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 +1,87 @@
+/*
+ * 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;
+
+namespace QuantConnect.Util
+{
+    /// <summary>
+    /// A never ending queue that will dequeue and reenqueue the same item
+    /// </summary>
+    public class CircularQueue<T>
+    {
+        private readonly T _head;
+        private readonly Queue<T> _queue;
+
+        /// <summary>
+        /// Fired when we do a full circle
+        /// </summary>
+        public event EventHandler CircleCompleted;
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="CircularQueue{T}"/> class
+        /// </summary>
+        /// <param name="items">The items in the queue</param>
+        public CircularQueue(params T[] items)
+            : this((IEnumerable<T>)items)
+        {
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="CircularQueue{T}"/> class
+        /// </summary>
+        /// <param name="items">The items in the queue</param>
+        public CircularQueue(IEnumerable<T> items)
+        {
+            _queue = new Queue<T>();
+
+            var first = true;
+            foreach (var item in items)
+            {
+                if (first)
+                {
+                    first = false;
+                    _head = item;
+                }
+                _queue.Enqueue(item);
+            }
+        }
+
+        /// <summary>
+        /// Dequeues the next item
+        /// </summary>
+        /// <returns>The next item</returns>
+        public T Dequeue()
+        {
+            var item = _queue.Dequeue();
+            if (item.Equals(_head))
+            {
+                OnCircleCompleted();
+            }
+            _queue.Enqueue(item);
+            return item;
+        }
+
+        /// <summary>
+        /// Event invocator for the <see cref="CircleCompleted"/> evet
+        /// </summary>
+        protected virtual void OnCircleCompleted()
+        {
+            var handler = CircleCompleted;
+            if (handler != null) handler(this, EventArgs.Empty);
+        }
+    }
+}