ADD: added new version of protobuf

libs/protobuf/csharp/src/Google.Protobuf/CodedInputStream.cs

@@ -32,7 +32,10 @@
 
 using Google.Protobuf.Collections;
 using System;
+using System.Collections.Generic;
 using System.IO;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
 using System.Security;
 
 namespace Google.Protobuf
@@ -646,6 +649,21 @@ namespace Google.Protobuf
             }
         }
 
+        /// <summary>
+        /// Called when buffer is empty to read more bytes from the
+        /// input.  If <paramref name="mustSucceed"/> is true, RefillBuffer() guarantees that
+        /// either there will be at least one byte in the buffer when it returns
+        /// or it will throw an exception.  If <paramref name="mustSucceed"/> is false,
+        /// RefillBuffer() returns false if no more bytes were available.
+        /// </summary>
+        /// <param name="mustSucceed"></param>
+        /// <returns></returns>
+        private bool RefillBuffer(bool mustSucceed)
+        {
+            var span = new ReadOnlySpan<byte>(buffer);
+            return state.segmentedBufferHelper.RefillBuffer(ref span, ref state, mustSucceed);
+        }
+
         /// <summary>
         /// Reads a fixed size of bytes from the input.
         /// </summary>