Re: [9fans] Regarding 9p based "protocols" message framing

[Dan Cross <crossd@gmail.com>]

On Tue, Mar 20, 2012 at 7:42 AM, Yaroslav <yarikos@gmail.com> wrote:
>>  Why was I puzzled: because as a non Plan9 user / developer, I
>> usually think of the underlaying transport technology (be it sockets
>> or 9p) as a stream of bytes without explicit framing.
>
> As I understand, 9P itself is designed to operate on top of a
> message-oriented transport; however, it has everything required to run
> over a stream, esp. message length at beginning of every message.
> Framing is done by the library: the read9pmsg routine performs as many
> reads as necessary to return a complete 9P message to the caller.

Perhaps initially: over an IP network, 9P used to run over IL.  With
9P2000, IL was deprecated and 9P was most typically run over TCP.
There was a very old message to 9fans (like, early 90's kind of old)
that implied that IL was much more efficient than TCP on the wire, but
it probably doesn't matter now.  9P itself is not a stream-oriented
protocol, nor is it what one would generally call, 'transport
technology.'

        - Dan C.