chore: import upstream snapshot with attribution

2026-07-13 13:02:50 +08:00
commit 0fc60fdcb1
5008 changed files with 910633 additions and 0 deletions
@@ -0,0 +1,71 @@
+/*
+ * QUANTCONNECT.COM - Democratizing Finance, Empowering Individuals.
+ * Lean Algorithmic Trading Engine v2.0. Copyright 2014 QuantConnect Corporation.
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License"); 
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+*/
+
+using System;
+using Newtonsoft.Json;
+
+namespace QuantConnect.Util
+{
+    /// <summary>
+    /// Converts the string "null" into a new instance of T.
+    /// This converter only handles deserialization concerns.
+    /// </summary>
+    /// <typeparam name="T">The output type of the converter</typeparam>
+    public class NullStringValueConverter<T> : JsonConverter
+        where T : new()
+    {
+        /// <summary>
+        /// Writes the JSON representation of the object.
+        /// </summary>
+        /// <param name="writer">The <see cref="T:Newtonsoft.Json.JsonWriter"/> to write to.</param>
+        /// <param name="value">The value.</param>
+        /// <param name="serializer">The calling serializer.</param>
+        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
+        {
+            throw new NotImplementedException();
+        }
+
+        /// <summary>
+        /// Reads the JSON representation of the object.
+        /// </summary>
+        /// <param name="reader">The <see cref="T:Newtonsoft.Json.JsonReader"/> to read from.</param>
+        /// <param name="objectType">Type of the object.</param>
+        /// <param name="existingValue">The existing value of object being read.</param>
+        /// <param name="serializer">The calling serializer.</param>
+        /// <returns>
+        /// The object value.
+        /// </returns>
+        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
+        {
+            if (reader.TokenType == JsonToken.Null || (reader.TokenType == JsonToken.String && (string)reader.Value == "null"))
+            {
+                return new T();
+            }
+            return serializer.Deserialize<T>(reader);
+        }
+
+        /// <summary>
+        /// Determines whether this instance can convert the specified object type.
+        /// </summary>
+        /// <param name="objectType">Type of the object.</param>
+        /// <returns>
+        /// <c>true</c> if this instance can convert the specified object type; otherwise, <c>false</c>.
+        /// </returns>
+        public override bool CanConvert(Type objectType)
+        {
+            throw new NotImplementedException();
+        }
+    }
+}