[webfansplz]

Summary

Two costs that grow with project size made the inspect collector compete with Vite for the main thread:

1. The public module id cache stopped working in large projects. It was capped at 10,000 entries and cleared when full. Projects with more modules than that kept clearing it, so every recorded hook recomputed the id normalization (including path.relative for dependencies) on the hot path.
2. The panel's module list blocked the event loop. With the panel open, each edit triggers about two get-modules-list queries (one from the HMR update, one after the follow-up requests settle). Each query rebuilt the whole list in one synchronous run, so Vite couldn't serve any request in the meantime: about 100 ms per query at 15,000 modules.

Changes

• Raise the public module id cache cap from 10,000 to 100,000, and note that it has to stay well above the module count of large projects.
• Cache the module list per environment. The store now exposes getChangeVersion(), which increases on every write that can change recorded modules (clearPendingLoadMetrics doesn't count). getModulesList returns the previous list until the version changes.
• Build the list in slices, yielding to the event loop about every 4 ms, so a long rebuild no longer stalls Vite in one block.

Impact

Measured locally with a synthetic project (half of the modules under node_modules, 20 plugins), median of 3 runs.

With the panel open, per edit:

	5,000 modules	15,000 modules
First query, main-thread time	18 → 23 ms (within noise)	104 → 61 ms
First query, longest stall	18 → 17 ms	104 → 35 ms
Second query	19 → 0.1 ms	100 → 0.1 ms
Total main-thread time per edit	~37 → ~23 ms	~204 → ~61 ms

Without the panel, cold-start transform overhead at 15,000 modules goes from +33% to +21% because the id cache keeps hitting. Smaller projects already fit in the old cap and are unchanged.

The id cache uses about 9 MB when completely full (100,000 entries, about 97 bytes each, measured as heap with the cache filled minus heap after clearing it). It only grows that large in large projects or very long sessions.

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commit: 1d51c55