Crate rocket_cache_response 

Cache Response for Rocket Framework

This crate provides a response struct used for HTTP cache control.

use rocket::get;
use rocket_cache_response::CacheResponse;

#[get("/")]
fn index() -> CacheResponse<&'static str> {
    CacheResponse::public("Hello world!", 3600)
}

Every directive is a public field of CacheControl, so an uncommon combination can be built with the struct update syntax.

use rocket::get;
use rocket_cache_response::{CacheControl, CacheResponse};

#[get("/")]
fn index() -> CacheResponse<&'static str> {
    CacheResponse::new("Hello world!", CacheControl {
        s_max_age:              Some(86400),
        stale_while_revalidate: Some(30),
        ..CacheControl::public(60)
    })
}

A browser holding on to an old response is a nuisance during development, so only_release drops the Cache-Control header when the program is built in the debug mode.

use rocket::get;
use rocket_cache_response::CacheResponse;

#[get("/")]
fn index() -> CacheResponse<&'static str> {
    CacheResponse::public("Hello world!", 3600).only_release()
}

Which Cache-Control Should I Use?

Situation	Directives	Shortcut
A static file whose URL changes whenever its content changes, such as app.9f2c1a.js	public, max-age=31536000, immutable	CacheResponse::immutable(responder)
A public page or asset that only changes once in a while	public, max-age=3600	CacheResponse::public(responder, 3600)
A public response that a CDN should keep longer than a browser does	public, max-age=60, s-maxage=86400	CacheControl { s_max_age: Some(86400), ..CacheControl::public(60) }
A page or an API response that belongs to the logged-in user	private, max-age=0	CacheResponse::private(responder, 0)
A response that has to be checked with the server before every reuse	no-cache	CacheResponse::no_cache(responder)
Personal data, payment details or anything else sensitive	no-store	CacheResponse::no_store(responder)

Things that are easy to get wrong:

• no-cache does not mean “do not cache”. A cache may still store the response; it just has to ask the origin server whether the stored copy is still good before every reuse. Use no-store when the response must never be written to a cache at all.
• no-cache on its own still lets shared caches, such as a CDN or a company proxy, store the response. Add private whenever the body is meant for one user only.
• must-revalidate only takes effect after max-age has passed. It forbids a cache from serving the stale copy while the origin server is unreachable.
• immutable is honored even when the user presses the reload button, so only use it for URLs that get a new name whenever the content changes.
• max-age is counted by each cache on its own, so a CDN and a browser may hold their copies for different amounts of time. s-maxage is the way to give shared caches a lifetime of their own.

Re-exports

pub extern crate rocket;

Structs

CacheControl

The directives of a Cache-Control response header.

CacheResponse

The responder with a Cache-Control header.

Enums

Cacheability

Which caches are allowed to store a response.