luci-go/common/dirwalk: Code for walking a directory tree efficiently

common/dirwalk/util.go

+// Copyright 2016 The LUCI Authors. All rights reserved.
+// Use of this source code is governed under the Apache License, Version 2.0
+// that can be found in the LICENSE file.
+
+package dirwalk
+
+import "io"
+
+type multiReadCloser struct {
+        io.Reader
+        closers []io.Closer
+}
+
+func (mrc multiReadCloser) Close() error {
+        for _, c := range mrc.closers {
+                if err := c.Close(); err != nil {
+                        return err
+                }
+        }
+        return nil
+}
+
+type stringStack struct {
+        elements []string
+}
+
+func (s *stringStack) push(v string) {
+        s.elements = append(s.elements, v)
+}
+
+func (s *stringStack) pop() string {
+        var v string
+        v, s.elements = s.elements[s.last()], s.elements[:s.last()]
+        return v
+}
+
+func (s *stringStack) peek() string {
+        return s.elements[s.last()]
+}
+
+func (s *stringStack) size() int {
+        return len(s.elements)
+}
+
+func (s *stringStack) last() int {
+        return len(s.elements) - 1
+}
+
+func newStringStack() *stringStack {
+        return &stringStack{elements: make([]string, 0)}
+}