- From: Pan Deng <pan.pdeng6@gmail.com>
- Date: Tue, 13 Nov 2012 17:43:41 +0800
- To: James Simonsen <simonjam@chromium.org>
- Cc: public-web-perf <public-web-perf@w3.org>
- Message-ID: <CA+Ro6hxqSNsf2hmtWWi702dBuHaGWp5_p-i2BQxBR8NhOY1Qhw@mail.gmail.com>
For case #1, I agree the second shall not be populated. For case #2, I think the second one should be populated, to align with resource timing motivation “provide complete timing information related to resources on a document”. I prefer its resource timing entry: 1) Phases that before second “resource fetch” initiate should be 0, 2) Others should be the same to phases in the first timing entry. thanks Pan 2012/11/13 James Simonsen <simonjam@chromium.org> > I wanted to continue the discussion about Resource Timing from the > workshop... > > The relevant piece of the spec is step 6 of the processing model [1]: > > "If the resource is not to be fetched from the networking layer, such as > being fetched from an in-memory cache, abort the remaining steps." > > My question is what to do in situations where multiple objects are > requesting the same resource. There are two important cases: > > 1. The easier case is when two requesters are in the same document. > 2. The harder case is when two requesters are in different documents. > > In case #1, I think it's clear the first one should "win" and the second > request is ignored. This should be explicitly called out in the spec. > Otherwise, technically, the second requester is waiting for the resource > "to be fetched from the networking layer." That means the current spec _is_ > saying we should have duplicates. > > In case #2, neither one should "win" IMO. The second document may be > blocked on that resource and it'd be unfortunate if it didn't show up in > its timeline. > > However, if we do show it in case #2, then the timeline may be confusing. > For instance, the second document may have been created after the resource > began fetching, which would mean some of the high res times would be > negative. > > Another option would just be to show the time spent waiting in each phase. > So if the DNS lookup occurred before the second document started fetching, > that'd be 0, but the rest of the fields would be populated. > > Thoughts? > > James > > [1] http://w3c-test.org/webperf/specs/ResourceTiming/#processing-model >
Received on Tuesday, 13 November 2012 09:44:11 UTC