[jfoutz]

Gosh, i don't know of anything off the top of my head.

The only real tip i have is to byte length encode variable length requests, because scanning strings sucks.

having a frame for messages for messages is nice, stick your fixed with stuff up front, and create fixed with length indicators. It sucks that you waste a little space with 0's, but avoiding the scan is pretty wonderful.

    GET /foo HTTP/1.1

    GET HTTP 01.10 0004/foo

Some things need to happen in order, you need to be authenticated before being granted access to resources, but that doesn't necessarily require the client knowing. the state at each step,

Traditionally you'd have something like

    HELO jfoutz hunter2
        OK
    REQEUEST 1
        OK <bytes for resource 1>
    REQUEST 2
        OK <bytes for resource 2>

but really, the server knows if you're authenticated so i could send

    HELO jfoutz hunter2
    REQUEST 1
    REQUEST 1

and then get back either

    OK
    OK <bytes for resource 1>
    OK <bytes for resource 2>

or

    NO
    NO
    NO

or, whatever. generally it's just going to be a bunch of request/response pairs. sometimes you can't make later requests without actually looking at a response. You don't know what css or images to request until the html is parsed, for example. Usually, you can request a bunch of stuff at once, and it'll work out however it works out.

[userbinator]

The only real tip i have is to byte length encode variable length requests, because scanning strings sucks.

This is really, really good advice to use whenever possible: it means clients can determine apriori how much data they need to read, and perhaps decide whether the length is valid and/or allocate sufficient memory. One of my annoyances with the traditional "almost-text-based" protocols like HTTP, FTP, SMTP, etc. is that parsing them is not trivial and often you need to keep reading until you hit the delimiter or reach an internal limit. In contrast, "read a length, then read length bytes" makes for simple and efficient implementation.

There are certainly cases when the amount of data cannot be determined ahead of time, and in those cases I'd suggest chunked-length-prefixing; delimiters are really a method of last resort.