storage

type Range struct {
	Start int64
	End   int64
}

type Reader interface {
	// Size returns an object's size without reading its contents.
	Size(context.Context, string) (int64, error)
	// Open opens a full object when the range is nil or one inclusive range.
	// It returns the length of the opened stream.
	Open(context.Context, string, *Range) (io.ReadCloser, int64, error)
}