From bb655a06ac20751f170bb64324123ea1ed945f8b Mon Sep 17 00:00:00 2001
From: morkt <morkt@users.noreply.github.com>
Date: Sat, 23 Mar 2019 19:50:27 +0400
Subject: [PATCH] (BinaryStreamExtension): serialization extension for
 IBinaryStream.

---
 GameRes/GameRes.csproj         |   1 +
 GameRes/StructSerialization.cs | 108 +++++++++++++++++++++++++++++++++
 2 files changed, 109 insertions(+)
 create mode 100644 GameRes/StructSerialization.cs

diff --git a/GameRes/GameRes.csproj b/GameRes/GameRes.csproj
index 9da79f84..66ded7b1 100644
--- a/GameRes/GameRes.csproj
+++ b/GameRes/GameRes.csproj
@@ -98,6 +98,7 @@
       <DesignTime>True</DesignTime>
       <DependentUpon>garStrings.resx</DependentUpon>
     </Compile>
+    <Compile Include="StructSerialization.cs" />
     <Compile Include="Utility.cs" />
     <Compile Include="ZLibStream.cs" />
   </ItemGroup>
diff --git a/GameRes/StructSerialization.cs b/GameRes/StructSerialization.cs
new file mode 100644
index 00000000..8b292318
--- /dev/null
+++ b/GameRes/StructSerialization.cs
@@ -0,0 +1,108 @@
+//! \file       ReadStruct.cs
+//! \date       2019 Mar 22
+//! \brief      Struct deserialization from a binary stream.
+//
+// Copyright (C) 2019 by morkt
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to
+// deal in the Software without restriction, including without limitation the
+// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+// sell copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+// IN THE SOFTWARE.
+//
+
+using System;
+using System.Reflection;
+using System.Text;
+
+namespace GameRes.Utility.Serialization
+{
+    public static class BinaryStreamExtension
+    {
+        public static void ReadStruct<Type> (this IBinaryStream input, out Type data) where Type : new()
+        {
+            object tmp = new Type();
+            ReadStruct (input, typeof(Type), ref tmp);
+            data = (Type)tmp;
+        }
+
+        internal static void ReadStruct (this IBinaryStream input, Type type, ref object instance)
+        {
+            if (type.IsPrimitive || type.IsArray)
+                throw new ArgumentException ("Invalid deserialization type.");
+
+            var fields = type.GetFields (BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance);
+            foreach (var field in fields)
+            {
+                if (field.IsDefined (typeof(IgnoreAttribute)))
+                    continue;
+
+                if (field.FieldType.IsArray)
+                    throw new NotSupportedException ("Array serialization is not supported.");
+
+                var field_value = ReadField (input, field);
+                field.SetValue (instance, field_value);
+            }
+        }
+
+        internal static object ReadField (this IBinaryStream input, FieldInfo field)
+        {
+            var field_type = field.FieldType;
+            var type_code = Type.GetTypeCode (field_type);
+            switch (type_code)
+            {
+            case TypeCode.SByte:    return input.ReadInt8();
+            case TypeCode.Byte:     return input.ReadUInt8();
+            case TypeCode.Int16:    return input.ReadInt16();
+            case TypeCode.UInt16:   return input.ReadUInt16();
+            case TypeCode.Int32:    return input.ReadInt32();
+            case TypeCode.UInt32:   return input.ReadUInt32();
+            case TypeCode.Int64:    return input.ReadInt64();
+            case TypeCode.UInt64:   return input.ReadUInt64();
+            case TypeCode.Char:     return (char)input.ReadInt16();
+
+            case TypeCode.String:
+                var cstring_attr = field.GetCustomAttribute<CStringAttribute>();
+                if (cstring_attr != null)
+                {
+                    var encoding = cstring_attr.Encoding ?? Encodings.cp932;
+                    if (cstring_attr.IsLengthDefined)
+                        return input.ReadCString (cstring_attr.Length, encoding);
+                    else
+                        return input.ReadCString (encoding);
+                }
+                throw new FormatException ("Serialization method for string field is not defined.");
+
+            case TypeCode.Object:
+                object val = Activator.CreateInstance (field_type);
+                ReadStruct (input, field_type, ref val); // FIXME check object graph for cycles
+                return val;
+
+            default:
+                throw new NotSupportedException ("Not supported serialization type.");
+            }
+        }
+    }
+
+    public class IgnoreAttribute : Attribute { }
+
+    public class CStringAttribute : Attribute
+    {
+        public int      Length = -1; // by default string is limited by null byte
+        public Encoding Encoding;
+
+        public bool IsLengthDefined { get { return Length >= 0; } }
+    }
+}