Reduced memory usage and fixed several memory leaks (#933)

app/MindWork AI Studio/Chat/ContentBlockComponent.razor.cs

@@ -8,7 +8,7 @@ namespace AIStudio.Chat;
 /// <summary>
 /// The UI component for a chat content block, i.e., for any IContent.
 /// </summary>
-public partial class ContentBlockComponent : MSGComponentBase, IAsyncDisposable
+public partial class ContentBlockComponent : MSGComponentBase
 {
     private const string CHAT_MATH_SYNC_FUNCTION = "chatMath.syncContainer";
     private const string CHAT_MATH_DISPOSE_FUNCTION = "chatMath.disposeContainer";
@@ -601,16 +601,24 @@ public partial class ContentBlockComponent : MSGComponentBase, IAsyncDisposable
     private async Task OpenAttachmentsDialog()
     {
         var result = await ReviewAttachmentsDialog.OpenDialogAsync(this.DialogService, this.Content.FileAttachments.ToHashSet());
-        this.Content.FileAttachments = result.ToList();
+        this.Content.FileAttachments = [.. result];
     }
 
-    public async ValueTask DisposeAsync()
+    protected override async ValueTask DisposeResourcesAsync()
     {
         if (this.isDisposed)
             return;
 
         this.isDisposed = true;
+
+        //
+        // Our handlers close over this component, while the content belongs to the chat thread and
+        // outlives us. We only detach what is still ours, though: when this content is streaming
+        // again, another component has registered its own handlers in the meantime.
+        //
+        if (this.Content.StreamingDone == this.AfterStreaming)
+            this.Content.ResetStreamingHandlers();
+
         await this.DisposeMathContainerIfNeededAsync();
-        this.Dispose();
     }
 }

app/MindWork AI Studio/Chat/ContentImage.cs

@@ -22,11 +22,11 @@ public sealed class ContentImage : IContent, IImageSource
 
     /// <inheritdoc />
     [JsonIgnore]
-    public Func<Task> StreamingDone { get; set; } = () => Task.CompletedTask;
+    public Func<Task> StreamingDone { get; set; } = IContent.NO_STREAMING_HANDLER;
 
     /// <inheritdoc />
     [JsonIgnore]
-    public Func<Task> StreamingEvent { get; set; } = () => Task.CompletedTask;
+    public Func<Task> StreamingEvent { get; set; } = IContent.NO_STREAMING_HANDLER;
 
     /// <inheritdoc />
     public List<Source> Sources { get; set; } = [];

app/MindWork AI Studio/Chat/ContentText.cs

@@ -37,11 +37,11 @@ public sealed class ContentText : IContent
 
     /// <inheritdoc />
     [JsonIgnore]
-    public Func<Task> StreamingDone { get; set; } = () => Task.CompletedTask;
+    public Func<Task> StreamingDone { get; set; } = IContent.NO_STREAMING_HANDLER;
 
     /// <inheritdoc />
     [JsonIgnore]
-    public Func<Task> StreamingEvent { get; set; } = () => Task.CompletedTask;
+    public Func<Task> StreamingEvent { get; set; } = IContent.NO_STREAMING_HANDLER;
 
     /// <inheritdoc />
     public List<Source> Sources { get; set; } = [];

app/MindWork AI Studio/Chat/IContent.cs

@@ -38,6 +38,11 @@ public interface IContent
     [JsonIgnore]
     public Func<Task> StreamingDone { get; set; }
 
+    /// <summary>
+    /// What a content does while nobody listens to its stream: nothing.
+    /// </summary>
+    public static readonly Func<Task> NO_STREAMING_HANDLER = () => Task.CompletedTask;
+
     /// <summary>
     /// The provided sources, if any.
     /// </summary>

app/MindWork AI Studio/Chat/IContentExtensions.cs

@@ -0,0 +1,20 @@
+namespace AIStudio.Chat;
+
+public static class IContentExtensions
+{
+    /// <summary>
+    /// Detaches whoever listens to the stream of this content.
+    /// </summary>
+    /// <remarks>
+    /// The streaming handlers are closures over the component which registered them. A content
+    /// object belongs to the chat thread and therefore outlives every component which renders it,
+    /// so handlers left behind would keep those components alive for as long as the thread exists.
+    /// Whoever registers a handler calls this when it is no longer needed.
+    /// </remarks>
+    /// <param name="content">The content whose streaming handlers you want to detach.</param>
+    public static void ResetStreamingHandlers(this IContent content)
+    {
+        content.StreamingEvent = IContent.NO_STREAMING_HANDLER;
+        content.StreamingDone = IContent.NO_STREAMING_HANDLER;
+    }
+}