- From: Philippe Le Hegaret <plh@w3.org>
- Date: Thu, 10 Jul 2014 14:36:46 -0400
- To: Boris Zbarsky <bzbarsky@MIT.EDU>
- Cc: Arvind Jain <arvind@google.com>, "public-web-perf@w3.org" <public-web-perf@w3.org>
On Thu, 2014-07-10 at 12:19 -0400, Boris Zbarsky wrote: > > I read that part and I interpreted as the "primary buffer for > > PerformanceResourceTiming resources" > > Sure. My point is that nothing actually clearly defines which objects > getEntries and company will return. It seems to be assumed in the spec > that for resource timing entries only the ones in the primary buffer > will be returned, but nothing actually _says_ that. ok. That should be made explicit as part of the step on creation. I'm wondering how far we need to go along that path however. For example, we never indicated when the initial window.performance object gets created. So far, it's assumed to be there as soon as a script can be executed, ie by dom loading, like several objects available from window. > > It's possible to maintain the PerformanceNavigationTiming object around. > > It's possible to do all sorts of things. The question is what behavior > this spec requires, if any. And the answer is that as far as I can tell > I can implement whatever the heck I want for getEntries and it will not > obviously violate the spec. > > I mean, I can obviously reverse engineer other UAs and implement what > they did. Hence https://twitter.com/bz_moz/status/487049670024523776 > > > The processing model notes: > > [[ > > Some user agents maintain the DOM structure of the document in memory > > I'm not talking about this case. I'm talking about the case when the > old document is discarded. It seems to me that we need to define this in performance timeline. In others words, each specification (like Navigation or Resource Timing) should define when the objects get created and added to the entries list, but Performance Timeline should define when the entries get discarded by default (Performance.clearResourceTimings() would then complement that behavior). In that case, we would need to add the following to Performance Timeline: [[ A part of the steps defined in "unload a document" [See Unloading documents, HTML], if both the Document's salvageable state and recycle are false, the Document's browsing context must discard all instances of PerformanceEntry objects after discarding the Document and getEntries() must return an empty PerformanceEntryList. ]] Philippe
Received on Thursday, 10 July 2014 18:36:49 UTC