diff options
author | Damien Neil <dneil@google.com> | 2024-04-24 10:58:56 -0700 |
---|---|---|
committer | Damien Neil <dneil@google.com> | 2024-04-26 23:07:50 +0000 |
commit | ceef0633b3c5bbf5d17a12d6e663c136b30b3f36 (patch) | |
tree | 612eb4650548318aa416086f910570ed77440cdd /src/path | |
parent | ad22356ec660844ec43ccbe9a834845f1a6f7cf8 (diff) | |
download | go-ceef0633b3c5bbf5d17a12d6e663c136b30b3f36.tar.gz go-ceef0633b3c5bbf5d17a12d6e663c136b30b3f36.zip |
path/filepath, internal/filepathlite: move parts of filepath to filepathlite
The path/filepath package needs to depend on the os package to
implement Abs, Walk, and other functions. Move the implementation
of purely lexical functions from path/filepath into
internal/filepathlite, so they can be used by os and
other low-level packages.
Change-Id: Id211e547d6f1f58c82419695ff2d75cd6cd14a12
Reviewed-on: https://go-review.googlesource.com/c/go/+/566556
Reviewed-by: Behroz Karimpor <behrozkarimpor201@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Diffstat (limited to 'src/path')
-rw-r--r-- | src/path/filepath/match.go | 3 | ||||
-rw-r--r-- | src/path/filepath/path.go | 214 | ||||
-rw-r--r-- | src/path/filepath/path_nonwindows.go | 9 | ||||
-rw-r--r-- | src/path/filepath/path_plan9.go | 19 | ||||
-rw-r--r-- | src/path/filepath/path_unix.go | 19 | ||||
-rw-r--r-- | src/path/filepath/path_windows.go | 200 | ||||
-rw-r--r-- | src/path/filepath/symlink.go | 9 |
7 files changed, 33 insertions, 440 deletions
diff --git a/src/path/filepath/match.go b/src/path/filepath/match.go index 12f0bfa7d3..67124796db 100644 --- a/src/path/filepath/match.go +++ b/src/path/filepath/match.go @@ -6,6 +6,7 @@ package filepath import ( "errors" + "internal/filepathlite" "os" "runtime" "sort" @@ -307,7 +308,7 @@ func cleanGlobPath(path string) string { // cleanGlobPathWindows is windows version of cleanGlobPath. func cleanGlobPathWindows(path string) (prefixLen int, cleaned string) { - vollen := volumeNameLen(path) + vollen := filepathlite.VolumeNameLen(path) switch { case path == "": return 0, "." diff --git a/src/path/filepath/path.go b/src/path/filepath/path.go index cd70c2b318..b0f3cbbfe9 100644 --- a/src/path/filepath/path.go +++ b/src/path/filepath/path.go @@ -13,58 +13,13 @@ package filepath import ( "errors" + "internal/bytealg" "internal/filepathlite" "io/fs" "os" - "slices" "sort" - "strings" ) -// A lazybuf is a lazily constructed path buffer. -// It supports append, reading previously appended bytes, -// and retrieving the final string. It does not allocate a buffer -// to hold the output until that output diverges from s. -type lazybuf struct { - path string - buf []byte - w int - volAndPath string - volLen int -} - -func (b *lazybuf) index(i int) byte { - if b.buf != nil { - return b.buf[i] - } - return b.path[i] -} - -func (b *lazybuf) append(c byte) { - if b.buf == nil { - if b.w < len(b.path) && b.path[b.w] == c { - b.w++ - return - } - b.buf = make([]byte, len(b.path)) - copy(b.buf, b.path[:b.w]) - } - b.buf[b.w] = c - b.w++ -} - -func (b *lazybuf) prepend(prefix ...byte) { - b.buf = slices.Insert(b.buf, 0, prefix...) - b.w += len(prefix) -} - -func (b *lazybuf) string() string { - if b.buf == nil { - return b.volAndPath[:b.volLen+b.w] - } - return b.volAndPath[:b.volLen] + string(b.buf[:b.w]) -} - const ( Separator = os.PathSeparator ListSeparator = os.PathListSeparator @@ -98,78 +53,7 @@ const ( // Getting Dot-Dot Right,” // https://9p.io/sys/doc/lexnames.html func Clean(path string) string { - originalPath := path - volLen := volumeNameLen(path) - path = path[volLen:] - if path == "" { - if volLen > 1 && os.IsPathSeparator(originalPath[0]) && os.IsPathSeparator(originalPath[1]) { - // should be UNC - return FromSlash(originalPath) - } - return originalPath + "." - } - rooted := os.IsPathSeparator(path[0]) - - // Invariants: - // reading from path; r is index of next byte to process. - // writing to buf; w is index of next byte to write. - // dotdot is index in buf where .. must stop, either because - // it is the leading slash or it is a leading ../../.. prefix. - n := len(path) - out := lazybuf{path: path, volAndPath: