JCS-pub/common/pkgs/storage/rclone/dir_reader.go

package rclone

import (
	"context"
	"io"

	"github.com/rclone/rclone/fs"
	stgtypes "gitlink.org.cn/cloudream/jcs-pub/common/pkgs/storage/types"
	jcstypes "gitlink.org.cn/cloudream/jcs-pub/common/types"
)

type DirReader struct {
	fs       fs.Fs
	rootPath string
	// ReadDir函数传递进来的path参数
	rootJPath  jcstypes.JPath
	init       bool
	curEntries []DirEntry
}

func NewDirReader(fs fs.Fs, rootPath string, rootJPath jcstypes.JPath) *DirReader {
	return &DirReader{
		fs:        fs,
		rootPath:  rootPath,
		rootJPath: rootJPath,
	}
}

func (r *DirReader) Next() (stgtypes.DirEntry, error) {
	e, err := r.NextRaw()
	if err != nil {
		return stgtypes.DirEntry{}, err
	}

	eFullJPath := r.rootJPath.ConcatNew(e.Dir)
	// 如果根路径就是一个文件，那么Name就为空
	if e.Name != "" {
		eFullJPath.Push(e.Name)
	}

	switch e2 := e.Entry.(type) {
	case fs.Object:
		return stgtypes.DirEntry{
			Path:    eFullJPath,
			Size:    e2.Size(),
			ModTime: e2.ModTime(context.Background()),
			IsDir:   false,
		}, nil

	default:
		return stgtypes.DirEntry{
			Path:    eFullJPath,
			Size:    0,
			ModTime: e2.ModTime(context.Background()),
			IsDir:   true,
		}, nil
	}
}

func (r *DirReader) NextRaw() (DirEntry, error) {
	if !r.init {
		info, err := r.fs.NewObject(context.Background(), r.rootPath)
		if err == nil {
			r.init = true
			return DirEntry{
				Dir:   jcstypes.JPath{},
				Entry: info,
				Name:  "",
			}, nil
		}

		if err != fs.ErrorIsDir {
			return DirEntry{}, err
		}

		es, err := r.fs.List(context.Background(), r.rootPath)
		if err != nil {
			return DirEntry{}, err
		}

		for _, e := range es {
			r.curEntries = append(r.curEntries, DirEntry{
				Dir:   jcstypes.JPath{},
				Entry: e,
				Name:  BaseName(e.Remote()),
			})
		}

		r.init = true
	}
	if len(r.curEntries) == 0 {
		return DirEntry{}, io.EOF
	}

	entry := r.curEntries[0]
	r.curEntries = r.curEntries[1:]

	_, isDir := entry.Entry.(fs.Directory)
	if isDir {
		dirPath := Join(r.rootPath, entry.Dir.String(), entry.Name)
		es, err := r.fs.List(context.Background(), dirPath)
		if err != nil {
			return DirEntry{}, err
		}

		// 多个entry对象共享同一个JPath对象，但因为不会修改JPath，所以没问题
		dir := entry.Dir.Clone()
		dir.Push(entry.Name)
		for _, e := range es {
			r.curEntries = append(r.curEntries, DirEntry{
				Dir:   dir,
				Entry: e,
				Name:  BaseName(e.Remote()),
			})
		}
	}

	return entry, nil
}

func (r *DirReader) Close() {

}

type DirEntry struct {
	Dir   jcstypes.JPath
	Entry fs.DirEntry
	Name  string
}