/// <summary>
/// Invoked when the request is beginning.
/// </summary>
/// <param name="sender"></param>
/// <param name="args"></param>
/// <param name="cb"></param>
/// <param name="extraData"></param>
/// <returns></returns>
IAsyncResult BeginOnBeginRequestAsync(object sender, EventArgs args, AsyncCallback cb, object extraData)
{
// ignore spurious calls
var context = HttpContext.Current;
if (context == null)
{
return(new CompletedAsyncResult(null, null));
}
// only generate for classic ASP requests
if (IsAspPage(context))
{
// generate new proxy reference to current request context
var proxy = new ComponentContextProxy(() => GetAutofacRequestContext(context.ApplicationInstance));
context.Items[ContextProxyKey] = proxy;
// add serialized object ref into a header, reachable by classic ASP
var intPtr = Marshal.GetIUnknownForObject(proxy);
context.Request.Headers.Add(ComponentContextUtil.HeadersProxyItemKey, intPtr.ToInt64().ToString("X"));
// ensures that the reference is released if the context is abandoned
context.Items[DisposerActionKey] = new DisposableAction(() =>
{
while (Marshal.Release(intPtr) > 0)
{
continue;
}
});
}
return(new CompletedAsyncResult(null, null));
}
/// <summary>
/// Initializes the instance.
/// </summary>
/// <param name="context"></param>
public void Init(HttpApplication context)
{
lock (rootSyncRoot)
{
// only enable if Autofac.Web is configured
if (context is IContainerProviderAccessor accessor)
{
// connect the app domain proxy to the root container
var container = GetAutofacApplicationContext(context);
var rootProxy = new ComponentContextProxy(() => container);
// store reference to this application in the default app domain
var appDomainKey = $"{ComponentContextUtil.AppDomainItemPrefix}{HostingEnvironment.ApplicationID}";
new mscoree.CorRuntimeHost().GetDefaultDomain(out var adv);
if (adv is AppDomain ad && ad.IsDefaultAppDomain() && ad.GetData(appDomainKey) == null)
{
ad.SetData(appDomainKey, Marshal.GetIUnknownForObject(rootProxy));
}
}
}
// register request events for context
context.AddOnBeginRequestAsync(BeginOnBeginRequestAsync, EndOnBeginRequestAsync);
context.AddOnEndRequestAsync(BeginOnEndRequestAsync, EndOnEndRequestAsync);
}
