Module cache 

In-memory response cache middleware.

CacheLayer implements Middleware and short-circuits the inner application for cacheable GET responses within their TTL. Entries are bounded by a configurable capacity; the oldest entry is evicted when the store is full and no expired entries remain.

What is cached

• Method: GET only; all other methods bypass the cache.
• Status: 2xx responses (200, 201, 203, 204, 206, …).
• Response Cache-Control: no-store or private — not cached.
• Private or partial requests — Authorization, Cookie or Range — skip the cache entirely (no lookup, no store): their responses may differ per user or cover only part of the resource.
• Responses that set a cookie (Set-Cookie) or stream their body (stream_file / stream_pipe, not held in memory) are not cached.
• Request Cache-Control: no-cache — cache is bypassed, handler is called, but the fresh response is stored (revalidation).
• How long: the response’s Cache-Control: s-maxage, else max-age, capped by the layer’s ttl; the ttl when it says neither. max-age=0 is not stored (since 18.11.0; before, every response was kept for the ttl). Hits carry an Age header.

Example

use rust_web_server::app::App;
use rust_web_server::cache::CacheLayer;
use rust_web_server::core::New;

let app = App::new()
    .wrap(CacheLayer::memory(1000).ttl(60).vary_by_header("Accept"));

Modules

registry

Named caches for the admin API: the binary’s own and one per config-file route that has [route.middleware.cache].

Structs

CacheLayer

An in-memory response cache middleware.

Enums

Purge

What CacheLayer::purge removes. A cache key is the request target (path and query) plus the values of vary_by_headers, so Exact removes every variant of one target.