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RE: [Web Timing] Navigation Timing updates

From: Anderson Quach <aquach@microsoft.com>
Date: Fri, 22 Oct 2010 18:33:39 +0000
To: Zhiheng Wang <zhihengw@google.com>
CC: public-web-perf <public-web-perf@w3.org>
Message-ID: <1E1FF4102DEA7A40AF9CC342044ECE5D2E220C9E@TK5EX14MBXW603.wingroup.windeploy.ntdev.microsoft.com>
Thanks for going over the feedback. Also interesting to note, in section [4.3 The NavigationInfo Interaface] stated is a statement that appears to be a normative requirement on the sort order of the timing attributes.

The recommendation here is to either have no sort order or to specify a specific order as in the one listed in section [4.2 The NavigationTiming Interface] and additional attributes are appended. I presume the sort order is to preserve an ordering while iterating over the NavigationTiming. The rationale to not having a sort order is to consider these cases:

i.                     The chronological ordering of unload may come before or after phases like redirect or request. Thus there is no reliable order.

ii.                   User agents or Site developers adding attributes to the Navigation Timing objects, or the future extensibility of adding attributes to the NavigationTiming timeline.

Stating a particular sort order implies that site developers may be dependent on this order and any change to the structure can break future compatibility.

Thanks,
Anderson Quach
IE Program Manager

From: Zhiheng Wang [mailto:zhihengw@google.com]
Sent: Friday, October 22, 2010 1:30 AM
To: Anderson Quach
Cc: public-web-perf
Subject: Re: [Web Timing] Navigation Timing updates

   I've fixed the draft accordingly, including Sigbjørn's comments from another thread.
On Thu, Oct 21, 2010 at 4:51 PM, Anderson Quach <aquach@microsoft.com<mailto:aquach@microsoft.com>> wrote:
Hi Zhiheng,

Thanks for working together and all the great progress we've made thus far. I have some additional feedback to incorporate with the working draft with respect to the edits from the 10/19/2910 draft of the Navigation Timing [1].

[Section 4.1 Introduction]
Recommended text for an informative statement stating:
User agents may perform internal processing in between timings, which allow for non-normative intervals between timings.

   I put it in 4.5, just above the graph. How does that sound?


[Section 4.2 The NavigationTiming Interface]
We should stick to the name for domContentLoaded. In this case the event names should be:
readonly attribute unsigned long long domContentLoadedEventStart<http://dvcs.w3.org/hg/webperf/raw-file/tip/specs/NavigationTiming/Overview.html#nt-dom-content-event-start>;
readonly attribute unsigned long long domContentLoadedEventEnd<http://dvcs.w3.org/hg/webperf/raw-file/tip/specs/NavigationTiming/Overview.html#nt-dom-content-event-end>;

[Section 4.5 Processing Model]
To reduce confusion, the recommendation here is to use either multi-level numbering. E.g. in Step 1, sub-steps can be 1.1, 1.2 and etc.

Step 8 reads:
If no domain lookup is required, go to step 11<http://dvcs.w3.org/hg/webperf/raw-file/tip/specs/NavigationTiming/Overview.html#step-connect-start>. Otherwise, immediately before a user agent starts the domain name lookup, record the time as domainLookupStart<http://dvcs.w3.org/hg/webperf/raw-file/tip/specs/NavigationTiming/Overview.html#nt-domain-lookupstart>.

Recommended Text:
If no domain lookup is required, go to step 10<http://dvcs.w3.org/hg/webperf/raw-file/tip/specs/NavigationTiming/Overview.html#step-connect-start>. Otherwise, immediately before a user agent starts the domain name lookup, record the time as domainLookupStart<http://dvcs.w3.org/hg/webperf/raw-file/tip/specs/NavigationTiming/Overview.html#nt-domain-lookupstart>.

   good catch!


Step 14.4
Should exclude the timings for unload and the navigationStart.

   either navigationStart should be excluded depends on where to put it, so I will leave it for now till we have a verdict. (I still need to send a summary
about this.) Good catch for unload.

cheers,
Zhiheng


Recommended Text:
Set all the attributes in window.performance.timing to 0 except redirectStart<http://dvcs.w3.org/hg/webperf/raw-file/tip/specs/NavigationTiming/Overview.html#nt-redirect-start>, redirectEnd<http://dvcs.w3.org/hg/webperf/raw-file/tip/specs/NavigationTiming/Overview.html#nt-redirect-end>, unloadEventStart, unloadEventEnd, and navigationStart.

[1] http://dvcs.w3.org/hg/webperf/raw-file/tip/specs/NavigationTiming/Overview.html

Thanks!
Anderson Quach
IE Program Manager
Received on Friday, 22 October 2010 18:35:42 GMT

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