| 1 | // Copyright 2016 The Go Authors. All rights reserved. |
|---|---|
| 2 | // Use of this source code is governed by a BSD-style |
| 3 | // license that can be found in the LICENSE file. |
| 4 | |
| 5 | package vfs |
| 6 | |
| 7 | import ( |
| 8 | "fmt" |
| 9 | "os" |
| 10 | "time" |
| 11 | ) |
| 12 | |
| 13 | // NewNameSpace returns a NameSpace pre-initialized with an empty |
| 14 | // emulated directory mounted on the root mount point "/". This |
| 15 | // allows directory traversal routines to work properly even if |
| 16 | // a folder is not explicitly mounted at root by the user. |
| 17 | func NewNameSpace() NameSpace { |
| 18 | ns := NameSpace{} |
| 19 | ns.Bind("/", &emptyVFS{}, "/", BindReplace) |
| 20 | return ns |
| 21 | } |
| 22 | |
| 23 | // type emptyVFS emulates a FileSystem consisting of an empty directory |
| 24 | type emptyVFS struct{} |
| 25 | |
| 26 | // Open implements Opener. Since emptyVFS is an empty directory, all |
| 27 | // attempts to open a file should returns errors. |
| 28 | func (e *emptyVFS) Open(path string) (ReadSeekCloser, error) { |
| 29 | if path == "/" { |
| 30 | return nil, fmt.Errorf("open: / is a directory") |
| 31 | } |
| 32 | return nil, os.ErrNotExist |
| 33 | } |
| 34 | |
| 35 | // Stat returns os.FileInfo for an empty directory if the path is |
| 36 | // is root "/" or error. os.FileInfo is implemented by emptyVFS |
| 37 | func (e *emptyVFS) Stat(path string) (os.FileInfo, error) { |
| 38 | if path == "/" { |
| 39 | return e, nil |
| 40 | } |
| 41 | return nil, os.ErrNotExist |
| 42 | } |
| 43 | |
| 44 | func (e *emptyVFS) Lstat(path string) (os.FileInfo, error) { |
| 45 | return e.Stat(path) |
| 46 | } |
| 47 | |
| 48 | // ReadDir returns an empty os.FileInfo slice for "/", else error. |
| 49 | func (e *emptyVFS) ReadDir(path string) ([]os.FileInfo, error) { |
| 50 | if path == "/" { |
| 51 | return []os.FileInfo{}, nil |
| 52 | } |
| 53 | return nil, os.ErrNotExist |
| 54 | } |
| 55 | |
| 56 | func (e *emptyVFS) String() string { |
| 57 | return "emptyVFS(/)" |
| 58 | } |
| 59 | |
| 60 | func (e *emptyVFS) RootType(path string) RootType { |
| 61 | return "" |
| 62 | } |
| 63 | |
| 64 | // These functions below implement os.FileInfo for the single |
| 65 | // empty emulated directory. |
| 66 | |
| 67 | func (e *emptyVFS) Name() string { |
| 68 | return "/" |
| 69 | } |
| 70 | |
| 71 | func (e *emptyVFS) Size() int64 { |
| 72 | return 0 |
| 73 | } |
| 74 | |
| 75 | func (e *emptyVFS) Mode() os.FileMode { |
| 76 | return os.ModeDir | os.ModePerm |
| 77 | } |
| 78 | |
| 79 | func (e *emptyVFS) ModTime() time.Time { |
| 80 | return time.Time{} |
| 81 | } |
| 82 | |
| 83 | func (e *emptyVFS) IsDir() bool { |
| 84 | return true |
| 85 | } |
| 86 | |
| 87 | func (e *emptyVFS) Sys() interface{} { |
| 88 | return nil |
| 89 | } |
| 90 |
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