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-rw-r--r--src/io/fs/fs.go257
-rw-r--r--src/io/fs/fs_test.go49
-rw-r--r--src/io/fs/glob.go119
-rw-r--r--src/io/fs/glob_test.go87
-rw-r--r--src/io/fs/readdir.go47
-rw-r--r--src/io/fs/readdir_test.go43
-rw-r--r--src/io/fs/readfile.go63
-rw-r--r--src/io/fs/readfile_test.go59
-rw-r--r--src/io/fs/stat.go31
-rw-r--r--src/io/fs/stat_test.go36
-rw-r--r--src/io/fs/sub.go127
-rw-r--r--src/io/fs/sub_test.go57
-rw-r--r--src/io/fs/walk.go127
-rw-r--r--src/io/fs/walk_test.go129
14 files changed, 1231 insertions, 0 deletions
diff --git a/src/io/fs/fs.go b/src/io/fs/fs.go
new file mode 100644
index 0000000..3d2e2ee
--- /dev/null
+++ b/src/io/fs/fs.go
@@ -0,0 +1,257 @@
+// 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"
+ "unicode/utf8"
+)
+
+// An FS provides access to a hierarchical file system.
+//
+// The FS interface is the minimum implementation required of the file system.
+// A file system may implement additional interfaces,
+// such as ReadFileFS, to provide additional or optimized functionality.
+type FS interface {
+ // Open opens the named file.
+ //
+ // When Open returns an error, it should be of type *PathError
+ // with the Op field set to "open", the Path field set to name,
+ // and the Err field describing the problem.
+ //
+ // Open should reject attempts to open names that do not satisfy
+ // ValidPath(name), returning a *PathError with Err set to
+ // ErrInvalid or ErrNotExist.
+ Open(name string) (File, error)
+}
+
+// ValidPath reports whether the given path name
+// is valid for use in a call to Open.
+//
+// Path names passed to open are UTF-8-encoded,
+// unrooted, slash-separated sequences of path elements, like “x/y/z”.
+// Path names must not contain an element that is “.” or “..” or the empty string,
+// except for the special case that the root directory is named “.”.
+// Paths must not start or end with a slash: “/x” and “x/” are invalid.
+//
+// Note that paths are slash-separated on all systems, even Windows.
+// Paths containing other characters such as backslash and colon
+// are accepted as valid, but those characters must never be
+// interpreted by an FS implementation as path element separators.
+func ValidPath(name string) bool {
+ if !utf8.ValidString(name) {
+ return false
+ }
+
+ if name == "." {
+ // special case
+ return true
+ }
+
+ // Iterate over elements in name, checking each.
+ for {
+ i := 0
+ for i < len(name) && name[i] != '/' {
+ i++
+ }
+ elem := name[:i]
+ if elem == "" || elem == "." || elem == ".." {
+ return false
+ }
+ if i == len(name) {
+ return true // reached clean ending
+ }
+ name = name[i+1:]
+ }
+}
+
+// A File provides access to a single file.
+// The File interface is the minimum implementation required of the file.
+// A file may implement additional interfaces, such as
+// ReadDirFile, ReaderAt, or Seeker, to provide additional or optimized functionality.
+type File interface {
+ Stat() (FileInfo, error)
+ Read([]byte) (int, error)
+ Close() error
+}
+
+// A DirEntry is an entry read from a directory
+// (using the ReadDir function or a ReadDirFile's ReadDir method).
+type DirEntry interface {
+ // Name returns the name of the file (or subdirectory) described by the entry.
+ // This name is only the final element of the path (the base name), not the entire path.
+ // For example, Name would return "hello.go" not "/home/gopher/hello.go".
+ Name() string
+
+ // IsDir reports whether the entry describes a directory.
+ IsDir() bool
+
+ // Type returns the type bits for the entry.
+ // The type bits are a subset of the usual FileMode bits, those returned by the FileMode.Type method.
+ Type() FileMode
+
+ // Info returns the FileInfo for the file or subdirectory described by the entry.
+ // The returned FileInfo may be from the time of the original directory read
+ // or from the time of the call to Info. If the file has been removed or renamed
+ // since the directory read, Info may return an error satisfying errors.Is(err, ErrNotExist).
+ // If the entry denotes a symbolic link, Info reports the information about the link itself,
+ // not the link's target.
+ Info() (FileInfo, error)
+}
+
+// A ReadDirFile is a directory file whose entries can be read with the ReadDir method.
+// Every directory file should implement this interface.
+// (It is permissible for any file to implement this interface,
+// but if so ReadDir should return an error for non-directories.)
+type ReadDirFile interface {
+ File
+
+ // ReadDir reads the contents of the directory and returns
+ // a slice of up to n DirEntry values in directory order.
