vfscopy/vfs.go

69 lines
1.6 KiB
Go

package vfscopy
import (
"os"
"io"
"path/filepath"
"path"
"strings"
"errors"
)
// FileSystem is copied from http.FileSystem
type FileSystem interface {
Open(name string) (File, error)
}
// File is copied from http.File
type File interface {
io.Closer
io.Reader
io.Seeker
Readdir(count int) ([]os.FileInfo, error)
Stat() (os.FileInfo, error)
}
// Dir is an implementation of a Virtual FileSystem
type Dir string
// mapDirOpenError maps the provided non-nil error from opening name
// to a possibly better non-nil error. In particular, it turns OS-specific errors
// about opening files in non-directories into os.ErrNotExist. See Issue 18984.
func mapDirOpenError(originalErr error, name string) error {
if os.IsNotExist(originalErr) || os.IsPermission(originalErr) {
return originalErr
}
parts := strings.Split(name, string(filepath.Separator))
for i := range parts {
if parts[i] == "" {
continue
}
fi, err := os.Stat(strings.Join(parts[:i+1], string(filepath.Separator)))
if err != nil {
return originalErr
}
if !fi.IsDir() {
return os.ErrNotExist
}
}
return originalErr
}
// Open opens a file relative to a virtual filesystem
func (d Dir) Open(name string) (File, error) {
if filepath.Separator != '/' && strings.ContainsRune(name, filepath.Separator) {
return nil, errors.New("http: invalid character in file path")
}
dir := string(d)
if dir == "" {
dir = "."
}
fullName := filepath.Join(dir, filepath.FromSlash(path.Clean("/"+name)))
f, err := os.Open(fullName)
if err != nil {
return nil, mapDirOpenError(err, fullName)
}
return f, nil
}