[dotnet] [bidi] Deserialize message fast instead of defer it (#16403)

Author: nvborisenko

dotnet/src/webdriver/BiDi/Communication/Broker.cs

@@ -38,7 +38,7 @@ public sealed class Broker : IAsyncDisposable
     private readonly ITransport _transport;
 
     private readonly ConcurrentDictionary<long, CommandInfo> _pendingCommands = new();
-    private readonly BlockingCollection<MessageEvent> _pendingEvents = [];
+    private readonly BlockingCollection<(string Method, EventArgs Params)> _pendingEvents = [];
     private readonly Dictionary<string, JsonTypeInfo> _eventTypesMap = [];
 
     private readonly ConcurrentDictionary<string, List<EventHandler>> _eventHandlers = new();
@@ -143,20 +143,20 @@ public async Task<TResult> ExecuteCommandAsync<TCommand, TResult>(TCommand comma
         where TResult : EmptyResult
     {
         command.Id = Interlocked.Increment(ref _currentCommandId);
-        var tcs = new TaskCompletionSource<JsonElement>(TaskCreationOptions.RunContinuationsAsynchronously);
+        var tcs = new TaskCompletionSource<EmptyResult>(TaskCreationOptions.RunContinuationsAsynchronously);
         var timeout = options?.Timeout ?? TimeSpan.FromSeconds(30);
         using var cts = new CancellationTokenSource(timeout);
         cts.Token.Register(() => tcs.TrySetCanceled(cts.Token));
-        var commandInfo = new CommandInfo(command.Id, command.ResultType, tcs);
+        var commandInfo = new CommandInfo(command.Id, tcs, jsonResultTypeInfo);
         _pendingCommands[command.Id] = commandInfo;
         var data = JsonSerializer.SerializeToUtf8Bytes(command, jsonCommandTypeInfo);
 
         await _transport.SendAsync(data, cts.Token).ConfigureAwait(false);
-        var resultJson = await tcs.Task.ConfigureAwait(false);
-        return JsonSerializer.Deserialize(resultJson, jsonResultTypeInfo)!;
+
+        return (TResult)await tcs.Task.ConfigureAwait(false);
     }
 
-    public async Task<Subscription> SubscribeAsync<TEventArgs>(string eventName, Action<TEventArgs> action, SubscriptionOptions? options, JsonTypeInfo jsonTypeInfo)
+    public async Task<Subscription> SubscribeAsync<TEventArgs>(string eventName, Action<TEventArgs> action, SubscriptionOptions? options, JsonTypeInfo<TEventArgs> jsonTypeInfo)
         where TEventArgs : EventArgs
     {
         _eventTypesMap[eventName] = jsonTypeInfo;
@@ -185,7 +185,7 @@ public async Task<Subscription> SubscribeAsync<TEventArgs>(string eventName, Act
         }
     }
 
-    public async Task<Subscription> SubscribeAsync<TEventArgs>(string eventName, Func<TEventArgs, Task> func, SubscriptionOptions? options, JsonTypeInfo jsonTypeInfo)
+    public async Task<Subscription> SubscribeAsync<TEventArgs>(string eventName, Func<TEventArgs, Task> func, SubscriptionOptions? options, JsonTypeInfo<TEventArgs> jsonTypeInfo)
         where TEventArgs : EventArgs
     {
         _eventTypesMap[eventName] = jsonTypeInfo;
@@ -301,7 +301,7 @@ private void ProcessReceivedMessage(byte[]? data)
 
                 if (_pendingCommands.TryGetValue(id.Value, out var successCommand))
                 {
-                    successCommand.TaskCompletionSource.SetResult(JsonElement.ParseValue(ref resultReader));
+                    successCommand.TaskCompletionSource.SetResult((EmptyResult)JsonSerializer.Deserialize(ref resultReader, successCommand.JsonResultTypeInfo)!);
                     _pendingCommands.TryRemove(id.Value, out _);
                 }
                 else
@@ -318,7 +318,7 @@ private void ProcessReceivedMessage(byte[]? data)
                 {
                     var eventArgs = (EventArgs)JsonSerializer.Deserialize(ref paramsReader, eventInfo)!;
 
-                    var messageEvent = new MessageEvent(method, eventArgs);
+                    var messageEvent = (method, eventArgs);
                     _pendingEvents.Add(messageEvent);
                 }
                 else
@@ -345,10 +345,12 @@ private void ProcessReceivedMessage(byte[]? data)
         }
     }
 
-    class CommandInfo(long id, Type resultType, TaskCompletionSource<JsonElement> taskCompletionSource)
+    class CommandInfo(long id, TaskCompletionSource<EmptyResult> taskCompletionSource, JsonTypeInfo jsonResultTypeInfo)
     {
         public long Id { get; } = id;
 
-        public TaskCompletionSource<JsonElement> TaskCompletionSource { get; } = taskCompletionSource;
+        public TaskCompletionSource<EmptyResult> TaskCompletionSource { get; } = taskCompletionSource;
+
+        public JsonTypeInfo JsonResultTypeInfo { get; } = jsonResultTypeInfo;
     };
 }

dotnet/src/webdriver/BiDi/Communication/EventHandler.cs

@@ -23,32 +23,32 @@
 
 namespace OpenQA.Selenium.BiDi.Communication;
 
-public abstract class EventHandler(string eventName, Type eventArgsType, IEnumerable<BrowsingContext.BrowsingContext>? contexts = null)
+public abstract class EventHandler(string eventName, IEnumerable<BrowsingContext.BrowsingContext>? contexts = null)
 {
     public string EventName { get; } = eventName;
-    public Type EventArgsType { get; set; } = eventArgsType;
+
     public IEnumerable<BrowsingContext.BrowsingContext>? Contexts { get; } = contexts;
 
-    public abstract ValueTask InvokeAsync(object args);
+    public abstract ValueTask InvokeAsync(EventArgs args);
 }
 
 internal class AsyncEventHandler<TEventArgs>(string eventName, Func<TEventArgs, Task> func, IEnumerable<BrowsingContext.BrowsingContext>? contexts = null)
-    : EventHandler(eventName, typeof(TEventArgs), contexts) where TEventArgs : EventArgs
+    : EventHandler(eventName, contexts) where TEventArgs : EventArgs
 {
     private readonly Func<TEventArgs, Task> _func = func;
 
-    public override async ValueTask InvokeAsync(object args)
+    public override async ValueTask InvokeAsync(EventArgs args)
     {
         await _func((TEventArgs)args).ConfigureAwait(false);
     }
 }
 
 internal class SyncEventHandler<TEventArgs>(string eventName, Action<TEventArgs> action, IEnumerable<BrowsingContext.BrowsingContext>? contexts = null)
-    : EventHandler(eventName, typeof(TEventArgs), contexts) where TEventArgs : EventArgs
+    : EventHandler(eventName, contexts) where TEventArgs : EventArgs
 {
     private readonly Action<TEventArgs> _action = action;
 
-    public override ValueTask InvokeAsync(object args)
+    public override ValueTask InvokeAsync(EventArgs args)
     {
         _action((TEventArgs)args);