+ // Subsequent calls on the same file will yield further DirEntry values.
+ //
+ // If n > 0, ReadDir returns at most n DirEntry structures.
+ // In this case, if ReadDir returns an empty slice, it will return
+ // a non-nil error explaining why.
+ // At the end of a directory, the error is io.EOF.
+ //
+ // If n <= 0, ReadDir returns all the DirEntry values from the directory
+ // in a single slice. In this case, if ReadDir succeeds (reads all the way
+ // to the end of the directory), it returns the slice and a nil error.
+ // If it encounters an error before the end of the directory,
+ // ReadDir returns the DirEntry list read until that point and a non-nil error.
+ ReadDir(n int) ([]DirEntry, error)
+}
+
+// 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()
+}
diff --git a/src/io/fs/fs_test.go b/src/io/fs/fs_test.go
new file mode 100644
index 0000000..aae1a76
--- /dev/null
+++ b/src/io/fs/fs_test.go
@@ -0,0 +1,49 @@
+// 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_test
+
+import (
+ . "io/fs"
+ "testing"
+)
+
+var isValidPathTests = []struct {
+ name string
+ ok bool
+}{
+ {".", true},
+ {"x", true},
+ {"x/y", true},
+
+ {"", false},
+ {"..", false},
+ {"/", false},
+ {"x/", false},
+ {"/x", false},
+ {"x/y/", false},
+ {"/x/y", false},
+ {"./", false},
+ {"./x", false},
+ {"x/.", false},
+ {"x/./y", false},
+ {"../", false},
+ {"../x", false},
+ {"x/..", false},
+ {"x/../y", false},
+ {"x//y", false},
+ {`x\`, true},
+ {`x\y`, true},
+ {`x:y`, true},
+ {`\x`, true},
+}
+
+func TestValidPath(t *testing.T) {
+ for _, tt := range isValidPathTests {
+ ok := ValidPath(tt.name)
+ if ok != tt.ok {
+ t.Errorf("ValidPath(%q) = %v, want %v", tt.name, ok, tt.ok)
+ }
+ }
+}
diff --git a/src/io/fs/glob.go b/src/io/fs/glob.go
new file mode 100644
index 0000000..45d9cb6
--- /dev/null
+++ b/src/io/fs/glob.go
@@ -0,0 +1,119 @@
+// 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
+
+import (
+ "path"
+)
+
+// A GlobFS is a file system with a Glob method.
+type GlobFS interface {
+ FS
+
+ // Glob returns the names of all files matching pattern,
+ // providing an implementation of the top-level
+ // Glob function.
+ Glob(pattern string) ([]string, error)
+}
+
+// Glob returns the names of all files matching pattern or nil
+// if there is no matching file. The syntax of patterns is the same
+// as in path.Match. The pattern may describe hierarchical names such as
+// usr/*/bin/ed.
+//
+// Glob ignores file system errors such as I/O errors reading directories.
+// The only possible returned error is path.ErrBadPattern, reporting that
+// the pattern is malformed.
+//
+// If fs implements GlobFS, Glob calls fs.Glob.
+// Otherwise, Glob uses ReadDir to traverse the directory tree
+// and look for matches for the pattern.
+func Glob(fsys FS, pattern string) (matches []string, err error) {
+ if fsys, ok := fsys.(GlobFS); ok {
+ return fsys.Glob(pattern)
+ }
+
+ // Check pattern is well-formed.
+ if _, err := path.Match(pattern, ""); err != nil {
+ return nil, err
+ }
+ if !hasMeta(pattern) {
+ if _, err = Stat(fsys, pattern); err != nil {
+ return nil, nil
+ }
+ return []string{pattern}, nil
+ }
+
+ dir, file := path.Split(pattern)
+ dir = cleanGlobPath(dir)
+
+ if !hasMeta(dir) {
+ return glob(fsys, dir, file, nil)
+ }
+
+ // Prevent infinite recursion. See issue 15879.
+ if dir == pattern {
+ return nil, path.ErrBadPattern
+ }
+
+ var m []string
+ m, err = Glob(fsys, dir)
+ if err != nil {
+ return
+ }
+ for _, d := range m {
+ matches, err = glob(fsys, d, file, matches)
+ if err != nil {
+ return
+ }
+ }
+ return
+}
+
+// cleanGlobPath prepares path for glob matching.
+func cleanGlobPath(path string) string {
+ switch path {
+ case "":
+ return "."
+ default:
+ return path[0 : len(path)-1] // chop off trailing separator
+ }
+}
+
+// glob searches for files matching pattern in the directory dir
+// and appends them to matches, returning the updated slice.
+// If the directory cannot be opened, glob returns the existing matches.
+// New matches are added in lexicographical order.
