Re: [ResourceTiming] The clock base to use in ResourceTiming is not defined

On 9/30/13 2:51 PM, Boris Zbarsky wrote:
> On 9/30/13 2:30 PM, Philippe Le Hegaret wrote:
>> The DOMHighResTimeStamp type is used to store a time value measured
>> relative to the navigationStart attribute of the PerformanceTiming
>> interface [NavigationTiming], the start of navigation of the document,
>> or a time value that represents a duration between two
>> DOMHighResTimeStamps.
>
> Indeed, but the point is that Resource Timing doesn't say which of those
> three cases it's using.
>
>> Therefore, unless the attribute represents a duration (such as
>> PerformanceEntry.duration), the 0 time is relative to navigationStart.
>
> Why?  The spec doesn't say this anywhere.  My point is that it needs to,
> if it means that.  Presumably in the processing model.

To be specific, even if we grant this, why is it "navigationStart" and 
not "the start of navigation of the document"?  Or is the claim that 
those are the same thing (in which case the way DOMHighResTimeStamp is 
defined is pretty confusing)?

The upshot is that I have now seen two different implementors be 
confused about what the spec wanted here and resort to 
reverse-engineering existing implementations, so clearly the spec is not 
clear enough.

-Boris

Received on Monday, 30 September 2013 18:56:50 UTC