public void InitializeInstanceContext(InstanceContext instanceContext, System.ServiceModel.Channels.Message message, IContextChannel channel)
{
//Look if the Client has given us a unique ID to add to this InstanceContext
int headerIndex = message.Headers.FindHeader(CustomHeader.HeaderName, CustomHeader.HeaderNamespace);
String headerId = null;
if (headerIndex != -1)
{
headerId = message.Headers.GetHeader <string>(headerIndex);
}
if (headerId == null)
{
//If no header was sent by the Client, then create a new one and assign it to this InstanceContext.
headerId = Guid.NewGuid().ToString();
Utility.WriteMessageToConsole(String.Format(ResourceHelper.GetString("NoHeaderFound")));
}
Utility.WriteMessageToConsole(String.Format(ResourceHelper.GetString("InstanceContextAddedToCache"), headerId));
//Add this to the Cache
this.instanceContextCache[headerId] = instanceContext;
//Register the Closing event of this InstancContext so it can be removed from the collection
instanceContext.Closing += this.RemoveInstanceContext;
IExtension <InstanceContext> customLeaseExtension =
new CustomLeaseExtension(timeout, headerId);
instanceContext.Extensions.Add(customLeaseExtension);
}
/// <summary>
/// This implements a PerCall InstanceContextMode behavior. If a cached InstanceContext is not found
/// then WCF will create a new one.
/// </summary>
public InstanceContext GetExistingInstanceContext(System.ServiceModel.Channels.Message message, IContextChannel channel)
{
//Per Session behavior
//To implement a PerSession behavior (If underlyin binding supports it) where in all
//methods from one ChannelFactory will be serviced by the same InstanceContext
//Check if the incoming request has the InstanceContext id it wants to connect with.
if (message.Headers.FindHeader(CustomHeader.HeaderName, CustomHeader.HeaderNamespace) != -1)
{
String sharingId = message.Headers.GetHeader <string>(CustomHeader.HeaderName, CustomHeader.HeaderNamespace);
if (sharingId != null && instanceContextCache.ContainsKey(sharingId))
{
Utility.WriteMessageToConsole(String.Format(ResourceHelper.GetString("InstanceContextLookup"), sharingId));
//Retrieve the InstanceContext from the map
InstanceContext context = instanceContextCache[sharingId];
if (context != null)
{
//Before returning, stop the timer on this InstanceContext
CustomLeaseExtension extension = context.Extensions.Find <CustomLeaseExtension>();
Utility.WriteMessageToConsole(String.Format(ResourceHelper.GetString("StopInstanceContextIdleTimer"), sharingId));
extension.StopTimer();
Utility.WriteMessageToConsole(ResourceHelper.GetString("CachedInstanceContextFound"));
return(instanceContextCache[sharingId]);
}
}
}
//No existing InstanceContext was found so return null and WCF will create a new one.
return(null);
}
public void RemoveInstanceContext(object o, EventArgs args)
{
InstanceContext context = o as InstanceContext;
CustomLeaseExtension extension = context.Extensions.Find <CustomLeaseExtension>();
String id = (extension != null) ? extension.InstanceId : null;
if (this.instanceContextCache[id] != null)
{
Utility.WriteMessageToConsole(String.Format(ResourceHelper.GetString("InstanceContextRemovedFromCache"), id));
this.instanceContextCache.Remove(id);
}
}
