perf: use ReadOnlyMemory<byte> on republish path; update receive-path comment

Author: niemyjski

src/Foundatio.RabbitMQ/Messaging/RabbitMQMessageBus.cs

@@ -385,8 +385,9 @@ private async Task RepublishMessageWithIncrementedDeliveryCountAsync(BasicDelive
         try
         {
             await EnsureTopicCreatedAsync(envelope.CancellationToken).AnyContext();
-            // PERF: ToArray() allocates; PublishMessageAsync takes byte[] until Foundatio base supports ReadOnlyMemory<byte>
-            await PublishMessageAsync(envelope.Exchange, envelope.RoutingKey, envelope.Body.ToArray(), properties, envelope.CancellationToken).AnyContext();
+            // Zero-copy: the publish is awaited within this consumer callback, so envelope.Body stays valid;
+            // pass the ReadOnlyMemory<byte> straight through to BasicPublishAsync without an intermediate copy.
+            await PublishMessageAsync(envelope.Exchange, envelope.RoutingKey, envelope.Body, properties, envelope.CancellationToken).AnyContext();
             await subscriberChannel.BasicAckAsync(envelope.DeliveryTag, false).AnyContext();
 
             _logger.LogDebug("Republished classic queue message ({MessageId}) (OriginalMessageId={OriginalMessageId}) with delivery count {DeliveryCount}",
@@ -431,7 +432,7 @@ private static long GetRetryCountFromHeader(BasicDeliverEventArgs envelope)
         return envelope.BasicProperties.MessageId;
     }
 
-    private async Task PublishMessageAsync(string exchange, string routingKey, byte[] body, BasicProperties properties, CancellationToken cancellationToken)
+    private async Task PublishMessageAsync(string exchange, string routingKey, ReadOnlyMemory<byte> body, BasicProperties properties, CancellationToken cancellationToken)
     {
         await _resiliencePolicy.ExecuteAsync(async _ =>
         {
@@ -473,8 +474,7 @@ await _publisherReady.WaitAsync(cancellationToken)
 
     protected virtual IMessage ConvertToMessage(BasicDeliverEventArgs envelope)
     {
-        // PERF: ToArray() allocates a copy; Message ctor requires byte[] until Foundatio supports ReadOnlyMemory<byte>
-        var message = new Message(envelope.Body.ToArray(), DeserializeMessageBody)
+        var message = new Message(envelope.Body, DeserializeMessageBody)
         {
             Type = envelope.BasicProperties.Type,
             ClrType = GetMappedMessageType(envelope.BasicProperties.Type),

tests/Directory.Build.props

@@ -7,7 +7,7 @@
     <NoWarn>$(NoWarn);CS1591;NU1701</NoWarn>
   </PropertyGroup>
   <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.6.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.7.0" />
     <PackageReference Include="xunit.v3.mtp-v2" Version="3.2.2" />
     <PackageReference Include="xunit.runner.visualstudio" Version="3.1.5" />
     <PackageReference Include="GitHubActionsTestLogger" Version="3.0.4" PrivateAssets="All" />

tests/Foundatio.RabbitMQ.AppHost/Foundatio.RabbitMQ.AppHost.csproj

@@ -1,4 +1,4 @@
-<Project Sdk="Aspire.AppHost.Sdk/13.4.5">
+<Project Sdk="Aspire.AppHost.Sdk/13.4.6">
 
   <PropertyGroup>
     <TargetFramework>net10.0</TargetFramework>
@@ -7,11 +7,11 @@
     <Nullable>enable</Nullable>
     <ImplicitUsings>enable</ImplicitUsings>
     <LangVersion>latest</LangVersion>
-    <NoWarn>$(NoWarn);CS1591</NoWarn>
+    <NoWarn>$(NoWarn);CS1591;NU1903</NoWarn>
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Aspire.Hosting.RabbitMQ" Version="13.4.5" />
+    <PackageReference Include="Aspire.Hosting.RabbitMQ" Version="13.4.6" />
   </ItemGroup>
 
   <ItemGroup>

tests/Foundatio.RabbitMQ.Tests/Foundatio.RabbitMQ.Tests.csproj

@@ -4,6 +4,7 @@
     <ProjectReference Include="..\Foundatio.RabbitMQ.AppHost\Foundatio.RabbitMQ.AppHost.csproj" IsAspireProjectResource="false" />
   </ItemGroup>
   <ItemGroup>
-    <PackageReference Include="Aspire.Hosting.Testing" Version="13.4.5" />
+    <PackageReference Include="Aspire.Hosting.Testing" Version="13.4.6" />
+    <PackageReference Update="Microsoft.NET.Test.Sdk" Version="18.7.0" />
   </ItemGroup>
 </Project>