package cacheroot import (	"fmt"	"os"	"path/filepath"	"runtime"	"strings" 	"github.com/pkg/errors"	"github.com/rclone/rclone/lib/encoder"	"github.com/rclone/rclone/lib/file") // CreateCacheRoot will derive and make a subsystem cache path.//// Returned root OS path is an absolute path with UNC prefix,// OS-specific path separators, and encoded with OS-specific encoder.//// Additionally it is returned as a standard path without UNC prefix,// with slash path separators, and standard (internal) encoding.//// Care is taken when creating OS paths so that the ':' separator// following a drive letter is not encoded, e.g. into unicode fullwidth colon.//// parentOSPath should contain an absolute local path in OS encoding.//// Note: instead of fs.Fs it takes name and root as plain strings// to prevent import loops due to dependency on the fs package.func CreateCacheRoot(parentOSPath, fsName, fsRoot, cacheName string) (rootOSPath, standardPath string, err error) {	// Get a relative cache path representing the remote.	relativeDir := fsRoot	if runtime.GOOS == "windows" && strings.HasPrefix(relativeDir, `//?/`) {		// Trim off the leading "//" to make the result		// valid for appending to another path.		relativeDir = relativeDir[2:]	}	relativeDir = fsName + "/" + relativeDir 	// Derive and make the cache root directory	relativeOSPath := filepath.FromSlash(encoder.OS.FromStandardPath(relativeDir))	rootOSPath = file.UNCPath(filepath.Join(parentOSPath, cacheName, relativeOSPath))	if err = os.MkdirAll(rootOSPath, 0700); err != nil {		return "", "", errors.Wrapf(err, "failed to create %s cache directory", cacheName)	} 	parentStdPath := encoder.OS.ToStandardPath(filepath.ToSlash(parentOSPath))	standardPath = fmt.Sprintf("%s/%s/%s", parentStdPath, cacheName, relativeDir)	return rootOSPath, standardPath, nil}