Single lookups into concurrent dictionary (#2231)

Author: jnyrup

lib/PuppeteerSharp/ChromeTargetManager.cs

@@ -89,18 +89,8 @@ public async Task InitializeAsync()
 
         public void AddTargetInterceptor(CDPSession session, TargetInterceptor interceptor)
         {
-            lock (_targetInterceptors)
-            {
-                _targetInterceptors.TryGetValue(session, out var interceptors);
-
-                if (interceptors == null)
-                {
-                    interceptors = new List<TargetInterceptor>();
-                    _targetInterceptors.TryAdd(session, interceptors);
-                }
-
-                interceptors.Add(interceptor);
-            }
+            var interceptors = _targetInterceptors.GetOrAdd(session, static _ => new());
+            interceptors.Add(interceptor);
         }
 
         public void RemoveTargetInterceptor(CDPSession session, TargetInterceptor interceptor)

lib/PuppeteerSharp/FirefoxTargetManager.cs

@@ -46,18 +46,8 @@ public FirefoxTargetManager(
 
         public void AddTargetInterceptor(CDPSession session, TargetInterceptor interceptor)
         {
-            lock (_targetInterceptors)
-            {
-                _targetInterceptors.TryGetValue(session, out var interceptors);
-
-                if (interceptors == null)
-                {
-                    interceptors = new List<TargetInterceptor>();
-                    _targetInterceptors.TryAdd(session, interceptors);
-                }
-
-                interceptors.Add(interceptor);
-            }
+            var interceptors = _targetInterceptors.GetOrAdd(session, static _ => new());
+            interceptors.Add(interceptor);
         }
 
         public void RemoveTargetInterceptor(CDPSession session, TargetInterceptor interceptor)

lib/PuppeteerSharp/FrameTree.cs

@@ -44,8 +44,7 @@ internal Task<Frame> WaitForFrameAsync(string frameId)
             }
 
             var deferred = new TaskCompletionSource<Frame>(TaskCreationOptions.RunContinuationsAsynchronously);
-            _waitRequests.TryAdd(frameId, new List<TaskCompletionSource<Frame>>());
-            _waitRequests.TryGetValue(frameId, out var callbacks);
+            var callbacks = _waitRequests.GetOrAdd(frameId, static _ => new());
             callbacks.Add(deferred);
 
             return deferred.Task;
@@ -58,8 +57,7 @@ internal void AddFrame(Frame frame)
             {
                 _parentIds.TryAdd(frame.Id, frame.ParentId);
 
-                _childIds.TryAdd(frame.ParentId, new List<string>());
-                _childIds.TryGetValue(frame.ParentId, out var childIds);
+                var childIds = _childIds.GetOrAdd(frame.ParentId, static _ => new());
                 childIds.Add(frame.Id);
             }
             else