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Re: is anyone looking at specifying something for background requests/downloads?

From: 陈智昌 <willchan@chromium.org>
Date: Wed, 9 Oct 2013 13:23:53 -0700
Message-ID: <CAA4WUYgr2XzVLeSDPpDkf+yjSEk+9x1M4oGoSVEMcxZLgAAPNw@mail.gmail.com>
To: Tobie Langel <tobie@w3.org>
Cc: "public-web-perf@w3.org" <public-web-perf@w3.org>, Alex Russell <slightlyoff@google.com>
On Thu, Oct 3, 2013 at 6:49 AM, Tobie Langel <tobie@w3.org> wrote:

> +Alex
>
> On Tuesday, October 1, 2013 at 1:23 PM, William Chan (陈智昌) wrote:
> > * Downloading a large chunk of data in the background. Let the user
> agent know that if there's contention, this network request should yield to
> any interactive one. E.g. web apps can download their next version (which
> may be large).
> So this particular use case seems already possible with ServiceWorkers[1]
> as an implementation-specific optimization.
>

I ran into Alex at the office last week and we chatted a bit about
ServiceWorkers. I don't recall him mentioning this. Can you mention what
specific part of ServiceWorkers addresses this? I don't see anything
indicating the nature of the network request so the user agent can pause
these bulk network requests so they don't contend with interactive ones.


>
> That said, I think there are similar use cases that would not benefit from
> this optimization and would need a dedicated solution. For example, a
> newspaper web application might want to bulk download todays news
> overnight, so that the application has fresh content to display when it is
> visited by the user on his network-less commute the next morning. Bulk
> uploads (e.g. uploading pictures overnight while on the home Wifi network)
> have similar requirements. I don't think ServiceWorkers, in their current
> incarnation, would support that. Alex (Cc'ed) would know.
>

I'm probably missing something due to my relative unfamiliarity with these
issues, but why isn't a timer-based XHR appropriate for prefreshing the
caches? Is it because the cache management logic lives in the
ServiceWorker, so it's weird to move this prefreshing logic outside of it?


>
> --tobie
>
> ---
> [1]: https://github.com/slightlyoff/ServiceWorker
>
>
Received on Wednesday, 9 October 2013 20:24:20 UTC

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