A MessageBuilder allocates a single large buffer, writes into it, and only allocates further if that buffer is exhausted. If you use a preallocated buffer you c

A MessageBuilder allocates a single large buffer, writes into it, and only allocates further if that buffer is exhausted. If you use a preallocated buffer you can avoid allocation entirely. Very different from Protobuf which allocates strings, arrays, and sub-messages all as separate heap objects.