코드

PacketFormat.cs

   class PacketFormat
    {
		// {0} 패킷 이름/번호 목록
		// {1} 패킷 목록
		public static string fileFormat =
@"using System;
using System.Collections.Generic;
using System.Text;
using System.Net;
using ServerCore;

public enum PacketID
{{
	{0}
}}

interface IPacket
{{
	ushort Protocol {{ get; }}
	void Read(ArraySegment<byte> segment);
	ArraySegment<byte> Write();
}}

{1}
";

		// {0} 패킷 이름
		// {1} 패킷 번호
		public static string packetEnumFormat =
@"{0} = {1},";

		// {0} : 패킷이름
		// {1} : 멤버 변수들
		// {2} : 멤버 변수 Read
		// {3} : 멤버변수 Write
		public static string packetFormat =
@"
class {0}
{{
	{1}	

    public void Read(ArraySegment<byte> segment)
    {{
		ushort pos = 0;

		ReadOnlySpan<byte> s = new ReadOnlySpan<byte>(segment.Array, segment.Offset, segment.Count);

		pos += sizeof(ushort);
		pos += sizeof(ushort);

		{2}
	}}

    public ArraySegment<byte> Write()
    {{
		ArraySegment<byte> segment = SendBufferHelper.Open(4096); // SendBuffer의 _buffer

		ushort size = 0;
		bool success = true;

		Span<byte> s = new Span<byte>(segment.Array, segment.Offset, segment.Count);

		size += sizeof(ushort); // 2 : 패킷 size 사이즈
		success &= BitConverter.TryWriteBytes(s.Slice(size, s.Length - size), (ushort)PacketID.{0}); // Slice가 Span<byte> 만들어서 반환하면 packetId를 그 범위에 바이트로 변환해서 씀
		size += sizeof(ushort); // packetId 사이즈

		{3}
		
		success &= BitConverter.TryWriteBytes(s, size);

		if (success == false)
			return null; // 반환해서 밖에서 null체크

		return SendBufferHelper.Close(size); // 최종 패킷 크기
	}}
}}
";

		// {0} 변수 형식
		// {1} 변수 이름
		public static string memberFormat =
@"public {0} {1};";

		// {0} 리스트 이름 [대문자]
		// {1} 리스트 이름 [소문자]
		// {2} 멤버 변수들
		// {3} 멤버 변수 Read
		// {4} 멤버 변수 Write
		public static string memberListFormat =
@"public class {0}
{{
	{2}

	public void Read(ReadOnlySpan<byte> s, ref ushort count)
	{{
		{3}
	}}

	public bool Write(Span<byte> s, ref ushort count)
	{{
		bool success = true;
		{4}
		return success;
	}}	
}}
public List<{0}> {1}s = new List<{0}>();";

		// {0} : 변수 이름
		// {1} : To~ 변수 형식
		// {2} : 변수 형식
		public static string readFormat =
@"this.{0} = BitConverter.{1}(s.Slice(pos, s.Length - pos));
pos += sizeof({2});";

		// {0} 변수 이름
		// {1} 변수 형식
		public static string readByteFormat =
@"this.{0} = ({1})segment.Array[segment.Offset + count];
count += sizeof({1});";

		// {0} 변수 이름
		public static string readStringFormat =
@"ushort {0}Len = BitConverter.ToUInt16(s.Slice(count, s.Length - count));
count += sizeof(ushort);
this.{0} = Encoding.Unicode.GetString(s.Slice(count, {0}Len));
count += {0}Len;";

		// {0} 리스트 이름 [대문자]
		// {1} 리스트 이름 [소문자]
		public static string readListFormat =
@"this.{1}s.Clear();
ushort {1}Len = BitConverter.ToUInt16(s.Slice(count, s.Length - count));
count += sizeof(ushort);
for (int i = 0; i < {1}Len; i++)
{{
	{0} {1} = new {0}();
	{1}.Read(s, ref count);
	{1}s.Add({1});
}}";

		// {0} 변수 이름
		// {1} 변수 형식
		public static string writeFormat =
@"success &= BitConverter.TryWriteBytes(s.Slice(count, s.Length - count), this.{0});
count += sizeof({1});";

		// {0} 변수 이름
		// {1} 변수 형식
		public static string writeByteFormat =
@"segment.Array[segment.Offset + count] = (byte)this.{0};
count += sizeof({1});";

		// {0} 변수 이름
		public static string writeStringFormat =
@"ushort {0}Len = (ushort)Encoding.Unicode.GetBytes(this.{0}, 0, this.{0}.Length, segment.Array, segment.Offset + count + sizeof(ushort));
success &= BitConverter.TryWriteBytes(s.Slice(count, s.Length - count), {0}Len);
count += sizeof(ushort);
count += {0}Len;";

		// {0} 리스트 이름 [대문자]
		// {1} 리스트 이름 [소문자]
		public static string writeListFormat =
@"success &= BitConverter.TryWriteBytes(s.Slice(count, s.Length - count), (ushort)this.{1}s.Count);
count += sizeof(ushort);
foreach ({0} {1} in this.{1}s)
	success &= {1}.Write(s, ref count);";
	}

Program

  class Program
    {
        static string genPackets;
        static ushort packetId;
        static string packetEnums;

        static void Main(string[] args)
        {
            XmlReaderSettings settings = new XmlReaderSettings()
            {
                IgnoreComments = true,
                IgnoreWhitespace = true
            };

            using (XmlReader r = XmlReader.Create("PDL.xml", settings))
            {
                r.MoveToContent();

                while(r.Read())
                {
                    if (r.Depth == 1 && r.NodeType == XmlNodeType.Element)
                        ParsePacket(r);

