move files around

src/SharpCompress/IO/ReadOnlySubStream.cs

@@ -0,0 +1,94 @@
+using System.IO;
+
+namespace SharpCompress.IO
+{
+    internal class ReadOnlySubStream : Stream
+    {
+        public ReadOnlySubStream(Stream stream, long bytesToRead)
+            : this(stream, null, bytesToRead)
+        {
+        }
+
+        public ReadOnlySubStream(Stream stream, long? origin, long bytesToRead)
+        {
+            Stream = stream;
+            if (origin != null)
+            {
+                stream.Position = origin.Value;
+            }
+            BytesLeftToRead = bytesToRead;
+        }
+
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing)
+            {
+                //Stream.Dispose();
+            }
+        }
+
+        private long BytesLeftToRead { get; set; }
+
+        public Stream Stream { get; private set; }
+
+        public override bool CanRead
+        {
+            get { return true; }
+        }
+
+        public override bool CanSeek
+        {
+            get { return false; }
+        }
+
+        public override bool CanWrite
+        {
+            get { return false; }
+        }
+
+        public override void Flush()
+        {
+            throw new System.NotSupportedException();
+        }
+
+        public override long Length
+        {
+            get { throw new System.NotSupportedException(); }
+        }
+
+        public override long Position
+        {
+            get { throw new System.NotSupportedException(); }
+            set { throw new System.NotSupportedException(); }
+        }
+
+        public override int Read(byte[] buffer, int offset, int count)
+        {
+            if (BytesLeftToRead < count)
+            {
+                count = (int)BytesLeftToRead;
+            }
+            int read = Stream.Read(buffer, offset, count);
+            if (read > 0)
+            {
+                BytesLeftToRead -= read;
+            }
+            return read;
+        }
+
+        public override long Seek(long offset, SeekOrigin origin)
+        {
+            throw new System.NotSupportedException();
+        }
+
+        public override void SetLength(long value)
+        {
+            throw new System.NotSupportedException();
+        }
+
+        public override void Write(byte[] buffer, int offset, int count)
+        {
+            throw new System.NotSupportedException();
+        }
+    }
+}