@@ -4,82 +4,135 @@ import (
44 "errors"
55 "io"
66 "os"
7+ "time"
78)
89
910var (
10- ErrClosed = errors .New ("file: Writing on closed file. " )
11- ErrReadOnly = errors .New ("this is a read-only filesystem " )
12- ErrNotSupported = errors .New ("feature not supported " )
11+ ErrReadOnly = errors .New ("read-only filesystem " )
12+ ErrNotSupported = errors .New ("feature not supported " )
13+ ErrCrossedBoundary = errors .New ("chroot boundary crossed " )
1314)
1415
1516// Filesystem abstract the operations in a storage-agnostic interface.
16- // It allows you to:
17- // * Create files.
18- // * Open existing files.
19- // * Get info about files.
20- // * List files in a directory.
21- // * Get a temporal file.
22- // * Rename files.
23- // * Remove files.
24- // * Create directories.
25- // * Join parts of path.
26- // * Obtain a filesystem starting on a subdirectory in the current filesystem.
27- // * Get the base path for the filesystem.
28- // Each method implementation varies from implementation to implementation. Refer to
29- // the specific documentation for more info.
17+ // Each method implementation mimics the behavior of the equivalent functions
18+ // at the os package from the standard library.
3019type Filesystem interface {
20+ Basic
21+ TempFile
22+ Dir
23+ Symlink
24+ Chroot
25+ }
26+
27+ // Basic abstract the basic operations in a storage-agnostic interface as
28+ // an extension to the Basic interface.
29+ type Basic interface {
30+ // Create creates the named file with mode 0666 (before umask), truncating
31+ // it if it already exists. If successful, methods on the returned File can
32+ // be used for I/O; the associated file descriptor has mode O_RDWR.
3133 Create (filename string ) (File , error )
34+ // Open opens the named file for reading. If successful, methods on the
35+ // returned file can be used for reading; the associated file descriptor has
36+ // mode O_RDONLY.
3237 Open (filename string ) (File , error )
38+ // OpenFile is the generalized open call; most users will use Open or Create
39+ // instead. It opens the named file with specified flag (O_RDONLY etc.) and
40+ // perm, (0666 etc.) if applicable. If successful, methods on the returned
41+ // File can be used for I/O.
3342 OpenFile (filename string , flag int , perm os.FileMode ) (File , error )
3443 // Stat returns a FileInfo describing the named file.
35- Stat (filename string ) (FileInfo , error )
44+ Stat (filename string ) (os.FileInfo , error )
45+ // Rename renames (moves) oldpath to newpath. If newpath already exists and
46+ // is not a directory, Rename replaces it. OS-specific restrictions may
47+ // apply when oldpath and newpath are in different directories.
48+ Rename (oldpath , newpath string ) error
49+ // Remove removes the named file or directory.
50+ Remove (filename string ) error
51+ // Join joins any number of path elements into a single path, adding a
52+ // Separator if necessary. Join calls filepath.Clean on the result; in
53+ // particular, all empty strings are ignored. On Windows, the result is a
54+ // UNC path if and only if the first path element is a UNC path.
55+ Join (elem ... string ) string
56+ }
57+
58+ type TempFile interface {
59+ // TempFile creates a new temporary file in the directory dir with a name
60+ // beginning with prefix, opens the file for reading and writing, and
61+ // returns the resulting *os.File. If dir is the empty string, TempFile
62+ // uses the default directory for temporary files (see os.TempDir).
63+ // Multiple programs calling TempFile simultaneously will not choose the
64+ // same file. The caller can use f.Name() to find the pathname of the file.
65+ // It is the caller's responsibility to remove the file when no longer
66+ // needed.
67+ TempFile (dir , prefix string ) (File , error )
68+ }
69+
70+ // Dir abstract the dir related operations in a storage-agnostic interface as
71+ // an extension to the Basic interface.
72+ type Dir interface {
73+ // ReadDir reads the directory named by dirname and returns a list of
74+ // directory entries sorted by filename.
75+ ReadDir (path string ) ([]os.FileInfo , error )
76+ // MkdirAll creates a directory named path, along with any necessary
77+ // parents, and returns nil, or else returns an error. The permission bits
78+ // perm are used for all directories that MkdirAll creates. If path is/
79+ // already a directory, MkdirAll does nothing and returns nil.
80+ MkdirAll (filename string , perm os.FileMode ) error
81+ }
82+
83+ // Symlink abstract the symlink related operations in a storage-agnostic
84+ // interface as an extension to the Basic interface.
85+ type Symlink interface {
3686 // Lstat returns a FileInfo describing the named file. If the file is a
3787 // symbolic link, the returned FileInfo describes the symbolic link. Lstat
3888 // makes no attempt to follow the link.
39- Lstat (filename string ) (FileInfo , error )
40- ReadDir (path string ) ([]FileInfo , error )
41- TempFile (dir , prefix string ) (File , error )
42- Rename (from , to string ) error
43- Remove (filename string ) error
44- MkdirAll (filename string , perm os.FileMode ) error
45- Join (elem ... string ) string
46- Dir (path string ) Filesystem
89+ Lstat (filename string ) (os.FileInfo , error )
4790 // Symlink creates a symbolic-link from link to target. target may be an
4891 // absolute or relative path, and need not refer to an existing node.
4992 // Parent directories of link are created as necessary.
5093 Symlink (target , link string ) error
51- // Readlink returns the target path of link. An error is returned if link is
52- // not a symbolic-link.
94+ // Readlink returns the target path of link.
5395 Readlink (link string ) (string , error )
54- Base () string
5596}
5697
57- // File implements io.Closer, io.Reader, io.Seeker, and io.Writer>
58- // Provides method to obtain the file name and the state of the file (open or closed).
98+ // Change abstract the FileInfo change related operations in a storage-agnostic
99+ // interface as an extension to the Basic interface
100+ type Change interface {
101+ // Chmod changes the mode of the named file to mode. If the file is a
102+ // symbolic link, it changes the mode of the link's target.
103+ Chmod (name string , mode os.FileMode ) error
104+ // Lchown changes the numeric uid and gid of the named file. If the file is
105+ // a symbolic link, it changes the uid and gid of the link itself.
106+ Lchown (name string , uid , gid int ) error
107+ // Chown changes the numeric uid and gid of the named file. If the file is a
108+ // symbolic link, it changes the uid and gid of the link's target.
109+ Chown (name string , uid , gid int ) error
110+ // Chtimes changes the access and modification times of the named file,
111+ // similar to the Unix utime() or utimes() functions.
112+ //
113+ // The underlying filesystem may truncate or round the values to a less
114+ // precise time unit.
115+ Chtimes (name string , atime time.Time , mtime time.Time ) error
116+ }
117+
118+ // Chroot abstract the chroot related operations in a storage-agnostic interface
119+ // as an extension to the Basic interface.
120+ type Chroot interface {
121+ // Chroot returns a new filesystem from the same type where the new root is
122+ // the given path. Files outside of the designated directory tree cannot be
123+ // accessed.
124+ Chroot (path string ) (Basic , error )
125+ // Root returns the root path of the filesystem.
126+ Root () string
127+ }
128+
129+ // File represent a file, being a subset of the os.File
59130type File interface {
60- Filename () string
61- IsClosed () bool
131+ // Name returns the name of the file as presented to Open.
132+ Name () string
62133 io.Writer
63134 io.Reader
135+ io.ReaderAt
64136 io.Seeker
65137 io.Closer
66138}
67-
68- type FileInfo os.FileInfo
69-
70- type BaseFile struct {
71- BaseFilename string
72- Closed bool
73- }
74-
75- func (f * BaseFile ) Filename () string {
76- return f .BaseFilename
77- }
78-
79- func (f * BaseFile ) IsClosed () bool {
80- return f .Closed
81- }
82-
83- type removerAll interface {
84- RemoveAll (string ) error
85- }
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