Fix tracing problems #9622
Fix tracing problems #9622
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| if (!loadConfig) { | ||
| return; | ||
| } | ||
| return measureAsyncFunction( |
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what's the goal of measuring internal functions like this? This would be captured by the normal v8 profiler already. I thought the goal of tracing is to capture high level timings for user-facing things like plugins. If we start tracing internal things in Parcel core this gets muddier and harder for end users to understand.
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The goal is to capture high-level timings, so lower resolution than what the profiler will spit out (& lower or close to none overhead).
We could trace more internal bits though. It should not be granular.
I don't really care about the measurements added in this diff. More about the fixes.
For the measureAsyncFunction / measureFunction helpers ; they prevent mistakes where .end isn't currently called.
That was the case on packages/core/core/src/Transformation.js, where you can see I added measurement.end() calls that were previously not there. For those branches we had missing traces. Ideally we'd replace all measurement.end() calls with function wrappers, since then we can't not call .end().
| @@ -66,6 +74,7 @@ export default (new Reporter({ | |||
| case 'buildSuccess': | |||
| case 'buildFailure': | |||
| nullthrows(tracer).flush(); | |||
| writeStream?.write(']'); | |||
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Doesn't hurt, but not really necessary for a trace - the format is designed to work when the writer died before it could cleanly finish.
| @@ -1979,7 +1979,8 @@ export type ValidationEvent = {| | |||
| * @section reporter | |||
| */ | |||
| export type TraceEvent = {| | |||
| +type: 'trace', | |||
| @@ -1979,7 +1979,8 @@ export type ValidationEvent = {| | |||
| * @section reporter | |||
| */ | |||
| export type TraceEvent = {| | |||
| +type: 'trace', | |||
| +type: 'trace.start' | 'trace.end', | |||
| +id: string, | |||
| +ts: number, | |||
| +duration: number, | |||
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There's a flow error in your calls to .trace() because the trace event expects a duration which now won't be relevant with begin/end events.
This PR fixes issues with the tracing implementation
Namely: