Re: [hybi] thewebsocketprotocol #28 (new): Fragmentation

[John Tamplin <[e-mail]>]

On Wed, Nov 24, 2010 at 1:01 PM, Zhong Yu <[e-mail]> wrote:

> > Right now, WS provides *two* abstractions: The one to app developers,
> > and the one over TCP.
> >
> > Some of us believe they *should not be the same* due to network
> > engineering issues *because that makes the app developer's job easier*.
> >
> > Right now, the "simplicity" of WS means *robust* apps need to
> > implement half of TCP in Javascript on the client, which is not a good
>
> That's where frameworks come in, which can provide degrees of
> robustness suitable for different applications. I don't think WS
> should or could address these application level concerns.
>
> The #1 feature needed for robustness is auto reconnect. Nobody
> proposed to build that feature in the WS protocol.
>
> > sign.  (For example the "tic tac toe" example, which is supposed to be
> > simple, can lock up on real networks: No more moves when a TCP is
> > silently dropped.  A HTTP equivalent doesn't have this problem.)
> >
> > Why do you think the two abstractions should be the same?
>
> They should not be. But no matter how complex the protocol must
> become, I wish it won't jeopardize the simple application abstraction.
> I don't want WebSocket to become WebService, and everybody needs to
> buy a 1000 page "The Definitive Guide".


A simple implementation, which does not implement any extensions, is still
quite simple.  See
http://code.google.com/p/websocket-draft-eval/source/browse/trunk/src/com/google/websocket/SimpleWebSocket.java
for
an example.

We are making slow enough progress as it is -- we don't need to be
revisiting framing decisions agreed upon months ago.


> chunks within a frame. frames can't overlap, therefore messages cannot
> overlap.
>

And how do you identify the chunk and frame boundaries if you don't know the
length up front?  This exact suggestion was made and rejected months ago --
please read the archives.

-- 
John A. Tamplin
Software Engineer (GWT), Google