DockerCLI/vendor/github.com/tonistiigi/fsutil/fs.go

121 lines
2.8 KiB
Go

package fsutil
import (
"context"
"io"
"io/ioutil"
"os"
"path"
"path/filepath"
"sort"
"strings"
"syscall"
"github.com/pkg/errors"
"github.com/tonistiigi/fsutil/types"
)
type FS interface {
Walk(context.Context, filepath.WalkFunc) error
Open(string) (io.ReadCloser, error)
}
func NewFS(root string, opt *WalkOpt) FS {
return &fs{
root: root,
opt: opt,
}
}
type fs struct {
root string
opt *WalkOpt
}
func (fs *fs) Walk(ctx context.Context, fn filepath.WalkFunc) error {
return Walk(ctx, fs.root, fs.opt, fn)
}
func (fs *fs) Open(p string) (io.ReadCloser, error) {
rc, err := os.Open(filepath.Join(fs.root, p))
return rc, errors.WithStack(err)
}
type Dir struct {
Stat types.Stat
FS FS
}
func SubDirFS(dirs []Dir) (FS, error) {
sort.Slice(dirs, func(i, j int) bool {
return dirs[i].Stat.Path < dirs[j].Stat.Path
})
m := map[string]Dir{}
for _, d := range dirs {
if path.Base(d.Stat.Path) != d.Stat.Path {
return nil, errors.WithStack(&os.PathError{Path: d.Stat.Path, Err: syscall.EISDIR, Op: "invalid path"})
}
if _, ok := m[d.Stat.Path]; ok {
return nil, errors.WithStack(&os.PathError{Path: d.Stat.Path, Err: syscall.EEXIST, Op: "duplicate path"})
}
m[d.Stat.Path] = d
}
return &subDirFS{m: m, dirs: dirs}, nil
}
type subDirFS struct {
m map[string]Dir
dirs []Dir
}
func (fs *subDirFS) Walk(ctx context.Context, fn filepath.WalkFunc) error {
for _, d := range fs.dirs {
fi := &StatInfo{Stat: &d.Stat}
if !fi.IsDir() {
return errors.WithStack(&os.PathError{Path: d.Stat.Path, Err: syscall.ENOTDIR, Op: "walk subdir"})
}
if err := fn(d.Stat.Path, fi, nil); err != nil {
return err
}
if err := d.FS.Walk(ctx, func(p string, fi os.FileInfo, err error) error {
stat, ok := fi.Sys().(*types.Stat)
if !ok {
return errors.WithStack(&os.PathError{Path: d.Stat.Path, Err: syscall.EBADMSG, Op: "fileinfo without stat info"})
}
stat.Path = path.Join(d.Stat.Path, stat.Path)
if stat.Linkname != "" {
if fi.Mode()&os.ModeSymlink != 0 {
if strings.HasPrefix(stat.Linkname, "/") {
stat.Linkname = path.Join("/"+d.Stat.Path, stat.Linkname)
}
} else {
stat.Linkname = path.Join(d.Stat.Path, stat.Linkname)
}
}
return fn(filepath.Join(d.Stat.Path, p), &StatInfo{stat}, nil)
}); err != nil {
return err
}
}
return nil
}
func (fs *subDirFS) Open(p string) (io.ReadCloser, error) {
parts := strings.SplitN(filepath.Clean(p), string(filepath.Separator), 2)
if len(parts) == 0 {
return ioutil.NopCloser(&emptyReader{}), nil
}
d, ok := fs.m[parts[0]]
if !ok {
return nil, errors.WithStack(&os.PathError{Path: parts[0], Err: syscall.ENOENT, Op: "open"})
}
return d.FS.Open(parts[1])
}
type emptyReader struct {
}
func (*emptyReader) Read([]byte) (int, error) {
return 0, io.EOF
}