Profiling the live app showed the single biggest CPU cost was the relay pool
verifying every incoming event's schnorr signature synchronously on the main
thread: ~1.2s of secp256k1 work ([email protected] 855ms) during feed load and tab
switches, dropping to ~16ms when skipped. The pool was constructed as
`new SimplePool()` with no options, so nostr-tools used its default verifying
verifyEvent; the `verifyEvent: () => true` that looked like it disabled this
only existed on a mock tools object and was never wired to the real pool.
Move verification off the main thread instead of dropping it:
- Construct the pool with `verifyEvent: () => true` so it never blocks.
- Add signatureVerifyWorker (+ client) that verifies event batches in a Web
Worker and returns the valid ids; falls back to main-thread verification only
when Workers are unavailable (never silently trusts).
- VideoEventBuffer verifies each batch via the worker before committing, and
drops events that fail (fails closed). The verifier is injectable so tests can
virtualize the worker; subscribeVideos passes it through and returns the flush
promise from EOSE so commits are awaitable.
Tests: new signatureVerifyWorkerClient.test.mjs (worker protocol + drop-invalid
+ empty/no-id handling); videoEventBuffer.test.mjs and client.test.mjs adapted
to the async, verified commit path with a passthrough verifier.
Note: tests/nostr-delete-flow.test.mjs has a PRE-EXISTING failure on
`should not trigger subscription callbacks` (fails on clean unstable, and is a
standalone script not run by the unit-test runner); its edits here only adapt it
to the now-async flush.
Co-Authored-By: Claude Opus 4.8 <[email protected]>