+func glob(fs FS, dir, pattern string, matches []string) (m []string, e error) {
+ m = matches
+ infos, err := ReadDir(fs, dir)
+ if err != nil {
+ return // ignore I/O error
+ }
+
+ for _, info := range infos {
+ n := info.Name()
+ matched, err := path.Match(pattern, n)
+ if err != nil {
+ return m, err
+ }
+ if matched {
+ m = append(m, path.Join(dir, n))
+ }
+ }
+ return
+}
+
+// hasMeta reports whether path contains any of the magic characters
+// recognized by path.Match.
+func hasMeta(path string) bool {
+ for i := 0; i < len(path); i++ {
+ switch path[i] {
+ case '*', '?', '[', '\\':
+ return true
+ }
+ }
+ return false
+}
diff --git a/src/io/fs/glob_test.go b/src/io/fs/glob_test.go
new file mode 100644
index 0000000..f19bebe
--- /dev/null
+++ b/src/io/fs/glob_test.go
@@ -0,0 +1,87 @@
+// 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_test
+
+import (
+ . "io/fs"
+ "os"
+ "path"
+ "testing"
+)
+
+var globTests = []struct {
+ fs FS
+ pattern, result string
+}{
+ {os.DirFS("."), "glob.go", "glob.go"},
+ {os.DirFS("."), "gl?b.go", "glob.go"},
+ {os.DirFS("."), `gl\ob.go`, "glob.go"},
+ {os.DirFS("."), "*", "glob.go"},
+ {os.DirFS(".."), "*/glob.go", "fs/glob.go"},
+}
+
+func TestGlob(t *testing.T) {
+ for _, tt := range globTests {
+ matches, err := Glob(tt.fs, tt.pattern)
+ if err != nil {
+ t.Errorf("Glob error for %q: %s", tt.pattern, err)
+ continue
+ }
+ if !contains(matches, tt.result) {
+ t.Errorf("Glob(%#q) = %#v want %v", tt.pattern, matches, tt.result)
+ }
+ }
+ for _, pattern := range []string{"no_match", "../*/no_match", `\*`} {
+ matches, err := Glob(os.DirFS("."), pattern)
+ if err != nil {
+ t.Errorf("Glob error for %q: %s", pattern, err)
+ continue
+ }
+ if len(matches) != 0 {
+ t.Errorf("Glob(%#q) = %#v want []", pattern, matches)
+ }
+ }
+}
+
+func TestGlobError(t *testing.T) {
+ bad := []string{`[]`, `nonexist/[]`}
+ for _, pattern := range bad {
+ _, err := Glob(os.DirFS("."), pattern)
+ if err != path.ErrBadPattern {
+ t.Errorf("Glob(fs, %#q) returned err=%v, want path.ErrBadPattern", pattern, err)
+ }
+ }
+}
+
+// contains reports whether vector contains the string s.
+func contains(vector []string, s string) bool {
+ for _, elem := range vector {
+ if elem == s {
+ return true
+ }
+ }
+ return false
+}
+
+type globOnly struct{ GlobFS }
+
+func (globOnly) Open(name string) (File, error) { return nil, ErrNotExist }
+
+func TestGlobMethod(t *testing.T) {
+ check := func(desc string, names []string, err error) {
+ t.Helper()
+ if err != nil || len(names) != 1 || names[0] != "hello.txt" {
+ t.Errorf("Glob(%s) = %v, %v, want %v, nil", desc, names, err, []string{"hello.txt"})
+ }
+ }
+
+ // Test that ReadDir uses the method when present.
+ names, err := Glob(globOnly{testFsys}, "*.txt")
+ check("readDirOnly", names, err)
+
+ // Test that ReadDir uses Open when the method is not present.
+ names, err = Glob(openOnly{testFsys}, "*.txt")
+ check("openOnly", names, err)
+}
diff --git a/src/io/fs/readdir.go b/src/io/fs/readdir.go
new file mode 100644
index 0000000..3a5aa6d
--- /dev/null
+++ b/src/io/fs/readdir.go
@@ -0,0 +1,47 @@
+// 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
+
+import (
+ "errors"
+ "sort"
+)
+
+// ReadDirFS is the interface implemented by a file system
+// that provides an optimized implementation of ReadDir.
+type ReadDirFS interface {
+ FS
+
+ // ReadDir reads the named directory
+ // and returns a list of directory entries sorted by filename.
+ ReadDir(name string) ([]DirEntry, error)
+}
+
+// ReadDir reads the named directory
+// and returns a list of directory entries sorted by filename.
+//
+// If fs implements ReadDirFS, ReadDir calls fs.ReadDir.
+// Otherwise ReadDir calls fs.Open and uses ReadDir and Close
+// on the returned file.
