[Twisted-Python] Supporting a two-part client protocol.

[Go Luhng]

Hi there,

I'm planning to use Twisted to write a client for the following protocol:

Each messages is composed of two separate messages:

1. A header, which is a serialized C struct, containing multiple
fields, among them a `length` field.
2. A Protocol Buffer payload, which length is specified by the
aforementioned `length` field on the header.

While the initial implementation is focused on TCP, I do hope to
support this same protocol over UDP eventually.

What's the best way for me to implement such a client with Twisted?
Specifically, to implement support for sending/receiving messages in
the above format to/from a server?

Thanks, Go