Vendor shutil from: bcacb06fec

internal/shutil/shutil.go

@@ -0,0 +1,326 @@
+package shutil
+
+import (
+  "fmt"
+  "io"
+  "io/ioutil"
+  "os"
+  "path/filepath"
+)
+
+
+type SameFileError struct {
+  Src string
+  Dst string
+}
+
+func (e SameFileError) Error() string {
+  return fmt.Sprintf("%s and %s are the same file", e.Src, e.Dst)
+}
+
+type SpecialFileError struct {
+  File string
+  FileInfo os.FileInfo
+}
+
+func (e SpecialFileError) Error() string {
+  return fmt.Sprintf("`%s` is a named pipe", e.File)
+}
+
+type NotADirectoryError struct {
+  Src string
+}
+
+func (e NotADirectoryError) Error() string {
+  return fmt.Sprintf("`%s` is not a directory", e.Src)
+}
+
+
+type AlreadyExistsError struct {
+  Dst string
+}
+
+func (e AlreadyExistsError) Error() string {
+  return fmt.Sprintf("`%s` already exists", e.Dst)
+}
+
+
+func samefile(src string, dst string) bool {
+  srcInfo, _ := os.Stat(src)
+  dstInfo, _ := os.Stat(dst)
+  return os.SameFile(srcInfo, dstInfo)
+}
+
+func specialfile(fi os.FileInfo) bool {
+  return (fi.Mode() & os.ModeNamedPipe) == os.ModeNamedPipe
+}
+
+func stringInSlice(a string, list []string) bool {
+    for _, b := range list {
+        if b == a {
+            return true
+        }
+    }
+    return false
+}
+
+func IsSymlink(fi os.FileInfo) bool {
+  return (fi.Mode() & os.ModeSymlink) == os.ModeSymlink
+}
+
+
+// Copy data from src to dst
+//
+// If followSymlinks is not set and src is a symbolic link, a
+// new symlink will be created instead of copying the file it points
+// to.
+func CopyFile(src, dst string, followSymlinks bool) (error) {
+  if samefile(src, dst) {
+    return &SameFileError{src, dst}
+  }
+
+  // Make sure src exists and neither are special files
+  srcStat, err := os.Lstat(src)
+  if err != nil {
+    return err
+  }
+  if specialfile(srcStat) {
+    return &SpecialFileError{src, srcStat}
+  }
+
+  dstStat, err := os.Stat(dst)
+  if err != nil && !os.IsNotExist(err) {
+    return err
+  } else if err == nil {
+    if specialfile(dstStat) {
+      return &SpecialFileError{dst, dstStat}
+    }
+  }
+
+  // If we don't follow symlinks and it's a symlink, just link it and be done
+  if !followSymlinks && IsSymlink(srcStat) {
+    return os.Symlink(src, dst)
+  }
+
+  // If we are a symlink, follow it
+  if IsSymlink(srcStat) {
+    src, err = os.Readlink(src)
+    if err != nil {
+      return err
+    }
+    srcStat, err = os.Stat(src)
+    if err != nil {
+      return err
+    }
+  }
+
+  // Do the actual copy
+  fsrc, err := os.Open(src)
+  if err != nil {
+    return err
+  }
+  defer fsrc.Close()
+
+  fdst, err := os.Create(dst)
+  if err != nil {
+    return err
+  }
+  defer fdst.Close()
+
+  size, err := io.Copy(fdst, fsrc)
+  if err != nil {
+    return err
+  }
+
+  if size != srcStat.Size() {
+    return fmt.Errorf("%s: %d/%d copied", src, size, srcStat.Size())
+  }
+
+  return nil
+}
+
+
+// Copy mode bits from src to dst.
+//
+// If followSymlinks is false, symlinks aren't followed if and only
+// if both `src` and `dst` are symlinks. If `lchmod` isn't available
+// and both are symlinks this does nothing. (I don't think lchmod is
+// available in Go)
+func CopyMode(src, dst string, followSymlinks bool) error {
+  srcStat, err := os.Lstat(src)
+  if err != nil {
+    return err
+  }
+
+  dstStat, err := os.Lstat(dst)
+  if err != nil {
+    return err
+  }
+
+  // They are both symlinks and we can't change mode on symlinks.
