hermes-agent/apps
Brooklyn Nicholson ea510a7c02 perf(desktop): memoize MarkdownText plugins to stop churning Streamdown
The inline `plugins={{ math: mathPlugin, ...(isStreaming ? {} : { code }) }}`
on `<StreamdownTextPrimitive>` constructed a new object literal on every
parent render. That broke `<Streamdown>`'s outer memo and forced its
internal `rehypePlugins` / `remarkPlugins` array useMemos to rebuild,
which propagates a new identity into every `<Block>` and defeats Block's
memoization for stable historical blocks.

After memoizing on `[isStreaming]` (the only real dimension of variance),
CPU profile during a 5 s synthetic stream on the 34 MB session shows
`parser` self-time dropping out of the top 10, `compile` cut roughly in
half, and `bn$1` / `m$1` (micromark internals) leaving the top entries.

Doesn't move the visible longtask count on its own — Streamdown's
per-Block parse cost still dominates whenever the last block's content
changes — but it removes a class of unnecessary re-parses for historical
blocks during streaming. See `scripts/profile-typing-lag.md` for the
full investigation.
2026-05-21 20:08:32 -05:00
..
dashboard Merge branch 'main' into bb/gui 2026-05-20 16:01:41 -04:00
desktop perf(desktop): memoize MarkdownText plugins to stop churning Streamdown 2026-05-21 20:08:32 -05:00
shared feat: move dashboard to apps/ so we can share ws proto 2026-05-02 13:38:49 -05:00