+++ /dev/null
-// Copyright 2019 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 carchive_test
-
-import (
- "io"
- "os"
- "path/filepath"
- "strings"
-)
-
-// overlayDir makes a minimal-overhead copy of srcRoot in which new files may be added.
-//
-// TODO: Once we no longer need to support the misc module in GOPATH mode,
-// factor this function out into a package to reduce duplication.
-func overlayDir(dstRoot, srcRoot string) error {
- dstRoot = filepath.Clean(dstRoot)
- if err := os.MkdirAll(dstRoot, 0777); err != nil {
- return err
- }
-
- srcRoot, err := filepath.Abs(srcRoot)
- if err != nil {
- return err
- }
-
- return filepath.Walk(srcRoot, func(srcPath string, info os.FileInfo, err error) error {
- if err != nil || srcPath == srcRoot {
- return err
- }
-
- suffix := strings.TrimPrefix(srcPath, srcRoot)
- for len(suffix) > 0 && suffix[0] == filepath.Separator {
- suffix = suffix[1:]
- }
- dstPath := filepath.Join(dstRoot, suffix)
-
- perm := info.Mode() & os.ModePerm
- if info.Mode()&os.ModeSymlink != 0 {
- info, err = os.Stat(srcPath)
- if err != nil {
- return err
- }
- perm = info.Mode() & os.ModePerm
- }
-
- // Always copy directories (don't symlink them).
- // If we add a file in the overlay, we don't want to add it in the original.
- if info.IsDir() {
- return os.MkdirAll(dstPath, perm|0200)
- }
-
- // If the OS supports symlinks, use them instead of copying bytes.
- if err := os.Symlink(srcPath, dstPath); err == nil {
- return nil
- }
-
- // Otherwise, copy the bytes.
- src, err := os.Open(srcPath)
- if err != nil {
- return err
- }
- defer src.Close()
-
- dst, err := os.OpenFile(dstPath, os.O_WRONLY|os.O_CREATE|os.O_EXCL, perm)
- if err != nil {
- return err
- }
-
- _, err = io.Copy(dst, src)
- if closeErr := dst.Close(); err == nil {
- err = closeErr
- }
- return err
- })
-}