+  if !followSymlinks && IsSymlink(srcStat) && IsSymlink(dstStat) {
+    return nil
+  }
+
+  // Atleast one is not a symlink, get the actual file stats
+  srcStat, _ = os.Stat(src)
+  err = os.Chmod(dst, srcStat.Mode())
+  return err
+}
+
+
+// Copy data and mode bits ("cp src dst"). Return the file's destination.
+//
+// The destination may be a directory.
+//
+// If followSymlinks is false, symlinks won't be followed. This
+// resembles GNU's "cp -P src dst".
+//
+// If source and destination are the same file, a SameFileError will be
+// rased.
+func Copy(src, dst string, followSymlinks bool) (string, error){
+  dstInfo, err := os.Stat(dst)
+
+  if err == nil && dstInfo.Mode().IsDir() {
+    dst = filepath.Join(dst, filepath.Base(src))
+  }
+
+  if err != nil && !os.IsNotExist(err) {
+    return dst, err
+  }
+
+  err = CopyFile(src, dst, followSymlinks)
+  if err != nil {
+    return dst, err
+  }
+
+  err = CopyMode(src, dst, followSymlinks)
+  if err != nil {
+    return dst, err
+  }
+
+  return dst, nil
+}
+
+type CopyTreeOptions struct {
+  Symlinks bool
+  IgnoreDanglingSymlinks bool
+  CopyFunction func (string, string, bool) (string, error)
+  Ignore func (string, []os.FileInfo) []string
+}
+
+// Recursively copy a directory tree.
+//
+// The destination directory must not already exist.
+//
+// If the optional Symlinks flag is true, symbolic links in the
+// source tree result in symbolic links in the destination tree; if
+// it is false, the contents of the files pointed to by symbolic
+// links are copied. If the file pointed by the symlink doesn't
+// exist, an error will be returned.
+//
+// You can set the optional IgnoreDanglingSymlinks flag to true if you
+// want to silence this error. Notice that this has no effect on
+// platforms that don't support os.Symlink.
+//
+// The optional ignore argument is a callable. If given, it
+// is called with the `src` parameter, which is the directory
+// being visited by CopyTree(), and `names` which is the list of
+// `src` contents, as returned by ioutil.ReadDir():
+//
+//   callable(src, entries) -> ignoredNames
+//
+// Since CopyTree() is called recursively, the callable will be
+// called once for each directory that is copied. It returns a
+// list of names relative to the `src` directory that should
+// not be copied.
+//
+// The optional copyFunction argument is a callable that will be used
+// to copy each file. It will be called with the source path and the
+// destination path as arguments. By default, Copy() is used, but any
+// function that supports the same signature (like Copy2() when it
+// exists) can be used.
+func CopyTree(src, dst string, options *CopyTreeOptions) error {
+  if options == nil {
+    options = &CopyTreeOptions{Symlinks:false,
+                               Ignore:nil,
+                               CopyFunction:Copy,
+                               IgnoreDanglingSymlinks:false}
+  }
+
+
+  srcFileInfo, err := os.Stat(src)
+  if err != nil {
+    return err
+  }
+
+  if !srcFileInfo.IsDir() {
+    return &NotADirectoryError{src}
+  }
+
+  _, err = os.Open(dst)
+  if !os.IsNotExist(err) {
+    return &AlreadyExistsError{dst}
+  }
+
+  entries, err := ioutil.ReadDir(src)
+  if err != nil {
+    return err
+  }
+
+  err = os.MkdirAll(dst, srcFileInfo.Mode())
+  if err != nil {
+    return err
+  }
+
+  ignoredNames := []string{}
+  if options.Ignore != nil {
+    ignoredNames = options.Ignore(src, entries)
+  }
+
+  for _, entry := range entries {
+    if stringInSlice(entry.Name(), ignoredNames) {
+      continue
+    }
+    srcPath := filepath.Join(src, entry.Name())
+    dstPath := filepath.Join(dst, entry.Name())
+
+    entryFileInfo, err := os.Lstat(srcPath)
+    if err != nil {
+      return err
+    }
+
