util: Glob function

Signed-off-by: Máximo Cuadros <[email protected]>

Author: mcuadros

util/glob.go

@@ -0,0 +1,111 @@
+package util
+
+import (
+	"path/filepath"
+	"sort"
+	"strings"
+
+	"gopkg.in/src-d/go-billy.v4"
+)
+
+// 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 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 ErrBadPattern, when pattern
+// is malformed.
+//
+// Function originally from https://golang.org/src/path/filepath/match_test.go
+func Glob(fs billy.Filesystem, pattern string) (matches []string, err error) {
+	if !hasMeta(pattern) {
+		if _, err = fs.Lstat(pattern); err != nil {
+			return nil, nil
+		}
+		return []string{pattern}, nil
+	}
+
+	dir, file := filepath.Split(pattern)
+	// Prevent infinite recursion. See issue 15879.
+	if dir == pattern {
+		return nil, filepath.ErrBadPattern
+	}
+
+	var m []string
+	m, err = Glob(fs, cleanGlobPath(dir))
+	if err != nil {
+		return
+	}
+	for _, d := range m {
+		matches, err = glob(fs, d, file, matches)
+		if err != nil {
+			return
+		}
+	}
+	return
+}
+
+// cleanGlobPath prepares path for glob matching.
+func cleanGlobPath(path string) string {
+	switch path {
+	case "":
+		return "."
+	case string(filepath.Separator):
+		// do nothing to the path
+		return path
+	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. If the directory cannot be
+// opened, it returns the existing matches. New matches are
+// added in lexicographical order.
+func glob(fs billy.Filesystem, dir, pattern string, matches []string) (m []string, e error) {
+	m = matches
+	fi, err := fs.Stat(dir)
+	if err != nil {
+		return
+	}
+
+	if !fi.IsDir() {
+		return
+	}
+
+	names, _ := readdirnames(fs, dir)
+	sort.Strings(names)
+
+	for _, n := range names {
+		matched, err := filepath.Match(pattern, n)
+		if err != nil {
+			return m, err
+		}
+		if matched {
+			m = append(m, filepath.Join(dir, n))
+		}
+	}
+	return
+}
+
+// hasMeta reports whether path contains any of the magic characters
+// recognized by Match.
+func hasMeta(path string) bool {
+	// TODO(niemeyer): Should other magic characters be added here?
+	return strings.ContainsAny(path, "*?[")
+}
+
+func readdirnames(fs billy.Filesystem, dir string) ([]string, error) {
+	files, err := fs.ReadDir(dir)
+	if err != nil {
+		return nil, err
+	}
+
+	var names []string
+	for _, file := range files {
+		names = append(names, file.Name())
+	}
+
+	return names, nil
+}

util/glob_test.go

@@ -0,0 +1,34 @@
+package util_test
+
+import (
+	"path/filepath"
+	"sort"
+	"testing"
+
+	. "gopkg.in/check.v1"
+	"gopkg.in/src-d/go-billy.v4/memfs"
+	"gopkg.in/src-d/go-billy.v4/util"
+)
+
+func Test(t *testing.T) { TestingT(t) }
+
+var _ = Suite(&UtilSuite{})
+
+type UtilSuite struct{}
+
+func (s *UtilSuite) TestCreate(c *C) {
+	fs := memfs.New()
+	util.WriteFile(fs, "foo/qux", nil, 0644)
+	util.WriteFile(fs, "foo/bar", nil, 0644)
+	util.WriteFile(fs, "foo/baz/foo", nil, 0644)
+
+	names, err := util.Glob(fs, "*/b*")
+	c.Assert(err, IsNil)
+	c.Assert(names, HasLen, 2)
+	sort.Strings(names)
+	c.Assert(names, DeepEquals, []string{
+		filepath.Join("foo", "bar"),
+		filepath.Join("foo", "baz"),
+	})
+
+}