private async Task OnEnterAsync(object source, EventArgs eventArgs)
{
var app = (HttpApplication)source;
var helper = new OutputCacheHelper(new HttpContextWrapper(app.Context));
if (!helper.IsHttpMethodSupported())
{
return;
}
// Create a lookup key. Also store the key in global parameter _key to be used inside OnLeave() later
string key = helper.CreateOutputCachedItemKey(null);
// Lookup the cache vary using the key
object item = await helper.GetAsync(key);
if (item == null)
{
return;
}
// 'item' may be one of the following:
// - a CachedVary object (if the object varies by something)
// - a CachedRawResponse object (i.e. it doesn't vary on anything)
// First assume it's a CacheVary and try to get the cachedItem with it
CachedRawResponse cachedRawResponse = null;
var cachedVary = item as CachedVary;
if (cachedVary != null)
{
var cachedItem = await helper.GetAsCacheVaryAsync(cachedVary);
if (cachedItem != null)
{
cachedRawResponse = (CachedRawResponse)cachedItem;
}
}
if (cachedRawResponse == null)
{
cachedRawResponse = item as CachedRawResponse;
}
if (cachedRawResponse == null)
{
return;
}
// From this point on, we have an Raw Response entry to work with.
HttpCachePolicySettings settings = cachedRawResponse.CachePolicy;
if (helper.CheckCachedVary(cachedVary, settings))
{
return;
}
if (settings.IgnoreRangeRequests && helper.IsRangeRequest())
{
return;
}
if (helper.CheckHeaders(settings))
{
return;
}
if (await helper.CheckValidityAsync(key, settings))
{
return;
}
if (!helper.IsContentEncodingAcceptable(cachedVary, cachedRawResponse.RawResponse))
{
return;
}
helper.UpdateCachedResponse(settings, cachedRawResponse.RawResponse);
//Re-insert entry in kernel cache if necessary
if (helper.IsKernelCacheAPISupported() && cachedRawResponse.KernelCacheUrl != null)
{
OutputCacheUtility.SetupKernelCaching(cachedRawResponse.KernelCacheUrl, app.Context.Response);
}
//Complete request
app.CompleteRequest();
}
public string SetupKernelCaching(string originalCacheUrl, HttpContextBase context)
{
return(OutputCacheUtility.SetupKernelCaching(originalCacheUrl, context.ApplicationInstance.Response));
}
public void SetContentBuffers(HttpContextBase context, ArrayList buffers)
{
OutputCacheUtility.SetContentBuffers(context.ApplicationInstance.Response, buffers);
}
public IEnumerable <KeyValuePair <HttpCacheValidateHandler, object> > GetValidationCallbacks(HttpContextBase context)
{
return(OutputCacheUtility.GetValidationCallbacks(context.ApplicationInstance.Response));
}
public ArrayList GetContentBuffers(HttpContextBase context)
{
return(OutputCacheUtility.GetContentBuffers(context.ApplicationInstance.Response));
}
public CacheDependency CreateCacheDependency(HttpContextBase context)
{
return(OutputCacheUtility.CreateCacheDependency(context.ApplicationInstance.Response));
}