+func ReadDir(fsys FS, name string) ([]DirEntry, error) {
+ if fsys, ok := fsys.(ReadDirFS); ok {
+ return fsys.ReadDir(name)
+ }
+
+ file, err := fsys.Open(name)
+ if err != nil {
+ return nil, err
+ }
+ defer file.Close()
+
+ dir, ok := file.(ReadDirFile)
+ if !ok {
+ return nil, &PathError{Op: "readdir", Path: name, Err: errors.New("not implemented")}
+ }
+
+ list, err := dir.ReadDir(-1)
+ sort.Slice(list, func(i, j int) bool { return list[i].Name() < list[j].Name() })
+ return list, err
+}
diff --git a/src/io/fs/readdir_test.go b/src/io/fs/readdir_test.go
new file mode 100644
index 0000000..405bfa6
--- /dev/null
+++ b/src/io/fs/readdir_test.go
@@ -0,0 +1,43 @@
+// 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_test
+
+import (
+ . "io/fs"
+ "testing"
+)
+
+type readDirOnly struct{ ReadDirFS }
+
+func (readDirOnly) Open(name string) (File, error) { return nil, ErrNotExist }
+
+func TestReadDir(t *testing.T) {
+ check := func(desc string, dirs []DirEntry, err error) {
+ t.Helper()
+ if err != nil || len(dirs) != 2 || dirs[0].Name() != "hello.txt" || dirs[1].Name() != "sub" {
+ var names []string
+ for _, d := range dirs {
+ names = append(names, d.Name())
+ }
+ t.Errorf("ReadDir(%s) = %v, %v, want %v, nil", desc, names, err, []string{"hello.txt", "sub"})
+ }
+ }
+
+ // Test that ReadDir uses the method when present.
+ dirs, err := ReadDir(readDirOnly{testFsys}, ".")
+ check("readDirOnly", dirs, err)
+
+ // Test that ReadDir uses Open when the method is not present.
+ dirs, err = ReadDir(openOnly{testFsys}, ".")
+ check("openOnly", dirs, err)
+
+ // Test that ReadDir on Sub of . works (sub_test checks non-trivial subs).
+ sub, err := Sub(testFsys, ".")
+ if err != nil {
+ t.Fatal(err)
+ }
+ dirs, err = ReadDir(sub, ".")
+ check("sub(.)", dirs, err)
+}
diff --git a/src/io/fs/readfile.go b/src/io/fs/readfile.go
new file mode 100644
index 0000000..7ee9ead
--- /dev/null
+++ b/src/io/fs/readfile.go
@@ -0,0 +1,63 @@
+// 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
+
+import "io"
+
+// ReadFileFS is the interface implemented by a file system
+// that provides an optimized implementation of ReadFile.
+type ReadFileFS interface {
+ FS
+
+ // ReadFile reads the named file and returns its contents.
+ // A successful call returns a nil error, not io.EOF.
+ // (Because ReadFile reads the whole file, the expected EOF
+ // from the final Read is not treated as an error to be reported.)
+ ReadFile(name string) ([]byte, error)
+}
+
+// ReadFile reads the named file from the file system fs and returns its contents.
+// A successful call returns a nil error, not io.EOF.
+// (Because ReadFile reads the whole file, the expected EOF
+// from the final Read is not treated as an error to be reported.)
+//
+// If fs implements ReadFileFS, ReadFile calls fs.ReadFile.
+// Otherwise ReadFile calls fs.Open and uses Read and Close
+// on the returned file.
+func ReadFile(fsys FS, name string) ([]byte, error) {
+ if fsys, ok := fsys.(ReadFileFS); ok {
+ return fsys.ReadFile(name)
+ }
+
+ file, err := fsys.Open(name)
+ if err != nil {
+ return nil, err
+ }
+ defer file.Close()
+
+ var size int
+ if info, err := file.Stat(); err == nil {
+ size64 := info.Size()
+ if int64(int(size64)) == size64 {
+ size = int(size64)
+ }
+ }
+
+ data := make([]byte, 0, size+1)
+ for {
+ if len(data) >= cap(data) {
+ d := append(data[:cap(data)], 0)
+ data = d[:len(data)]
+ }
+ n, err := file.Read(data[len(data):cap(data)])
+ data = data[:len(data)+n]
+ if err != nil {
+ if err == io.EOF {
+ err = nil
+ }
+ return data, err
+ }
+ }
+}
diff --git a/src/io/fs/readfile_test.go b/src/io/fs/readfile_test.go
new file mode 100644
index 0000000..07219c1
--- /dev/null
+++ b/src/io/fs/readfile_test.go
@@ -0,0 +1,59 @@
+// 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_test
+
+import (
+ . "io/fs"
+ "testing"
+ "testing/fstest"
+ "time"
+)
+
+var testFsys = fstest.MapFS{
+ "hello.txt": {
+ Data: []byte("hello, world"),
+ Mode: 0456,
+ ModTime: time.Now(),
+ Sys: &sysValue,
+ },
+ "sub/goodbye.txt": {
+ Data: []byte("goodbye, world"),
+ Mode: 0456,
+ ModTime: time.Now(),
+ Sys: &sysValue,
+ },
+}
+
+var sysValue int
+
+type readFileOnly struct{ ReadFileFS }
+
+func (readFileOnly) Open(name string) (File, error) { return nil, ErrNotExist }
+
+type openOnly struct{ FS }
+
+func TestReadFile(t *testing.T) {
+ // Test that ReadFile uses the method when present.
