The size is useful when you want to know the length of an object without unpacking it. The size is uncompressed length and not the size on disk. For example, i

The size is useful when you want to know the length of an object without unpacking it. The size is uncompressed length and not the size on disk. For example, if you want to stream the blob over http you can use it to set the content-length. Otherwise, you have to use chunked transfer.