originalPath, volLen: volLen} - r, dotdot := 0, 0 - if rooted { - out.append(Separator) - r, dotdot = 1, 1 - } - - for r < n { - switch { - case os.IsPathSeparator(path[r]): - // empty path element - r++ - case path[r] == '.' && (r+1 == n || os.IsPathSeparator(path[r+1])): - // . element - r++ - case path[r] == '.' && path[r+1] == '.' && (r+2 == n || os.IsPathSeparator(path[r+2])): - // .. element: remove to last separator - r += 2 - switch { - case out.w > dotdot: - // can backtrack - out.w-- - for out.w > dotdot && !os.IsPathSeparator(out.index(out.w)) { - out.w-- - } - case !rooted: - // cannot backtrack, but not rooted, so append .. element. - if out.w > 0 { - out.append(Separator) - } - out.append('.') - out.append('.') - dotdot = out.w - } - default: - // real path element. - // add slash if needed - if rooted && out.w != 1 || !rooted && out.w != 0 { - out.append(Separator) - } - // copy element - for ; r < n && !os.IsPathSeparator(path[r]); r++ { - out.append(path[r]) - } - } - } - - // Turn empty string into "." - if out.w == 0 { - out.append('.') - } - - postClean(&out) // avoid creating absolute paths on Windows - return FromSlash(out.string()) + return filepathlite.Clean(path) } // IsLocal reports whether path, using lexical analysis only, has all of these properties: @@ -187,29 +71,7 @@ func Clean(path string) string { // In particular, it does not account for the effect of any symbolic links // that may exist in the filesystem. func IsLocal(path string) bool { - return isLocal(path) -} - -func unixIsLocal(path string) bool { - if IsAbs(path) || path == "" { - return false - } - hasDots := false - for p := path; p != ""; { - var part string - part, p, _ = strings.Cut(p, "/") - if part == "." || part == ".." { - hasDots = true - break - } - } - if hasDots { - path = Clean(path) - } - if path == ".." || strings.HasPrefix(path, "../") { - return false - } - return true + return filepathlite.IsLocal(path) } // Localize converts a slash-separated path into an operating system path. @@ -228,10 +90,7 @@ func Localize(path string) (string, error) { // in path with a slash ('/') character. Multiple separators are // replaced by multiple slashes. func ToSlash(path string) string { - if Separator == '/' { - return path - } - return strings.ReplaceAll(path, string(Separator), "/") + return filepathlite.ToSlash(path) } // FromSlash returns the result of replacing each slash ('/') character @@ -241,10 +100,7 @@ func ToSlash(path string) string { // See also the Localize function, which converts a slash-separated path // as used by the io/fs package to an operating system path. func FromSlash(path string) string { - if Separator == '/' { - return path - } - return strings.ReplaceAll(path, "/", string(Separator)) + return filepathlite.FromSlash(path) } // SplitList splits a list of paths joined by the OS-specific [ListSeparator], @@ -261,12 +117,7 @@ func SplitList(path string) []string { // and file set to path. // The returned values have the property that path = dir+file. func Split(path string) (dir, file string) { - vol := VolumeName(path) - i := len(path) - 1 - for i >= len(vol) && !os.IsPathSeparator(path[i]) { - i-- - } - return path[:i+1], path[i+1:] + return filepathlite.Split(path) } // Join joins any number of path elements into a single path, @@ -285,12 +136,7 @@ func Join(elem ...string) string { // in the final element of path; it is empty if there is // no dot. func Ext(path string) string { - for i := len(path) - 1; i >= 0 && !os.IsPathSeparator(path[i]); i-- { - if path[i] == '.' { - return path[i:] - } - } - return "" + return filepathlite.Ext(path) } // EvalSymlinks returns the path name after the evaluation of any symbolic @@ -302,6 +148,11 @@ func EvalSymlinks(path string) (string, error) { return evalSymlinks(path) } +// IsAbs reports whether the path is absolute. +func IsAbs(path string) bool { + return filepathlite.IsAbs(path) +} + // Abs returns an absolute representation of path. // If the path is not absolute it will be joined with the current // working directory to turn it into an absolute path. The absolute @@ -342,7 +193,7 @@ func Rel(basepath, targpath