fix(core): Adds back persistence. (#419)

- [X] Adds persistence back

Notes:
- Optimizations and parallel writing will not be supported in this PR.

Projects/Server/Serialization/Persistence.cs

@@ -0,0 +1,70 @@
+/*************************************************************************
+ * ModernUO                                                              *
+ * Copyright (C) 2019-2021 - ModernUO Development Team                   *
+ * Email: hi@modernuo.com                                                *
+ * File: Persistence.cs                                                  *
+ *                                                                       *
+ * This program is free software: you can redistribute it and/or modify  *
+ * it under the terms of the GNU General Public License as published by  *
+ * the Free Software Foundation, either version 3 of the License, or     *
+ * (at your option) any later version.                                   *
+ *                                                                       *
+ * You should have received a copy of the GNU General Public License     *
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>. *
+ *************************************************************************/
+
+using System;
+using System.IO;
+
+namespace Server
+{
+    public static class Persistence
+    {
+        public static void Serialize(string path, Action<IGenericWriter> serializer)
+        {
+            AssemblyHandler.EnsureDirectory(Path.GetDirectoryName(path));
+
+            using var fs = new FileStream(path, FileMode.Open, FileAccess.Write, FileShare.None);
+            var writer = new BinaryFileWriter(fs, true);
+
+            try
+            {
+                serializer(writer);
+            }
+            catch (Exception e)
+            {
+                Console.WriteLine("[Persistence]: Failed to serialize");
+                Console.WriteLine(e);
+            }
+        }
+
+        public static void Deserialize(string path, Action<IGenericReader> deserializer, bool ensure = true)
+        {
+            AssemblyHandler.EnsureDirectory(Path.GetDirectoryName(path));
+
+            if (!File.Exists(path))
+            {
+                if (ensure)
+                {
+                    new FileInfo(path).Create().Close();
+                }
+
+                return;
+            }
+
+            using FileStream fs = new FileStream(path, FileMode.Open, FileAccess.Read, FileShare.Read);
+            // TODO: Support files larger than 2GB
+            var buffer = GC.AllocateUninitializedArray<byte>((int)fs.Length);
+
+            try
+            {
+                deserializer(new BufferReader(buffer));
+            }
+            catch (Exception e)
+            {
+                Console.WriteLine("[Persistence]: Failed to deserialize");
+                Console.WriteLine(e);
+            }
+        }
+    }
+}