ring.middleware.not-modified

(source)
Middleware that returns a 304 Not Modified response for responses with Last-Modified headers.

For more info about this library see:

https://github.com/ring-clojure/ring/wiki
Public Variable Short Description
not-modified-response (clj) Returns 304 or original response based on response and request.
wrap-not-modified (clj) Middleware that returns a 304 Not Modified from the wrapped handler if the handler response has an ETag or Last-Modified header, and the request has a If-None-Match or If-Modified-Since header that matches the response.