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From: cinap_lenrek@felloff.net
To: 9fans@9fans.net
Subject: Re: [9fans] A couple questions about /dev/draw and /dev/kbmap
Date: Thu,  5 May 2016 15:56:25 +0200	[thread overview]
Message-ID: <3115414fc57b1a87c6ffe6744f4a65a0@felloff.net> (raw)
In-Reply-To: <CAG2UyHoT_1XHrVEJeCL1gSCjb_SUnoFuM9FfWzUM8F8iFdJ=bA@mail.gmail.com>

> In that case, is there any way to get the current max packet size that 9p
> will allow for
> a read or write, or to determine if you're drawing to a local machine or
> not? I'm not seeing anything obvious under /dev or /env.

the iounit is negotiated before you mount with the Tversion/Rversion
message:

               size[4] Tversion tag[2] msize[4] version[s]
               size[4] Rversion tag[2] msize[4] version[s]

plan9 has the iounit syscall for retriving the negotiated value
for a particular file descriptor. (see iounit(2))

libdraw determines the iounit in initdraw() and sizes
its write buffer accordingly. uploading pixels into a image
will split the y/Y operation in multiple ones so they fit
into the buffer.

--
cinap



  parent reply	other threads:[~2016-05-05 13:56 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-05-04 20:20 Dave MacFarlane
2016-05-04 21:53 ` hiro
2016-05-05  2:45 ` cinap_lenrek
2016-05-05 13:12   ` Dave MacFarlane
2016-05-05 13:16     ` Aram Hăvărneanu
2016-05-05 13:56     ` cinap_lenrek [this message]
2016-05-05 16:00       ` Charles Forsyth
2016-05-05 15:38     ` Skip Tavakkolian

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