Imported Upstream version 5.0.0.42

Former-commit-id: fd56571888259555122d8a0f58c68838229cea2b

external/linker/cecil/Mono.Cecil.Metadata/BlobHeap.cs

@@ -0,0 +1,54 @@
+//
+// Author:
+//   Jb Evain (jbevain@gmail.com)
+//
+// Copyright (c) 2008 - 2015 Jb Evain
+// Copyright (c) 2008 - 2011 Novell, Inc.
+//
+// Licensed under the MIT/X11 license.
+//
+
+using System;
+
+namespace Mono.Cecil.Metadata {
+
+	sealed class BlobHeap : Heap {
+
+		public BlobHeap (byte [] data)
+			: base (data)
+		{
+		}
+
+		public byte [] Read (uint index)
+		{
+			if (index == 0 || index > this.data.Length - 1)
+				return Empty<byte>.Array;
+
+			int position = (int) index;
+			int length = (int) data.ReadCompressedUInt32 (ref position);
+
+			if (length > data.Length - position)
+				return Empty<byte>.Array;
+
+			var buffer = new byte [length];
+
+			Buffer.BlockCopy (data, position, buffer, 0, length);
+
+			return buffer;
+		}
+
+		public void GetView (uint signature, out byte [] buffer, out int index, out int length)
+		{
+			if (signature == 0 || signature > data.Length - 1) {
+				buffer = null;
+				index = length = 0;
+				return;
+			}
+
+			buffer = data;
+
+			index = (int) signature;
+			length = (int) buffer.ReadCompressedUInt32 (ref index);
+		}
+	}
+}