Optimize file I/O, caching, and per-frame calculations

[Copilot]

Performance analysis identified inefficient file system operations during static generation, expensive per-frame 3D calculations, and redundant library initializations.

Changes

File system caching (mdx.ts)

• Cache post slugs and parsed content at module level
• Use withFileTypes in directory reads to eliminate separate stat calls
• Filter slugs before loading posts in getTopicPosts

// Before: loads all posts then filters
const all = getAllPosts('topics')
const filtered = all.filter((post) => post.slug.startsWith(`${topicSlug}/`))

// After: filters slugs first, loads only needed posts
const slugs = getPostSlugs('topics')
const filteredSlugs = slugs.filter((slug) => slug.startsWith(topicPrefix))
const posts = filteredSlugs.map((slug) => getPostBySlug('topics', slug))

3D particle animation (ThreeBackground.tsx)

• Pre-calculate time factors outside particle loop
• Use squared distance comparisons to eliminate 6,400 sqrt() calls per frame

// Before: sqrt() for every particle
const dist = Math.sqrt(dx * dx + dy * dy)
if (dist < radius) { /* ... */ }

// After: compare squared distances
const distSq = dx * dx + dy * dy
if (distSq < radiusSq) { /* ... */ }

Mermaid rendering (MermaidBlock.tsx)

• Cache library instance at module level to prevent re-initialization per component mount
• Add rendering guard for duplicate render prevention

Search (PagefindSearch.tsx)

• Increase debounce to 200ms
• Simplify type guards

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• fonts.googleapis.com
  • Triggering command: /usr/local/bin/node node /home/REDACTED/work/cellstack/cellstack/node_modules/.bin/../next/dist/bin/next build (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Original prompt

Identify and suggest improvements to slow or inefficient code

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