all: remove large dependency
Closes #114
https://github.com/cuelang/cue/pull/114
GitOrigin-RevId: d1f74f78cfa08d3d1c1b330f1adaa88c0b0a63e7
Change-Id: Idba2820dc60bdfa3acc7c96008228eea1ceabcf9
Reviewed-on: https://cue-review.googlesource.com/c/cue/+/3320
Reviewed-by: Marcel van Lohuizen <mpvl@golang.org>
diff --git a/internal/copy/copy.go b/internal/copy/copy.go
new file mode 100644
index 0000000..e767b09
--- /dev/null
+++ b/internal/copy/copy.go
@@ -0,0 +1,131 @@
+// Copyright 2019 CUE Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package copy provides utilities to copy files and directories.
+package copy
+
+import (
+ "fmt"
+ "io"
+ "io/ioutil"
+ "os"
+ "path/filepath"
+)
+
+// File creates dst and copies the contents src to it.
+func File(src, dst string) error {
+ src = filepath.Clean(src)
+ dst = filepath.Clean(dst)
+
+ stat, err := os.Stat(src)
+ if err != nil {
+ return fmt.Errorf("copy file: %v", err)
+ }
+ err = copyFile(stat, src, dst)
+ if err != nil {
+ return fmt.Errorf("copy file: %v", err)
+ }
+ return nil
+}
+
+// Dir copies a src directory to its destination.
+func Dir(src, dst string) error {
+ src = filepath.Clean(src)
+ dst = filepath.Clean(dst)
+
+ stat, err := os.Stat(src)
+ if err != nil {
+ return fmt.Errorf("copy failed: %v", err)
+ } else if !stat.IsDir() {
+ return fmt.Errorf("copy failed: source is not a directory")
+ }
+
+ err = copyDir(stat, src, dst)
+ if err != nil {
+ return fmt.Errorf("copy failed: %v", err)
+ }
+ return nil
+}
+
+func copyDir(info os.FileInfo, src, dst string) error {
+ if _, err := os.Stat(dst); err != nil {
+ if !os.IsNotExist(err) {
+ return fmt.Errorf("dest err %s: %v", dst, err)
+ }
+ if err := os.MkdirAll(dst, info.Mode()); err != nil {
+ return fmt.Errorf("making dest %s: %v", dst, err)
+ }
+ }
+
+ entries, err := ioutil.ReadDir(src)
+ if err != nil {
+ return fmt.Errorf("reading dir %s: %v", src, err)
+ }
+
+ for _, e := range entries {
+ srcPath := filepath.Join(src, e.Name())
+ dstPath := filepath.Join(dst, e.Name())
+
+ switch mode := e.Mode(); mode & os.ModeType {
+ case os.ModeSymlink:
+ err = copySymLink(e, srcPath, dstPath)
+ case os.ModeDir:
+ err = copyDir(e, srcPath, dstPath)
+ default:
+ err = copyFile(e, srcPath, dstPath)
+ }
+ if err != nil {
+ return err
+ }
+ }
+ return nil
+}
+
+func copySymLink(info os.FileInfo, src, dst string) error {
+ mode := info.Mode()
+ link, err := os.Readlink(src)
+ if err != nil {
+ return err
+ }
+ err = os.Symlink(link, dst)
+ if err != nil {
+ return err
+ }
+ return os.Chmod(dst, mode)
+}
+
+func copyFile(info os.FileInfo, src, dst string) (err error) {
+ in, err := os.Open(src)
+ if err != nil {
+ return fmt.Errorf("error reading %s: %v", src, err)
+ }
+ defer in.Close()
+
+ out, err := os.OpenFile(dst, os.O_RDWR|os.O_CREATE|os.O_TRUNC, info.Mode())
+ if err != nil {
+ return fmt.Errorf("error creating %s: %v", dst, err)
+ }
+ defer func() {
+ cErr := out.Close()
+ if err == nil {
+ err = cErr
+ }
+ }()
+
+ _, err = io.Copy(out, in)
+ if err != nil {
+ return fmt.Errorf("error copying %s: %v", dst, err)
+ }
+ return err
+}
