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Re: [NavigationTiming] incorrect description for requestStart

From: Zhiheng Wang <zhihengw@google.com>
Date: Fri, 20 May 2011 15:18:12 -0700
Message-ID: <BANLkTikdML02b4qf3Oh1y9uFjgyOHcHBUA@mail.gmail.com>
To: Christian Biesinger <cbiesinger@gmail.com>
Cc: public-web-perf <public-web-perf@w3.org>, Jason Duell <jduell@mozilla.com>
    Thanks, Chris and Jason. Some good questions you have brought up.

On Thu, May 19, 2011 at 5:33 PM, Christian Biesinger
<cbiesinger@gmail.com>wrote:

> Hi,
>
> I just noticed a bug in the description for requestStart (Thanks jduell):
> > This attribute must return the time immediately before the user agent
> starts requesting the current document. It is set prior to checking HTTP
> cache.
>
> >From what I remember from the discussions and from the timeline below,
> the "HTTP cache" sentence should be removed here, because this
> attribute refers to the time immediately before the UA starts
> write()ing to the socket. Otherwise, this would be identical to
> fetchStart (which does have similar cache wording).
>

   "requesting the current document" can be to the network or the cache. In
case it's done through
the HTTP cache, domainLookupStart/End and
connectionStart/End/(secureConnectionStart if
available) should all be equal to fetchStart because they are non-existing,
and requestStart is
the beginning of the process to fetch resource from the cache.
   This is captured by our discussion here:
   http://lists.w3.org/Archives/Public/public-web-perf/2010Sep/0036.html

   fetchStart starts before checking of the app cache, which is different
from http cache here.

cheers,
Zhiheng



>
> -christian
>
>
Received on Friday, 20 May 2011 22:18:37 GMT

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