/// <summary>
/// When overriden, defines the custom behavior to be invoked after attempting to save the specified <paramref name="saga"/>.
/// </summary>
/// <param name="saga">The modified <see cref="Saga"/> instance if <paramref name="error"/> is <value>null</value>; otherwise the original <see cref="Saga"/> instance if <paramref name="error"/> is not <value>null</value>.</param>
/// <param name="context">The current <see cref="SagaContext"/> assocaited with the pending saga modifications.</param>
/// <param name="error">The <see cref="Exception"/> thrown if the save was unsuccessful; otherwise <value>null</value>.</param>
public override void PostSave(Saga saga, SagaContext context, Exception error)
{
base.PostSave(saga, context, error);
if (error is ConcurrencyException)
statistics.IncrementConflictCount();
}
/// <summary>
/// Initalizes a new instance of <see cref="SagaContext"/> with the specified <paramref name="sagaType"/> and <paramref name="sagaId"/>.
/// </summary>
/// <param name="sagaType">The underlying saga <see cref="Type"/> associated with this <see cref="SagaContext"/>.</param>
/// <param name="sagaId">The <see cref="Saga"/> correlation id associated with this <see cref="SagaContext"/>.</param>
/// <param name="e">The <see cref="Event"/>.</param>
public SagaContext(Type sagaType, Guid sagaId, Event e)
{
Verify.NotNull(sagaType, nameof(sagaType));
Verify.NotNull(e, nameof(e));
this.originalContext = currentContext;
this.thread = Thread.CurrentThread;
this.sagaType = sagaType;
this.sagaId = sagaId;
this.@event = e;
currentContext = this;
}
/// <summary>
/// Invokes the underlying <see cref="Saga"/> event handler method using the specified event <paramref name="context"/>.
/// </summary>
/// <param name="context">The current event context.</param>
public override void Handle(EventContext context)
{
Verify.NotNull(context, nameof(context));
var sagaId = sagaMetadata.GetCorrelationId(context.Event);
using (var sagaContext = new SagaContext(HandlerType, sagaId, context.Event))
{
Handle(sagaContext);
var commandPublisher = lazyCommandPublisher.Value;
foreach (var sagaCommand in sagaContext.GetPublishedCommands())
commandPublisher.Publish(sagaCommand.AggregateId, sagaCommand.Command, sagaCommand.Headers);
}
}
/// <summary>
/// Invokes the underlying <see cref="Saga"/> event handler method using the specified event <paramref name="context"/>.
/// </summary>
/// <param name="context">The current event context.</param>
public override void Handle(EventContext context)
{
Verify.NotNull(context, nameof(context));
var sagaId = sagaMetadata.GetCorrelationId(context.Event);
using (var sagaContext = new SagaContext(HandlerType, sagaId, context.Event))
{
Handle(sagaContext);
var commandPublisher = lazyCommandPublisher.Value;
foreach (var sagaCommand in sagaContext.GetPublishedCommands())
{
commandPublisher.Publish(sagaCommand.AggregateId, sagaCommand.Command, sagaCommand.Headers);
}
}
}
/// <summary>
/// Save the specified <paramref name="context"/> changes for the given <paramref name="saga"/>.
/// </summary>
/// <param name="saga">The current saga version for which the context applies.</param>
/// <param name="context">The saga context containing the saga changes to be applied.</param>
public Saga Save(Saga saga, SagaContext context)
{
InvokePreSaveHooks(saga, context);
try
{
var result = sagaStore.Save(saga, context);
InvokePostSaveHooks(result, context, null);
return(result);
}
catch (Exception ex)
{
InvokePostSaveHooks(saga, context, ex);
throw;
}
}
/// <summary>
/// Invokes the underlying <see cref="Saga"/> event handler method using the current saga <paramref name="context"/>.
/// </summary>
/// <param name="context">The current saga context.</param>
private void Handle(SagaContext context)
{
var e = context.Event;
var sagaId = context.SagaId;
var sagaType = context.SagaType;
var saga = GetOrCreateSaga(sagaType, sagaId, e);
if (saga != null)
{
HandleSagaEvent(saga, e);
sagaStore.Save(saga, context);
}
else
{
Log.Trace("{0} - {1} cannot be initiated by event {2}", sagaType, sagaId, context.Event);
}
}
/// <summary>
/// When overriden, defines the custom behavior to be invoked after attempting to save the specified <paramref name="saga"/>.
