public async Task WriteAsync(string topicName, string servicePath, HttpContext httpContext)
{
var gateConsumer = _gateTemporaryConsumers.GetOrAdd(topicName, _ =>
{
var serviceName = Guid.NewGuid().ToString();
return(_gateFactory.CreateConsumer <GateRequest, GateResponse>(serviceName, topicName,
async(genericContext, cancellationToken) =>
{
if (servicePath != genericContext.Message.ServicePath)
{
return;
}
var message = Encoding.UTF8.GetString(genericContext.Message.Content);
var messageParts = message.Split('\n');
if (_consumerContexts.TryGetValue(topicName, out var topicContexts))
{
foreach (var context in topicContexts.Values)
{
if (!string.IsNullOrEmpty(servicePath))
{
await context.Response.WriteAsync($"event: {servicePath}\n", cancellationToken);
}
foreach (var messagePart in messageParts)
{
await context.Response.WriteAsync($"data: {messagePart}\n", cancellationToken);
}
await context.Response.WriteAsync($"\n", cancellationToken);
await context.Response.Body.FlushAsync(cancellationToken);
}
}
}, () => { }, true, 1));
});
public async Task Subscribe_Test()
{
var gateConsumer = A.Fake <IGateConsumer>();
A.CallTo(() => _gateFactory.CreateConsumer("service-name", "topic-name",
A <Func <GateContext, CancellationToken, Task> > .Ignored, A <Action> .Ignored,
false, 10)).Returns(gateConsumer);
var consumer = await _toTest.SubscribeConsumerAsync("service-name", "topic-name",
new Uri("http://test-host"),
10, 20, 30);
Assert.AreEqual(new Uri("http://test-host"), consumer.Endpoint);
Assert.AreEqual(gateConsumer, consumer.GateConsumer);
Assert.AreEqual(20, consumer.RestartDelayInSeconds);
Assert.AreEqual(30, consumer.RestartCount);
}
public static IGateConsumer CreateConsumer <TMessage, TReply>(
this IGateFactory brokerFactory,
string serviceName,
string topicName,
Func <GateContext <TMessage, TReply>, CancellationToken, Task> messageHandler,
Action abortedHandler,
bool autoDelete, int maxConcurrentMessages)
{
serviceName = serviceName ?? throw new ArgumentNullException(nameof(serviceName));
topicName = topicName ?? throw new ArgumentNullException(nameof(topicName));
return(brokerFactory.CreateConsumer(serviceName, topicName, async(context, cancellationToken) =>
{
var genericContext = new GateContext <TMessage, TReply>(
message: Serializer.Deserialize <TMessage>(context.Message),
isRequest: context.IsRequest
);
await messageHandler(genericContext, cancellationToken);
if (genericContext.IsRequest)
{
context.Reply = Serializer.Serialize(genericContext.Reply);
}
}, abortedHandler, autoDelete, maxConcurrentMessages));
}
public async Task <ProxyConsumer> SubscribeConsumerAsync(
string serviceName,
string topicName,
Uri endpoint,
int maxConcurrentMessages,
int restartDelayInSeconds,
int restartCount,
CancellationToken cancellationToken = default)
{
serviceName = serviceName ?? throw new ArgumentNullException(nameof(serviceName));
topicName = topicName ?? throw new ArgumentNullException(nameof(topicName));
endpoint = endpoint ?? throw new ArgumentNullException(nameof(endpoint));
if (!endpoint.IsAbsoluteUri)
{
throw new ArgumentException("Endpoint uri must be absolute", nameof(endpoint));
}
var consumerId = $"{serviceName}_{topicName}_{endpoint}".ToSha256();
var proxyConsumer = new ProxyConsumer();
if (!_proxyConsumers.TryAdd(consumerId, proxyConsumer))
{
throw new InvalidOperationException("Consumer already exists");
}
try
{
proxyConsumer.Id = consumerId;
proxyConsumer.Endpoint = endpoint;
proxyConsumer.AbortTime = null;
proxyConsumer.RestartDelayInSeconds = restartDelayInSeconds;
proxyConsumer.RestartCount = restartCount;
proxyConsumer.HttpClient = _httpClientFactory.CreateClient();
proxyConsumer.UnsubscribeCompletionSource = null;
proxyConsumer.GateConsumer = _gateFactory.CreateConsumer <GateRequest, GateResponse>(serviceName,
topicName, async(genericContext, ct) =>
{
var httpRequestMessage = genericContext.Message.ToHttpRequestMessage(endpoint);
var httpResponseMessage = await proxyConsumer.HttpClient.SendAsync(httpRequestMessage, ct);
if (!httpResponseMessage.IsSuccessStatusCode && !genericContext.IsRequest)
{
if (!_fallbackServices.Any())
{
httpResponseMessage.EnsureSuccessStatusCode();
}
var fallbackExceptions = new List <Exception>();
foreach (var fallbackService in _fallbackServices)
{
try
{
await fallbackService.SendAsync(serviceName, topicName, genericContext.Message, ct);
break;
}
catch (Exception ex)
{
fallbackExceptions.Add(ex);
}
}
if (fallbackExceptions.Any())
{
throw new AggregateException("Can not send message to service or fallbacks", fallbackExceptions);
}
}
if (genericContext.IsRequest)
{
genericContext.Reply = await httpResponseMessage.ToGateResponseAsync();
}
}, () =>
{
proxyConsumer.AbortTime = DateTime.Now;
if (proxyConsumer.UnsubscribeCompletionSource != null)
{
proxyConsumer.UnsubscribeCompletionSource.TrySetResult(true);
}
else
{
proxyConsumer.RestartCancellationTokenSource = new CancellationTokenSource();
proxyConsumer.RestartTask = RestartHandler(consumerId);
}
}, false, maxConcurrentMessages);
await proxyConsumer.GateConsumer.StartConsumeAsync(cancellationToken);
return(proxyConsumer);
}
catch (Exception ex)
{
_logger.LogError(ex, "Error starting consumer");
_proxyConsumers.TryRemove(consumerId, out _);
throw;
}
}
