⚡️ [RUMF-1113] Notify performance entries by batch

[amortemousque]

Motivation

Notifying performance entries by batch instead of one by one could be a nice quick win to avoid repeating the same actions too many times, notably when computing the loading time. Since most of the time, performance entries are already provided as a list by the browser APIs, we could simply notify once for each list.

Changes

• Update performance collection to notify multiple entries at the same time
• Update performance entry event subscription accordingly

Testing

• Local
• Staging
• Unit
• End to end

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I have gone over the contributing documentation.

[codecov-commenter]

Codecov Report

Merging #1255 (043fa95) into main (0615e30) will increase coverage by 0.05%.
The diff coverage is 83.09%.

@@            Coverage Diff             @@
##             main    #1255      +/-   ##
==========================================
+ Coverage   89.93%   89.98%   +0.05%     
==========================================
  Files         105      105              
  Lines        4370     4385      +15     
  Branches      989      991       +2     
==========================================
+ Hits         3930     3946      +16     
+ Misses        440      439       -1     

Impacted Files	Coverage Δ
...ages/rum-core/src/browser/performanceCollection.ts	14.14% <0.00%> (+0.14%)	⬆️
packages/core/src/tools/utils.ts	86.11% <100.00%> (+0.39%)	⬆️
packages/rum-core/src/domain/lifeCycle.ts	100.00% <100.00%> (ø)
...rumEventsCollection/longTask/longTaskCollection.ts	100.00% <100.00%> (ø)
...rumEventsCollection/resource/resourceCollection.ts	97.22% <100.00%> (+0.07%)	⬆️
...umEventsCollection/view/trackInitialViewTimings.ts	100.00% <100.00%> (ø)
...omain/rumEventsCollection/view/trackViewMetrics.ts	100.00% <100.00%> (ø)
packages/rum-core/src/domain/waitIdlePage.ts	98.11% <100.00%> (-0.04%)	⬇️

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[BenoitZugmeyer]

💬 suggestion: ‏I find it a bit confusing to have different levels of filtering. Maybe this function could be used similarly to isIncompleteNavigation and isForbiddenResource? Or maybe we could simply remove it and let subscribers do the check themselves...

[amortemousque]

filterRumPerformanceEntries filters first because it garantes that the rest of the code deals only with RumPerformanceEntry. Maybe a different naming would be better?

[bcaudan]

I find it a bit confusing to have different levels of filtering.

+1

we could also have a filterRumAllowedPerformanceEntries that do all filtering operations

[BenoitZugmeyer]

💬 suggestion: ‏Also you could use a isRumPerformanceEntry(entry: PerformanceEntry): entry is RumPerformanceEntry to have a nice typeguard without needing to cast as unknown as RumPerformanceEntry

[amortemousque]

The type guard does not work because there is no type relation between PerformanceEntry and RumPerformanceEntry. Also having a single filterRumAllowedPerformanceEntries where there is every check is weird since we can have PerformanceEntry[] or RumPerformanceEntry[] as input.
I identified two possible options:

• The PerformanceEntry[] as to go through the first filter to be checked and cast to RumPerformanceEntry[].
• The filter function as to be defined something like filterRumAllowedPerformanceEntries(entries: Array<PerformanceEntry | RumPerformanceEntry>)

[amortemousque]

I changed the implementation according to what we said during the daily. Let me know what you think.

[amortemousque]

💭 thought: It's not directly related to this PR but by looking at the code all performance subscribers need only one entryType at a time.
To avoid filtering each time, we could:

• have different lifecycle events for each entryType
• transform performanceCollection to an observable to avoid polluting lifecycle events

Of course, it could be done later in a different PR.

[BenoitZugmeyer]

💬 suggestion: ‏Also you could use a isRumPerformanceEntry(entry: PerformanceEntry): entry is RumPerformanceEntry to have a nice typeguard without needing to cast as unknown as RumPerformanceEntry