mirror of
https://github.com/restic/restic.git
synced 2024-08-30 16:17:23 +02:00
Return valid directory info from Lstat() for parent directories of the specified filename. Previously only "/" and "." were valid directories. Also set directory mode as this is checked by archiver. Closes #2063
332 lines
7.3 KiB
Go
332 lines
7.3 KiB
Go
package fs
|
|
|
|
import (
|
|
"fmt"
|
|
"io"
|
|
"os"
|
|
"path"
|
|
"sync"
|
|
"syscall"
|
|
"time"
|
|
|
|
"github.com/restic/restic/internal/errors"
|
|
)
|
|
|
|
// Reader is a file system which provides a directory with a single file. When
|
|
// this file is opened for reading, the reader is passed through. The file can
|
|
// be opened once, all subsequent open calls return syscall.EIO. For Lstat(),
|
|
// the provided FileInfo is returned.
|
|
type Reader struct {
|
|
Name string
|
|
io.ReadCloser
|
|
|
|
// for FileInfo
|
|
Mode os.FileMode
|
|
ModTime time.Time
|
|
Size int64
|
|
|
|
AllowEmptyFile bool
|
|
|
|
open sync.Once
|
|
}
|
|
|
|
// statically ensure that Local implements FS.
|
|
var _ FS = &Reader{}
|
|
|
|
// VolumeName returns leading volume name, for the Reader file system it's
|
|
// always the empty string.
|
|
func (fs *Reader) VolumeName(path string) string {
|
|
return ""
|
|
}
|
|
|
|
// Open opens a file for reading.
|
|
func (fs *Reader) Open(name string) (f File, err error) {
|
|
switch name {
|
|
case fs.Name:
|
|
fs.open.Do(func() {
|
|
f = newReaderFile(fs.ReadCloser, fs.fi(), fs.AllowEmptyFile)
|
|
})
|
|
|
|
if f == nil {
|
|
return nil, syscall.EIO
|
|
}
|
|
|
|
return f, nil
|
|
case "/", ".":
|
|
f = fakeDir{
|
|
entries: []os.FileInfo{fs.fi()},
|
|
}
|
|
return f, nil
|
|
}
|
|
|
|
return nil, syscall.ENOENT
|
|
}
|
|
|
|
func (fs *Reader) fi() os.FileInfo {
|
|
return fakeFileInfo{
|
|
name: fs.Name,
|
|
size: fs.Size,
|
|
mode: fs.Mode,
|
|
modtime: fs.ModTime,
|
|
}
|
|
}
|
|
|
|
// OpenFile is the generalized open call; most users will use Open
|
|
// or Create instead. It opens the named file with specified flag
|
|
// (O_RDONLY etc.) and perm, (0666 etc.) if applicable. If successful,
|
|
// methods on the returned File can be used for I/O.
|
|
// If there is an error, it will be of type *PathError.
|
|
func (fs *Reader) OpenFile(name string, flag int, perm os.FileMode) (f File, err error) {
|
|
if flag & ^(O_RDONLY|O_NOFOLLOW) != 0 {
|
|
return nil, errors.Errorf("invalid combination of flags 0x%x", flag)
|
|
}
|
|
|
|
fs.open.Do(func() {
|
|
f = newReaderFile(fs.ReadCloser, fs.fi(), fs.AllowEmptyFile)
|
|
})
|
|
|
|
if f == nil {
|
|
return nil, syscall.EIO
|
|
}
|
|
|
|
return f, nil
|
|
}
|
|
|
|
// Stat returns a FileInfo describing the named file. If there is an error, it
|
|
// will be of type *PathError.
|
|
func (fs *Reader) Stat(name string) (os.FileInfo, error) {
|
|
return fs.Lstat(name)
|
|
}
|
|
|
|
// Lstat returns the FileInfo structure describing the named file.
|
|
// If the file is a symbolic link, the returned FileInfo
|
|
// describes the symbolic link. Lstat makes no attempt to follow the link.
