protected Task <TResult> DurablyInvoke <TResult>(DurableAttribute durableAttribute, IInvocation invocation)
{
if (!invocation.Method.ReturnType.IsAssignableTo <Task>())
{
throw new DurableInvocationException(
$"Method {invocation.Method} has a return type of {invocation.Method.ReturnType} but its application of {durableAttribute.GetType().Name} requries its return type be of type {typeof(Task)}."
);
}
var baseUrl = Context.Value.FunctionContext?.BaseUrl;
var functionName = durableAttribute.GetFunctionName();
var methodSpecificaiton = this.typeSerivce.Value.GetMethodSpecification(invocation.Method);
var instanceId = durableAttribute.IsSingleInstance ? durableAttribute.InstanceId ?? methodSpecificaiton : null;
var methodArguments = invocation.Method.GetParameters().Zip(invocation.Arguments, (a, b) => (a.Name, Value: b)).ToDictionary();
var durableContext = new DurableContext {
OrchestrationContext = Context.Value.OrchestrationContext,
OrchestrationClient = Context.Value.OrchestrationClient,
FunctionContext = new FunctionContext {
BaseUrl = baseUrl,
FunctionName = functionName,
InstanceId = instanceId,
MethodSpecification = methodSpecificaiton,
Instance = invocation.InvocationTarget,
Arguments = methodArguments
}
};
return(Context.Value?.FunctionContext?.MethodSpecification == methodSpecificaiton ||
durableAttribute.ExternalOrchestratorUrlOrAppSetting.IsNullOrWhiteSpace() ?
this.DurablyInvokeInternally <TResult>(durableAttribute, durableContext) :
this.DurablyInvokeExternally <TResult>(durableAttribute, durableContext));
}
protected async Task <TResult> DurablyInvokeExternally <TResult>(DurableAttribute durableAttribute, DurableContext durableContext)
{
const string eventName = "external-durable-invocation-complete";
durableContext.FunctionContext.CallbackUrl = durableContext.OrchestrationClient.CreateHttpManagementPayload(durableContext.OrchestrationContext.InstanceId).SendEventPostUri.Replace("{eventName}", eventName);
var url = this.configuration.GetValue <string>(durableAttribute.ExternalOrchestratorUrlOrAppSetting) ?? durableAttribute.ExternalOrchestratorUrlOrAppSetting;
await durableContext.OrchestrationContext.CallHttpAsync(
HttpMethod.Post,
new Uri(url),
durableContext.FunctionContext.ToJson()
);
return(await durableContext.OrchestrationContext.WaitForExternalEvent <TResult>(eventName));
}
protected async Task <TResult> DurablyInvokeInternally <TResult>(DurableAttribute durableAttribute, DurableContext durableContext)
{
return(await durableAttribute.Invoke <TResult>(durableContext));
}