feat(Event streams): add support for cancellation and IAsyncEnumerator

sdk/src/Core/Amazon.Runtime/EventStreams/Internal/EnumerableEventStream.cs

@@ -1,4 +1,4 @@
-/*******************************************************************************
+/*******************************************************************************
  *  Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
  *  Licensed under the Apache License, Version 2.0 (the "License"). You may not use
  *  this file except in compliance with the License. A copy of the License is located at
@@ -25,6 +25,7 @@
 using System.Diagnostics.CodeAnalysis;
 using System.IO;
 #if AWS_ASYNC_API
+using System.Threading;
 using System.Threading.Tasks;
 #endif
 
@@ -36,7 +37,12 @@ namespace Amazon.Runtime.EventStreams.Internal
     /// <typeparam name="T">An implementation of IEventStreamEvent (e.g. IS3Event).</typeparam>
     /// <typeparam name="TE">An implementation of EventStreamException (e.g. S3EventStreamException).</typeparam>
     [SuppressMessage("Microsoft.Naming", "CA1710", Justification = "IEventStreamCollection is not descriptive.")]
+#if AWS_ASYNC_ENUMERABLES_API
+
+    public interface IEnumerableEventStream<T, TE> : IEventStream<T, TE>, IEnumerable<T>, IAsyncEnumerable<T> where T : IEventStreamEvent where TE : EventStreamException, new()
+#else
     public interface IEnumerableEventStream<T, TE> : IEventStream<T, TE>, IEnumerable<T> where T : IEventStreamEvent where TE : EventStreamException, new()
+#endif
     {
     }
 
@@ -171,13 +177,72 @@ public override void StartProcessing()
         /// 
         /// The Task will be completed when all of the events from the stream have been processed.
         /// </summary>
-        public override async Task StartProcessingAsync()
+        public override async Task StartProcessingAsync(CancellationToken cancellationToken = default)
         {
             // If they are/have enumerated, the event-driven mode should be disabled
             if (IsEnumerated) throw new InvalidOperationException(MutuallyExclusiveExceptionMessage);
 
-            await base.StartProcessingAsync().ConfigureAwait(false);
+            await base.StartProcessingAsync(cancellationToken).ConfigureAwait(false);
+        }
+#endif
+
+#if AWS_ASYNC_ENUMERABLES_API
+        /// <summary>
+        /// Returns an async enumerator that iterates through the collection.
+        /// </summary>
+        /// <returns>An async enumerator that can be used to iterate through the collection.</returns>
+        public async IAsyncEnumerator<T> GetAsyncEnumerator(CancellationToken cancellationToken)
+        {
+            if (IsProcessing)
+            {
+                // If the queue has already begun processing, refuse to enumerate.
+                throw new InvalidOperationException(MutuallyExclusiveExceptionMessage);
+            }
+
+            // There could be more than 1 message created per decoder cycle.
+            var events = new Queue<T>();
+
+            // Opting out of events - letting the enumeration handle everything.
+            IsEnumerated = true;
+            IsProcessing = true;
+
+            // Enumeration is just magic over the event driven mechanism.
+            EventReceived += (sender, args) => events.Enqueue(args.EventStreamEvent);
+
+            var buffer = new byte[BufferSize];
+
+            while (IsProcessing)
+            {
+                // If there are already events ready to be served, do not ask for more.
+                if (events.Count > 0)
+                {
+                    var ev = events.Dequeue();
+                    // Enumeration handles terminal events on behalf of the user.
+                    if (ev is IEventStreamTerminalEvent)
+                    {
+                        IsProcessing = false;
+                        Dispose();
+                    }
+
+                    yield return ev;
+                }
+                else
+                {
+                    try
+                    {
+                        await ReadFromStreamAsync(buffer, cancellationToken).ConfigureAwait(false);
+                    }
+                    catch (Exception ex)
+                    {
+                        IsProcessing = false;
+                        Dispose();
+
+                        // Wrap exceptions as needed to match event-driven behavior.
+                        throw WrapException(ex);
+                    }
+                }
+            }
         }
 #endif
     }
-}
+}

