完善NetDatabase

LocalPackages/com.nimin.lowlevel/Runtime/NativeDataContainer.cs

@@ -32,6 +32,11 @@ namespace GameCore.LowLevel
             m_UnsafeDataPtr = null;
         }
 
+        public bool HasValue(int index)
+        {
+            return m_UnsafeDataPtr->HasValue(index);
+        }
+
         public bool Free(int index)
         {
             return m_UnsafeDataPtr->Free(index);

LocalPackages/com.nimin.lowlevel/Runtime/UnsafeDataContainer.cs

@@ -43,6 +43,12 @@ namespace GameCore.LowLevel
             m_Buffer.Dispose();
         }
 
+        public bool HasValue(int index)
+        {
+            var node = m_Buffer[index * m_NodeNumPerElement];
+            return node.next < 0;
+        }
+
         public bool Free(int index)
         {
             ref var node = ref m_Buffer.ElementAt(index * m_NodeNumPerElement);
@@ -83,7 +89,7 @@ namespace GameCore.LowLevel
         {
             ref var node = ref m_Buffer.ElementAt(index * m_NodeNumPerElement);
             if (node.next >= 0)
-                throw new IndexOutOfRangeException();
+                throw new Exception("Index out of range");
             
             return ref UnsafeUtility.As<FreeNode, T>(ref m_Buffer.ElementAt(index * m_NodeNumPerElement + 1));
         }