minio/pkg/fs/fs-utils.go
Harshavardhana d668117a99 fs: Improve upon proper lexical ordering for ListObjects()
Handle sorting properly making sure that we treat fs like a
flat namespace.
2015-11-11 14:52:03 -08:00

206 lines
5.3 KiB
Go

/*
* Minio Cloud Storage, (C) 2015 Minio, Inc.
*
* 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 fs
import (
"errors"
"io"
"os"
"path/filepath"
"sort"
"github.com/minio/minio-xl/pkg/probe"
)
// Check if a directory is empty
func isDirEmpty(dirname string) (bool, *probe.Error) {
f, err := os.Open(dirname)
defer f.Close()
if err != nil {
return false, probe.NewError(err)
}
names, err := f.Readdirnames(1)
if err != nil && err != io.EOF {
return false, probe.NewError(err)
}
if len(names) > 0 {
return false, nil
}
return true, nil
}
// Walk walks the file tree rooted at root, calling walkFn for each file or
// directory in the tree, including root.
func Walk(root string, walkFn WalkFunc) error {
info, err := os.Lstat(root)
if err != nil {
return walkFn(root, nil, err)
}
return walk(root, info, walkFn)
}
// WalkUnsorted walks the file tree rooted at root, calling walkFn for each file or
// directory in the tree, including root.
func WalkUnsorted(root string, walkFn WalkFunc) error {
info, err := os.Lstat(root)
if err != nil {
return walkFn(root, nil, err)
}
return walk(root, info, walkFn)
}
// getRealName - gets the proper filename for sorting purposes
// Readdir() filters out directory names without separators, add
// them back for proper sorting results.
func getRealName(info os.FileInfo) string {
if info.IsDir() {
// Make sure directory has its end separator.
return info.Name() + string(os.PathSeparator)
}
return info.Name()
}
// readDirNames reads the directory named by dirname and returns
// a sorted list of directory entries.
func readDirNames(dirname string) ([]string, error) {
names, err := readDirUnsortedNames(dirname)
if err != nil {
return nil, err
}
sort.Strings(names)
return names, nil
}
func readDirUnsortedNames(dirname string) ([]string, error) {
f, err := os.Open(dirname)
if err != nil {
return nil, err
}
nameInfos, err := f.Readdir(-1)
f.Close()
if err != nil {
return nil, err
}
var names []string
for _, nameInfo := range nameInfos {
names = append(names, getRealName(nameInfo))
}
return names, nil
}
// WalkFunc is the type of the function called for each file or directory
// visited by Walk. The path argument contains the argument to Walk as a
// prefix; that is, if Walk is called with "dir", which is a directory
// containing the file "a", the walk function will be called with argument
// "dir/a". The info argument is the os.FileInfo for the named path.
type WalkFunc func(path string, info os.FileInfo, err error) error
// ErrSkipDir is used as a return value from WalkFuncs to indicate that
// the directory named in the call is to be skipped. It is not returned
// as an error by any function.
var ErrSkipDir = errors.New("skip this directory")
// ErrSkipFile is used as a return value from WalkFuncs to indicate that
// the file named in the call is to be skipped. It is not returned
// as an error by any function.
var ErrSkipFile = errors.New("skip this file")
// ErrDirNotEmpty is used to throw error on directories which have atleast one regular
// file or a symlink left
var ErrDirNotEmpty = errors.New("directory not empty")
func walkUnsorted(path string, info os.FileInfo, walkFn WalkFunc) error {
err := walkFn(path, info, nil)
if err != nil {
if info.Mode().IsDir() && err == ErrSkipDir {
return nil
}
if info.Mode().IsRegular() && err == ErrSkipFile {
return nil
}
return err
}
if !info.IsDir() {
return nil
}
names, err := readDirUnsortedNames(path)
if err != nil {
return walkFn(path, info, err)
}
for _, name := range names {
filename := filepath.Join(path, name)
fileInfo, err := os.Lstat(filename)
if err != nil {
if err := walkFn(filename, fileInfo, err); err != nil && err != ErrSkipDir && err != ErrSkipFile {
return err
}
} else {
err = walk(filename, fileInfo, walkFn)
if err != nil {
if err == ErrSkipDir || err == ErrSkipFile {
return nil
}
return err
}
}
}
return nil
}
// walk recursively descends path, calling w.
func walk(path string, info os.FileInfo, walkFn WalkFunc) error {
err := walkFn(path, info, nil)
if err != nil {
if info.Mode().IsDir() && err == ErrSkipDir {
return nil
}
if info.Mode().IsRegular() && err == ErrSkipFile {
return nil
}
return err
}
if !info.IsDir() {
return nil
}
names, err := readDirNames(path)
if err != nil {
return walkFn(path, info, err)
}
for _, name := range names {
filename := filepath.Join(path, name)
fileInfo, err := os.Lstat(filename)
if err != nil {
if err := walkFn(filename, fileInfo, err); err != nil && err != ErrSkipDir && err != ErrSkipFile {
return err
}
} else {
err = walk(filename, fileInfo, walkFn)
if err != nil {
if err == ErrSkipDir || err == ErrSkipFile {
return nil
}
return err
}
}
}
return nil
}