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 +1,76 @@
+/*
+ * 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 System.Collections.Generic;
+using Newtonsoft.Json;
+
+namespace QuantConnect.Util
+{
+    /// <summary>
+    /// Reads json and always produces a List, even if the input has just an object
+    /// </summary>
+    public class SingleValueListConverter<T> : JsonConverter
+    {
+        /// <summary>
+        /// Writes the JSON representation of the object. If the instance is not a list then it will
+        /// be wrapped in a list
+        /// </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)
+        {
+            if (value is T)
+            {
+                value = new List<T> {(T)value};
+            }
+            serializer.Serialize(writer, value);
+        }
+
+        /// <summary>
+        /// Reads the JSON representation of the object. If the JSON represents a singular instance, it will be returned
+        /// in a list.
+        /// </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)
+        {
+            switch (reader.TokenType)
+            {
+                case JsonToken.String:
+                case JsonToken.StartObject:
+                    return new List<T> {serializer.Deserialize<T>(reader)};
+                case JsonToken.StartArray:
+                    return serializer.Deserialize<List<T>>(reader);
+                default:
+                    throw new ArgumentException("The JsonReader is expected to point at a JsonToken.StartObject or JsonToken.StartArray.");
+            }
+        }
+
+        /// <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)
+        {
+            return objectType == typeof(T) || objectType == typeof(List<T>);
+        }
+    }
+}