/// <summary>
/// Finds and returns saga instance with the given correlation ID.
/// You will get exceptions if TSaga does not match the actual saga data with the provided exception.
///
/// Actually creates an instance of saga from service locator, retrieves SagaData and Headers from the storage and populates the instance with these.
/// </summary>
/// <typeparam name="TSaga">Type of saga we are looking for</typeparam>
/// <param name="correlationId">CorrelationId to identify the saga</param>
/// <returns>An instance of the saga. Or Null if there is no saga with this ID.</returns>
public TSaga Find <TSaga>(Guid correlationId) where TSaga : class, IAccessibleSaga
{
Guard.ArgumentIsNotNull(correlationId, nameof(correlationId));
using (var connection = connectionFactory.CreateOpenConnection())
using (var database = new Database(connection))
{
var sql = Sql.Builder.Where("correlationId = @0", correlationId);
var persistedData = database.SingleOrDefault <SagaData>(sql);
if (persistedData == null)
{
return(null);
}
var sagaInstance = sagaFactory.ResolveSaga <TSaga>();
var sagaDataType = NSagaReflection.GetInterfaceGenericType <TSaga>(typeof(ISaga <>));
var sagaData = messageSerialiser.Deserialise(persistedData.BlobData, sagaDataType);
var headersSql = Sql.Builder.Where("correlationId = @0", correlationId);
var headersPersisted = database.Query <SagaHeaders>(headersSql);
var headers = headersPersisted.ToDictionary(k => k.Key, v => v.Value);
NSagaReflection.Set(sagaInstance, "CorrelationId", correlationId);
NSagaReflection.Set(sagaInstance, "SagaData", sagaData);
NSagaReflection.Set(sagaInstance, "Headers", headers);
return(sagaInstance);
}
}
/// <summary>
/// Finds and returns saga instance with the given correlation ID.
/// Actually creates an instance of saga from Saga factory, retrieves SagaData and Headers from the storage and populates the instance with these.
/// </summary>
/// <typeparam name="TSaga">Type of saga we are looking for</typeparam>
/// <param name="correlationId">CorrelationId to identify the saga</param>
/// <returns>
/// An instance of the saga. Or Null if there is no saga with this ID.
/// </returns>
public TSaga Find <TSaga>(Guid correlationId) where TSaga : class, IAccessibleSaga
{
string dataSerialised;
if (!DataDictionary.TryGetValue(correlationId, out dataSerialised))
{
return(null);
}
string headersSerialised;
var headers = new Dictionary <String, String>();
if (HeadersDictionary.TryGetValue(correlationId, out headersSerialised))
{
headers = messageSerialiser.Deserialise <Dictionary <String, String> >(headersSerialised);
}
var sagaDataType = NSagaReflection.GetInterfaceGenericType <TSaga>(typeof(ISaga <>));
var dataObject = messageSerialiser.Deserialise(dataSerialised, sagaDataType);
var saga = sagaFactory.ResolveSaga <TSaga>();
NSagaReflection.Set(saga, "SagaData", dataObject);
NSagaReflection.Set(saga, "CorrelationId", correlationId);
NSagaReflection.Set(saga, "Headers", headers);
return(saga);
}
/// <summary>
/// Consumes the specified initiating message and creates a new instance of the correlating saga.
/// <para>Saga is not persisted if operation have failed</para>
/// </summary>
/// <param name="initiatingMessage">The initiating message.</param>
/// <returns>
/// Result of the operation
/// </returns>
/// <exception cref="System.ArgumentException"></exception>
public OperationResult Consume(IInitiatingSagaMessage initiatingMessage)
{
Guard.CheckSagaMessage(initiatingMessage, nameof(initiatingMessage));
var resolvedSaga = sagaFactory.ResolveSagaInititatedBy(initiatingMessage);
var sagaType = resolvedSaga.GetType();
// try to find sagas that already exist
var existingSaga = NSagaReflection.InvokeGenericMethod(sagaRepository, "Find", sagaType, initiatingMessage.CorrelationId);
if (existingSaga != null)
{
throw new ArgumentException($"Trying to initiate the same saga twice. {initiatingMessage.GetType().Name} is Initiating Message, but saga of type {sagaType.Name} with CorrelationId {initiatingMessage.CorrelationId} already exists");
}
// now create an instance of saga and persist the data
var saga = sagaFactory.ResolveSaga(sagaType);
NSagaReflection.Set(saga, "CorrelationId", initiatingMessage.CorrelationId);
// if SagaData is null - create an instance of the object and assign to saga
var sagaData = NSagaReflection.Get(saga, "SagaData");
if (sagaData == null)
{
var sagaDataType = NSagaReflection.GetInterfaceGenericType(saga, typeof(ISaga <>));
var newSagaData = Activator.CreateInstance(sagaDataType);
NSagaReflection.Set(saga, "SagaData", newSagaData);
}
var sagaHeaders = NSagaReflection.Get(saga, "Headers");
if (sagaHeaders == null)
{
NSagaReflection.Set(saga, "Headers", new Dictionary <String, String>());
}
pipelineHook.BeforeInitialisation(new PipelineContext(initiatingMessage, (IAccessibleSaga)saga));
var errors = (OperationResult)NSagaReflection.InvokeMethod(saga, "Initiate", initiatingMessage);
pipelineHook.AfterInitialisation(new PipelineContext(initiatingMessage, (IAccessibleSaga)saga, errors));
if (errors.IsSuccessful)
{
sagaRepository.Save(saga);
pipelineHook.AfterSave(new PipelineContext(initiatingMessage, (IAccessibleSaga)saga, errors));
}
return(errors);
}
/// <summary>
/// Finds and returns saga instance with the given correlation ID.
/// You will get exceptions if TSaga does not match the actual saga data with the provided exception.
///
/// Actually creates an instance of saga from service locator, retrieves SagaData and Headers from the storage and populates the instance with these.
/// </summary>
/// <typeparam name="TSaga">Type of saga we are looking for</typeparam>
/// <param name="correlationId">CorrelationId to identify the saga</param>
/// <returns>An instance of the saga. Or Null if there is no saga with this ID.</returns>
public TSaga Find <TSaga>(Guid correlationId) where TSaga : class, IAccessibleSaga
{
Guard.ArgumentIsNotNull(correlationId, nameof(correlationId));
var persistedData = database.GetById <SagaData>(correlationId).FirstOrDefault();
if (persistedData == null)
{
return(null);
}
var sagaInstance = sagaFactory.ResolveSaga <TSaga>();
var sagaDataType = NSagaReflection.GetInterfaceGenericType <TSaga>(typeof(ISaga <>));
var sagaData = messageSerialiser.Deserialise(persistedData.BlobData, sagaDataType);
var headersPersisted = database.GetById <SagaHeaders>(correlationId);
var headers = headersPersisted.ToDictionary(k => k.Key, v => v.Value);
sagaInstance.CorrelationId = correlationId;
sagaInstance.Headers = headers;
NSagaReflection.Set(sagaInstance, "SagaData", sagaData);
return(sagaInstance);
}