+    // Deal with symlinks
+    if IsSymlink(entryFileInfo) {
+      linkTo, err := os.Readlink(srcPath)
+      if err != nil {
+        return err
+      }
+      if options.Symlinks {
+        os.Symlink(linkTo, dstPath)
+        //CopyStat(srcPath, dstPath, false)
+      } else {
+        // ignore dangling symlink if flag is on
+        _, err = os.Stat(linkTo)
+        if os.IsNotExist(err) && options.IgnoreDanglingSymlinks {
+          continue
+        }
+        _, err = options.CopyFunction(srcPath, dstPath, false)
+        if err != nil {
+          return err
+        }
+      }
+    } else if entryFileInfo.IsDir() {
+      err = CopyTree(srcPath, dstPath, options)
+      if err != nil {
+        return err
+      }
+    } else {
+      _, err = options.CopyFunction(srcPath, dstPath, false)
+      if err != nil {
+        return err
+      }
+    }
+  }
+  return nil
+}

internal/shutil/shutil_test.go

@@ -0,0 +1,155 @@
+package shutil
+
+import (
+  "bytes"
+  "io/ioutil"
+  "os"
+  "testing"
+)
+
+
+func filesMatch(src, dst string) (bool, error) {
+  srcContents, err := ioutil.ReadFile(src)
+  if err != nil {
+    return false, err
+  }
+
+  dstContents, err := ioutil.ReadFile(dst)
+  if err != nil {
+    return false, err
+  }
+
+  if bytes.Compare(srcContents, dstContents) != 0 {
+    return false, nil
+  }
+  return true, nil
+}
+
+
+func TestSameFileError(t *testing.T) {
+  _, err := Copy("test/testfile", "test/testfile", false)
+  _, ok := err.(*SameFileError)
+  if !ok {
+    t.Error(err)
+  }
+}
+
+
+func TestCopyFile(t *testing.T) {
+  // clear out existing files if they exist
+  os.Remove("test/testfile3")
+
+  err := CopyFile("test/testfile", "test/testfile3", false)
+  if err != nil {
+    t.Error(err)
+    return
+  }
+
+  match, err := filesMatch("test/testfile", "test/testfile3")
+  if err != nil {
+    t.Error(err)
+    return
+  }
+  if !match {
+    t.Fail()
+    return
+  }
+
+  // And again without clearing the files
+  err = CopyFile("test/testfile2", "test/testfile3", false)
+  if err != nil {
+    t.Error(err)
+    return
+  }
+
+  match2, err := filesMatch("test/testfile2", "test/testfile3")
+  if err != nil {
+    t.Error(err)
+    return
+  }
+
+  if !match2 {
+    t.Fail()
+    return
+  }
+}
+
+
+func TestCopy(t *testing.T) {
+  // clear out existing files if they exist
+  os.Remove("test/testfile3")
+
+  _, err := Copy("test/testfile", "test/testfile3", false)
+  if err != nil {
+    t.Error(err)
+    return
+  }
+
+  match, err := filesMatch("test/testfile", "test/testfile3")
+  if err != nil {
+    t.Error(err)
+    return
+  }
+  if !match {
+    t.Fail()
+    return
+  }
+
+  // And again without clearing the files
+  _, err = Copy("test/testfile2", "test/testfile3", false)
+  if err != nil {
+    t.Error(err)
+    return
+  }
+
+  match2, err := filesMatch("test/testfile2", "test/testfile3")
+  if err != nil {
+    t.Error(err)
+    return
+  }
+
+  if !match2 {
+    t.Fail()
+    return
+  }
+}
+
+
+func TestCopyTree(t *testing.T) {
+  // clear out existing files if they exist
+  os.RemoveAll("test/testdir3")
+
+  err := CopyTree("test/testdir", "test/testdir3", nil)
+  if err != nil {
+    t.Error(err)
+    return
+  }
+
+  match, err := filesMatch("test/testdir/file1", "test/testdir3/file1")
+  if err != nil {
+    t.Error(err)
+    return
+  }
+  if !match {
+    t.Fail()
+    return
+  }
+
+  // // And again without clearing the files
+  // _, err = Copy("test/testfile2", "test/testfile3", false)
+  // if err != nil {
+  //   t.Error(err)
+  //   return
+  // }
+
+  // match2, err := filesMatch("test/testfile2", "test/testfile3")
+  // if err != nil {
+  //   t.Error(err)
+  //   return
+  // }
+
+  // if !match2 {
+  //   t.Fail()
+  //   return
+  // }
+}