Web Perf

[legendecas]

Currently, the implementation status of the WebPerf spec is as following table:

Spec	API	Node.js	Deno	Cloudflare Worker
User Timing	Performance.mark	✅	✅	❌
User Timing	Performance.measure	✅	✅	❌
User Timing	Performance.clearMarks	✅	✅	❌
User Timing	Performance.clearMeasures	✅	✅	❌
Performance Timeline	Performance.getEntries	✅	✅	❌
Performance Timeline	Performance.getEntriesByType	✅	✅	❌
Performance Timeline	Performance.getEntriesByName	✅	✅	❌
Performance Timeline	PerformanceObserver	✅	❌	❌
High Resolution Time	Performance.now	✅	✅	❌
High Resolution Time	Performance.timeOrigin	✅	✅ Pending	❌
Resource Timing	PerformanceResourceTiming	Pending	❌	❌

I believe APIs that are included in User Timing, Performance Timeline, and HR Time are met the bar of at least two runtimes implemented and can be added to the list of the common minimum api.

[jasnell]

@lucacasonato ... does Deno have plans to implement PerformanceObserver?

I can say definitively that Workers will not be providing an impl of this API for general users due to a number of spectre-related security concerns but it definitely does meet the basic At-Least-Two criteria.

[lucacasonato]

Yes, we want to implement that API in the limit.

@legendecas Deno is shipping timeOrigin in 1.22 (tomorrow) by the way

[jasnell]

We spoke briefly about this on the last wintercg call. Where we landed was that this likely falls under the "normative optional" category. That is, it doesn't likely belong in the minimum common api document but, if it is going to be implemented it should be done in a consistent way. A separate note documenting the minimum expectations should be written up.

[legendecas]

Created wintercg/performance#2 to continue the efforts.