Module LoadFromCache 

Extension Manifest Cache Loader (B7.P08)

Loads the pre-baked extension manifest from Target/debug/extensions.manifest.json (written by Maintain/Build/Manifest/PreBake.ts as part of the debug build step).

Why this exists

Mountain’s ScanAndPopulateExtensions currently reads 113+ package.json files sequentially from disk during boot, taking ~1200 ms on cold storage. After the build step runs PreBake.ts, the manifests are pre-merged into a single JSON blob. LoadFromCache reads that blob with a single fs::read and deserializes with serde_json::from_slice, reducing boot cost to <50 ms.

Fallback

If the cache file is missing, stale (older than 10 min), or corrupt, the caller falls back to the normal ScanAndPopulateExtensions path.

Cache format (written by PreBake.ts)

{
  "version": 1,
  "count": 113,
  "extensions": [
    { "id": "publisher.name", "path": "/abs/path/to/ext", "manifest": { … } }
  ]
}

Structs

CacheBlob 🔒

Top-level cache blob.

CachedEntry 🔒

One entry in the pre-baked cache file.

Constants

MAX_CACHE_AGE 🔒

Maximum cache age for dev/repo runs (binary sits next to the cache file).

Functions

Fn

Try to load extension descriptors from the pre-baked manifest cache.