readdir.go

Documentation: io/fs

		 1  // Copyright 2020 The Go Authors. All rights reserved.
		 2  // Use of this source code is governed by a BSD-style
		 3  // license that can be found in the LICENSE file.
		 4  
		 5  package fs
		 6  
		 7  import (
		 8  	"errors"
		 9  	"sort"
		10  )
		11  
		12  // ReadDirFS is the interface implemented by a file system
		13  // that provides an optimized implementation of ReadDir.
		14  type ReadDirFS interface {
		15  	FS
		16  
		17  	// ReadDir reads the named directory
		18  	// and returns a list of directory entries sorted by filename.
		19  	ReadDir(name string) ([]DirEntry, error)
		20  }
		21  
		22  // ReadDir reads the named directory
		23  // and returns a list of directory entries sorted by filename.
		24  //
		25  // If fs implements ReadDirFS, ReadDir calls fs.ReadDir.
		26  // Otherwise ReadDir calls fs.Open and uses ReadDir and Close
		27  // on the returned file.
		28  func ReadDir(fsys FS, name string) ([]DirEntry, error) {
		29  	if fsys, ok := fsys.(ReadDirFS); ok {
		30  		return fsys.ReadDir(name)
		31  	}
		32  
		33  	file, err := fsys.Open(name)
		34  	if err != nil {
		35  		return nil, err
		36  	}
		37  	defer file.Close()
		38  
		39  	dir, ok := file.(ReadDirFile)
		40  	if !ok {
		41  		return nil, &PathError{Op: "readdir", Path: name, Err: errors.New("not implemented")}
		42  	}
		43  
		44  	list, err := dir.ReadDir(-1)
		45  	sort.Slice(list, func(i, j int) bool { return list[i].Name() < list[j].Name() })
		46  	return list, err
		47  }
		48  
		49  // dirInfo is a DirEntry based on a FileInfo.
		50  type dirInfo struct {
		51  	fileInfo FileInfo
		52  }
		53  
		54  func (di dirInfo) IsDir() bool {
		55  	return di.fileInfo.IsDir()
		56  }
		57  
		58  func (di dirInfo) Type() FileMode {
		59  	return di.fileInfo.Mode().Type()
		60  }
		61  
		62  func (di dirInfo) Info() (FileInfo, error) {
		63  	return di.fileInfo, nil
		64  }
		65  
		66  func (di dirInfo) Name() string {
		67  	return di.fileInfo.Name()
		68  }
		69  
		70  // FileInfoToDirEntry returns a DirEntry that returns information from info.
		71  // If info is nil, FileInfoToDirEntry returns nil.
		72  func FileInfoToDirEntry(info FileInfo) DirEntry {
		73  	if info == nil {
		74  		return nil
		75  	}
		76  	return dirInfo{fileInfo: info}
		77  }
		78
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