rework refresh queue

MediaBrowser.Providers/Manager/IFixedSizePriorityQueue.cs

@@ -0,0 +1,28 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Priority_Queue
+{
+    /// <summary>
+    /// Credit: https://github.com/BlueRaja/High-Speed-Priority-Queue-for-C-Sharp
+    /// A helper-interface only needed to make writing unit tests a bit easier (hence the 'internal' access modifier)
+    /// </summary>
+    internal interface IFixedSizePriorityQueue<TItem, in TPriority> : IPriorityQueue<TItem, TPriority>
+        where TPriority : IComparable<TPriority>
+    {
+        /// <summary>
+        /// Resize the queue so it can accept more nodes.  All currently enqueued nodes are remain.
+        /// Attempting to decrease the queue size to a size too small to hold the existing nodes results in undefined behavior
+        /// </summary>
+        void Resize(int maxNodes);
+
+        /// <summary>
+        /// Returns the maximum number of items that can be enqueued at once in this queue.  Once you hit this number (ie. once Count == MaxSize),
+        /// attempting to enqueue another item will cause undefined behavior.
+        /// </summary>
+        int MaxSize { get; }
+    }
+}