cache,chunker,combine,compress,crypt,hasher,union: implement MkdirMetadata and related Features

backend/union/entry.go

@@ -27,6 +27,7 @@ type Object struct {
 // This is a wrapped object contains all candidates
 type Directory struct {
 	*upstream.Directory
+	fs *Fs // what this directory is part of
 	cd []upstream.Entry
 }
 
@@ -227,7 +228,56 @@ func (d *Directory) Size() (s int64) {
 	return s
 }
 
+// SetMetadata sets metadata for an DirEntry
+//
+// It should return fs.ErrorNotImplemented if it can't set metadata
+func (d *Directory) SetMetadata(ctx context.Context, metadata fs.Metadata) error {
+	entries, err := d.fs.actionEntries(d.candidates()...)
+	if err != nil {
+		return err
+	}
+	var wg sync.WaitGroup
+	errs := Errors(make([]error, len(entries)))
+	multithread(len(entries), func(i int) {
+		if d, ok := entries[i].(*upstream.Directory); ok {
+			err := d.SetMetadata(ctx, metadata)
+			if err != nil {
+				errs[i] = fmt.Errorf("%s: %w", d.UpstreamFs().Name(), err)
+			}
+		} else {
+			errs[i] = fs.ErrorIsFile
+		}
+	})
+	wg.Wait()
+	return errs.Err()
+}
+
+// SetModTime sets the metadata on the DirEntry to set the modification date
+//
+// If there is any other metadata it does not overwrite it.
+func (d *Directory) SetModTime(ctx context.Context, t time.Time) error {
+	entries, err := d.fs.actionEntries(d.candidates()...)
+	if err != nil {
+		return err
+	}
+	var wg sync.WaitGroup
+	errs := Errors(make([]error, len(entries)))
+	multithread(len(entries), func(i int) {
+		if d, ok := entries[i].(*upstream.Directory); ok {
+			err := d.SetModTime(ctx, t)
+			if err != nil {
+				errs[i] = fmt.Errorf("%s: %w", d.UpstreamFs().Name(), err)
+			}
+		} else {
+			errs[i] = fs.ErrorIsFile
+		}
+	})
+	wg.Wait()
+	return errs.Err()
+}
+
 // Check the interfaces are satisfied
 var (
-	_ fs.FullObject = (*Object)(nil)
+	_ fs.FullObject    = (*Object)(nil)
+	_ fs.FullDirectory = (*Directory)(nil)
 )