02.GeekServer的序列化分析

2024.02.23 需求

GeekServer当前版本：

commit a0ccffd89617ecf0f0400a6c4ff34328c62c7fed (HEAD -> main, origin/main, origin/HEAD)
Author: lixiuzhi <1642267742@qq.com>
Date:   Thu Nov 9 15:22:29 2023 +0800

    修复生成agent wrapper没有处理partial class的情况

TcpServer -> Client

• 数据结构:
  • 消息长度 (Int)
  • 消息MsgId (Int)
  • 消息体 (Message)
• 写入:

TcpChannel.cs

public override void Write(Message msg)  
{  
    if (IsClose())  
        return;  
    var bytes = Serializer.Serialize(msg);  
    int len = 8 + bytes.Length;  
    Span<byte> span = stackalloc byte[len];  
    int offset = 0;  
    span.WriteInt(len, ref offset);  
    span.WriteInt(msg.MsgId, ref offset);  
    span.WriteBytesWithoutLength(bytes, ref offset);  
  
    lock (sendStream)  
    {        
        sendStream.Write(span);  
    }  
    sendSemaphore.Release();  
}

• 读取:

ClientTcpChannel.cs

protected virtual bool TryParseMessage(ref ReadOnlySequence<byte> input)  
{            var reader = new SequenceReader<byte>(input);  

    if (!reader.TryReadBigEndian(out int length) || reader.Remaining < length - 4)  
    {return false;  
    }  
    var payload = input.Slice(reader.Position, length - 4);  
    if (payload.Length < 4)  
        throw new Exception("消息长度不够");   
    //消息id  
    reader.TryReadBigEndian(out int msgId);  
    var msgType = MsgFactory.GetType(msgId);  
    if (msgType == null)  
    {                LOGGER.Error($"消息ID:{msgId} 找不到对应的Msg.");  
    }            else  
    {  
        var message = MessagePackSerializer.Deserialize<Message>(payload.Slice(4));  
#if UNITY_EDITOR  
        Debug.Log("收到消息:" + MessagePackSerializer.SerializeToJson(message));  
#endif  
        if (message.MsgId != msgId)  
        {                    throw new Exception($"解析消息错误，注册消息id和消息无法对应.real:{message.MsgId}, register:{msgId}");  
        }  
        onMessage(message);  
    }            input = input.Slice(input.GetPosition(length));  
    return true;  
}