check / check (push) Canceled after 0s
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