perf: reduce _prerenderRoutes memory footprint

[Hebilicious]

🔗 Linked issue

Related #1535
Related #1480
Related nuxt/nuxt#22449

❓ Type of change

• 📖 Documentation (updates to the documentation, readme, or JSdoc annotations)
• 🐞 Bug fix (a non-breaking change that fixes an issue)
• 👌 Enhancement (improving an existing functionality like performance)
• ✨ New feature (a non-breaking change that adds functionality)
• 🧹 Chore (updates to the build process or auxiliary tools and libraries)
• ⚠️ Breaking change (fix or feature that would cause existing functionality to change)

📚 Description

Based on @simkuns patch. Internal _prerenderedRoutes now only contains route and fileName to reduce the memory footprint

📝 Checklist

• I have linked an issue or discussion.
• I have updated the documentation accordingly.

[codecov]

Codecov Report

Merging #1529 (abd59cf) into main (451d314) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main    #1529   +/-   ##
=======================================
  Coverage   76.25%   76.25%           
=======================================
  Files          73       73           
  Lines        7478     7481    +3     
  Branches      734      734           
=======================================
+ Hits         5702     5705    +3     
  Misses       1775     1775           
  Partials        1        1           

Files Changed	Coverage Δ
src/prerender.ts	87.17% <100.00%> (+0.10%)	⬆️

[danielroe]

Nice! ❤️

[parzychu]

Great! <3

[pi0]

sorry but i cannot let this to be merged in nitro. please consider proposing framework agnostic solutions AND make sure there is a nitro minimal reproduction that makes sure it actually proves and solves an issue instead of hiding root causes.

[pi0]

Requirements:

• Framework agnostic implementation
• Nitro minimal reproduction to make sure there is an issue with Nitro itself, not downstream framework (Nuxt) or modules.

As a Nuxt team member and nitro maintainer, I tend to fix the root cause of issues not patching them around.

[Hebilicious]

Thanks for the feedback @pi0

I'm open to suggestions for a framework agnostic design.
What if we accept a regex from the settings likenitro.options.prerender.prependExtractedLinkRegex?
This can then be used by Nuxt to achieve such a behaviour.

Edit @danielroe proposed a hook to do that, I'll refactor and open another PR

[pi0]

(i am working on reproduction and alternative fix for content issue)

@Hebilicious Can you please explain more why we would need to reorder prerender routes and how it relates to a possible fix?

[Hebilicious]

(i am working on reproduction and alternative fix for content issue)

@Hebilicious Can you please explain more why we would need to reorder prerender routes and how it relates to a possible fix?

This re-ordering was based on this comment that included a nice heap profile.
#1480 (comment)

However with daniel suggestion, I now think its better to expose a hook (before runParallel) so that frameworks (nuxt, modules ...) can inspect and re-order routes if they wish to do so.

For testing we could test the perf differences with nuxt/nuxt#22465 and #1529 and see how much re-ordering with payload routes first would impact things.

[pi0]

Thanks for PR and explanations @Hebilicious and pin pointing the exact issue @danielroe i have made a better rework in #1536 which seems to fix (reproducable) issue.

@Hebilicious I would recommend to try nuxt edge + nitro edge with both fixes (LRU cache and #1536) and rerun any previous benchmarks again to make sure sorting with fixes makes a difference. If it does, we already have prerender:routes(routes) hook that get's called before parallel run and can be used to reorder. We might think of another hook too prerender:extractedlinks (or similar that is called inside generateRoute) if sorting of later discovered. I think generally would be a nice addition but again, please test.