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author | Russ Cox <rsc@golang.org> | 2020-07-06 09:49:20 -0400 |
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committer | Russ Cox <rsc@golang.org> | 2020-10-20 02:32:41 +0000 |
commit | d4da735091986868015369e01c63794af9cc9b84 (patch) | |
tree | 4f23c46dc0786122d9d8883f1dfb8003c514909e /src/io | |
parent | 627959eb04ee0edc4a985a7526ed7fe838ad2573 (diff) | |
download | go-d4da735091986868015369e01c63794af9cc9b84.tar.gz go-d4da735091986868015369e01c63794af9cc9b84.zip |
io/fs: move FileInfo, FileMode, PathError, ErrInvalid, ... from os to io/fs
First step of creating the new io/fs package.
For #41190.
Change-Id: I1339b1abdd533b0f1deab283628088b2f706fb5b
Reviewed-on: https://go-review.googlesource.com/c/go/+/243906
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Diffstat (limited to 'src/io')
-rw-r--r-- | src/io/fs/fs.go | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/src/io/fs/fs.go b/src/io/fs/fs.go new file mode 100644 index 0000000000..de5c465d9d --- /dev/null +++ b/src/io/fs/fs.go @@ -0,0 +1,140 @@ +// Copyright 2020 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package fs defines basic interfaces to a file system. +// A file system can be provided by the host operating system +// but also by other packages. +package fs + +import ( + "internal/oserror" + "time" +) + +// Generic file system errors. +// Errors returned by file systems can be tested against these errors +// using errors.Is. +var ( + ErrInvalid = errInvalid() // "invalid argument" + ErrPermission = errPermission() // "permission denied" + ErrExist = errExist() // "file already exists" + ErrNotExist = errNotExist() // "file does not exist" + ErrClosed = errClosed() // "file already closed" +) + +func errInvalid() error { return oserror.ErrInvalid } +func errPermission() error { return oserror.ErrPermission } +func errExist() error { return oserror.ErrExist } +func errNotExist() error { return oserror.ErrNotExist } +func errClosed() error { return oserror.ErrClosed } + +// A FileInfo describes a file and is returned by Stat. +type FileInfo interface { + Name() string // base name of the file + Size() int64 // length in bytes for regular files; system-dependent for others + Mode() FileMode // file mode bits + ModTime() time.Time // modification time + IsDir() bool // abbreviation for Mode().IsDir() + Sys() interface{} // underlying data source (can return nil) +} + +// A FileMode represents a file's mode and permission bits. +// The bits have the same definition on all systems, so that +// information about files can be moved from one system +// to another portably. Not all bits apply to all systems. +// The only required bit is ModeDir for directories. +type FileMode uint32 + +// The defined file mode bits are the most significant bits of the FileMode. +// The nine least-significant bits are the standard Unix rwxrwxrwx permissions. +// The values of these bits should be considered part of the public API and +// may be used in wire protocols or disk representations: they must not be +// changed, although new bits might be added. +const ( + // The single letters are the abbreviations + // used by the String method's formatting. + ModeDir FileMode = 1 << (32 - 1 - iota) // d: is a directory + ModeAppend // a: append-only + ModeExclusive // l: exclusive use + ModeTemporary // T: temporary file; Plan 9 only + ModeSymlink // L: symbolic link + ModeDevice // D: device file + ModeNamedPipe // p: named pipe (FIFO) + ModeSocket // S: Unix domain socket + ModeSetuid // u: setuid + ModeSetgid // g: setgid + ModeCharDevice // c: Unix character device, when ModeDevice is set + ModeSticky // t: sticky + ModeIrregular // ?: non-regular file; nothing else is known about this file + + // Mask for the type bits. For regular files, none will be set. + ModeType = ModeDir | ModeSymlink | ModeNamedPipe | ModeSocket | ModeDevice | ModeCharDevice | ModeIrregular + + ModePerm FileMode = 0777 // Unix permission bits +) + +func (m FileMode) String() string { + const str = "dalTLDpSugct?" + var buf [32]byte // Mode is uint32. + w := 0 + for i, c := range str { + if m&(1<<uint(32-1-i)) != 0 { + buf[w] = byte(c) + w++ + } + } + if w == 0 { + buf[w] = '-' + w++ + } + const rwx = "rwxrwxrwx" + for i, c := range rwx { + if m&(1<<uint(9-1-i)) != 0 { + buf[w] = byte(c) + } else { + buf[w] = '-' + } + w++ + } + return string(buf[:w]) +} + +// IsDir reports whether m describes a directory. +// That is, it tests for the ModeDir bit being set in m. +func (m FileMode) IsDir() bool { + return m&ModeDir != 0 +} + +// IsRegular reports whether m describes a regular file. +// That is, it tests that no mode type bits are set. +func (m FileMode) IsRegular() bool { + return m&ModeType == 0 +} + +// Perm returns the Unix permission bits in m (m & ModePerm). +func (m FileMode) Perm() FileMode { + return m & ModePerm +} + +// Type returns type bits in m (m & ModeType). +func (m FileMode) Type() FileMode { + return m & ModeType +} + +// PathError records an error and the operation and file path that caused it. +type PathError struct { + Op string + Path string + Err error +} + +func (e *PathError) Error() string { return e.Op + " " + e.Path + ": " + e.Err.Error() } + +func (e *PathError) Unwrap() error { return e.Err } + +// Timeout reports whether this error represents a timeout. +func (e *PathError) Timeout() bool { + t, ok := e.Err.(interface{ Timeout() bool }) + return ok && t.Timeout() +} |