/// </summary>
/// <param name="saga">The modified <see cref="Saga"/> instance if <paramref name="error"/> is <value>null</value>; otherwise the original <see cref="Saga"/> instance if <paramref name="error"/> is not <value>null</value>.</param>
/// <param name="context">The current <see cref="SagaContext"/> assocaited with the pending saga modifications.</param>
/// <param name="error">The <see cref="Exception"/> thrown if the save was unsuccessful; otherwise <value>null</value>.</param>
public override void PostSave(Saga saga, SagaContext context, Exception error)
{
if (!context.TimeoutChanged || saga == null || error != null)
{
return;
}
if (saga.Timeout.HasValue && !saga.Completed)
{
var timeout = saga.Timeout.Value;
TimeoutCache.ScheduleTimeout(new SagaTimeout(saga.GetType(), saga.CorrelationId, timeout));
}
else
{
TimeoutCache.ClearTimeout(new SagaReference(saga.GetType(), saga.CorrelationId));
}
RescheduleTimer(TimeoutCache.GetNextScheduledTimeout());
}
/// <summary>
/// Releases all managed resources used by the current instance of the <see cref="SagaContext"/> class.
/// </summary>
public void Dispose()
{
if (disposed)
{
return;
}
if (this.thread != Thread.CurrentThread)
{
throw new InvalidOperationException(Exceptions.SagaContextInterleaved);
}
if (this != Current)
{
throw new InvalidOperationException(Exceptions.SagaContextInvalidThread);
}
disposed = true;
currentContext = originalContext;
}
/// <summary>
/// Invokes zero or more customized <see cref="PipelineHook.PreSave"/> implementations.
/// </summary>
/// <param name="saga">The saga to be modified by the current <paramref name="context"/>.</param>
/// <param name="context">The current <see cref="SagaContext"/> associated with the pending saga modifications.</param>
private void InvokePreSaveHooks(Saga saga, SagaContext context)
{
foreach (var pipelineHook in preSaveHooks)
{
Log.Trace("Invoking pre-save pipeline hook: {0}", pipelineHook);
pipelineHook.PreSave(saga, context);
}
}
/// <summary>
/// Releases all managed resources used by the current instance of the <see cref="SagaContext"/> class.
/// </summary>
public void Dispose()
{
if (disposed)
return;
if (this.thread != Thread.CurrentThread)
throw new InvalidOperationException(Exceptions.SagaContextInterleaved);
if (this != Current)
throw new InvalidOperationException(Exceptions.SagaContextInvalidThread);
disposed = true;
currentContext = originalContext;
}
/// <summary>
/// When overriden, defines the custom behavior to be invoked after attempting to save the specified <paramref name="saga"/>.
/// </summary>
/// <param name="saga">The modified <see cref="Saga"/> instance if <paramref name="error"/> is <value>null</value>; otherwise the original <see cref="Saga"/> instance if <paramref name="error"/> is not <value>null</value>.</param>
/// <param name="context">The current <see cref="SagaContext"/> assocaited with the pending saga modifications.</param>
/// <param name="error">The <see cref="Exception"/> thrown if the save was unsuccessful; otherwise <value>null</value>.</param>
public override void PostSave(Saga saga, SagaContext context, Exception error)
{
if (!context.TimeoutChanged || saga == null || error != null)
return;
if (saga.Timeout.HasValue && !saga.Completed)
{
var timeout = saga.Timeout.Value;
TimeoutCache.ScheduleTimeout(new SagaTimeout(saga.GetType(), saga.CorrelationId, timeout));
}
else
{
TimeoutCache.ClearTimeout(new SagaReference(saga.GetType(), saga.CorrelationId));
}
RescheduleTimer(TimeoutCache.GetNextScheduledTimeout());
}
/// <summary>
/// When overriden, defines the custom behavior to be invoked after attempting to save the specified <paramref name="saga"/>.
/// </summary>
/// <param name="saga">The modified <see cref="Saga"/> instance if <paramref name="error"/> is <value>null</value>; otherwise the original <see cref="Saga"/> instance if <paramref name="error"/> is not <value>null</value>.</param>
/// <param name="context">The current <see cref="SagaContext"/> assocaited with the pending saga modifications.</param>
/// <param name="error">The <see cref="Exception"/> thrown if the save was unsuccessful; otherwise <value>null</value>.</param>
public virtual void PostSave(Saga saga, SagaContext context, Exception error)
{
}
/// <summary>
/// Invokes the underlying <see cref="Saga"/> event handler method using the current saga <paramref name="context"/>.
/// </summary>
/// <param name="context">The current saga context.</param>
private void Handle(SagaContext context)
{
var e = context.Event;
var sagaId = context.SagaId;
var sagaType = context.SagaType;
var saga = GetOrCreateSaga(sagaType, sagaId, e);
if (saga != null)
{
HandleSagaEvent(saga, e);
sagaStore.Save(saga, context);
}
else
{
Log.Trace("{0} - {1} cannot be initiated by event {2}", sagaType, sagaId, context.Event);
}
}
/// <summary>
/// Save the specified <paramref name="context"/> changes for the given <paramref name="saga"/>.
