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 (file *File) Readdirnames(n int) (names []string, err Error) { + fi, err := file.Readdir(n) names = make([]string, len(fi)) - err = nil - for i := range fi { names[i] = fi[i].Name } - return } diff --git a/src/pkg/os/dir_windows.go b/src/pkg/os/dir_windows.go index a4df9d3eab7..d76e88fdb77 100644 --- a/src/pkg/os/dir_windows.go +++ b/src/pkg/os/dir_windows.go @@ -6,11 +6,6 @@ package os 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 && err != nil { - return nil, err - } names = make([]string, len(fis)) for i, fi := range fis { names[i] = fi.Name diff --git a/src/pkg/os/file_unix.go b/src/pkg/os/file_unix.go index c65c5b3ffd7..def9b3bf07d 100644 --- a/src/pkg/os/file_unix.go +++ b/src/pkg/os/file_unix.go @@ -69,12 +69,12 @@ func (file *File) Stat() (fi *FileInfo, err Error) { } // Readdir reads the contents of the directory associated with file and -// returns an array of up to count FileInfo structures, as would be returned +// returns an array of up to n FileInfo structures, as would be returned // by Lstat, in directory order. Subsequent calls on the same file will yield // further FileInfos. // -// 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 +// If n > 0, Readdir returns at most n FileInfo structures. In this case, if +// Readdir 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 @@ -89,11 +89,7 @@ func (file *File) Readdir(n int) (fi []FileInfo, err Error) { dirname = "." } dirname += "/" - wantAll := n < 0 - names, namesErr := file.Readdirnames(n) - if namesErr != nil && !wantAll { - return nil, namesErr - } + names, err := file.Readdirnames(n) fi = make([]FileInfo, len(names)) for i, filename := range names { fip, err := Lstat(dirname + filename) @@ -103,9 +99,6 @@ func (file *File) Readdir(n int) (fi []FileInfo, err Error) { 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 ac37b8e2d34..80886f6f525 100644 --- a/src/pkg/os/file_windows.go +++ b/src/pkg/os/file_windows.go @@ -123,12 +123,12 @@ func (file *File) Stat() (fi *FileInfo, err Error) { } // Readdir reads the contents of the directory associated with file and -// returns an array of up to count FileInfo structures, as would be returned +// returns an array of up to n FileInfo structures, as would be returned // by Lstat, in directory order. Subsequent calls on the same file will yield // further FileInfos. // -// 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 +// If n > 0, Readdir returns at most n FileInfo structures. In this case, if +// Readdir 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