Sliding Max and Min Aggregate optimization by not storing covered values

Sources/Core/Microsoft.StreamProcessing/Aggregates/MinMaxState.cs

@@ -2,11 +2,35 @@
 // Copyright (c) Microsoft Corporation.  All rights reserved.
 // Licensed under the MIT License
 // *********************************************************************
+using System.Collections.Generic;
 using System.ComponentModel;
 using System.Runtime.Serialization;
 
 namespace Microsoft.StreamProcessing.Internal
 {
+    /// <summary>
+    /// The value representation with its timestamp.
+    /// </summary>
+    /// <typeparam name="T">The type of the underlying elements being aggregated.</typeparam>
+    [DataContract]
+    [EditorBrowsable(EditorBrowsableState.Never)]
+    public struct ValueAndTimestamp<T>
+    {
+        /// <summary>
+        /// The timestamp of the payload.
+        /// </summary>
+        [DataMember]
+        [EditorBrowsable(EditorBrowsableState.Never)]
+        public long timestamp;
+
+        /// <summary>
+        /// Payload of the event
+        /// </summary>
+        [DataMember]
+        [EditorBrowsable(EditorBrowsableState.Never)]
+        public T value;
+    }
+
     /// <summary>
     /// The state object used in minimum and maximum aggregates.
     /// </summary>
@@ -22,6 +46,13 @@ public struct MinMaxState<T>
         [EditorBrowsable(EditorBrowsableState.Never)]
         public SortedMultiSet<T> savedValues;
 
+        /// <summary>
+        /// List of values and its timestamp
+        /// </summary>
+        [DataMember]
+        [EditorBrowsable(EditorBrowsableState.Never)]
+        public ElasticCircularBuffer<ValueAndTimestamp<T>> values;
+
         /// <summary>
         /// The current value if the aggregate were to be computed immediately.
         /// </summary>