Add receiver in stream tutorial 2 for .NET

acogoluegnes · acogoluegnes · commit 6783644664bf · 2024-07-10T15:08:03.000+02:00
diff --git a/dotnet-stream/OffsetTrackingReceive/OffsetTrackingReceive.cs b/dotnet-stream/OffsetTrackingReceive/OffsetTrackingReceive.cs
@@ -0,0 +1,49 @@
+﻿using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+using RabbitMQ.Stream.Client;
+using RabbitMQ.Stream.Client.Reliable;
+
+var streamSystem = await StreamSystem.Create(new StreamSystemConfig());
+
+var stream = "stream-offset-tracking-dotnet";
+await streamSystem.CreateStream(new StreamSpec(stream));
+
+var consumerName = "offset-tracking-tutorial"; 
+IOffsetType offsetSpecification;
+try {
+    ulong storedOffset = await streamSystem.QueryOffset(consumerName, stream).ConfigureAwait(false);
+    offsetSpecification = new OffsetTypeOffset(storedOffset + 1);
+} catch (OffsetNotFoundException) {
+    offsetSpecification = new OffsetTypeFirst();
+}
+ulong initialValue = UInt64.MaxValue;
+ulong firstOffset = initialValue;
+int messageCount = 0;
+ulong lastOffset = initialValue;
+var consumedCde = new CountdownEvent(1);
+var consumer = await Consumer.Create(new ConsumerConfig(streamSystem, stream)
+{
+    OffsetSpec = offsetSpecification,
+    Reference =  consumerName,
+    MessageHandler = async (_, consumer, context, message) => {
+        if (Interlocked.CompareExchange(ref firstOffset, context.Offset, initialValue) == initialValue) {
+            Console.WriteLine("First message received.");
+        }
+        if (Interlocked.Increment(ref messageCount) % 10 == 0) {
+            await consumer.StoreOffset(context.Offset).ConfigureAwait(false);
+        }
+        if ("marker".Equals(Encoding.UTF8.GetString(message.Data.Contents))) {
+            Interlocked.Exchange(ref lastOffset, context.Offset);
+            await consumer.StoreOffset(context.Offset).ConfigureAwait(false);
+            await consumer.Close();
+            consumedCde.Signal();
+        }
+        await Task.CompletedTask;
+    }
+});
+Console.WriteLine("Started consuming...");
+
+consumedCde.Wait();
+Console.WriteLine("Done consuming, first offset {0}, last offset {1}", firstOffset, lastOffset);
+await streamSystem.Close();
diff --git a/dotnet-stream/OffsetTrackingReceive/OffsetTrackingReceive.csproj b/dotnet-stream/OffsetTrackingReceive/OffsetTrackingReceive.csproj
@@ -0,0 +1,14 @@
+﻿<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="RabbitMQ.Stream.Client" Version="1.8.7" />
+  </ItemGroup>
+
+</Project>
