Re: [hybi] hum #3: Message

[Dave Cridland <[e-mail]>]

On Thu Aug  5 22:18:01 2010, Maciej Stachowiak wrote:
> 
> On Aug 5, 2010, at 2:09 PM, Maciej Stachowiak wrote:
> 
> >
> > On Aug 5, 2010, at 1:43 PM, Jack Moffitt wrote:
> >
> >>>> Sending a file from disk to the network without processing it  
> in any way
> >>>> is more efficient than cutting it into slices and interleaving  
> with headers.
> >>>> The IP layer is already going to cut it into slices, in a way  
> that almost
> >>>> certainly won't line up with WebSocket-level fragment  
> boundaries.
> >>>
> >>> There's no way to "send a file over the network without  
> processing". You
> >>> need to read it into memory, and then write it to the network.  
> Of course
> >>> adding frame headers *is* overhead, but it's really identical  
> or close to
> >>> the overhead on the wire, nothing more.
> >>
> >> The kernel's sendfile() is responsible for a lot of the HTTP  
> server
> >> optimization for static resources, and for this case, I think it  
> is
> >> true that doing any framing that shows up in the middle of the  
> file
> >> would lead to a big inefficiency.
> >>
> >> I'm not sure how useful this pattern is with dynamic data  
> though. I
> >> think people will continue to send most static resources via  
> regular
> >> HTTP because it is very, very good at it.
> >
> > I think there's definitely use cases for transferring large  
> static resources over WebSocket. Consider syncing a media library  
> where items may have been added on either end.  Sync seems like a  
> pretty likely target for WebSocket. You will want to do large  
> static transfers in both directions, and it seems better to use the  
> existing warmed-up WebSocket TCP connection than to make fresh HTTP  
> connections.
> 
> If it's an optional extension that intermediaries could ignore,  
> that makes it unlikely that there will be a default expectation  
> that it should be sent and have a correct value.

I'm fine withdefining the extension in the core spec, and making this  
a SHOULD. I can see cases meaning it cannot be a MUST. Would this  
satisfy?

Dave.
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