|
|
// If there is an error, it will be of type *PathError.
|
|
func (fs *Reader) Lstat(name string) (os.FileInfo, error) {
|
|
getDirInfo := func(name string) os.FileInfo {
|
|
fi := fakeFileInfo{
|
|
name: fs.Base(name),
|
|
size: 0,
|
|
mode: os.ModeDir | 0755,
|
|
modtime: time.Now(),
|
|
}
|
|
return fi
|
|
}
|
|
|
|
switch name {
|
|
case fs.Name:
|
|
return fs.fi(), nil
|
|
case "/", ".":
|
|
return getDirInfo(name), nil
|
|
}
|
|
|
|
dir := fs.Dir(fs.Name)
|
|
for {
|
|
if dir == "/" || dir == "." {
|
|
break
|
|
}
|
|
if name == dir {
|
|
return getDirInfo(name), nil
|
|
}
|
|
dir = fs.Dir(dir)
|
|
}
|
|
|
|
return nil, os.ErrNotExist
|
|
}
|
|
|
|
// Join joins any number of path elements into a single path, adding a
|
|
// Separator if necessary. Join calls Clean on the result; in particular, all
|
|
// empty strings are ignored. On Windows, the result is a UNC path if and only
|
|
// if the first path element is a UNC path.
|
|
func (fs *Reader) Join(elem ...string) string {
|
|
return path.Join(elem...)
|
|
}
|
|
|
|
// Separator returns the OS and FS dependent separator for dirs/subdirs/files.
|
|
func (fs *Reader) Separator() string {
|
|
return "/"
|
|
}
|
|
|
|
// IsAbs reports whether the path is absolute. For the Reader, this is always the case.
|
|
func (fs *Reader) IsAbs(p string) bool {
|
|
return true
|
|
}
|
|
|
|
// Abs returns an absolute representation of path. If the path is not absolute
|
|
// it will be joined with the current working directory to turn it into an
|
|
// absolute path. The absolute path name for a given file is not guaranteed to
|
|
// be unique. Abs calls Clean on the result.
|
|
//
|
|
// For the Reader, all paths are absolute.
|
|
func (fs *Reader) Abs(p string) (string, error) {
|
|
return path.Clean(p), nil
|
|
}
|
|
|
|
// Clean returns the cleaned path. For details, see filepath.Clean.
|
|
func (fs *Reader) Clean(p string) string {
|
|
return path.Clean(p)
|
|
}
|
|
|
|
// Base returns the last element of p.
|
|
func (fs *Reader) Base(p string) string {
|
|
return path.Base(p)
|
|
}
|
|
|
|
// Dir returns p without the last element.
|
|
func (fs *Reader) Dir(p string) string {
|
|
return path.Dir(p)
|
|
}
|
|
|
|
func newReaderFile(rd io.ReadCloser, fi os.FileInfo, allowEmptyFile bool) *readerFile {
|
|
return &readerFile{
|
|
ReadCloser: rd,
|
|
AllowEmptyFile: allowEmptyFile,
|
|
fakeFile: fakeFile{
|
|
FileInfo: fi,
|
|
name: fi.Name(),
|
|
},
|
|
}
|
|
}
|
|
|
|
type readerFile struct {
|
|
io.ReadCloser
|
|
AllowEmptyFile, bytesRead bool
|
|
|
|
fakeFile
|
|
}
|
|
|
|
// ErrFileEmpty is returned inside a *os.PathError by Read() for the file
|
|
// opened from the fs provided by Reader when no data could be read and
|
|
// AllowEmptyFile is not set.
