Re: [agenda] Web Performance WG Teleconference #28 Agenda 2011-04-13

On Wed, Apr 13, 2011 at 7:08 PM, Zhiheng Wang <zhihengw@google.com> wrote:
> * If there is no previous document, navigationStart must return the same value as fetchStart. unloadEventStart/End must return 0.

As promised on last week's call, I submitted a test for this. Please review:
http://w3c-test.org/webperf/tests/submission/Google/NavigationTiming/test_no_previous_document.htm

It only checks that unload times are 0, not that navigationStart ==
fetchStart. I'd like to raise a issue/question about that.

In section 4.2, the spec says "If there is no previous document, this
attribute must return the same value as fetchStart." However, the more
descriptive processing model (section 5.1) describes them being
recorded as two distinct times. That sentence might typically be true
when there are no 3xx redirects, but certainly isn't true for
redirects. Even in the non-redirect case, if two distinct times are
recorded back-to-back, there is a non-zero chance that the second one
will be later than the first. I propose we stick with the processing
model and drop that sentence from 4.2.

-Tony

Received on Wednesday, 20 April 2011 16:51:40 UTC