public ServiceContext
(DataModelDbContext serviceDataModel
, ServiceCommandFactory serviceCommandFactory
, IIngressQueue dataIngressTopic)
{
if (serviceDataModel == null)
{
throw new ArgumentNullException(nameof(serviceDataModel));
}
if (serviceCommandFactory == null)
{
throw new ArgumentNullException(nameof(serviceCommandFactory));
}
if (dataIngressTopic == null)
{
throw new ArgumentNullException(nameof(dataIngressTopic));
}
ServiceDataModel = serviceDataModel;
ServiceCommandFactory = serviceCommandFactory;
DataIngressTopic = dataIngressTopic;
}
public IngressGatewayTopicHandler()
{
serviceCommandFactory = new ServiceCommandFactory();
}
private static void processMessageInServiceLayer
(DataModelDbContext dataModel
, BrokeredMessage message
, ServiceCommandFactory serviceCommandFactory)
{
if (dataModel == null)
{
throw new ArgumentNullException(nameof(dataModel));
}
if (message == null)
{
throw new ArgumentNullException(nameof(message));
}
if (serviceCommandFactory == null)
{
throw new ArgumentNullException(nameof(serviceCommandFactory));
}
var messageId
= Guid.Parse(message.MessageId);
// If there is an exception between before the commit you do not
// want to complete the message. If there there is a problem
// between the commit and the message being completed then we
// have a message that will be processed twice so we take the
// hit and just check to see if we have seen the message before
// and if so just return and let the message be cleared of the
// subscription.
if (dataModel.HasSeenMessage(messageId))
{
return;
}
var transaction
= dataModel
.Database
.BeginTransaction(IsolationLevel.Serializable);
try {
dataModel
.AddMessageAsSeen(messageId);
var serviceRequest
= new ServiceRequest(
dataModel
, Guid.Parse(message.CorrelationId)
, messageId
, TopicSourceName
, message.ContentType
, message.GetBody <string>()
, DateTime.Now
);
// Because topics are heterogeneous we need to identify the
// correct service command for the message. Different messages
// have different handlers.
//
// It may be valid that we are not interested in auditing
// certain messages in which case we need a default handler.
serviceCommandFactory[message.ContentType]
.Match(
just: serviceCommand => serviceCommand
, nothing: () => new UnhandledMessage()
)
.Handle(serviceRequest);
dataModel.SaveChanges();
transaction.Commit();
} finally {
transaction.Dispose();
}
}