sdk/src/Core/Amazon.Runtime/EventStreams/Internal/EventStream.cs

@@ -1,4 +1,4 @@
-/*
+/*
  * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License").
@@ -17,10 +17,9 @@
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using System.IO;
+using System.Threading;
 #if AWS_ASYNC_API
 using System.Threading.Tasks;
-#else
-using System.Threading;
 #endif
 
 namespace Amazon.Runtime.EventStreams.Internal
@@ -55,7 +54,7 @@ namespace Amazon.Runtime.EventStreams.Internal
         /// 
         /// The Task will be completed when all of the events from the stream have been processed.
         /// </summary>
-        Task StartProcessingAsync();
+        Task StartProcessingAsync(CancellationToken cancellationToken = default);
 #endif
     }
 
@@ -262,23 +261,23 @@ protected void Process()
         {
 #if AWS_ASYNC_API
             // Task only exists in framework 4.5 and up, and Standard.
-            Task.Run(() => ProcessLoopAsync());
+            Task.Run(() => ProcessLoopAsync(CancellationToken.None));
 #else
             // ThreadPool only exists in 3.5 and below. These implementations do not have the Task library.
             ThreadPool.QueueUserWorkItem(ProcessLoop);
 #endif
         }
 
 #if AWS_ASYNC_API
-        private async Task ProcessLoopAsync()
+        private async Task ProcessLoopAsync(CancellationToken cancellationToken)
         {
             var buffer = new byte[BufferSize];
 
             try
             {
                 while (IsProcessing)
                 {
-                    await ReadFromStreamAsync(buffer).ConfigureAwait(false);
+                    await ReadFromStreamAsync(buffer, cancellationToken).ConfigureAwait(false);
                 }
             }
             // These exceptions are raised on the background thread. They are fired as events for visibility.
@@ -351,9 +350,10 @@ protected void ReadFromStream(byte[] buffer)
         /// each message it decodes.
         /// </summary>
         /// <param name="buffer">The buffer to store the read bytes from the stream.</param>
-        protected async Task ReadFromStreamAsync(byte[] buffer)
+        /// <param name="cancellationToken">A cancellation token.</param>
+        protected async Task ReadFromStreamAsync(byte[] buffer, CancellationToken cancellationToken)
         {
-            var bytesRead = await NetworkStream.ReadAsync(buffer, 0, buffer.Length).ConfigureAwait(false);
+            var bytesRead = await NetworkStream.ReadAsync(buffer, 0, buffer.Length, cancellationToken).ConfigureAwait(false);
             if (bytesRead > 0)
             {
                 // Decoder raises MessageReceived for every message it encounters.
@@ -408,13 +408,13 @@ public virtual void StartProcessing()
         /// 
         /// The Task will be completed when all of the events from the stream have been processed.
         /// </summary>
-        public virtual async Task StartProcessingAsync()
+        public virtual async Task StartProcessingAsync(CancellationToken cancellationToken = default)
         {
             if (IsProcessing) 
                 return;
 
             IsProcessing = true;
-            await ProcessLoopAsync().ConfigureAwait(false);
+            await ProcessLoopAsync(cancellationToken).ConfigureAwait(false);
         }
 #endif
 

