/// <inheritdoc/>
public virtual async Task CorrelateAsync(V1CorrelationContext context, CancellationToken cancellationToken = default)
{
if (context == null)
{
throw new ArgumentNullException(nameof(context));
}
await this.SignalStream.WriteAsync(new(V1RuntimeSignalType.Correlate, Dynamic.FromObject(context)), cancellationToken);
}
/// <summary>
/// Performs a correlation on a <see cref="V1Event"/>, in a given <see cref="V1CorrelationContext"/> and using the specified <see cref="V1EventFilter"/>
/// </summary>
/// <param name="correlation">The <see cref="V1Correlation"/> to perform</param>
/// <param name="correlationContext">The <see cref="V1CorrelationContext"/> in which to perform the <see cref="V1Correlation"/></param>
/// <param name="e">The <see cref="V1Event"/> to correlate</param>
/// <param name="filter">The <see cref="V1EventFilter"/> used to correlate the <see cref="V1Event"/></param>
/// <param name="cancellationToken">A <see cref="CancellationToken"/></param>
/// <returns>A new awaitable <see cref="Task"/></returns>
protected virtual async Task CorrelateAsync(V1Correlation correlation, V1CorrelationContext correlationContext, V1Event e, V1EventFilter filter, CancellationToken cancellationToken = default)
{
this.Logger.LogInformation("Correlating event to context with id '{contextId}'...", correlationContext.Id);
correlationContext.Correlate(e, filter.CorrelationMappings.Keys, true);
correlation = await this.Correlations.UpdateAsync(correlation, cancellationToken);
await this.Correlations.SaveChangesAsync(cancellationToken);
this.Logger.LogInformation("Event successfully correlated to context with id '{contextId}'", correlationContext.Id);
this.Logger.LogInformation("Attempting to complete the correlation with id '{correlationId}' in context with id '{contextId}'...", correlation.Id, correlationContext.Id);
if (!correlation.TryComplete(correlationContext))
{
this.Logger.LogInformation("Correlations conditions are not met in the specified correlation context");
return;
}
this.Logger.LogInformation("Correlation with id '{correlationId}' has been completed in context with id '{contextId}. Computing outcome...", correlation.Id, correlationContext.Id);
switch (correlation.Outcome.Type)
{
case V1CorrelationOutcomeType.Start:
await this.Mediator.ExecuteAndUnwrapAsync(new V1CreateWorkflowInstanceCommand(correlation.Outcome.Target, V1WorkflowInstanceActivationType.Trigger, new(), correlationContext, true, null), cancellationToken);
break;
case V1CorrelationOutcomeType.Correlate:
await this.Mediator.ExecuteAndUnwrapAsync(new V1CorrelateWorkflowInstanceCommand(correlation.Outcome.Target, correlationContext), cancellationToken);
break;
default:
throw new NotSupportedException($"The specified {nameof(V1CorrelationOutcomeType)} '{correlation.Outcome.Type}' is not supported");
}
correlation.ReleaseContext(correlationContext);
correlation = await this.Correlations.UpdateAsync(correlation, cancellationToken);
await this.Correlations.SaveChangesAsync(cancellationToken);
if (correlation.Lifetime == V1CorrelationLifetime.Singleton)
{
this.Logger.LogInformation("The correlation with id '{correlationId}' is a singleton and its context has been released. Disposing of it...", correlation.Id);
await this.Mediator.ExecuteAndUnwrapAsync(new V1DeleteCorrelationCommand(correlation.Id), cancellationToken);
this.Logger.LogInformation("The correlation with id '{correlationId}' has been successfully disposed of", correlation.Id);
}
this.Logger.LogInformation("Correlation outcome successfully computed");
}
/// <inheritdoc/>
public virtual async Task <IOperationResult> HandleAsync(V1CorrelateEventCommand command, CancellationToken cancellationToken = default)
{
this.Logger.LogInformation("Processing event with id '{eventId}', type '{eventType}' and source '{eventSource}'...", command.Event.Id, command.Event.Type, command.Event.Source);
var correlations = await this.Mediator.ExecuteAndUnwrapAsync(new V1GetEventCorrelationsQuery(command.Event), cancellationToken);
await foreach (var correlation in correlations)
{
this.Logger.LogInformation("Processing correlation with id '{correlationId}'...", correlation.Id);
var matchingCondition = correlation.GetMatchingConditionFor(command.Event) !;
var matchingFilter = matchingCondition.GetMatchingFilterFor(command.Event) !;
var matchingContexts = correlation.Contexts
.Where(c => c.CorrelatesTo(command.Event))
.ToList();
switch (correlation.Lifetime)
{
case V1CorrelationLifetime.Singleton:
var matchingContext = matchingContexts.FirstOrDefault();
if (matchingContext == null)
{
this.Logger.LogInformation("Failed to find a matching correlation context");
if (correlation.Contexts.Any())
{
throw new Exception("Failed to correlate event"); //should not happen
}
this.Logger.LogInformation("Creating a new correlation context...");
matchingContext = V1CorrelationContext.CreateFor(command.Event, matchingFilter.CorrelationMappings.Keys);
correlation.AddContext(matchingContext);
await this.Correlations.UpdateAsync(correlation, cancellationToken);
await this.Correlations.SaveChangesAsync(cancellationToken);
this.Logger.LogInformation("Correlation context with id '{contextId}' successfully created", matchingContext.Id);
this.Logger.LogInformation("Event successfully correlated to context with id '{contextId}'", matchingContext.Id);
}
else
{
await this.CorrelateAsync(correlation, matchingContext, command.Event, matchingFilter, cancellationToken);
}
break;
case V1CorrelationLifetime.Transient:
matchingContext = matchingContexts.FirstOrDefault();
if (matchingContext == null)
{
this.Logger.LogInformation("Failed to find a matching correlation context");
this.Logger.LogInformation("Creating a new correlation context...");
matchingContext = V1CorrelationContext.CreateFor(command.Event, matchingFilter.CorrelationMappings.Keys);
correlation.AddContext(matchingContext);
await this.Correlations.UpdateAsync(correlation, cancellationToken);
await this.Correlations.SaveChangesAsync(cancellationToken);
this.Logger.LogInformation("Correlation context with id '{contextId}' successfully created", matchingContext.Id);
this.Logger.LogInformation("Event successfully correlated to context with id '{contextId}'", matchingContext.Id);
matchingContexts.Add(matchingContext);
}
this.Logger.LogInformation("Found {matchingContextCount} matching correlation contexts", matchingContexts.Count());
foreach (var context in matchingContexts)
{
await this.CorrelateAsync(correlation, context, command.Event, matchingFilter, cancellationToken);
}
break;
default:
throw new NotSupportedException($"The specified {nameof(V1CorrelationLifetime)} '{correlation.Lifetime}' is not supported");
}
}
return(this.Ok());
}
/// <summary>
/// Initializes a new <see cref="V1CorrelateWorkflowInstanceCommand"/>
/// </summary>
/// <param name="id">The id of the <see cref="V1WorkflowInstance"/> to correlate</param>
/// <param name="correlationContext">The <see cref="V1CorrelationContext"/> to correlate the <see cref="V1WorkflowInstance"/> with</param>
public V1CorrelateWorkflowInstanceCommand(string id, V1CorrelationContext correlationContext)
{
this.Id = id;
this.CorrelationContext = correlationContext;
}