+ data, err := ReadFile(readFileOnly{testFsys}, "hello.txt")
+ if string(data) != "hello, world" || err != nil {
+ t.Fatalf(`ReadFile(readFileOnly, "hello.txt") = %q, %v, want %q, nil`, data, err, "hello, world")
+ }
+
+ // Test that ReadFile uses Open when the method is not present.
+ data, err = ReadFile(openOnly{testFsys}, "hello.txt")
+ if string(data) != "hello, world" || err != nil {
+ t.Fatalf(`ReadFile(openOnly, "hello.txt") = %q, %v, want %q, nil`, data, err, "hello, world")
+ }
+
+ // Test that ReadFile on Sub of . works (sub_test checks non-trivial subs).
+ sub, err := Sub(testFsys, ".")
+ if err != nil {
+ t.Fatal(err)
+ }
+ data, err = ReadFile(sub, "hello.txt")
+ if string(data) != "hello, world" || err != nil {
+ t.Fatalf(`ReadFile(sub(.), "hello.txt") = %q, %v, want %q, nil`, data, err, "hello, world")
+ }
+}
diff --git a/src/io/fs/stat.go b/src/io/fs/stat.go
new file mode 100644
index 0000000..735a6e3
--- /dev/null
+++ b/src/io/fs/stat.go
@@ -0,0 +1,31 @@
+// 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
+
+// A StatFS is a file system with a Stat method.
+type StatFS interface {
+ FS
+
+ // Stat returns a FileInfo describing the file.
+ // If there is an error, it should be of type *PathError.
+ Stat(name string) (FileInfo, error)
+}
+
+// Stat returns a FileInfo describing the named file from the file system.
+//
+// If fs implements StatFS, Stat calls fs.Stat.
+// Otherwise, Stat opens the file to stat it.
+func Stat(fsys FS, name string) (FileInfo, error) {
+ if fsys, ok := fsys.(StatFS); ok {
+ return fsys.Stat(name)
+ }
+
+ file, err := fsys.Open(name)
+ if err != nil {
+ return nil, err
+ }
+ defer file.Close()
+ return file.Stat()
+}
diff --git a/src/io/fs/stat_test.go b/src/io/fs/stat_test.go
new file mode 100644
index 0000000..e312b6f
--- /dev/null
+++ b/src/io/fs/stat_test.go
@@ -0,0 +1,36 @@
+// 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_test
+
+import (
+ "fmt"
+ . "io/fs"
+ "testing"
+)
+
+type statOnly struct{ StatFS }
+
+func (statOnly) Open(name string) (File, error) { return nil, ErrNotExist }
+
+func TestStat(t *testing.T) {
+ check := func(desc string, info FileInfo, err error) {
+ t.Helper()
+ if err != nil || info == nil || info.Mode() != 0456 {
+ infoStr := "<nil>"
+ if info != nil {
+ infoStr = fmt.Sprintf("FileInfo(Mode: %#o)", info.Mode())
+ }
+ t.Fatalf("Stat(%s) = %v, %v, want Mode:0456, nil", desc, infoStr, err)
+ }
+ }
+
+ // Test that Stat uses the method when present.
+ info, err := Stat(statOnly{testFsys}, "hello.txt")
+ check("statOnly", info, err)
+
+ // Test that Stat uses Open when the method is not present.
+ info, err = Stat(openOnly{testFsys}, "hello.txt")
+ check("openOnly", info, err)
+}
diff --git a/src/io/fs/sub.go b/src/io/fs/sub.go
new file mode 100644
index 0000000..64cdffe
--- /dev/null
+++ b/src/io/fs/sub.go
@@ -0,0 +1,127 @@
+// 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
+
+import (
+ "errors"
+ "path"
+)
+
+// A SubFS is a file system with a Sub method.
+type SubFS interface {
+ FS
+
+ // Sub returns an FS corresponding to the subtree rooted at dir.
+ Sub(dir string) (FS, error)
+}
+
+// Sub returns an FS corresponding to the subtree rooted at fsys's dir.
+//
+// If fs implements SubFS, Sub calls returns fsys.Sub(dir).
