perf: Replacing "else if" with a "switch case" statement to improve Typescript performance #1142
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…ipt performance I generated a trace from the build process and using [typescript-analyze-trace](https://github.com/microsoft/typescript-analyze-trace) to analyze the hotspots. It turns out that time is spent in this kind of code: ``` if (object.choice?.$case === "aNumber" && object.choice?.value !== undefined && object.choice?.value !== null) { message.choice = { $case: "aNumber", value: object.choice.value }; } else if ( object.choice?.$case === "aString" && object.choice?.value !== undefined && object.choice?.value !== null ) { message.choice = { $case: "aString", value: object.choice.value }; } else if ( //... ``` The previous PR I opened adding "else if" does nothing regarding Typescript perf. With "else if", my test file trace looks like this: ``` npx analyze-trace traceDir Hot Spots ├─ Check file /home/dan/projects/ts-proto/integration/large/messages.ts (31108ms) │ ├─ Check deferred node from (line 6267, char 3) to (line 6539, char 4) (13123ms) │ ├─ Check deferred node from (line 15342, char 3) to (line 15591, char 4) (7092ms) │ ├─ Check deferred node from (line 10849, char 3) to (line 11059, char 4) (4460ms) │ ├─ Check deferred node from (line 17320, char 3) to (line 17496, char 4) (2146ms) │ ├─ Check deferred node from (line 3720, char 3) to (line 3832, char 4) (610ms) │ └─ Check deferred node from (line 8791, char 3) to (line 8915, char 4) (516ms) └─ Check file /home/dan/projects/ts-proto/node_modules/typescript/lib/lib.dom.d.ts (1109ms) ``` Now, with this commit, I'm replace else if with switch statement. The analysis of the build looks like this: ``` Hot Spots ├─ Check file /home/dan/projects/ts-proto/integration/large/messages.ts (3139ms) │ └─ Check deferred node from (line 6278, char 3) to (line 6573, char 4) (525ms) └─ Check file /home/dan/projects/ts-proto/node_modules/typescript/lib/lib.dom.d.ts (617ms) ``` The biggest switch statement takes 525ms to analyze (down from 13seconds with "else if") Implementation-wise, the hardest part is knowning when to close the switch statement. I'm doing a test at the beginning of each loop and at the very end of the function.
stephenh
approved these changes
Nov 28, 2024
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| // add a check for each incoming field | ||
| messageDesc.field.forEach((field) => { | ||
| const fieldName = getFieldName(field, options); | ||
| const messageProperty = getPropertyAccessor("message", fieldName); | ||
| const objectProperty = getPropertyAccessor("object", fieldName); | ||
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| if (currentSwitchTarget && !isWithinOneOfThatShouldBeUnion(options, field)) { | ||
| // We are exiting a switch, we need to close it |
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Nice, thanks for the in-source comment!
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Woah! Merged in 28 minutes. You are a hell of a maintainer. Thanks for all you are doing @stephenh ! |
stephenh
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Nov 28, 2024
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🎉 This issue has been resolved in version 2.4.2 🎉 The release is available on: Your semantic-release bot 📦🚀 |
moufmouf
added a commit
to workadventure/workadventure
that referenced
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Nov 28, 2024
This version contains a performance fix for Typescript 5.1+. See stephenh/ts-proto#1142
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This is a follow-up (and solution) to #1135 and #1141
I generated a trace from the build process and using typescript-analyze-trace to analyze the hotspots.
It turns out that time is spent almost exclusively in this kind of code:
The previous PR I opened adding "else if" does nothing regarding Typescript perf.
With "else if", my test file trace looks like this:
Now, with this commit, I'm replace
else ifwith aswitchstatement.The analysis of the build looks like this:
The biggest
switchstatement takes 525ms to analyze (down from 13seconds withelse if)Implementation-wise, the hardest part is knowing when to close the switch statement. I'm doing a test at the beginning of each loop and at the very end of the function.