Deoptimize the exceptional cases in favor of optimal path

Author: lewing

src/Components/Components/src/PersistentComponentState.cs

@@ -84,12 +84,10 @@ public PersistingComponentStateSubscription RegisterOnPersisting(Func<Task> call
             throw new InvalidOperationException("Persisting state is only allowed during an OnPersisting callback.");
         }
 
-        if (_currentState.ContainsKey(key))
+        if (!_currentState.TryAdd(key, JsonSerializer.SerializeToUtf8Bytes(instance, JsonSerializerOptionsProvider.Options)))
         {
             throw new ArgumentException($"There is already a persisted object under the same key '{key}'");
         }
-
-        _currentState.Add(key, JsonSerializer.SerializeToUtf8Bytes(instance, JsonSerializerOptionsProvider.Options));
     }
 
     [RequiresUnreferencedCode("JSON serialization and deserialization might require types that cannot be statically analyzed.")]
@@ -102,12 +100,10 @@ internal void PersistAsJson(string key, object instance, [DynamicallyAccessedMem
             throw new InvalidOperationException("Persisting state is only allowed during an OnPersisting callback.");
         }
 
-        if (_currentState.ContainsKey(key))
+        if (!_currentState.TryAdd(key, JsonSerializer.SerializeToUtf8Bytes(instance, type, JsonSerializerOptionsProvider.Options)))
         {
             throw new ArgumentException($"There is already a persisted object under the same key '{key}'");
         }
-
-        _currentState.Add(key, JsonSerializer.SerializeToUtf8Bytes(instance, type, JsonSerializerOptionsProvider.Options));
     }
 
     /// <summary>
@@ -124,12 +120,10 @@ internal void PersistAsBytes(string key, byte[] data)
             throw new InvalidOperationException("Persisting state is only allowed during an OnPersisting callback.");
         }
 
-        if (_currentState.ContainsKey(key))
+        if (!_currentState.TryAdd(key, data))
         {
             throw new ArgumentException($"There is already a persisted object under the same key '{key}'");
         }
-
-        _currentState.Add(key, data);
     }
 
     /// <summary>