Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Web/Hosting/ReadAsyncResult.cs

@@ -0,0 +1,54 @@
+//------------------------------------------------------------------------------
+// <copyright file="ReadAsyncResult.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>                                                                
+//------------------------------------------------------------------------------
+
+/*
+ * IAsyncResult for asynchronous read.
+ *
+ * Copyright (c) 2010 Microsoft Corporation
+ */
+
+namespace System.Web.Hosting {
+    using System;
+    using System.Threading;
+    using System.Web.Util;
+
+    internal class ReadAsyncResult : AsyncResultBase {
+        private int              _bytesRead;
+        private byte[]           _buffer;
+        private int              _offset;
+        private int              _count;
+        private bool             _updatePerfCounter;
+
+        internal ReadAsyncResult(AsyncCallback cb, Object state, byte[] buffer, int offset, int count, bool updatePerfCounter): base(cb, state) {
+            _buffer = buffer;
+            _offset = offset;
+            _count = count;
+            _updatePerfCounter = updatePerfCounter;
+        }
+
+        internal override void Complete(int bytesRead, int hresult, IntPtr pbAsyncReceiveBuffer, bool synchronous) {
+            if (_updatePerfCounter && bytesRead > 0) {
+                PerfCounters.IncrementCounterEx(AppPerfCounter.REQUEST_BYTES_IN, bytesRead);
+            }
+
+            if (bytesRead != 0) {
+                CopyBytes(pbAsyncReceiveBuffer, bytesRead);
+            }
+            _bytesRead = bytesRead;
+
+            Complete(hresult, synchronous);
+        }
+
+        private unsafe void CopyBytes(IntPtr pbAsyncReceiveBuffer, int bytesRead) {
+            byte * src = ((byte *)pbAsyncReceiveBuffer);
+            fixed (byte * dst = _buffer) {
+                StringUtil.memcpyimpl(src, dst + _offset, bytesRead);
+            }
+        }
+
+        internal int BytesRead { get { return _bytesRead; } set { _bytesRead = value; } }
+    }
+}