public static async Task <TResult> Call <TResult>(this IHttpService service,
string remoteAddress,
string contract,
object shardKey,
Func <IHttpTransport, CancellationToken?, Task <TResult> > body,
CancellationToken?cancellation = null,
string network = null,
string binding = null)
{
body.NonNull(nameof(body));
var assignments = service.NonNull(nameof(service))
.GetEndpointsForCall(remoteAddress, contract, shardKey, network, binding);
var tries = 1;
List <Exception> errors = null;
foreach (var assigned in assignments)
{
if (!assigned.Endpoint.IsAvailable)
{
continue; //offline or Circuit tripped todo: instrument
}
var ep = assigned.Endpoint as IEndpointImplementation;
var transport = service.AcquireTransport(assigned);
try
{
var http = (transport as IHttpTransport).NonNull("Implementation error: cast to IHttpTransport");
var result = await body(http, cancellation);
CallGuardException.Protect(ep, _ => _.NotifyCallSuccess(transport));
return(result);
}
catch (Exception error)
{
//Implementation error
if (error is CallGuardException)
{
throw;
}
//TaskCanceledException gets thrown on simple timeout even when cancellation was NOT requested
if (error is TaskCanceledException && cancellation.HasValue && cancellation.Value.IsCancellationRequested)
{
throw;
}
var errorClass = ep.NotifyCallError(transport, error);
//todo instrument
if (errorClass == CallErrorClass.ServiceLogic)
{
throw; //throw logical errors
}
if (errors == null)
{
errors = new List <Exception>();
}
errors.Add(error);
}
finally
{
service.ReleaseTransport(transport);
}
tries++;
}//foreach
throw new ClientException("Call eventually failed; {0} endpoints tried; See .InnerException".Args(tries),
errors != null ? new AggregateException(errors) :
new AggregateException("No inner errors")); //todo LOG etc...
}