Re: Specifying Range in Link preload header for HTTP/2 Push?

[Roger Pantos <[e-mail]>]

Thanks for the guidance, Mark. It sounds like the preload repo is the way to go. I went ahead and created a new issue there: https://github.com/w3c/preload/issues/139


Roger.

> On Jul 10, 2019, at 11:02 PM, Mark Nottingham <[e-mail]> wrote:
> 
> Hi Roger,
> 
> The philosophy of RFC8288 (which obsoleted 5988) is that individual link relation types are responsible for defining what the appropriate / meaningful set of target attributes is. So, in this case, "preload" would need to define it; as Yoav pointed out, the right place to talk about that is the preload repo and the Web Performance WG in the W3C.
> 
> We have previously talked about common parameters that are useful for more than one link relation type, but they still need to be "opted into." A while back I wrote down a starter collection of these, it might be good to dust them off and consider adding something like this. See:
>  https://mnot.github.io/I-D/link-hint/ <https://mnot.github.io/I-D/link-hint/>
> 
> Cheers,
> 
> 
>> On 10 Jul 2019, at 2:55 am, Roger Pantos <[e-mail]> wrote:
>> 
>> Greetings HTTP experts,
>> 
>> I’m interested in employing HTTP/2 Push of Range requests for media streaming. It seems like the core h2 protocol handles this well enough; the PUSH_PROMISE can contain a Range header, and at the very least if that ends up in the client push cache then a request for that exact Range should match.
>> 
>> That being said, I’d also like to signal the push request to downstream HTTP caches. Push is typically signaled via the Link header with rel=preload, but https://www.w3.org/TR/preload/ doesn’t seem to define signaling and associated Range.
>> 
>> Has anyone defined a Link extension to signal an associated Range?
>> 
>> If not, would anyone object to the following Link extension?
>> 
>> range-link-extension = “range” = ranges-specifier
>> 
>> where ranges-specifier is defined in RFC 2616.
>> 
>> An example would be:
>> 
>> Link: </media.mp4>; rel=preload; as=video; type=video/mp4; range=1380-14226
>> 
>> 
> 
> --
> Mark Nottingham   https://www.mnot.net/ <https://www.mnot.net/>