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 +1,110 @@
+/*
+ * 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.Collections;
+using System.Collections.Generic;
+
+namespace QuantConnect.Util
+{
+    /// <summary>
+    /// Provides an implementation of an add-only fixed length, unique queue system
+    /// </summary>
+    public class FixedSizeHashQueue<T> : IEnumerable<T>
+    {
+        private readonly int _size;
+        private readonly Queue<T> _queue; 
+        private readonly HashSet<T> _hash; 
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="FixedSizeHashQueue{T}"/> class
+        /// </summary>
+        /// <param name="size">The maximum number of items to hold</param>
+        public FixedSizeHashQueue(int size)
+        {
+            _size = size;
+            _queue = new Queue<T>(size);
+            _hash = new HashSet<T>();
+        }
+
+        /// <summary>
+        /// Returns true if the item was added and didn't already exists
+        /// </summary>
+        public bool Add(T item)
+        {
+            if (_hash.Add(item))
+            {
+                _queue.Enqueue(item);
+                if (_queue.Count > _size)
+                {
+                    // remove the item from both
+                    _hash.Remove(_queue.Dequeue());
+                }
+                return true;
+            }
+            return false;
+        }
+
+        /// <summary>
+        /// Tries to inspect the first item in the queue
+        /// </summary>
+        public bool TryPeek(out T item)
+        {
+            return _queue.TryPeek(out item);
+        }
+
+        /// <summary>
+        /// Dequeues and returns the next item in the queue
+        /// </summary>
+        public T Dequeue()
+        {
+            var item = _queue.Dequeue();
+            _hash.Remove(item);
+            return item;
+        }
+
+        /// <summary>
+        /// Returns true if the specified item exists in the collection
+        /// </summary>
+        public bool Contains(T item)
+        {
+            return _hash.Contains(item);
+        }
+
+        /// <summary>
+        /// Returns an enumerator that iterates through the collection.
+        /// </summary>
+        /// <returns>
+        /// A <see cref="T:System.Collections.Generic.IEnumerator`1"/> that can be used to iterate through the collection.
+        /// </returns>
+        /// <filterpriority>1</filterpriority>
+        public IEnumerator<T> GetEnumerator()
+        {
+            return _queue.GetEnumerator();
+        }
+
+        /// <summary>
+        /// Returns an enumerator that iterates through a collection.
+        /// </summary>
+        /// <returns>
+        /// An <see cref="T:System.Collections.IEnumerator"/> object that can be used to iterate through the collection.
+        /// </returns>
+        /// <filterpriority>2</filterpriority>
+        IEnumerator IEnumerable.GetEnumerator()
+        {
+            return GetEnumerator();
+        }
+    }
+}