public static void AppendETags <TRegion>(this HttpResponse response, ICacheRegion <TRegion> cache, string cacheKey, byte[] stream)
{
response.Headers.TryAdd(HeaderNames.ETag, new StringValues(new[]
{
cacheKey.WeakETag(true, cache), stream.StrongETag(cache)
}));
}
public DynamicController(IRecordStore store, ICacheRegion <SyndicationFeed> feeds)
{
_store = store;
_feeds = feeds;
_example = new T();
ObjectValidator = new DynamicModelValidator();
}
public static ulong GetSeed <T>(this ICacheRegion <T> cache)
{
if (!cache.TryGetValue(nameof(GetSeed), out ulong seed))
{
cache.Set(nameof(GetSeed), seed = BitConverter.ToUInt64(Encoding.UTF8.GetBytes(typeof(T).Name), 0));
}
return(seed);
}
public static bool IfModifiedSince <TRegion>(this HttpRequest request, string cacheKey,
ICacheRegion <TRegion> cache, out DateTimeOffset?lastModified, out IActionResult result)
{
var headers = request.GetTypedHeaders();
var ifModifiedSince = headers.IfModifiedSince;
if (cache.TryGetValue($"{cacheKey}:{HeaderNames.LastModified}", out lastModified) &&
lastModified <= ifModifiedSince)
{
result = new StatusCodeResult((int)HttpStatusCode.NotModified);
return(false);
}
result = default;
return(true);
}
public IMethodReturn Invoke(IMethodInvocation input, GetNextInterceptionBehaviorDelegate getNext)
{
if (IsMethodCachable(input))
{
string regionName = _cacheRegionNameGenerator.CreateRegionName(
string.Format("{0}.{1}", input.Target.GetType().FullName, input.MethodBase.Name));
string cacheKey = _cacheKeyGenerator.CreateCacheKey(input.Inputs);
ICacheRegion cacheRegion = _cacheProvider.GetRegion(regionName);
return(cacheRegion.GetOrAdd(cacheKey,
() => getNext.Invoke().Invoke(input, getNext)
));
}
return(getNext()
.Invoke(input, getNext));
}
public static bool IsContentStale <TRegion>(this HttpRequest request, string cacheKey,
ICacheRegion <TRegion> cache, out byte[] stream, out DateTimeOffset?lastModified, out IActionResult result)
{
// https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/If-None-Match
if (!request.IfNoneMatch(cacheKey, cache, out stream, out result))
{
lastModified = default;
return(false);
}
// https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/If-Modified-Since
// "When used in combination with If-None-Match, it is ignored, unless the server doesn't support If-None-Match."
if (!request.IfModifiedSince(cacheKey, cache, out lastModified, out result))
{
return(false);
}
return(true);
}
public RemoteAddressFilter(ICacheRegion <HttpContext> cache)
{
_cache = cache;
}
public InvalidateCachesWhenRecordAdded(ICacheRegion <SyndicationFeed> cache)
{
_cache = cache;
}
public static string StrongETag <TRegion>(this byte[] data, ICacheRegion <TRegion> cache)
{
var value = WyHash64.ComputeHash64(data, cache.GetSeed());
return($"\"{value}\"");
}
public static bool IfNoneMatch <TRegion>(this HttpRequest request, string cacheKey, ICacheRegion <TRegion> cache,
out byte[] stream, out IActionResult result)
{
var headers = request.GetTypedHeaders();
foreach (var etag in headers.IfNoneMatch)
{
if (etag.IsWeak)
{
if (!etag.Tag.Equals(cacheKey.WeakETag(false, cache)))
{
continue;
}
result = new StatusCodeResult((int)HttpStatusCode.NotModified);
stream = default;
return(false);
}
if (!cache.TryGetValue(cacheKey, out stream) || !etag.Tag.Equals(stream.StrongETag(cache)))
{
continue;
}
result = new StatusCodeResult((int)HttpStatusCode.NotModified);
return(false);
}
result = default;
stream = default;
return(true);
}
public static string WeakETag <TRegion>(this string key, bool prefix, ICacheRegion <TRegion> cache)
{
var value = WyHash64.ComputeHash64(Encoding.UTF8.GetBytes(key), cache.GetSeed());
return(prefix ? $"W/\"{value}\"" : $"\"{value}\"");
}