.NET: Update AgentThread, MessageStores and Context Providers to deserialize via constructor. (#779)

* Update AgentThread, MessageStores and Context Providers to deserialize via constructor.

* Fix pr comment.

* Add additional validation for AgentThread deserialization

* Update WorkflowMessageStore desreialize to improve error checking.

* Reduce allocations in InMemoryChatMessageStore

---------

Co-authored-by: Chris <66376200+crickman@users.noreply.github.com>

dotnet/samples/GettingStarted/Agents/Agent_Step06_PersistedConversations/Program.cs

@@ -40,7 +40,7 @@ await File.WriteAllTextAsync(tempFilePath, JsonSerializer.Serialize(serializedTh
 JsonElement reloadedSerializedThread = JsonSerializer.Deserialize<JsonElement>(await File.ReadAllTextAsync(tempFilePath));
 
 // Deserialize the thread state after loading from storage.
-AgentThread resumedThread = await agent.DeserializeThreadAsync(reloadedSerializedThread);
+AgentThread resumedThread = agent.DeserializeThread(reloadedSerializedThread);
 
 // Run the agent again with the resumed thread.
 Console.WriteLine(await agent.RunAsync("Now tell the same joke in the voice of a pirate, and add some emojis to the joke.", resumedThread));

dotnet/samples/GettingStarted/Agents/Agent_Step07_3rdPartyThreadStorage/Program.cs

@@ -38,12 +38,12 @@ AIAgent agent = new AzureOpenAIClient(
      {
          Name = JokerName,
          Instructions = JokerInstructions,
-         ChatMessageStoreFactory = () =>
+         ChatMessageStoreFactory = (jsonElement, jso) =>
          {
              // Create a new chat message store for this agent that stores the messages in a vector store.
              // Each thread must get its own copy of the VectorChatMessageStore, since the store
              // also contains the id that the thread is stored under.
-             return new VectorChatMessageStore(vectorStore);
+             return new VectorChatMessageStore(vectorStore, jsonElement, jso);
          }
      });
 
@@ -65,7 +65,7 @@ Console.WriteLine(JsonSerializer.Serialize(serializedThread, new JsonSerializerO
 // and loaded again later.
 
 // Deserialize the thread state after loading from storage.
-AgentThread resumedThread = await agent.DeserializeThreadAsync(serializedThread);
+AgentThread resumedThread = agent.DeserializeThread(serializedThread);
 
 // Run the agent with the thread that stores conversation history in the vector store a second time.
 Console.WriteLine(await agent.RunAsync("Now tell the same joke in the voice of a pirate, and add some emojis to the joke.", resumedThread));
@@ -75,10 +75,21 @@ namespace SampleApp
     /// <summary>
     /// A sample implementation of <see cref="IChatMessageStore"/> that stores chat messages in a vector store.
     /// </summary>
-    /// <param name="vectorStore">The vector store to store the messages in.</param>
-    internal sealed class VectorChatMessageStore(VectorStore vectorStore) : IChatMessageStore
+    internal sealed class VectorChatMessageStore : IChatMessageStore
     {
         private string? _threadId;
+        private readonly VectorStore _vectorStore;
+
+        public VectorChatMessageStore(VectorStore vectorStore, JsonElement serializedStoreState, JsonSerializerOptions? jsonSerializerOptions = null)
+        {
+            this._vectorStore = vectorStore ?? throw new ArgumentNullException(nameof(vectorStore));
+
+            if (serializedStoreState.ValueKind == JsonValueKind.String)
+            {
+                // Here we can deserialize the thread id so that we can access the same messages as before the suspension.
+                this._threadId = JsonSerializer.Deserialize<string>(serializedStoreState);
+            }
+        }
 
         public string? ThreadId => this._threadId;
 
@@ -86,7 +97,7 @@ namespace SampleApp
         {
             this._threadId ??= Guid.NewGuid().ToString();
 
