Refactor

- use null conditional access in case some connections been
  cancelled unexpectedly and may cause null reference exception
- Refine error message
- use conditional operator to simplify some code

Signed-off-by: Syrone Wong <wong.syrone@gmail.com>

shadowsocks-csharp/Controller/FileManager.cs

@@ -24,20 +24,23 @@ namespace Shadowsocks.Controller
 
         public static void UncompressFile(string fileName, byte[] content)
         {
-            // Because the uncompressed size of the file is unknown,
-            // we are using an arbitrary buffer size.
-            byte[] buffer = new byte[4096];
-            int n;
+            try {
+                // Because the uncompressed size of the file is unknown,
+                // we are using an arbitrary buffer size.
+                byte[] buffer = new byte[4096];
+                int n;
 
-            using(var fs = File.Create(fileName))
-            using (var input = new GZipStream(
-                new MemoryStream(content),
-                CompressionMode.Decompress, false))
-            {
-                while ((n = input.Read(buffer, 0, buffer.Length)) > 0)
-                {
-                    fs.Write(buffer, 0, n);
-                }
+                using(var fs = File.Create(fileName))
+                using (var input = new GZipStream(new MemoryStream(content),
+                        CompressionMode.Decompress, false))
+                    {
+                        while ((n = input.Read(buffer, 0, buffer.Length)) > 0)
+                        {
+                            fs.Write(buffer, 0, n);
+                        }
+                    }
+            } catch ( Exception e ) {
+                Logging.LogUsefulException( e );
             }
         }
 

shadowsocks-csharp/Controller/Service/Listener.cs

@@ -63,14 +63,9 @@ namespace Shadowsocks.Controller
                 _tcpSocket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, true);
                 _udpSocket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, true);
                 IPEndPoint localEndPoint = null;
-                if (_shareOverLAN)
-                {
-                    localEndPoint = new IPEndPoint(IPAddress.Any, _config.localPort);
-                }
-                else
-                {
-                    localEndPoint = new IPEndPoint(IPAddress.Loopback, _config.localPort);
-                }
+                localEndPoint = _shareOverLAN
+                    ? new IPEndPoint(IPAddress.Any, _config.localPort)
+                    : new IPEndPoint(IPAddress.Loopback, _config.localPort);
 
                 // Bind the socket to the local endpoint and listen for incoming connections.
                 _tcpSocket.Bind(localEndPoint);

shadowsocks-csharp/Controller/Service/TCPRelay.cs

@@ -207,7 +207,7 @@ namespace Shadowsocks.Controller
                         response = new byte[] { 0, 91 };
                         Logging.Error("socks 5 protocol error");
                     }
-                    connection.BeginSend(response, 0, response.Length, SocketFlags.None, new AsyncCallback(HandshakeSendCallback), null);
+                    connection?.BeginSend(response, 0, response.Length, SocketFlags.None, new AsyncCallback(HandshakeSendCallback), null);
                 }
                 else
                     Close();
@@ -328,7 +328,7 @@ namespace Shadowsocks.Controller
         {
             try
             {
-                connection.EndSend(ar);
+                connection?.EndSend(ar);
                 StartConnect();
             }
             catch (Exception e)
@@ -420,7 +420,7 @@ namespace Shadowsocks.Controller
             var ep = ((ProxyTimer)sender).DestEndPoint;
 
             Logging.Info($"Proxy {ep} timed out");
-            remote.Close();
+            remote?.Close();
             RetryConnect();
         }
 
@@ -485,7 +485,7 @@ namespace Shadowsocks.Controller
             IStrategy strategy = controller.GetCurrentStrategy();
             strategy?.SetFailure(server);
             Logging.Info($"{server.FriendlyName()} timed out");
-            remote.Close();
+            remote?.Close();
             RetryConnect();
         }
 
@@ -513,7 +513,7 @@ namespace Shadowsocks.Controller
                 timer.Dispose();
 
                 // Complete the connection.
-                remote.EndConnectDest(ar);
+                remote?.EndConnectDest(ar);
                 
                 _destConnected = true;
 
