Caching of hydra:ApiDocumentation and Entrypoint

[lazka]

For using the json-ld/hydra API I have to check https://demo.api-platform.com/docs.jsonld and https://demo.api-platform.com/.jsonld to figure out the types and operations which means two extra requests before the first real API call. These requests aren't cached, and slow things down.

I wonder if this couldn't be cached with etags since the content is static anyway. Am I missing something maybe?

[dunglas]

You're right, we must set etags and basic HTTP cache header on these endpoints, this could improve the performance of the admin a lot.

PR welcome!!

[J3m5]

It would be really nice to have this.
Not only the admin but all the clients that use the api doc parser.
For us, the docs are about 280 KB in size and takes 1.3 s to fetch.

[abderrahimghazali]

Opened #7929 to address this. The PR adds an event listener that sets a strong ETag (md5 of the body) plus Cache-Control: public, max-age=0, must-revalidate on api_doc and api_entrypoint responses, and lets Response::isNotModified() short-circuit to a 304 when the client sends a matching If-None-Match. Feedback welcome!