                    // Console.WriteLine(r.Name + " " + r["name"]);
                }

                string fileText = string.Format(PacketFormat.fileFormat, packetEnums, genPackets);
                File.WriteAllText("GenPackets.cs", fileText);
            }
        }

        public static void ParsePacket(XmlReader r)
        {
            if (r.NodeType == XmlNodeType.EndElement)
                return;

            if (r.Name.ToLower() != "packet")
            {
                Console.WriteLine("Packet 노드 invaild");
                return;
            }

            string packetName = r["name"];

            if(string.IsNullOrEmpty(packetName))
            {
                Console.WriteLine("Packet 이름 없음");
                return;
            }

            Tuple<string, string, string> t = ParseMembers(r);
            genPackets += string.Format(PacketFormat.packetFormat, 
                packetName, t.Item1, t.Item2, t.Item3);
            packetEnums += string.Format(PacketFormat.packetEnumFormat, packetName, ++packetId) + Environment.NewLine + "\t"; 
                ;
        }

        // {1} : 멤버 변수들
        // {2} : 멤버 변수 Read
        // {3} : 멤버변수 Write
        public static Tuple<string,string,string> ParseMembers(XmlReader r)
        {
            string packetName = r["name"];

            string memberCode = "";
            string readCode = "";
            string writeCode = "";

            int depth = r.Depth + 1; 

            while(r.Read())
            {
                if (r.Depth != depth) 
                    break;

                string memberName = r["name"];
                if(string.IsNullOrEmpty(memberName))
                {
                    Console.WriteLine("member 이름 없음");
                    return null;
                }

                if (string.IsNullOrEmpty(memberCode) == false)
                    memberCode += Environment.NewLine; // 엔터 붙여줌
                if (string.IsNullOrEmpty(readCode) == false)
                    readCode += Environment.NewLine;
                if (string.IsNullOrEmpty(writeCode) == false)
                    writeCode += Environment.NewLine;


                string memberType = r.Name.ToLower();
                switch(memberType)
                {
                    case "byte":
                    case "sbyte":
                        memberCode += string.Format(PacketFormat.memberFormat, memberType, memberName);
                        readCode += string.Format(PacketFormat.readByteFormat, memberName, memberType);
                        writeCode += string.Format(PacketFormat.writeByteFormat, memberName, memberType);
                        break;
                    case "bool":
                    case "short":
                    case "ushort":
                    case "int":
                    case "long":
                    case "float":
                    case "double":
                        memberCode += string.Format(PacketFormat.memberFormat, memberType, memberName);
                        readCode += string.Format(PacketFormat.readFormat, memberName, ToMemberType(memberType), memberType);
                        writeCode += string.Format(PacketFormat.writeFormat, memberName, memberType);
                        break;
                    case "string":
                        memberCode += string.Format(PacketFormat.memberFormat, memberType, memberName);
                        readCode += string.Format(PacketFormat.readStringFormat, memberName);
                        writeCode += string.Format(PacketFormat.writeStringFormat, memberName);
                        break;
                    case "list":
                        Tuple<string, string, string> t = ParseList(r);
                        memberCode += t.Item1;
                        readCode += t.Item2;
                        writeCode += t.Item3;
                        break;
                    default:
                        break;
                }
            }

            memberCode = memberCode.Replace("\n", "\n\t");
            readCode = readCode.Replace("\n", "\n\t\t");
            writeCode = writeCode.Replace("\n", "\n\t\t");
            return new Tuple<string, string, string>(memberCode, readCode, writeCode);
        }

        public static Tuple<string, string,string> ParseList(XmlReader r)
        {
            string listName = r["name"];
            if(string.IsNullOrEmpty(listName))
            {
                Console.WriteLine("리스트 이름 없음");
                return null;
            }

            Tuple<string, string, string> t = ParseMembers(r);
            string memberCode = string.Format(PacketFormat.memberListFormat,
                FirstCharToUpper(listName),
                FirstCharToLower(listName),
                t.Item1,
                t.Item2,
                t.Item3);

            string readCode = string.Format(PacketFormat.readListFormat,
                FirstCharToUpper(listName),
                FirstCharToLower(listName));

            string writeCode = string.Format(PacketFormat.writeListFormat,
                FirstCharToUpper(listName),
                FirstCharToLower(listName));

            return new Tuple<string,string,string>(memberCode, readCode,writeCode);
        }

        public static string ToMemberType(string memberType)
        {
            switch(memberType)
            {
                case "bool":
                    return "ToBoolean";
                case "short":
                    return "ToInt16";
                case "ushort":
                    return "ToUInt16";
                case "int":
                    return "ToInt32";
                case "long":
                    return "ToInt64";
                case "float":
                    return "ToSingle";
                case "double":
                    return "ToDouble";
                default:
                    return "";
            }
        }

        public static string FirstCharToUpper(string input)
        {
            if (string.IsNullOrEmpty(input))
                return "";
            return input[0].ToString().ToUpper() + input.Substring(1);
        }

        public static string FirstCharToLower(string input)
        {
            if (string.IsNullOrEmpty(input))
                return "";
            return input[0].ToString().ToLower() + input.Substring(1);
        }
    }