@@ -550,8 +550,8 @@ namespace Shadowsocks.Controller
             try
             {
                 _startReceivingTime = DateTime.Now;
-                remote.BeginReceive(_remoteRecvBuffer, 0, RecvSize, SocketFlags.None, new AsyncCallback(PipeRemoteReceiveCallback), null);
-                connection.BeginReceive(_connetionRecvBuffer, 0, RecvSize, SocketFlags.None, new AsyncCallback(PipeConnectionReceiveCallback), null);
+                remote?.BeginReceive(_remoteRecvBuffer, 0, RecvSize, SocketFlags.None, new AsyncCallback(PipeRemoteReceiveCallback), null);
+                connection?.BeginReceive(_connetionRecvBuffer, 0, RecvSize, SocketFlags.None, new AsyncCallback(PipeConnectionReceiveCallback), null);
             }
             catch (Exception e)
             {
@@ -565,6 +565,7 @@ namespace Shadowsocks.Controller
             if (_closed) return;
             try
             {
+                if ( remote == null ) return;
                 int bytesRead = remote.EndReceive(ar);
                 _totalRead += bytesRead;
                 _tcprelay.UpdateInboundCounter(server, bytesRead);
@@ -600,6 +601,7 @@ namespace Shadowsocks.Controller
             if (_closed) return;
             try
             {
+                if(connection == null) return;
                 int bytesRead = connection.EndReceive(ar);
                 _totalWrite += bytesRead;
                 if (bytesRead > 0)
@@ -664,8 +666,8 @@ namespace Shadowsocks.Controller
             if (_closed) return;
             try
             {
-                remote.EndSend(ar);
-                connection.BeginReceive(_connetionRecvBuffer, 0, RecvSize, SocketFlags.None, new AsyncCallback(PipeConnectionReceiveCallback), null);
+                remote?.EndSend(ar);
+                connection?.BeginReceive(_connetionRecvBuffer, 0, RecvSize, SocketFlags.None, new AsyncCallback(PipeConnectionReceiveCallback), null);
             }
             catch (Exception e)
             {
@@ -679,8 +681,8 @@ namespace Shadowsocks.Controller
             if (_closed) return;
             try
             {
-                connection.EndSend(ar);
-                remote.BeginReceive(_remoteRecvBuffer, 0, RecvSize, SocketFlags.None, new AsyncCallback(PipeRemoteReceiveCallback), null);
+                connection?.EndSend(ar);
+                remote?.BeginReceive(_remoteRecvBuffer, 0, RecvSize, SocketFlags.None, new AsyncCallback(PipeRemoteReceiveCallback), null);
             }
             catch (Exception e)
             {

shadowsocks-csharp/Controller/Service/UDPRelay.cs

@@ -85,20 +85,21 @@ namespace Shadowsocks.Controller
                 int outlen;
                 encryptor.Encrypt(dataIn, length - 3, dataOut, out outlen);
                 Logging.Debug(_localEndPoint, _remoteEndPoint, outlen, "UDP Relay");
-                _remote.SendTo(dataOut, outlen, SocketFlags.None, _remoteEndPoint);
+                _remote?.SendTo(dataOut, outlen, SocketFlags.None, _remoteEndPoint);
             }
 
             public void Receive()
             {
                 EndPoint remoteEndPoint = new IPEndPoint(IPAddress.Any, 0);
                 Logging.Debug($"++++++Receive Server Port, size:" + _buffer.Length);
-                _remote.BeginReceiveFrom(_buffer, 0, _buffer.Length, 0, ref remoteEndPoint, new AsyncCallback(RecvFromCallback), null);
+                _remote?.BeginReceiveFrom(_buffer, 0, _buffer.Length, 0, ref remoteEndPoint, new AsyncCallback(RecvFromCallback), null);
             }
 
             public void RecvFromCallback(IAsyncResult ar)
             {
                 try
                 {
+                    if (_remote == null) return;
                     EndPoint remoteEndPoint = new IPEndPoint(IPAddress.Any, 0);
                     int bytesRead = _remote.EndReceiveFrom(ar, ref remoteEndPoint);
 
@@ -112,7 +113,7 @@ namespace Shadowsocks.Controller
                     Array.Copy(dataOut, 0, sendBuf, 3, outlen);
 