+// Otherwise, if dir is ".", Sub returns fsys unchanged.
+// Otherwise, Sub returns a new FS implementation sub that,
+// in effect, implements sub.Open(dir) as fsys.Open(path.Join(dir, name)).
+// The implementation also translates calls to ReadDir, ReadFile, and Glob appropriately.
+//
+// Note that Sub(os.DirFS("/"), "prefix") is equivalent to os.DirFS("/prefix")
+// and that neither of them guarantees to avoid operating system
+// accesses outside "/prefix", because the implementation of os.DirFS
+// does not check for symbolic links inside "/prefix" that point to
+// other directories. That is, os.DirFS is not a general substitute for a
+// chroot-style security mechanism, and Sub does not change that fact.
+func Sub(fsys FS, dir string) (FS, error) {
+ if !ValidPath(dir) {
+ return nil, &PathError{Op: "sub", Path: dir, Err: errors.New("invalid name")}
+ }
+ if dir == "." {
+ return fsys, nil
+ }
+ if fsys, ok := fsys.(SubFS); ok {
+ return fsys.Sub(dir)
+ }
+ return &subFS{fsys, dir}, nil
+}
+
+type subFS struct {
+ fsys FS
+ dir string
+}
+
+// fullName maps name to the fully-qualified name dir/name.
+func (f *subFS) fullName(op string, name string) (string, error) {
+ if !ValidPath(name) {
+ return "", &PathError{Op: op, Path: name, Err: errors.New("invalid name")}
+ }
+ return path.Join(f.dir, name), nil
+}
+
+// shorten maps name, which should start with f.dir, back to the suffix after f.dir.
+func (f *subFS) shorten(name string) (rel string, ok bool) {
+ if name == f.dir {
+ return ".", true
+ }
+ if len(name) >= len(f.dir)+2 && name[len(f.dir)] == '/' && name[:len(f.dir)] == f.dir {
+ return name[len(f.dir)+1:], true
+ }
+ return "", false
+}
+
+// fixErr shortens any reported names in PathErrors by stripping dir.
+func (f *subFS) fixErr(err error) error {
+ if e, ok := err.(*PathError); ok {
+ if short, ok := f.shorten(e.Path); ok {
+ e.Path = short
+ }
+ }
+ return err
+}
+
+func (f *subFS) Open(name string) (File, error) {
+ full, err := f.fullName("open", name)
+ if err != nil {
+ return nil, err
+ }
+ file, err := f.fsys.Open(full)
+ return file, f.fixErr(err)
+}
+
+func (f *subFS) ReadDir(name string) ([]DirEntry, error) {
+ full, err := f.fullName("read", name)
+ if err != nil {
+ return nil, err
+ }
+ dir, err := ReadDir(f.fsys, full)
+ return dir, f.fixErr(err)
+}
+
+func (f *subFS) ReadFile(name string) ([]byte, error) {
+ full, err := f.fullName("read", name)
+ if err != nil {
+ return nil, err
+ }
+ data, err := ReadFile(f.fsys, full)
+ return data, f.fixErr(err)
+}
+
+func (f *subFS) Glob(pattern string) ([]string, error) {
+ // Check pattern is well-formed.
+ if _, err := path.Match(pattern, ""); err != nil {
+ return nil, err
+ }
+ if pattern == "." {
+ return []string{"."}, nil
+ }
+
+ full := f.dir + "/" + pattern
+ list, err := Glob(f.fsys, full)
+ for i, name := range list {
+ name, ok := f.shorten(name)
+ if !ok {
+ return nil, errors.New("invalid result from inner fsys Glob: " + name + " not in " + f.dir) // can't use fmt in this package
+ }
+ list[i] = name
+ }
+ return list, f.fixErr(err)
+}
diff --git a/src/io/fs/sub_test.go b/src/io/fs/sub_test.go
new file mode 100644
index 0000000..451b0ef
--- /dev/null
+++ b/src/io/fs/sub_test.go
@@ -0,0 +1,57 @@
+// 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_test
+
+import (
+ . "io/fs"
+ "testing"
+)
+
+type subOnly struct{ SubFS }
+
+func (subOnly) Open(name string) (File, error) { return nil, ErrNotExist }
+
+func TestSub(t *testing.T) {
+ check := func(desc string, sub FS, err error) {
+ t.Helper()
+ if err != nil {
+ t.Errorf("Sub(sub): %v", err)
+ return
+ }
+ data, err := ReadFile(sub, "goodbye.txt")
+ if string(data) != "goodbye, world" || err != nil {
+ t.Errorf(`ReadFile(%s, "goodbye.txt" = %q, %v, want %q, nil`, desc, string(data), err, "goodbye, world")
+ }
+
+ dirs, err := ReadDir(sub, ".")
