[e-lang] Sending files with E?

Kevin Reid kpreid at mac.com
Sat Oct 11 08:26:38 CDT 2008


On Oct 7, 2008, at 15:30, Bill Frantz wrote:
> kpreid at mac.com (Kevin Reid) on Tuesday, October 7, 2008 wrote:
>
>> All my work so far addresses basic stream objects and OS-level IO
>> (files, pipes and sockets) -- I haven't started on the problem of
>> efficiently streaming data over a CapTP connection.
>
> It seems to me that any streaming of data over CapTP connections
> will run into the flow-control problem. Flow control is currently
> left as an application issue.

I propose this classification of solutions:


1. Set up a separate OS/network level connection, and make use of its  
flow control rather than hiding it.

(Hm: This is an application for VatTP without CapTP, no?)

This would work fine for data, and could be made reasonably  
transparent in the EIO subsystem, I think, but gets tricky if you want  
to transport caps/objects over the flow-controlled stream, as you have  
to have some kind of interconnection with the primary CapTP stream.


2. Provide a way for (authorized) applications to see the flow  
information that is being hidden by CapTP (due to its ordering and non- 
blocking guarantees).

For example, getting reports on how many of the messages you've sent  
over some far ref have been delivered to the remote side, and thus how  
many more you can send to maintain reasonable flow.


3. Implement flow control at the application level as you described.


Comments? Missed options?

-- 
Kevin Reid                            <http://homepage.mac.com/kpreid/>




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