string) (string, error) { targ = targ[len(targVol):] if base == "." { base = "" - } else if base == "" && volumeNameLen(baseVol) > 2 /* isUNC */ { + } else if base == "" && filepathlite.VolumeNameLen(baseVol) > 2 /* isUNC */ { // Treat any targetpath matching `\\host\share` basepath as absolute path. base = string(Separator) } @@ -381,7 +232,7 @@ func Rel(basepath, targpath string) (string, error) { } if b0 != bl { // Base elements left. Must go up before going down. - seps := strings.Count(base[b0:bl], string(Separator)) + seps := bytealg.CountString(base[b0:bl], Separator) size := 2 + seps*3 if tl != t0 { size += 1 + tl - t0 @@ -602,28 +453,7 @@ func readDirNames(dirname string) ([]string, error) { // If the path is empty, Base returns ".". // If the path consists entirely of separators, Base returns a single separator. func Base(path string) string { - if path == "" { - return "." - } - // Strip trailing slashes. - for len(path) > 0 && os.IsPathSeparator(path[len(path)-1]) { - path = path[0 : len(path)-1] - } - // Throw away volume name - path = path[len(VolumeName(path)):] - // Find the last element - i := len(path) - 1 - for i >= 0 && !os.IsPathSeparator(path[i]) { - i-- - } - if i >= 0 { - path = path[i+1:] - } - // If empty now, it had only slashes. - if path == "" { - return string(Separator) - } - return path + return filepathlite.Base(path) } // Dir returns all but the last element of path, typically the path's directory. @@ -633,17 +463,7 @@ func Base(path string) string { // If the path consists entirely of separators, Dir returns a single separator. // The returned path does not end in a separator unless it is the root directory. func Dir(path string) string { - vol := VolumeName(path) - i := len(path) - 1 - for i >= len(vol) && !os.IsPathSeparator(path[i]) { - i-- - } - dir := Clean(path[len(vol) : i+1]) - if dir == "." && len(vol) > 2 { - // must be UNC - return vol - } - return vol + dir + return filepathlite.Dir(path) } // VolumeName returns leading volume name. @@ -651,5 +471,5 @@ func Dir(path string) string { // Given "\\host\share\foo" it returns "\\host\share". // On other platforms it returns "". func VolumeName(path string) string { - return FromSlash(path[:volumeNameLen(path)]) + return filepathlite.VolumeName(path) } diff --git a/src/path/filepath/path_nonwindows.go b/src/path/filepath/path_nonwindows.go deleted file mode 100644 index db69f0228b..0000000000 --- a/src/path/filepath/path_nonwindows.go +++ /dev/null @@ -1,9 +0,0 @@ -// Copyright 2023 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. - -//go:build !windows - -package filepath - -func postClean(out *lazybuf) {} diff --git a/src/path/filepath/path_plan9.go b/src/path/filepath/path_plan9.go index 453206aee3..0e5147b90b 100644 --- a/src/path/filepath/path_plan9.go +++ b/src/path/filepath/path_plan9.go @@ -4,22 +4,9 @@ package filepath -import "strings" - -func isLocal(path string) bool { - return unixIsLocal(path) -} - -// IsAbs reports whether the path is absolute. -func IsAbs(path string) bool { - return strings.HasPrefix(path, "/") || strings.HasPrefix(path, "#") -} - -// volumeNameLen returns length of the leading volume name on Windows. -// It returns 0 elsewhere. -func volumeNameLen(path string) int { - return 0 -} +import ( + "strings" +) // HasPrefix exists for historical compatibility and should not be used. // diff --git a/src/path/filepath/path_unix.go b/src/path/filepath/path_unix.go index 57e6217434..6bc974db3f 100644 --- a/src/path/filepath/path_unix.go +++ b/src/path/filepath/path_unix.go @@ -6,22 +6,9 @@ package filepath -import "strings" - -func isLocal(path string) bool { - return unixIsLocal(path) -} - -// IsAbs reports whether the path is absolute. -func IsAbs(path string) bool { - return strings.HasPrefix(path, "/") -} - -// volumeNameLen returns length of the leading volume name on Windows. -// It returns 0 elsewhere. -func volumeNameLen(path string) int { - return 0 -} +import ( + "strings" +) // HasPrefix exists for historical compatibility and should not be used. // diff --git a/src/path/filepath/path_windows.go b/src/path/filepath/path_windows.go index 