|
|
var ErrFileEmpty = errors.New("no data read")
|
|
|
|
func (r *readerFile) Read(p []byte) (int, error) {
|
|
n, err := r.ReadCloser.Read(p)
|
|
if n > 0 {
|
|
r.bytesRead = true
|
|
}
|
|
|
|
// return an error if we did not read any data
|
|
if err == io.EOF && !r.AllowEmptyFile && !r.bytesRead {
|
|
fmt.Printf("reader: %d bytes read, err %v, bytesRead %v, allowEmpty %v\n", n, err, r.bytesRead, r.AllowEmptyFile)
|
|
return n, &os.PathError{
|
|
Path: r.fakeFile.name,
|
|
Op: "read",
|
|
Err: ErrFileEmpty,
|
|
}
|
|
}
|
|
|
|
return n, err
|
|
}
|
|
|
|
func (r *readerFile) Close() error {
|
|
return r.ReadCloser.Close()
|
|
}
|
|
|
|
// ensure that readerFile implements File
|
|
var _ File = &readerFile{}
|
|
|
|
// fakeFile implements all File methods, but only returns errors for anything
|
|
// except Stat() and Name().
|
|
type fakeFile struct {
|
|
name string
|
|
os.FileInfo
|
|
}
|
|
|
|
// ensure that fakeFile implements File
|
|
var _ File = fakeFile{}
|
|
|
|
func (f fakeFile) Fd() uintptr {
|
|
return 0
|
|
}
|
|
|
|
func (f fakeFile) Readdirnames(n int) ([]string, error) {
|
|
return nil, os.ErrInvalid
|
|
}
|
|
|
|
func (f fakeFile) Readdir(n int) ([]os.FileInfo, error) {
|
|
return nil, os.ErrInvalid
|
|
}
|
|
|
|
func (f fakeFile) Seek(int64, int) (int64, error) {
|
|
return 0, os.ErrInvalid
|
|
}
|
|
|
|
func (f fakeFile) Write(p []byte) (int, error) {
|
|
return 0, os.ErrInvalid
|
|
}
|
|
|
|
func (f fakeFile) Read(p []byte) (int, error) {
|
|
return 0, os.ErrInvalid
|
|
}
|
|
|
|
func (f fakeFile) Close() error {
|
|
return nil
|
|
}
|
|
|
|
func (f fakeFile) Stat() (os.FileInfo, error) {
|
|
return f.FileInfo, nil
|
|
}
|
|
|
|
func (f fakeFile) Name() string {
|
|
return f.name
|
|
}
|
|
|
|
// fakeDir implements Readdirnames and Readdir, everything else is delegated to fakeFile.
|
|
type fakeDir struct {
|
|
entries []os.FileInfo
|
|
fakeFile
|
|
}
|
|
|
|
func (d fakeDir) Readdirnames(n int) ([]string, error) {
|
|
if n >= 0 {
|
|
return nil, errors.New("not implemented")
|
|
}
|
|
names := make([]string, 0, len(d.entries))
|
|
for _, entry := range d.entries {
|
|
names = append(names, entry.Name())
|
|
}
|
|
|
|
return names, nil
|
|
}
|
|
|
|
func (d fakeDir) Readdir(n int) ([]os.FileInfo, error) {
|
|
if n >= 0 {
|
|
return nil, errors.New("not implemented")
|
|
}
|
|
return d.entries, nil
|
|
}
|
|
|
|
// fakeFileInfo implements the bare minimum of os.FileInfo.
|
|
type fakeFileInfo struct {
|
|
name string
|
|
size int64
|
|
mode os.FileMode
|
|
modtime time.Time
|
|
sys interface{}
|
|
}
|
|
|
|
func (fi fakeFileInfo) Name() string {
|
|
return fi.name
|
|
}
|
|
|
|
func (fi fakeFileInfo) Size() int64 {
|
|
return fi.size
|
|
}
|
|
|
|
func (fi fakeFileInfo) Mode() os.FileMode {
|
|
return fi.mode
|
|
}
|
|
|
|
func (fi fakeFileInfo) ModTime() time.Time {
|
|
return fi.modtime
|
|
}
|
|
|
|
func (fi fakeFileInfo) IsDir() bool {
|
|
return fi.mode&os.ModeDir > 0
|
|
}
|
|
|
|
func (fi fakeFileInfo) Sys() interface{} {
|
|
return fi.sys
|
|
}
|