static IEnumerable <string> CacheVisibility(CacheProxyAttribute proxy, CacheClientAttribute client)
{
if (proxy == null && client == null)
{
yield break;
}
switch (proxy?.Level)
{
case CacheLevel.Everything:
yield return("public");
break;
case CacheLevel.DoNotCache when client?.Level == CacheLevel.DoNotCache:
yield return("no-cache");
break;
case null when client.Level != CacheLevel.DoNotCache:
case CacheLevel.DoNotCache when client?.Level != CacheLevel.DoNotCache:
yield return("private");
break;
}
}
static IEnumerable <string> CacheMaxAge(CacheProxyAttribute proxy, CacheClientAttribute client)
{
TimeSpan proxyAge = TimeSpan.MinValue, browserAge = TimeSpan.MinValue;
if (proxy?.MaxAge != null)
{
TimeSpan.TryParse(proxy.MaxAge, out proxyAge);
}
if (client?.MaxAge != null)
{
TimeSpan.TryParse(client.MaxAge, out browserAge);
}
if (proxyAge == TimeSpan.MinValue && browserAge == TimeSpan.MinValue)
{
yield break;
}
if (proxyAge != TimeSpan.MinValue && browserAge != TimeSpan.MinValue)
{
yield return("s-max-age=" + proxyAge.TotalSeconds);
}
yield return("max-age=" + (proxyAge != TimeSpan.MinValue
? proxyAge.TotalSeconds
: browserAge.TotalSeconds));
}
static IEnumerable<string> CacheRevalidation(CacheProxyAttribute proxy, CacheBrowserAttribute browser)
{
if (proxy != null && proxy.MustRevalidate && browser != null && browser.MustRevalidate)
yield return "must-revalidate";
else if (proxy != null && proxy.MustRevalidate)
yield return "proxy-revalidate";
}
// ReSharper disable once ParameterOnlyUsedForPreconditionCheck.Local
static void ValidateProxyAttribute(CacheProxyAttribute proxy)
{
if (proxy?.MaxAge != null && proxy.Level == CacheLevel.DoNotCache)
{
throw new InvalidOperationException("Cannot set MaxAge to a value and have the proxy cache disabled");
}
}
protected void given_attribute(
CacheClientAttribute client = null,
CacheProxyAttribute proxy = null)
{
this.client = client;
_proxy = proxy;
}
static void SetupLocalCaching(CacheProxyAttribute proxy, ResponseCachingState response)
{
TimeSpan parsedMaxAge;
if (proxy.MaxAge != null && TimeSpan.TryParse(proxy.MaxAge, out parsedMaxAge))
{
response.LocalCacheEnabled = true;
response.LocalCacheMaxAge = parsedMaxAge;
}
}
static IEnumerable <string> CacheRevalidation(CacheProxyAttribute proxy, CacheClientAttribute client)
{
if (proxy?.MustRevalidateWhenStale == true && client?.MustRevalidateWhenStale == false)
{
yield return("proxy-revalidate");
}
if (proxy?.MustRevalidateWhenStale == true || proxy?.MustRevalidateWhenStale == true)
{
yield return("must-revalidate");
}
}
static IEnumerable<string> CacheVisibility(CacheProxyAttribute proxy, CacheBrowserAttribute browser)
{
if (proxy == null && browser == null)
yield break;
if (proxy != null && proxy.Level == ProxyCacheLevel.Everything)
yield return "public";
else if ((proxy == null || proxy.Level == ProxyCacheLevel.None) &&
(browser == null || browser.Level == BrowserCacheLevel.Default))
yield return "private";
else if (proxy != null && browser != null && proxy.Level == ProxyCacheLevel.None && browser.Level == BrowserCacheLevel.None)
yield return "no-cache";
}
// TODO: Reduce all those horrible enumerator allocations!
public static ResponseCachingState GetResponseDirective(
CacheProxyAttribute proxy = null,
CacheClientAttribute client = null)
{
ValidateProxyAttribute(proxy);
var instructions =
CacheVisibility(proxy, client)
.Concat(CacheRevalidation(proxy, client))
.Concat(CacheMaxAge(proxy, client));
return(new ResponseCachingState(instructions));
}
public Func <IOperationAsync, Task <IEnumerable <OutputMember> > > Compose(
Func <IOperationAsync, Task <IEnumerable <OutputMember> > > next)
{
return(async operation =>
{
var outputMembers = await next(operation);
_proxy = operation.FindAttribute <CacheProxyAttribute>();
_client = operation.FindAttribute <CacheClientAttribute>();
_data[CacheKeys.ResponseCache] = CacheResponse.GetResponseDirective(_proxy, _client);
return outputMembers;
});
}
public bool BeforeExecute(IOperation operation)
{
_proxy = operation.FindAttribute<CacheProxyAttribute>();
_browser = operation.FindAttribute<CacheBrowserAttribute>();
_server = operation.FindAttribute<CacheServerAttribute>();
var cacheEntry = TryGetValidCacheEntry(_request.Uri.AbsolutePath);
if (cacheEntry != null)
{
_cachedValue = cacheEntry.Value;
}
return true;
}
static IEnumerable<string> CacheMaxAge(CacheProxyAttribute proxy, CacheBrowserAttribute browser)
{
TimeSpan proxyAge = TimeSpan.MinValue, browserAge = TimeSpan.MinValue;
if (proxy != null && proxy.MaxAge != null) TimeSpan.TryParse(proxy.MaxAge, out proxyAge);
if (browser != null && browser.MaxAge != null) TimeSpan.TryParse(browser.MaxAge, out browserAge);
if (proxyAge == TimeSpan.MinValue && browserAge == TimeSpan.MinValue)
yield break;
if (proxyAge != TimeSpan.MinValue && browserAge != TimeSpan.MinValue)
yield return "s-max-age=" + proxyAge.TotalSeconds;
yield return "max-age=" + (proxyAge != TimeSpan.MinValue
? proxyAge.TotalSeconds
: browserAge.TotalSeconds);
}
public static ResponseCachingState GetResponseDirective(
CacheProxyAttribute proxy,
CacheBrowserAttribute browser,
CacheServerAttribute server)
{
ValidateProxyAttribute(proxy);
var instructions = CacheVisibility(proxy, browser)
.Concat(CacheRevalidation(proxy, browser))
.Concat(CacheMaxAge(proxy, browser));
var response = new ResponseCachingState(instructions);
// SetupLocalCaching(proxy, response);
return response;
}
static void ValidateProxyAttribute(CacheProxyAttribute proxy)
{
if (proxy != null && proxy.MaxAge != null && proxy.Level == ProxyCacheLevel.None)
throw new InvalidOperationException("Cannot set MaxAge to a value and have the proxy cache disabled");
}