+ if err != nil || len(dirs) != 1 || dirs[0].Name() != "goodbye.txt" {
+ var names []string
+ for _, d := range dirs {
+ names = append(names, d.Name())
+ }
+ t.Errorf(`ReadDir(%s, ".") = %v, %v, want %v, nil`, desc, names, err, []string{"goodbye.txt"})
+ }
+ }
+
+ // Test that Sub uses the method when present.
+ sub, err := Sub(subOnly{testFsys}, "sub")
+ check("subOnly", sub, err)
+
+ // Test that Sub uses Open when the method is not present.
+ sub, err = Sub(openOnly{testFsys}, "sub")
+ check("openOnly", sub, err)
+
+ _, err = sub.Open("nonexist")
+ if err == nil {
+ t.Fatal("Open(nonexist): succeeded")
+ }
+ pe, ok := err.(*PathError)
+ if !ok {
+ t.Fatalf("Open(nonexist): error is %T, want *PathError", err)
+ }
+ if pe.Path != "nonexist" {
+ t.Fatalf("Open(nonexist): err.Path = %q, want %q", pe.Path, "nonexist")
+ }
+}
diff --git a/src/io/fs/walk.go b/src/io/fs/walk.go
new file mode 100644
index 0000000..534876b
--- /dev/null
+++ b/src/io/fs/walk.go
@@ -0,0 +1,127 @@
+// 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
+
+import (
+ "errors"
+ "path"
+)
+
+// SkipDir is used as a return value from WalkDirFuncs to indicate that
+// the directory named in the call is to be skipped. It is not returned
+// as an error by any function.
+var SkipDir = errors.New("skip this directory")
+
+// WalkDirFunc is the type of the function called by WalkDir to visit
+// each file or directory.
+//
+// The path argument contains the argument to WalkDir as a prefix.
+// That is, if WalkDir is called with root argument "dir" and finds a file
+// named "a" in that directory, the walk function will be called with
+// argument "dir/a".
+//
+// The d argument is the fs.DirEntry for the named path.
+//
+// The error result returned by the function controls how WalkDir
+// continues. If the function returns the special value SkipDir, WalkDir
+// skips the current directory (path if d.IsDir() is true, otherwise
+// path's parent directory). Otherwise, if the function returns a non-nil
+// error, WalkDir stops entirely and returns that error.
+//
+// The err argument reports an error related to path, signaling that
+// WalkDir will not walk into that directory. The function can decide how
+// to handle that error; as described earlier, returning the error will
+// cause WalkDir to stop walking the entire tree.
+//
+// WalkDir calls the function with a non-nil err argument in two cases.
+//
+// First, if the initial fs.Stat on the root directory fails, WalkDir
+// calls the function with path set to root, d set to nil, and err set to
+// the error from fs.Stat.
+//
+// Second, if a directory's ReadDir method fails, WalkDir calls the
+// function with path set to the directory's path, d set to an
+// fs.DirEntry describing the directory, and err set to the error from
+// ReadDir. In this second case, the function is called twice with the
+// path of the directory: the first call is before the directory read is
+// attempted and has err set to nil, giving the function a chance to
+// return SkipDir and avoid the ReadDir entirely. The second call is
+// after a failed ReadDir and reports the error from ReadDir.
+// (If ReadDir succeeds, there is no second call.)
+//
+// The differences between WalkDirFunc compared to filepath.WalkFunc are:
+//
+// - The second argument has type fs.DirEntry instead of fs.FileInfo.
+// - The function is called before reading a directory, to allow SkipDir
+// to bypass the directory read entirely.
+// - If a directory read fails, the function is called a second time
+// for that directory to report the error.
+//
+type WalkDirFunc func(path string, d DirEntry, err error) error
+
+// walkDir recursively descends path, calling walkDirFn.
+func walkDir(fsys FS, name string, d DirEntry, walkDirFn WalkDirFunc) error {
+ if err := walkDirFn(name, d, nil); err != nil || !d.IsDir() {
+ if err == SkipDir && d.IsDir() {
+ // Successfully skipped directory.
+ err = nil
+ }
+ return err
+ }
+
+ dirs, err := ReadDir(fsys, name)
+ if err != nil {
+ // Second call, to report ReadDir error.
+ err = walkDirFn(name, d, err)
+ if err != nil {
+ return err
+ }
+ }
+
+ for _, d1 := range dirs {
+ name1 := path.Join(name, d1.Name())
+ if err := walkDir(fsys, name1, d1, walkDirFn); err != nil {
+ if err == SkipDir {
+ break
+ }
+ return err
+ }
+ }
+ return nil
+}
+
+// WalkDir walks the file tree rooted at root, calling fn for each file or
+// directory in the tree, including root.
+//
+// All errors that arise visiting files and directories are filtered by fn:
+// see the fs.WalkDirFunc documentation for details.
