79 lines
1.8 KiB
Go
79 lines
1.8 KiB
Go
// 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 plugin_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
|
|
})
|
|
}
|