/// </summary>
/// <param name="saga">The current saga version for which the context applies.</param>
/// <param name="context">The saga context containing the saga changes to be applied.</param>
public Saga Save(Saga saga, SagaContext context)
{
Verify.NotNull(saga, nameof(saga));
Verify.NotNull(context, nameof(context));
var sagaType = saga.GetType();
var key = String.Concat(sagaType.GetFullNameWithAssembly(), "-", saga.CorrelationId);
using (var sagaLock = new SagaLock(sagaType, saga.CorrelationId))
{
sagaLock.Aquire();
try
{
sagaStore.Save(saga, context);
if (saga.Completed)
memoryCache.Remove(key);
else
memoryCache.Set(key, saga, CreateCacheItemPolicy());
return saga;
}
catch (ConcurrencyException)
{
memoryCache.Remove(key);
throw;
}
}
}
/// <summary>
/// When overriden, defines the custom behavior to be invoked prior to saving the specified <paramref name="saga"/>.
/// </summary>
/// <param name="saga">The saga to be modified using the current <paramref name="context"/>.</param>
/// <param name="context">The current <see cref="SagaContext"/> assocaited with the pending saga modifications.</param>
public virtual void PreSave(Saga saga, SagaContext context)
{
}
/// <summary>
/// Invokes zero or more customized <see cref="PipelineHook.PostSave"/> implementations.
/// </summary>
/// <param name="saga">The modified <see cref="Saga"/> instance if <paramref name="error"/> is <value>null</value>; otherwise the original <see cref="Saga"/> instance if <paramref name="error"/> is not <value>null</value>.</param>
/// <param name="context">The current <see cref="SagaContext"/> assocaited with the pending saga modifications.</param>
/// <param name="error">The <see cref="Exception"/> thrown if the save was unsuccessful; otherwise <value>null</value>.</param>
private void InvokePostSaveHooks(Saga saga, SagaContext context, Exception error)
{
foreach (var pipelineHook in postSaveHooks)
{
Log.Trace("Invoking post-save pipeline hook: {0}", pipelineHook);
pipelineHook.PostSave(saga, context, error);
}
}
/// <summary>
/// Save the specified <paramref name="context"/> changes for the given <paramref name="saga"/>.
/// </summary>
/// <param name="saga">The current saga version for which the context applies.</param>
/// <param name="context">The saga context containing the saga changes to be applied.</param>
public Saga Save(Saga saga, SagaContext context)
{
InvokePreSaveHooks(saga, context);
try
{
var result = sagaStore.Save(saga, context);
InvokePostSaveHooks(result, context, null);
return result;
}
catch (Exception ex)
{
InvokePostSaveHooks(saga, context, ex);
throw;
}
}
/// <summary>
/// When overriden, defines the custom behavior to be invoked prior to saving the specified <paramref name="saga"/>.
/// </summary>
/// <param name="saga">The saga to be modified using the current <paramref name="context"/>.</param>
/// <param name="context">The current <see cref="SagaContext"/> assocaited with the pending saga modifications.</param>
public virtual void PreSave(Saga saga, SagaContext context)
{
}
/// <summary>
/// When overriden, defines the custom behavior to be invoked after attempting to save the specified <paramref name="saga"/>.
/// </summary>
/// <param name="saga">The modified <see cref="Saga"/> instance if <paramref name="error"/> is <value>null</value>; otherwise the original <see cref="Saga"/> instance if <paramref name="error"/> is not <value>null</value>.</param>
/// <param name="context">The current <see cref="SagaContext"/> assocaited with the pending saga modifications.</param>
/// <param name="error">The <see cref="Exception"/> thrown if the save was unsuccessful; otherwise <value>null</value>.</param>
public virtual void PostSave(Saga saga, SagaContext context, Exception error)
{
}
/// <summary>
/// Save the specified <paramref name="context"/> changes for the given <paramref name="saga"/>.
/// </summary>
/// <param name="saga">The current saga version for which the context applies.</param>
/// <param name="context">The saga context containing the saga changes to be applied.</param>
public Saga Save(Saga saga, SagaContext context)
{
var result = sagaStore.Save(saga, context);
if (saga.Version == 1)
{
statistics.IncrementInsertCount();
}
else
{
if (saga.Completed)
{
statistics.IncrementDeleteCount();
}
else
{
statistics.IncrementUpdateCount();
}
}
return result;
}
