From b64202bc29b9c1cf0118878d1c0acc9cdb2308f6 Mon Sep 17 00:00:00 2001 From: Russ Cox Date: Mon, 6 Jul 2020 11:27:12 -0400 Subject: [PATCH] io/fs: add Glob and GlobFS Add Glob helper function, GlobFS interface, and test. Add Glob method to fstest.MapFS. Add testing of Glob method to fstest.TestFS. For #41190. Change-Id: If89dd7f63e310ba5ca2651340267a9ff39fcc0c7 Reviewed-on: https://go-review.googlesource.com/c/go/+/243915 Trust: Russ Cox Reviewed-by: Rob Pike --- src/go/build/deps_test.go | 2 +- src/io/fs/glob.go | 116 +++++++++++++++++++++++++++++++++++ src/io/fs/glob_test.go | 82 +++++++++++++++++++++++++ src/testing/fstest/mapfs.go | 4 ++ src/testing/fstest/testfs.go | 96 +++++++++++++++++++++++++++++ 5 files changed, 299 insertions(+), 1 deletion(-) create mode 100644 src/io/fs/glob.go create mode 100644 src/io/fs/glob_test.go diff --git a/src/go/build/deps_test.go b/src/go/build/deps_test.go index ccee539086..16a67791cf 100644 --- a/src/go/build/deps_test.go +++ b/src/go/build/deps_test.go @@ -123,7 +123,7 @@ var depsRules = ` < context < TIME; - TIME, io, sort + TIME, io, path, sort < io/fs; # MATH is RUNTIME plus the basic math packages. diff --git a/src/io/fs/glob.go b/src/io/fs/glob.go new file mode 100644 index 0000000000..77f6ebbaaf --- /dev/null +++ b/src/io/fs/glob.go @@ -0,0 +1,116 @@ +// 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 fs + +import ( + "path" + "runtime" +) + +// 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 (assuming the Separator is '/'). +// +// 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) + } + + 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++ { + c := path[i] + if c == '*' || c == '?' || c == '[' || runtime.GOOS == "windows" && c == '\\' { + 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 0000000000..0183a49b6c --- /dev/null +++ b/src/io/fs/glob_test.go @@ -0,0 +1,82 @@ +// Copyright 2009 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" + "testing" +) + +var globTests = []struct { + fs FS + pattern, result string +}{ + {os.DirFS("."), "glob.go", "glob.go"}, + {os.DirFS("."), "gl?b.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) { + _, err := Glob(os.DirFS("."), "[]") + if err == nil { + t.Error("expected error for bad pattern; got none") + } +} + +// 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/testing/fstest/mapfs.go b/src/testing/fstest/mapfs.go index 1eaf8f0040..10e56f5b3c 100644 --- a/src/testing/fstest/mapfs.go +++ b/src/testing/fstest/mapfs.go @@ -128,6 +128,10 @@ func (fsys MapFS) ReadDir(name string) ([]fs.DirEntry, error) { return fs.ReadDir(fsOnly{fsys}, name) } +func (fsys MapFS) Glob(pattern string) ([]string, error) { + return fs.Glob(fsOnly{fsys}, pattern) +} + // A mapFileInfo implements fs.FileInfo and fs.DirEntry for a given map file. type mapFileInfo struct { name string diff --git a/src/testing/fstest/testfs.go b/src/testing/fstest/testfs.go index 4ea6ed6095..21cd00e5b6 100644 --- a/src/testing/fstest/testfs.go +++ b/src/testing/fstest/testfs.go @@ -11,6 +11,8 @@ import ( "io" "io/fs" "io/ioutil" + "path" + "reflect" "sort" "strings" "testing/iotest" @@ -226,6 +228,8 @@ func (t *fsTester) checkDir(dir string) { t.errorf("%s: fs.ReadDir: list not sorted: %s before %s", dir, list2[i].Name(), list2[i+1].Name()) } } + + t.checkGlob(dir, list) } // formatEntry formats an fs.DirEntry into a string for error messages and comparison. @@ -243,6 +247,98 @@ func formatInfo(info fs.FileInfo) string { return fmt.Sprintf("%s IsDir=%v Mode=%v Size=%d ModTime=%v", info.Name(), info.IsDir(), info.Mode(), info.Size(), info.ModTime()) } +// checkGlob checks that various glob patterns work if the file system implements GlobFS. +func (t *fsTester) checkGlob(dir string, list []fs.DirEntry) { + if _, ok := t.fsys.(fs.GlobFS); !ok { + return + } + + // Make a complex glob pattern prefix that only matches dir. + var glob string + if dir != "." { + elem := strings.Split(dir, "/") + for i, e := range elem { + var pattern []rune + for j, r := range e { + if r == '*' || r == '?' || r == '\\' || r == '[' { + pattern = append(pattern, '\\', r) + continue + } + switch (i + j) % 5 { + case 0: + pattern = append(pattern, r) + case 1: + pattern = append(pattern, '[', r, ']') + case 2: + pattern = append(pattern, '[', r, '-', r, ']') + case 3: + pattern = append(pattern, '[', '\\', r, ']') + case 4: + pattern = append(pattern, '[', '\\', r, '-', '\\', r, ']') + } + } + elem[i] = string(pattern) + } + glob = strings.Join(elem, "/") + "/" + } + + // Try to find a letter that appears in only some of the final names. + c := rune('a') + for ; c <= 'z'; c++ { + have, haveNot := false, false + for _, d := range list { + if strings.ContainsRune(d.Name(), c) { + have = true + } else { + haveNot = true + } + } + if have && haveNot { + break + } + } + if c > 'z' { + c = 'a' + } + glob += "*" + string(c) + "*" + + var want []string + for _, d := range list { + if strings.ContainsRune(d.Name(), c) { + want = append(want, path.Join(dir, d.Name())) + } + } + + names, err := t.fsys.(fs.GlobFS).Glob(glob) + if err != nil { + t.errorf("%s: Glob(%#q): %v", dir, glob, err) + return + } + if reflect.DeepEqual(want, names) { + return + } + + if !sort.StringsAreSorted(names) { + t.errorf("%s: Glob(%#q): unsorted output:\n%s", dir, glob, strings.Join(names, "\n")) + sort.Strings(names) + } + + var problems []string + for len(want) > 0 || len(names) > 0 { + switch { + case len(want) > 0 && len(names) > 0 && want[0] == names[0]: + want, names = want[1:], names[1:] + case len(want) > 0 && (len(names) == 0 || want[0] < names[0]): + problems = append(problems, "missing: "+want[0]) + want = want[1:] + default: + problems = append(problems, "extra: "+names[0]) + names = names[1:] + } + } + t.errorf("%s: Glob(%#q): wrong output:\n%s", dir, glob, strings.Join(problems, "\n")) +} + // checkStat checks that a direct stat of path matches entry, // which was found in the parent's directory listing. func (t *fsTester) checkStat(path string, entry fs.DirEntry) {