change throw to return and fix bug: when error always throw

server/src/UdpServer.cs

@@ -5,6 +5,7 @@ using System.Text;
 using DotNext;
 using DotNext.Threading;
 using Newtonsoft.Json;
+using WebProtocol;
 
 /// <summary> UDP接受数据包格式 </summary>
 public class UDPData
@@ -58,9 +59,6 @@ public class UDPData
     }
 }
 
-/// <summary>
-/// UDP Server
-/// </summary>
 /// <summary>
 /// UDP 服务器
 /// </summary>
@@ -80,6 +78,15 @@ public class UDPServer
     /// </summary>
     public bool IsRunning { get { return isRunning; } }
 
+    /// <summary> UDP 服务器的错误代码 </summary>
+    public enum ErrorCode
+    {
+        Success = 0,
+        GetNoneAfterTimeout,
+        ResponseWrong,
+        NotRecvDataPackage,
+    }
+
     /// <summary>
     /// Construct a udp server with fixed port
     /// </summary>
@@ -132,8 +139,9 @@ public class UDPServer
         {
             var elapsed = DateTime.Now - startTime;
             isTimeout = elapsed >= TimeSpan.FromMilliseconds(timeout);
-            timeleft = TimeSpan.FromMilliseconds(timeout) - elapsed;
+            if (isTimeout) break;
 
+            timeleft = TimeSpan.FromMilliseconds(timeout) - elapsed;
             using (await udpData.AcquireWriteLockAsync(timeleft))
             {
                 if (udpData.ContainsKey(ipAddr) &&
@@ -150,11 +158,11 @@ public class UDPServer
         if (data is null)
         {
             logger.Trace("Get nothing even after time out");
-            return Optional<UDPData>.None;
+            return new(null);
         }
         else
         {
-            return Optional.Some((UDPData)data.DeepClone());
+            return new(data.DeepClone());
         }
     }
 
@@ -175,8 +183,9 @@ public class UDPServer
         {
             var elapsed = DateTime.Now - startTime;
             isTimeout = elapsed >= TimeSpan.FromMilliseconds(timeout);
-            timeleft = TimeSpan.FromMilliseconds(timeout) - elapsed;
+            if (isTimeout) break;
 
+            timeleft = TimeSpan.FromMilliseconds(timeout) - elapsed;
             using (await udpData.AcquireReadLockAsync(timeleft))
             {
                 if (udpData.ContainsKey(ipAddr) &&
@@ -193,11 +202,11 @@ public class UDPServer
         if (data is null)
         {
             logger.Trace("Get nothing even after time out");
-            return Optional<List<UDPData>>.None;
+            return new(null);
         }
         else
         {
-            return Optional.Some((List<UDPData>)data);
+            return new(data);
         }
     }
 
@@ -213,15 +222,15 @@ public class UDPServer
     {
         var data = await FindDataAsync(address, timeout);
         if (!data.HasValue)
-            throw new Exception("Get None even after time out!");
+            return new(new Exception("Get None even after time out!"));
 
         var recvData = data.Value;
         if (recvData.Address != address || (port > 0 && recvData.Port != port))
-            throw new Exception("Receive Data From Wrong Board!");
+            return new(new Exception("Receive Data From Wrong Board!"));
 
         var retPack = WebProtocol.RecvRespPackage.FromBytes(recvData.Data);
         if (!retPack.IsSuccessful)
-            throw new Exception("Not RecvDataPackage!", retPack.Error);
+            return new(new Exception("Not RecvDataPackage!", retPack.Error));
 
         return retPack.Value;
     }
@@ -233,20 +242,20 @@ public class UDPServer
     /// <param name="port">UDP 端口</param>
     /// <param name="timeout">超时时间范围</param>
     /// <returns>接收数据包</returns>
-    public async ValueTask<Result<WebProtocol.RecvDataPackage>> WaitForDataAsync
+    public async ValueTask<Result<RecvDataPackage>> WaitForDataAsync
         (string address, int port = -1, int timeout = 1000)
     {
         var data = await FindDataAsync(address, timeout);
         if (!data.HasValue)
-            throw new Exception("Get None even after time out!");
+            return new(new Exception("Get None even after time out!"));
 
         var recvData = data.Value;
         if (recvData.Address != address || (port >= 0 && recvData.Port != port))
-            throw new Exception("Receive Data From Wrong Board!");
+            return new(new Exception("Receive Data From Wrong Board!"));
 
         var retPack = WebProtocol.RecvDataPackage.FromBytes(recvData.Data);
         if (!retPack.IsSuccessful)
-            throw new Exception("Not RecvDataPackage!", retPack.Error);
+            return new(new Exception("Not RecvDataPackage!", retPack.Error));
 
         return retPack.Value;
     }