Three separate things that were each costing more than they needed to on the
hot path.
- Single-flight avatar renders. The disk cache was checked first and a miss
went straight to the upstream, with nothing shared between callers, so a page
requesting dozens of avatars at once turned N concurrent requests for one
figure into N renders. A render is the most expensive operation this app
does, and the duplication happened exactly when the cache had nothing to
offer. Eight concurrent requests now cause one render instead of eight. The
map lives on globalThis because Next can evaluate the module more than once
per process, and two copies would each start their own render.
- Let public read-only routes be cached by a shared cache. Every JSON response
was `cache-control: no-store`, so a CDN in front of the app could not answer
any of it and every request reached the origin. publicCacheControl() opts a
route in with s-maxage and stale-while-revalidate, using the same TTL as the
server-side cache so the two layers cannot disagree. The default stays
no-store: most routes here are personalised, admin-only or auth-dependent.
/api/badges/leaderboard is deliberately left alone because it returns
per-viewer rank entries to signed-in callers.
Note this only takes effect once a cache rule exists for /api/* at the CDN, or
the explicit `cache: "no-store"` is dropped from the client fetches (24 files
do that today, including the /api/online poll). The headers alone are inert
until one of those happens.
- Take the homepage row counts from the storage engine estimate instead of
COUNT(*), which walks an index and gets slower as the tables grow. A missing
or zero estimate falls back to the exact count rather than ever showing a
wrong zero. The online count stays exact: it is an indexed read over a small
subset and a few seconds of drift reads as broken rather than approximate.
The counters move into one module because the homepage and the boot warm-up
populate the same cache keys, so two implementations would race to write
different values into the same entry.
3223 tests pass.
openhands
f81b114b69