+//
+// The files are walked in lexical order, which makes the output deterministic
+// but requires WalkDir to read an entire directory into memory before proceeding
+// to walk that directory.
+//
+// WalkDir does not follow symbolic links found in directories,
+// but if root itself is a symbolic link, its target will be walked.
+func WalkDir(fsys FS, root string, fn WalkDirFunc) error {
+ info, err := Stat(fsys, root)
+ if err != nil {
+ err = fn(root, nil, err)
+ } else {
+ err = walkDir(fsys, root, &statDirEntry{info}, fn)
+ }
+ if err == SkipDir {
+ return nil
+ }
+ return err
+}
+
+type statDirEntry struct {
+ info FileInfo
+}
+
+func (d *statDirEntry) Name() string { return d.info.Name() }
+func (d *statDirEntry) IsDir() bool { return d.info.IsDir() }
+func (d *statDirEntry) Type() FileMode { return d.info.Mode().Type() }
+func (d *statDirEntry) Info() (FileInfo, error) { return d.info, nil }
diff --git a/src/io/fs/walk_test.go b/src/io/fs/walk_test.go
new file mode 100644
index 0000000..ebc4e50
--- /dev/null
+++ b/src/io/fs/walk_test.go
@@ -0,0 +1,129 @@
+// 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_test
+
+import (
+ . "io/fs"
+ "io/ioutil"
+ "os"
+ pathpkg "path"
+ "testing"
+ "testing/fstest"
+)
+
+type Node struct {
+ name string
+ entries []*Node // nil if the entry is a file
+ mark int
+}
+
+var tree = &Node{
+ "testdata",
+ []*Node{
+ {"a", nil, 0},
+ {"b", []*Node{}, 0},
+ {"c", nil, 0},
+ {
+ "d",
+ []*Node{
+ {"x", nil, 0},
+ {"y", []*Node{}, 0},
+ {
+ "z",
+ []*Node{
+ {"u", nil, 0},
+ {"v", nil, 0},
+ },
+ 0,
+ },
+ },
+ 0,
+ },
+ },
+ 0,
+}
+
+func walkTree(n *Node, path string, f func(path string, n *Node)) {
+ f(path, n)
+ for _, e := range n.entries {
+ walkTree(e, pathpkg.Join(path, e.name), f)
+ }
+}
+
+func makeTree(t *testing.T) FS {
+ fsys := fstest.MapFS{}
+ walkTree(tree, tree.name, func(path string, n *Node) {
+ if n.entries == nil {
+ fsys[path] = &fstest.MapFile{}
+ } else {
+ fsys[path] = &fstest.MapFile{Mode: ModeDir}
+ }
+ })
+ return fsys
+}
+
+func markTree(n *Node) { walkTree(n, "", func(path string, n *Node) { n.mark++ }) }
+
+func checkMarks(t *testing.T, report bool) {
+ walkTree(tree, tree.name, func(path string, n *Node) {
+ if n.mark != 1 && report {
+ t.Errorf("node %s mark = %d; expected 1", path, n.mark)
+ }
+ n.mark = 0
+ })
+}
+
+// Assumes that each node name is unique. Good enough for a test.
+// If clear is true, any incoming error is cleared before return. The errors
+// are always accumulated, though.
+func mark(entry DirEntry, err error, errors *[]error, clear bool) error {
+ name := entry.Name()
+ walkTree(tree, tree.name, func(path string, n *Node) {
+ if n.name == name {
+ n.mark++
+ }
+ })
+ if err != nil {
+ *errors = append(*errors, err)
+ if clear {
+ return nil
+ }
+ return err
+ }
+ return nil
+}
+
+func TestWalkDir(t *testing.T) {
+ tmpDir, err := ioutil.TempDir("", "TestWalk")
+ if err != nil {
+ t.Fatal("creating temp dir:", err)
+ }
+ defer os.RemoveAll(tmpDir)
+
+ origDir, err := os.Getwd()
+ if err != nil {
+ t.Fatal("finding working dir:", err)
+ }
+ if err = os.Chdir(tmpDir); err != nil {
+ t.Fatal("entering temp dir:", err)
+ }
+ defer os.Chdir(origDir)
+
+ fsys := makeTree(t)
+ errors := make([]error, 0, 10)
+ clear := true
+ markFn := func(path string, entry DirEntry, err error) error {
+ return mark(entry, err, &errors, clear)
+ }
+ // Expect no errors.
+ err = WalkDir(fsys, ".", markFn)
+ if err != nil {
+ t.Fatalf("no error expected, found: %s", err)
+ }
+ if len(errors) != 0 {
+ t.Fatalf("unexpected errors: %s", errors)
+ }
+ checkMarks(t, true)
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-15 15:17:24 +0000