Add Counter

ARMeilleure/Common/Counter.cs

@@ -0,0 +1,48 @@
+namespace ARMeilleure.Common
+{
+    /// <summary>
+    /// Represents an 8-bit counter.
+    /// </summary>
+    class Counter
+    {
+        private readonly int _index;
+        private readonly EntryTable<byte> _countTable;
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="Counter"/> class from the specified
+        /// <see cref="EntryTable{byte}"/> instance and index.
+        /// </summary>
+        /// <param name="countTable"><see cref="EntryTable{byte}"/> instance</param>
+        /// <param name="index">Index in the <see cref="EntryTable{TEntry}"/></param>
+        private Counter(EntryTable<byte> countTable, int index)
+        {
+            _countTable = countTable;
+            _index = index;
+        }
+
+        /// <summary>
+        /// Gets a reference to the value of the counter.
+        /// </summary>
+        public ref byte Value => ref _countTable.GetValue(_index);
+
+        /// <summary>
+        /// Tries to create a <see cref="Counter"/> instance from the specified <see cref="EntryTable{byte}"/> instance.
+        /// </summary>
+        /// <param name="countTable"><see cref="EntryTable{TEntry}"/> from which to create the <see cref="Counter"/></param>
+        /// <param name="counter"><see cref="Counter"/> instance if success; otherwise <see langword="null"/></param>
+        /// <returns><see langword="true"/> if success; otherwise <see langword="false"/></returns>
+        public static bool TryCreate(EntryTable<byte> countTable, out Counter counter)
+        {
+            if (countTable.TryAllocate(out int index))
+            {
+                counter = new Counter(countTable, index);
+
+                return true;
+            }
+
+            counter = null;
+
+            return false;
+        }
+    }
+}