alwaysCache

def alwaysCache[K](cache: Cache[K, RouteResult], keyer: PartialFunction[RequestContext, K]): Directive0

Description

Like cache but disregards a Cache-Control request header.

Example

Scala

//Example keyer for non-authenticated GET requests
val simpleKeyer: PartialFunction[RequestContext, Uri] = {
  val isGet: RequestContext ⇒ Boolean = _.request.method == GET
  val isAuthorized: RequestContext ⇒ Boolean = _.request.headers.exists(_.is(Authorization.lowercaseName))
  PartialFunction {
    case r: RequestContext if isGet(r) && !isAuthorized(r) ⇒ r.request.uri
  }
}

var i = 0
val route =
  alwaysCache(routeCache, simpleKeyer) {
    complete {
      i += 1
      i.toString
    }
  }

Get("/") ~> route ~> check {
  responseAs[String] shouldEqual "1"
}
// now cached
Get("/") ~> route ~> check {
  responseAs[String] shouldEqual "1"
}
Get("/") ~> `Cache-Control`(`no-cache`) ~> route ~> check {
  responseAs[String] shouldEqual "1"
}

Java

final CachingSettings cachingSettings = CachingSettings.create(system());
// Example keyer for non-authenticated GET requests
final JavaPartialFunction<RequestContext, Uri> simpleKeyer = new JavaPartialFunction<RequestContext, Uri>() {
  public Uri apply(RequestContext in, boolean isCheck) {
    final HttpRequest request = in.getRequest();
    final boolean isGet = request.method() == HttpMethods.GET;
    final boolean isAuthorized = request.getHeader(Authorization.class).isPresent();

    if (isGet && !isAuthorized)
      return request.getUri();
    else
      throw noMatch();
  }
};

final AtomicInteger count = new AtomicInteger(0);
final Route route = alwaysCache(routeCache(cachingSettings), simpleKeyer, () ->
  extractUri(uri ->
    complete(String.format("Request for %s @ count %d", uri, count.incrementAndGet()))
  )
);

// tests:
testRoute(route)
  .run(HttpRequest.GET("/"))
  .assertEntity("Request for http://example.com/ @ count 1");

// now cached
testRoute(route)
  .run(HttpRequest.GET("/"))
  .assertEntity("Request for http://example.com/ @ count 1");

final CacheControl noCache = CacheControl.create(CacheDirectives.NO_CACHE);
testRoute(route)
  .run(HttpRequest.GET("/").addHeader(noCache))
  .assertEntity("Request for http://example.com/ @ count 1");