Imported Upstream version 3.6.0

Former-commit-id: da6be194a6b1221998fc28233f2503bd61dd9d14

mcs/class/System.IO.Compression/SharpCompress/Common/Volume.cs

@@ -0,0 +1,51 @@
+using System.IO;
+using SharpCompress.IO;
+
+namespace SharpCompress.Common
+{
+    internal abstract class Volume : IVolume
+    {
+        private readonly Stream actualStream;
+
+        internal Volume(Stream stream, Options options)
+        {
+            actualStream = stream;
+            Options = options;
+        }
+
+        internal Stream Stream
+        {
+            get { return new NonDisposingStream(actualStream); }
+        }
+
+        internal Options Options { get; private set; }
+
+        /// <summary>
+        /// RarArchive is the first volume of a multi-part archive.
+        /// Only Rar 3.0 format and higher
+        /// </summary>
+        public virtual bool IsFirstVolume
+        {
+            get { return true; }
+        }
+
+        /// <summary>
+        /// RarArchive is part of a multi-part archive.
+        /// </summary>
+        public virtual bool IsMultiVolume
+        {
+            get { return true; }
+        }
+
+        private bool disposed;
+
+        public void Dispose()
+        {
+            if (!Options.HasFlag(Options.KeepStreamsOpen) && !disposed)
+            {
+                actualStream.Dispose();
+                disposed = true;
+            }
+        }
+    }
+}