44037c45ac..d53f87f1ac 100644 --- a/src/path/filepath/path_windows.go +++ b/src/path/filepath/path_windows.go @@ -1,179 +1,11 @@ -// Copyright 2010 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 filepath import ( - "internal/filepathlite" "os" "strings" "syscall" ) -func isSlash(c uint8) bool { - return c == '\\' || c == '/' -} - -func toUpper(c byte) byte { - if 'a' <= c && c <= 'z' { - return c - ('a' - 'A') - } - return c -} - -func isLocal(path string) bool { - if path == "" { - return false - } - if isSlash(path[0]) { - // Path rooted in the current drive. - return false - } - if strings.IndexByte(path, ':') >= 0 { - // Colons are only valid when marking a drive letter ("C:foo"). - // Rejecting any path with a colon is conservative but safe. - return false - } - hasDots := false // contains . or .. path elements - for p := path; p != ""; { - var part string - part, p, _ = cutPath(p) - if part == "." || part == ".." { - hasDots = true - } - if filepathlite.IsReservedName(part) { - return false - } - } - if hasDots { - path = Clean(path) - } - if path == ".." || strings.HasPrefix(path, `..\`) { - return false - } - return true -} - -// IsAbs reports whether the path is absolute. -func IsAbs(path string) (b bool) { - l := volumeNameLen(path) - if l == 0 { - return false - } - // If the volume name starts with a double slash, this is an absolute path. - if isSlash(path[0]) && isSlash(path[1]) { - return true - } - path = path[l:] - if path == "" { - return false - } - return isSlash(path[0]) -} - -// volumeNameLen returns length of the leading volume name on Windows. -// It returns 0 elsewhere. -// -// See: -// https://learn.microsoft.com/en-us/dotnet/standard/io/file-path-formats -// https://googleprojectzero.blogspot.com/2016/02/the-definitive-guide-on-win32-to-nt.html -func volumeNameLen(path string) int { - switch { - case len(path) >= 2 && path[1] == ':': - // Path starts with a drive letter. - // - // Not all Windows functions necessarily enforce the requirement that - // drive letters be in the set A-Z, and we don't try to here. - // - // We don't handle the case of a path starting with a non-ASCII character, - // in which case the "drive letter" might be multiple bytes long. - return 2 - - case len(path) == 0 || !isSlash(path[0]): - // Path does not have a volume component. - return 0 - - case pathHasPrefixFold(path, `\\.\UNC`): - // We're going to treat the UNC host and share as part of the volume - // prefix for historical reasons, but this isn't really principled; - // Windows's own GetFullPathName will happily remove the first - // component of the path in this space, converting - // \\.\unc\a\b\..\c into \\.\unc\a\c. - return uncLen(path, len(`\\.\UNC\`)) - - case pathHasPrefixFold(path, `\\.`) || - pathHasPrefixFold(path, `\\?`) || pathHasPrefixFold(path, `\??`): - // Path starts with \\.\, and is a Local Device path; or - // path starts with \\?\ or \??\ and is a Root Local Device path. - // - // We treat the next component after the \\.\ prefix as - // part of the volume name, which means Clean(`\\?\c:\`) - // won't remove the trailing \. (See #64028.) - if len(path) == 3 { - return 3 // exactly \\. - } - _, rest, ok := cutPath(path[4:]) - if !ok { - return len(path) - } - return len(path) - len(rest) - 1 - - case len(path) >= 2 && isSlash(path[1]): - // Path starts with \\, and is a UNC path. - return uncLen(path, 2) - } - return 0 -} - -// pathHasPrefixFold tests whether the path s begins with prefix, -// ignoring case and treating all path separators as equivalent. -// If s is longer than prefix, then s[len(prefix)] must be a path separator. -func pathHasPrefixFold(s, prefix string) bool { - if len(s) < len(prefix) { - return false - } - for i := 0; i < len(prefix); i++ { - if isSlash(prefix[i]) { - if !isSlash(s[i]) { - return false - } - } else if toUpper(prefix[i]) != toUpper(s[i]) { - return false - } - } - if len(s) > len(prefix) && !isSlash(s[len(prefix)]) { - return false - } - return true -} - -// uncLen returns the length of the volume prefix of a UNC path. -// prefixLen is the prefix prior to the start of the UNC host; -// for example, for "//host/share", the prefixLen is len("//")==2. -func uncLen(path string, prefixLen int) int { - count := 0 - for i := prefixLen; i < len(path); i++ { - if isSlash(path[i]) { - count++ - if count == 2 { - return i - } - } - } - return len(path) -} - -// cutPath slices path around the first path separator. -func cutPath(path string) (before, after string, found bool) { - for i := range path { - if isSlash(path[i]) { - return path[:i], path[i+1:], true - } - } - return path, "", false -} - // HasPrefix exists for historical compatibility and should not be used. // // Deprecated: HasPrefix does not respect path boundaries and @@ -237,7 +69,7 @@ func join(elem []string) string { switch { case b.Len() == 0: // Add the first non-empty path element unchanged. - case isSlash(lastChar): + case os.IsPathSeparator(lastChar): // If the path ends in a slash, strip any leading slashes from the next // path element to avoid creating a UNC path (any path starting with "\\") // from non-UNC elements. @@ -245,13 +77,13 @@ func join(elem []string) string { // The correct behavior for Join when the first element is an incomplete UNC // path (for example, "\\") is underspecified. We currently join subsequent // elements so Join("\\", "host", "share") produces "\\host\share". - for len(e) > 0 && isSlash(e[0]) { + for len(e) > 0 && os.IsPathSeparator(e[0]) { e = e[1:] } // If the path is \ and the next path element is ??, // add an extra .\ to create \.\?? rather than \??\ // (a Root Local Device path). - if b.Len() == 1 && pathHasPrefixFold(e, "??") { + if b.Len() == 1 && strings.HasPrefix(e, "??") && (len(e) == len("??") || os.IsPathSeparator(e[2])) { b.WriteString(`.\`) } case lastChar == ':': @@ -280,29 +112,3 @@ func join(elem []string) string { func sameWord(a, b string) bool { return strings.EqualFold(a, b) } - -// postClean adjusts the results of Clean to avoid turning a relative path -// into an absolute or rooted one. -func postClean(out *lazybuf) { - if out.volLen != 0 || out.buf == nil { - return - } - // If a ':' appears in the path element at the start of a path, - // insert a .\ at the beginning to avoid converting relative paths - // like a/../c: into c:. - for _, c := range out.buf { - if os.IsPathSeparator(c) { - break - } - if c == ':' { - out.prepend('.', Separator) - return - } - } - // If a path begins with \??\, insert a \. at the beginning - // to avoid converting paths like \a\..\??\c:\x into \??\c:\x - // (equivalent to c:\x). - if len(out.buf) >= 3 && os.IsPathSeparator(out.buf[0]) && out.buf[1] == '?' && out.buf[2] == '?' { - out.prepend(Separator, '.') - } -} diff --git a/src/path/filepath/symlink.go b/src/path/filepath/symlink.go index f9435e0d5b..a6047ae444 100644 --- a/src/path/filepath/symlink.go +++ b/src/path/filepath/symlink.go @@ -6,6 +6,7 @@ package filepath import ( "errors" + "internal/filepathlite" "io/fs" "os" "runtime" @@ -13,7 +14,7 @@ import ( ) func walkSymlinks(path string) (string, error) { - volLen := volumeNameLen(path) + volLen := filepathlite.VolumeNameLen(path) pathSeparator := string(os.PathSeparator) if volLen < len(path) && os.IsPathSeparator(path[volLen]) { @@ -34,7 +35,7 @@ func walkSymlinks(path string) (string, error) { // On Windows, "." can be a symlink. // We look it up, and use the value if it is absolute. // If not, we just return ".". - isWindowsDot := runtime.GOOS == "windows" && path[volumeNameLen(path):] == "." + isWindowsDot := runtime.GOOS == "windows" && path[filepathlite.VolumeNameLen(path):] == "." // The next path component is in path[start:end]. if end == start { @@ -73,7 +74,7 @@ func walkSymlinks(path string) (string, error) { // Ordinary path component. Add it to result. - if len(dest) > volumeNameLen(dest) && !os.IsPathSeparator(dest[len(dest)-1]) { + if len(dest) > filepathlite.VolumeNameLen(dest) && !os.IsPathSeparator(dest[len(dest)-1]) { dest += pathSeparator } @@ -113,7 +114,7 @@ func walkSymlinks(path string) (string, error) { path = link + path[end:] - v := volumeNameLen(link) + v := filepathlite.VolumeNameLen(link) if v > 0 { // Symlink to drive name is an absolute path. if v < len(link) && os.IsPathSeparator(link[v]) { |