-            var collection = vectorStore.GetCollection<string, ChatHistoryItem>("ChatHistory");
+            var collection = this._vectorStore.GetCollection<string, ChatHistoryItem>("ChatHistory");
             await collection.EnsureCollectionExistsAsync(cancellationToken);
 
             await collection.UpsertAsync(messages.Select(x => new ChatHistoryItem()
@@ -101,7 +112,7 @@ namespace SampleApp
 
         public async Task<IEnumerable<ChatMessage>> GetMessagesAsync(CancellationToken cancellationToken)
         {
-            var collection = vectorStore.GetCollection<string, ChatHistoryItem>("ChatHistory");
+            var collection = this._vectorStore.GetCollection<string, ChatHistoryItem>("ChatHistory");
             await collection.EnsureCollectionExistsAsync(cancellationToken);
 
             var records = await collection
@@ -124,13 +135,6 @@ namespace SampleApp
             return new ValueTask<JsonElement?>(JsonSerializer.SerializeToElement(this._threadId));
         }
 
-        public ValueTask DeserializeStateAsync(JsonElement? serializedStoreState, JsonSerializerOptions? jsonSerializerOptions = null, CancellationToken cancellationToken = default)
-        {
-            // Here we can deserialize the thread id so that we can access the same messages as before the suspension.
-            this._threadId = JsonSerializer.Deserialize<string>((JsonElement)serializedStoreState!);
-            return new ValueTask();
-        }
-
         /// <summary>
         /// The data structure used to store chat history items in the vector store.
         /// </summary>

dotnet/samples/GettingStarted/Agents/Agent_Step13_Memory/Program.cs

@@ -38,7 +38,7 @@ ChatClient chatClient = new AzureOpenAIClient(
 AIAgent agent = chatClient.CreateAIAgent(new ChatClientAgentOptions()
 {
     Instructions = "You are a friendly assistant. Always address the user by their name.",
-    AIContextProviderFactory = () => new SampleApp.UserInfoMemory(chatClient.AsIChatClient())
+    AIContextProviderFactory = (jse, jso) => new UserInfoMemory(chatClient.AsIChatClient(), jse, jso)
 });
 
 // Create a new thread for the conversation.
@@ -57,7 +57,7 @@ var threadElement = await thread.SerializeAsync();
 Console.WriteLine("\n>> Use deserialized thread with previously created memories\n");
 
 // Later we can deserialize the thread and continue the conversation with the previous memory component state.
-var deserializedThread = await agent.DeserializeThreadAsync(threadElement);
+var deserializedThread = agent.DeserializeThread(threadElement);
 Console.WriteLine(await agent.RunAsync("What is my name and age?", deserializedThread));
 
 Console.WriteLine("\n>> Read memories from memory component\n");
@@ -89,16 +89,30 @@ namespace SampleApp
     /// <summary>
     /// Sample memory component that can remember a user's name and age.
     /// </summary>
-    internal sealed class UserInfoMemory(IChatClient chatClient, UserInfo? userInfo = null) : AIContextProvider
+    internal sealed class UserInfoMemory : AIContextProvider
     {
-        public UserInfo UserInfo { get; set; } = userInfo ?? new();
+        private readonly IChatClient _chatClient;
+
+        public UserInfoMemory(IChatClient chatClient, UserInfo? userInfo = null)
+        {
+            this._chatClient = chatClient;
+            this.UserInfo = userInfo ?? new UserInfo();
+        }
+
+        public UserInfoMemory(IChatClient chatClient, JsonElement serializedState, JsonSerializerOptions? jsonSerializerOptions = null)
+        {
+            this._chatClient = chatClient;
+            this.UserInfo = JsonSerializer.Deserialize<UserInfo>(serializedState, jsonSerializerOptions) ?? new UserInfo();
+        }
+
+        public UserInfo UserInfo { get; set; }
 
         public override async ValueTask InvokedAsync(InvokedContext context, CancellationToken cancellationToken = default)
         {
             // Try and extract the user name and age from the message if we don't have it already and it's a user message.
             if ((this.UserInfo.UserName == null || this.UserInfo.UserAge == null) && context.RequestMessages.Any(x => x.Role == ChatRole.User))
             {
-                var result = await chatClient.GetResponseAsync<UserInfo>(
+                var result = await this._chatClient.GetResponseAsync<UserInfo>(
                     context.RequestMessages,
                     new ChatOptions()
                     {