sdk/src/Services/BedrockRuntime/BedrockRuntime.sln

@@ -26,6 +26,8 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "AWSSDK.IntegrationTests.Bed
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "AWSSDK.IntegrationTests.BedrockRuntime.Net45", "../../../test/Services/BedrockRuntime/IntegrationTests/AWSSDK.IntegrationTests.BedrockRuntime.Net45.csproj", "{086FF208-3CD6-40EC-9309-43F2EAA2F4D8}"
 EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "AWSSDK.IntegrationTests.BedrockRuntime.NetStandard", "../../../test/Services/BedrockRuntime/IntegrationTests/AWSSDK.IntegrationTests.BedrockRuntime.NetStandard.csproj", "{9F726137-4C28-4FEA-9A6C-962DEA25951D}"
+EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "AWSSDK.UnitTests.BedrockRuntime.Net35", "../../../test/Services/BedrockRuntime/UnitTests/AWSSDK.UnitTests.BedrockRuntime.Net35.csproj", "{AF460DBB-A029-440B-8C04-974E78043F09}"
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "AWSSDK.UnitTests.BedrockRuntime.Net45", "../../../test/Services/BedrockRuntime/UnitTests/AWSSDK.UnitTests.BedrockRuntime.Net45.csproj", "{8F243F98-2E75-4C9C-B4B3-61EC51BEF835}"
@@ -186,6 +188,10 @@ Global
 		{A657D500-DDA4-45FF-9459-8351CDD96B78}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{A657D500-DDA4-45FF-9459-8351CDD96B78}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{A657D500-DDA4-45FF-9459-8351CDD96B78}.Release|Any CPU.Build.0 = Release|Any CPU
+		{9F726137-4C28-4FEA-9A6C-962DEA25951D}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{9F726137-4C28-4FEA-9A6C-962DEA25951D}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{9F726137-4C28-4FEA-9A6C-962DEA25951D}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{9F726137-4C28-4FEA-9A6C-962DEA25951D}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -220,8 +226,9 @@ Global
 		{7BD5B7F3-2ED9-4747-9FCE-8F5622BFCC36} = {939EC5C2-8345-43E2-8F97-72EEEBEEA0AC}
 		{EE034587-0A31-4841-A4BB-055DB990990F} = {939EC5C2-8345-43E2-8F97-72EEEBEEA0AC}
 		{A657D500-DDA4-45FF-9459-8351CDD96B78} = {939EC5C2-8345-43E2-8F97-72EEEBEEA0AC}
+		{9F726137-4C28-4FEA-9A6C-962DEA25951D} = {12EC4E4B-7E2C-4B63-8EF9-7B959F82A89B}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {CE2F2305-8E72-44B6-9FAD-AA2E347C2B6A}
 	EndGlobalSection
-EndGlobal
+EndGlobal

sdk/test/Services/BedrockRuntime/IntegrationTests/AWSSDK.IntegrationTests.BedrockRuntime.NetStandard.csproj

@@ -0,0 +1,52 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+   <RunAnalyzersDuringBuild Condition="'$(RunAnalyzersDuringBuild)'==''">true</RunAnalyzersDuringBuild>
+    <TargetFrameworks>netstandard2.0;netcoreapp3.1;net8.0</TargetFrameworks>
+    <DefineConstants>$(DefineConstants);NETSTANDARD;AWS_ASYNC_API</DefineConstants>
+    <DefineConstants Condition="'$(TargetFramework)' == 'netstandard2.0'">$(DefineConstants);NETSTANDARD20;AWS_ASYNC_ENUMERABLES_API</DefineConstants>
+    <DefineConstants Condition="'$(TargetFramework)' == 'netcoreapp3.1'">$(DefineConstants);AWS_ASYNC_ENUMERABLES_API</DefineConstants>
+    <DefineConstants Condition="'$(TargetFramework)' == 'net8.0'">$(DefineConstants);AWS_ASYNC_ENUMERABLES_API</DefineConstants>
+    <DebugType>portable</DebugType>
+    <GenerateDocumentationFile>true</GenerateDocumentationFile>
+    <AssemblyName>AWSSDK.IntegrationTests.BedrockRuntime.NetStandard</AssemblyName>
+    <PackageId>AWSSDK.IntegrationTests.BedrockRuntime.NetStandard</PackageId>
+
+    <GenerateAssemblyTitleAttribute>false</GenerateAssemblyTitleAttribute>
+    <GenerateAssemblyConfigurationAttribute>false</GenerateAssemblyConfigurationAttribute>
+    <GenerateAssemblyProductAttribute>false</GenerateAssemblyProductAttribute>
+    <GenerateAssemblyCompanyAttribute>false</GenerateAssemblyCompanyAttribute>
+    <GenerateAssemblyCopyrightAttribute>false</GenerateAssemblyCopyrightAttribute>
+    <GenerateAssemblyVersionAttribute>false</GenerateAssemblyVersionAttribute>
+    <GenerateAssemblyFileVersionAttribute>false</GenerateAssemblyFileVersionAttribute>
+    <GenerateAssemblyDescriptionAttribute>false</GenerateAssemblyDescriptionAttribute>
+    <SignAssembly>true</SignAssembly>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
+
+    <NoWarn>CA1822</NoWarn>
+  </PropertyGroup>
+
+  <!-- Async Enumerable Compatibility -->
+  <PropertyGroup Condition="'$(TargetFramework)' == 'netstandard2.0'">
+    <LangVersion>8.0</LangVersion>
+  </PropertyGroup>
+
+  <ItemGroup>
+		<Compile Remove="**/35/**" />
+		<None Remove="**/35/**" />
+		<Compile Remove="**/obj/**" />
+		<None Remove="**/obj/**" />
+	</ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.11.1" />
+    <PackageReference Include="MSTest.TestAdapter" Version="3.6.2" />
+    <PackageReference Include="MSTest.TestFramework" Version="3.6.2" />
+  </ItemGroup>
+
+	<ItemGroup>
+		<ProjectReference Include="../../../../src/Core/AWSSDK.Core.NetStandard.csproj" />
+		<ProjectReference Include="../../../../src/Services/BedrockRuntime/AWSSDK.BedrockRuntime.NetStandard.csproj" />
+	</ItemGroup>
+
+
+</Project>

