only-if-cached yana neman amsa da aka adana daga proxy

Don buƙatar da ya kamata ta yi amfani da amsar da aka riga aka adana, HTTP yana bayyana Cache-Control: only-if-cached.

Abokin ciniki na iya aika ta ta hanyar proxy na cache na HTTP:

curl --proxy http://127.0.0.1:3128 \
  --header 'Cache-Control: only-if-cached' \
  --include http://www.example.org/report

Cache da ke mutunta wannan umarni ya kamata ya mayar da amsar da aka adana da ta dace da sauran sharuɗɗan buƙatar, ko 504 Gateway Timeout lokacin da ba zai iya biyan buƙatar ba. A nan 504 na iya nuna manufar cache maimakon haɗin TCP da ya kasa zuwa proxy.

Umarnin ba ya ba da izinin abin da ya tsufa kai tsaye. Sabo, bukatun tabbatarwa da filayen Vary masu dacewa har yanzu suna da muhimmanci. Umarnin buƙatar no-cache na iya neman tabbatarwa mai nasara a asali kafin sake amfani.

Wannan kuma ya bambanta da saita yanayin tabbatarwa na offline na cache. only-if-cached ana ɗaukarsa a kan buƙatar ɗaya kuma yana bayyana abin da abokin ciniki ya yarda ya karɓa.

Yi amfani da cache da ke goyan bayan wannan ɗabi'a. Umarnin buƙatar da aka yi watsi da shi ba shinge ba ne, don haka hana zirga-zirgar sama sosai yana buƙatar manufar cibiyar sadarwa ko uwar garke da aka aiwatar da ita da kanta.

Proxy na HTTPS CONNECT na yau da kullum ba ya ganin kanun HTTP da aka ɓoye kuma ba ya adana abubuwan shafi daga wannan rami. Misalin yana amfani da albarkatun HTTP mai sauƙi da cache zai iya sarrafawa da gangan.