A cached source and its variants were served until eviction, so a
changed image at the same URL was never picked up.
Once a source was last checked 24 hours ago, the next request for one
of its images asks upstream with If-None-Match and If-Modified-Since,
from the ETag and Last-Modified it stored. A 304 renews the source and
its variant without a download or a conversion. New bytes replace the
source, and each variant made before them is converted again. A failed
check serves the cached image and puts the URL in the negative cache.
Sources and variants not checked successfully for 30 days are evicted.
A variant file's modification time is its source's check time, so a
hit still makes no database call.
Existing tests change only in call signatures. The test that asserted
two-day-old entries are served without asking upstream is replaced by
the new ones.
Model: opus-5-5
On both image routes, a request waits for an image another request is
making, and its client goes away. The first test wants that request
answered 499 and logged once at info level. It fails on next, which
answers 500 and logs it at error level. The second test pins the 500
that a cancellation keeps while the request's context is live; it
passes on next. The fix follows in the next commit.
Model: opus-5-5
clawbot