sdk/test/Services/BedrockRuntime/IntegrationTests/BedrockRuntimeEventStreamTests.cs

@@ -1,4 +1,4 @@
-using Microsoft.VisualStudio.TestTools.UnitTesting;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
 using Amazon.BedrockRuntime;
 using Amazon.BedrockRuntime.Model;
 using System.Threading.Tasks;
@@ -8,6 +8,9 @@
 using System.Threading;
 using System;
 using System.Diagnostics.Contracts;
+using System.Collections.Generic;
+using Amazon;
+using Amazon.Runtime;
 namespace AWSSDK_DotNet.IntegrationTests.Tests
 {
     /// <summary>
@@ -22,7 +25,11 @@ namespace AWSSDK_DotNet.IntegrationTests.Tests
     /// </summary>
     [Ignore]
     [TestClass]
+#if NETSTANDARD
+    public class BedrockRuntimeEventStreamTests
+#else
     public class BedrockRuntimeEventStreamTests : TestBase<AmazonBedrockRuntimeClient>
+#endif
     {
 #if BCL35
         [TestMethod]
@@ -145,6 +152,48 @@ public async Task RequestWithInvalidBodyReturnsValidationException()
         }
 
 #endif
+
+#if AWS_ASYNC_ENUMERABLES_API
+        [TestMethod]
+        public async Task ConverseStreamCanBeEnumeratedAsynchronously()
+        {
+            // configure with credentials and region
+            var client = new AmazonBedrockRuntimeClient();
+
+            var request = new ConverseStreamRequest
+            {
+                ModelId = "meta.llama3-1-8b-instruct-v1:0"
+            };
+
+            request.Messages.Add(new Message
+            {
+                Content = new List<ContentBlock> { new ContentBlock { Text = "Who was the first US president" } },
+                Role = ConversationRole.User
+            });
+
+            var response = await client.ConverseStreamAsync(request);
+
+            Assert.IsNotNull(response);
+            Assert.IsNotNull(response.Stream);
+
+            using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(20));
+
+            var contentStringBuilder = new StringBuilder();
+            await foreach (var item in response.Stream.WithCancellation(cts.Token))
+            {
+                if (item is ContentBlockDeltaEvent deltaEvent)
+                {
+                    contentStringBuilder.Append(deltaEvent.Delta.Text);
+                }
+            }
+
+            var responseContent = contentStringBuilder.ToString();
+
+            // Since we don't know the contents of the response from Bedrock, we just assert that we received a response
+            Assert.IsTrue(responseContent.Length > 10);
+        }
+#endif
+
         static MemoryStream CreateStream(string query, bool createInvalidInput = false)
         {
             StringBuilder promptValueBuilder = new StringBuilder();