                     Logging.Debug(_localEndPoint, _remoteEndPoint, outlen, "UDP Relay");
-                    _local.SendTo(sendBuf, outlen + 3, 0, _localEndPoint);
+                    _local?.SendTo(sendBuf, outlen + 3, 0, _localEndPoint);
                     Receive();
                 }
                 catch (ObjectDisposedException)
@@ -132,7 +133,7 @@ namespace Shadowsocks.Controller
             {
                 try
                 {
-                    _remote.Close();
+                    _remote?.Close();
                 }
                 catch (ObjectDisposedException)
                 {

shadowsocks-csharp/Data/cn.txt

@@ -112,5 +112,5 @@ Failed to decode QRCode=无法解析二维码
 Failed to update registry=无法修改注册表
 System Proxy On: =系统代理已启用：
 Running: Port {0}=正在运行：端口 {0}
-Unexpect error, shadowsocks will be exit. Please report to=非预期错误，Shadowsocks将退出。请提交此错误到
+Unexpected error, shadowsocks will exit. Please report to=非预期错误，Shadowsocks将退出。请提交此错误到
  

shadowsocks-csharp/Program.cs

@@ -61,7 +61,7 @@ namespace Shadowsocks
             if (Interlocked.Increment(ref exited) == 1)
             {
                 Logging.Error(e.ExceptionObject?.ToString());
-                MessageBox.Show(I18N.GetString("Unexpect error, shadowsocks will be exit. Please report to") +
+                MessageBox.Show(I18N.GetString("Unexpected error, shadowsocks will exit. Please report to") +
                     " https://github.com/shadowsocks/shadowsocks-windows/issues " +
                     Environment.NewLine + (e.ExceptionObject?.ToString()),
                     "Shadowsocks Error", MessageBoxButtons.OK, MessageBoxIcon.Error);

shadowsocks-csharp/Proxy/DirectConnect.cs

@@ -58,13 +58,13 @@ namespace Shadowsocks.Proxy
 
         public void EndConnectDest(IAsyncResult asyncResult)
         {
-            _remote.EndConnect(asyncResult);
+            _remote?.EndConnect(asyncResult);
         }
 
         public void BeginSend(byte[] buffer, int offset, int size, SocketFlags socketFlags, AsyncCallback callback,
             object state)
         {
-            _remote.BeginSend(buffer, offset, size, socketFlags, callback, state);
+            _remote?.BeginSend(buffer, offset, size, socketFlags, callback, state);
         }
 
         public int EndSend(IAsyncResult asyncResult)
@@ -75,7 +75,7 @@ namespace Shadowsocks.Proxy
         public void BeginReceive(byte[] buffer, int offset, int size, SocketFlags socketFlags, AsyncCallback callback,
             object state)
         {
-            _remote.BeginReceive(buffer, offset, size, socketFlags, callback, state);
+            _remote?.BeginReceive(buffer, offset, size, socketFlags, callback, state);
         }
 
         public int EndReceive(IAsyncResult asyncResult)

shadowsocks-csharp/Proxy/Socks5Proxy.cs

@@ -115,7 +115,7 @@ namespace Shadowsocks.Proxy
 
             DestEndPoint = remoteEP;
 
-            _remote.BeginSend(request, 0, request.Length, 0, Socks5RequestSendCallback, st);
+            _remote?.BeginSend(request, 0, request.Length, 0, Socks5RequestSendCallback, st);
 
         }
 
@@ -132,7 +132,7 @@ namespace Shadowsocks.Proxy
         public void BeginSend(byte[] buffer, int offset, int size, SocketFlags socketFlags, AsyncCallback callback,
             object state)
         {
-            _remote.BeginSend(buffer, offset, size, socketFlags, callback, state);
+            _remote?.BeginSend(buffer, offset, size, socketFlags, callback, state);
         }
 
         public int EndSend(IAsyncResult asyncResult)
@@ -143,7 +143,7 @@ namespace Shadowsocks.Proxy
         public void BeginReceive(byte[] buffer, int offset, int size, SocketFlags socketFlags, AsyncCallback callback,
             object state)
         {
-            _remote.BeginReceive(buffer, offset, size, socketFlags, callback, state);
+            _remote?.BeginReceive(buffer, offset, size, socketFlags, callback, state);
         }
 
         public int EndReceive(IAsyncResult asyncResult)

shadowsocks-csharp/View/MenuViewController.cs

@@ -332,7 +332,9 @@ namespace Shadowsocks.View
 
         void controller_UpdatePACFromGFWListCompleted(object sender, GFWListUpdater.ResultEventArgs e)
         {
-            string result = e.Success ? I18N.GetString("PAC updated") : I18N.GetString("No updates found. Please report to GFWList if you have problems with it.");
+            string result = e.Success
+                ? I18N.GetString("PAC updated")
+                : I18N.GetString("No updates found. Please report to GFWList if you have problems with it.");
             ShowBalloonTip(I18N.GetString("Shadowsocks"), result, ToolTipIcon.Info, 1000);
         }