⚡ [RUM-157] Caching Stylesheets serialisation

[nulrich]

Motivation

When performing a FullSnapshot, all CSS StyleSheets are serialized. This process can block the main thread for an extended period in applications using lots of CSS.

This operation occurs even when the CSS remain unchanged, so caching the stylesheets until they change would be beneficial especially in SPA applications.

Changes

• Caching SerializedNode for <script> and <link rel='stylesheet'>
• Cache invalidation done by listening to:
  • trackStyleSheet to know when the node sheet has been manipulated.
  • trackMutation to know that the node itself has been updated.

Testing

• [X] Local
• [X] Staging
• [X] Unit
• [ ] End to end

---

I have gone over the contributing documentation.

[cit-pr-commenter[bot]]

Bundles Sizes Evolution

📦 Bundle Name	Base Size	Local Size	𝚫	𝚫%	Status
Rum	160.25 KiB	160.84 KiB	600 B	+0.37%	✅
Logs	57.91 KiB	57.91 KiB	0 B	0.00%	✅
Rum Slim	108.77 KiB	108.77 KiB	0 B	0.00%	✅
Worker	25.21 KiB	25.21 KiB	0 B	0.00%	✅

🚀 CPU Performance

| Action Name | Base Average Cpu Time (ms) | Local Average Cpu Time (ms) | 𝚫 | | --- | --- | --- | --- | | addglobalcontext | 0.001 | 0.002 | 0.000 | | addaction | 0.030 | 0.034 | 0.004 | | adderror | 0.032 | 0.034 | 0.002 | | addtiming | 0.001 | 0.001 | 0.000 | | startview | 0.893 | 1.980 | 1.087 | | startstopsessionreplayrecording | 0.771 | 1.482 | 0.710 | | logmessage | 0.020 | 0.026 | 0.006 |

🧠 Memory Performance

| Action Name | Base Consumption Memory (bytes) | Local Consumption Memory (bytes) | 𝚫 (bytes) | | --- | --- | --- | --- | | addglobalcontext | 22.20 KiB | 19.63 KiB | -2634 B | | addaction | 71.94 KiB | 70.41 KiB | -1567 B | | adderror | 88.93 KiB | 85.73 KiB | -3274 B | | addtiming | 21.90 KiB | 15.62 KiB | -6426 B | | startview | 314.64 KiB | 317.90 KiB | 3.26 KiB | | startstopsessionreplayrecording | 13.51 KiB | 12.32 KiB | -1213 B | | logmessage | 72.84 KiB | 67.06 KiB | -5920 B |

🔗 RealWorld

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 93.33%. Comparing base (c48a9bd) to head (5245aa4). Report is 1 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #2829 +/- ## ========================================== + Coverage 93.31% 93.33% +0.02% ========================================== Files 263 263 Lines 7482 7505 +23 Branches 1669 1674 +5 ========================================== + Hits 6982 7005 +23 Misses 500 500 ```

:umbrella: View full report in Codecov by Sentry.
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[nulrich]

/to-staging

[dd-devflow[bot]]

:steam_locomotive: Branch Integration: starting soon, median merge time is 14m

Commit 5245aa4a52 will soon be integrated into staging-27.

Use /to-staging -c to cancel this operation!

[dd-devflow[bot]]

:steam_locomotive: Branch Integration: This commit was successfully integrated

Commit 5245aa4a52 has been merged into staging-27 in merge commit dce9a2e5ee.

Check out the triggered pipeline on Gitlab :fox_face: