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 +1,135 @@
+/*
+ * 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.IO;
+using QuantConnect.Util;
+using System.Collections;
+using System.Collections.Generic;
+
+namespace QuantConnect.Lean.Engine.DataFeeds.Enumerators
+{
+    /// <summary>
+    /// Provides an implementation of <see cref="IEnumerator{T}"/> that will
+    /// always return true via MoveNext.
+    /// </summary>
+    /// <typeparam name="T"></typeparam>
+    public class RefreshEnumerator<T> : IEnumerator<T>
+    {
+        private T _current;
+        private IEnumerator<T> _enumerator;
+        private readonly Func<IEnumerator<T>> _enumeratorFactory;
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="RefreshEnumerator{T}"/> class
+        /// </summary>
+        /// <param name="enumeratorFactory">Enumerator factory used to regenerate the underlying
+        /// enumerator when it ends</param>
+        public RefreshEnumerator(Func<IEnumerator<T>> enumeratorFactory)
+        {
+            _enumeratorFactory = enumeratorFactory;
+        }
+
+        /// <summary>
+        /// Advances the enumerator to the next element of the collection.
+        /// </summary>
+        /// <returns>
+        /// true if the enumerator was successfully advanced to the next element; false if the enumerator has passed the end of the collection.
+        /// </returns>
+        /// <exception cref="T:System.InvalidOperationException">The collection was modified after the enumerator was created. </exception><filterpriority>2</filterpriority>
+        public bool MoveNext()
+        {
+            if (_enumerator == null)
+            {
+                _enumerator = _enumeratorFactory.Invoke();
+            }
+
+            var moveNext = false;
+            try
+            {
+                moveNext = _enumerator.MoveNext();
+                if (moveNext)
+                {
+                    _current = _enumerator.Current;
+                }
+            }
+            catch (IOException exception)
+            {
+                // we will ignore stale file handle exceptions and retry instead, enumerator will be refreshed
+                if (exception.Message == null || !exception.Message.Contains("Stale file handle", StringComparison.InvariantCultureIgnoreCase))
+                {
+                    throw;
+                }
+            }
+
+            if (!moveNext)
+            {
+                _enumerator.DisposeSafely();
+
+                _enumerator = null;
+                _current = default(T);
+            }
+
+            return true;
+        }
+
+        /// <summary>
+        /// Sets the enumerator to its initial position, which is before the first element in the collection.
+        /// </summary>
+        /// <exception cref="T:System.InvalidOperationException">The collection was modified after the enumerator was created. </exception><filterpriority>2</filterpriority>
+        public void Reset()
+        {
+            if (_enumerator != null)
+            {
+                _enumerator.Reset();
+            }
+        }
+
+        /// <summary>
+        /// Gets the element in the collection at the current position of the enumerator.
+        /// </summary>
+        /// <returns>
+        /// The element in the collection at the current position of the enumerator.
+        /// </returns>
+        public T Current
+        {
+            get { return _current; }
+        }
+
+        /// <summary>
+        /// Gets the current element in the collection.
+        /// </summary>
+        /// <returns>
+        /// The current element in the collection.
+        /// </returns>
+        /// <filterpriority>2</filterpriority>
+        object IEnumerator.Current
+        {
+            get { return Current; }
+        }
+
+        /// <summary>
+        /// Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.
+        /// </summary>
+        /// <filterpriority>2</filterpriority>
+        public void Dispose()
+        {
+            if (_enumerator != null)
+            {
+                _enumerator.Dispose();
+            }
+        }
+    }
+}