public static void Main(string[] args)
{
ArgumentHelper helper = new ArgumentHelperBuilder("Pull Subscription using primitive Expires In", args, Usage)
.DefaultStream("fetch-uc-stream")
.DefaultSubject("fetch-uc-subject")
.DefaultDurable("fetch-uc-durable")
.DefaultCount(15)
.Build();
try
{
using (IConnection c = new ConnectionFactory().CreateConnection(helper.MakeOptions()))
{
// Create a JetStreamManagement context.
IJetStreamManagement jsm = c.CreateJetStreamManagementContext();
// Use the utility to create a stream stored in memory.
JsUtils.CreateStreamExitWhenExists(jsm, helper.Stream, helper.Subject);
// Create our JetStream context.
IJetStream js = c.CreateJetStreamContext();
// Build our consumer configuration and subscription options.
// make sure the ack wait is sufficient to handle the reading and processing of the batch.
// Durable is REQUIRED for pull based subscriptions
ConsumerConfiguration cc = ConsumerConfiguration.Builder()
.WithAckWait(2500)
.Build();
PullSubscribeOptions pullOptions = PullSubscribeOptions.Builder()
.WithDurable(helper.Durable) // required
.WithConfiguration(cc)
.Build();
// 0.1 Initialize. subscription
// 0.2 Flush outgoing communication with/to the server, useful when app is both JsUtils.Publishing and subscribing.
Console.WriteLine("\n----------\n0. Initialize the subscription and pull.");
IJetStreamPullSubscription sub = js.PullSubscribe(helper.Subject, pullOptions);
c.Flush(1000);
// 1. Fetch, but there are no messages yet.
// - Read the messages, get them all (0)
Console.WriteLine("----------\n1. There are no messages yet");
IList <Msg> messages = sub.Fetch(10, 3000);
JsUtils.Report(messages);
foreach (Msg m in messages)
{
m.Ack();
}
Console.WriteLine("We should have received 0 total messages, we received: " + messages.Count);
// 2. Publish 10 messages
// - Fetch messages, get 10
Console.WriteLine("----------\n2. Publish 10 which satisfies the batch");
JsUtils.Publish(js, helper.Subject, "A", 10);
messages = sub.Fetch(10, 3000);
JsUtils.Report(messages);
foreach (Msg m in messages)
{
m.Ack();
}
Console.WriteLine("We should have received 10 total messages, we received: " + messages.Count);
// 3. Publish 20 messages
// - Fetch messages, only get 10
Console.WriteLine("----------\n3. Publish 20 which is larger than the batch size.");
JsUtils.Publish(js, helper.Subject, "B", 20);
messages = sub.Fetch(10, 3000);
JsUtils.Report(messages);
foreach (Msg m in messages)
{
m.Ack();
}
Console.WriteLine("We should have received 10 total messages, we received: " + messages.Count);
// 4. There are still messages left from the last
// - Fetch messages, get 10
Console.WriteLine("----------\n4. Get the rest of the JsUtils.Publish.");
messages = sub.Fetch(10, 3000);
JsUtils.Report(messages);
foreach (Msg m in messages)
{
m.Ack();
}
Console.WriteLine("We should have received 10 total messages, we received: " + messages.Count);
// 5. Publish 5 messages
// - Fetch messages, get 5
// - Since there are less than batch size we only get what the server has.
Console.WriteLine("----------\n5. Publish 5 which is less than batch size.");
JsUtils.Publish(js, helper.Subject, "C", 5);
messages = sub.Fetch(10, 3000);
JsUtils.Report(messages);
foreach (Msg m in messages)
{
m.Ack();
}
Console.WriteLine("We should have received 5 total messages, we received: " + messages.Count);
// 6. Publish 15 messages
// - Fetch messages, only get 10
Console.WriteLine("----------\n6. Publish 15 which is more than the batch size.");
JsUtils.Publish(js, helper.Subject, "D", 15);
messages = sub.Fetch(10, 3000);
JsUtils.Report(messages);
foreach (Msg m in messages)
{
m.Ack();
}
Console.WriteLine("We should have received 10 total messages, we received: " + messages.Count);
// 7. There are 5 messages left
// - Fetch messages, only get 5
Console.WriteLine("----------\n7. There are 5 messages left.");
messages = sub.Fetch(10, 3000);
JsUtils.Report(messages);
foreach (Msg m in messages)
{
m.Ack();
}
Console.WriteLine("We should have received 5 messages, we received: " + messages.Count);
// 8. Read but don't ack.
// - Fetch messages, get 10, but either take too long to ack them or don't ack them
Console.WriteLine("----------\n8. Fetch but don't ack.");
JsUtils.Publish(js, helper.Subject, "E", 10);
messages = sub.Fetch(10, 3000);
JsUtils.Report(messages);
Console.WriteLine("We should have received 10 message, we received: " + messages.Count);
Thread.Sleep(3000); // longer than the ackWait
// 9. Fetch messages,
// - get the 10 messages we didn't ack
Console.WriteLine("----------\n9. Fetch, get the messages we did not ack.");
messages = sub.Fetch(10, 3000);
JsUtils.Report(messages);
foreach (Msg m in messages)
{
m.Ack();
}
Console.WriteLine("We should have received 10 message, we received: " + messages.Count);
Console.WriteLine("----------\n");
// delete the stream since we are done with it.
jsm.DeleteStream(helper.Stream);
}
}
catch (Exception ex)
{
helper.ReportException(ex);
}
}