The Ghosts of Action View Cache

on YouTube ↗26m

" summary

Caches rendered HTML instead of relations, so switching to Action View fragment caching fixes a bug where an ActiveRecord relation was stored in Rails.cache and prevents that class of errors. Cache keys come from action_view_digestor by hex‑digesting template source plus its dependency tree parsed by the ERB tracker (regex with an ERB‑comment fallback). A utility, action_view_precompiler, uses Ruby parsers (ripper and prism render parser) to precompile templates at boot, lowering memory and enabling a CLI that found ~5% dead view templates in one app.

AI-written summary · about

" chapters (14)

1. 0:00Introduction
2. 1:06Rails upgrade ghost story
3. 2:30Action View fragment caching
4. 3:57Action View cache keys
5. 6:43Memory issues with Action View
6. 8:09Rails server worker forking
7. 10:58Action View pre-compiler
8. 13:25Template pre-compilation benefits
9. 14:28Dead view templates
10. 17:40Mark-sweep for dead code
11. 20:49Action View improvements
12. 22:56Upstreaming pre-compiler
13. 24:00Rails building blocks
14. 24:42Q&A

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