public async Task StartAsync()
{
Logger.Log(LogLevel.Trace, "Starting CQRS host");
try
{
if (_lock == null || _disposed)
{
throw new ObjectDisposedException(nameof(CQRSHost));
}
await _lock.WaitAsync();
if (_isStarted)
{
throw new Exception("Host already started.");
}
// Dispose the previous connection and operations (if any)
DisposeOperations();
DisposeConnection();
// Create a new RabbitMQ connection
_connection = _config.CreateConnection();
// Create the service exchange
using (var model = _connection.CreateModel())
{
model.ExchangeDeclare(ExchangeName, "direct", true, false);
}
// Create a model, queue, bindings and consumer for each operation
var hostOperationGenericType = typeof(HostOperation <,>);
var hostOperationSettings = new HostOperationSettings()
{
Connection = _connection,
Serializer = Serializer,
Logger = Logger,
ServiceName = ServiceName,
ExchangeName = ExchangeName
};
foreach (var operation in _config.Operations)
{
Type[] hostOperationTypeArgs =
{
operation.RequestType,
operation.ResponseType
};
var hostOperationType = hostOperationGenericType.MakeGenericType(hostOperationTypeArgs);
object[] hostOperationParams =
{
operation,
hostOperationSettings
};
var hostOperation = (IDisposable)Activator.CreateInstance(
hostOperationType,
BindingFlags.NonPublic | BindingFlags.Instance,
null,
hostOperationParams,
CultureInfo.InvariantCulture);
_operations.Add(hostOperation);
}
Logger.Log(LogLevel.Trace, "Started CQRS host");
_isStarted = true;
}
finally
{
_lock?.Release();
}
}