C++高性能服务框架revolver：协议接口描述和翻译语言

在一个稍微复杂的系统中会涉及到多语言编程，例如：后端C++和JAVA，脚本用LUA,前端可能是C++ AS等等。所以所有模块之间的协议统一变得非常重要，这样做的目的是减少中间的调试和差错。在revolver框架中，实现了一个基于简单的接口语言来实现多语言之间接口协议的实现。所有的协议接口通过一个简单的def文件就可以将协议翻译成对应的语言程序代码，这样尽可能的避免中间环节的差错，也大大提高了编码效率。而且revolver使用的是标准网络字节序描述协议报文数据，所以可以在各种系统下使用各种语言进行混合编程。

协议接口例子

以下是一个revolver的sample_msg.def事例接口程序文档:
#生成的文件名
filetitle = sample_msg
#命名空间
namespace = BASE
#ip地址类型声明
datatype(Inet_Addr)


#数组定义
typedef array<int8> : INT8_ARRAY
typedef array<int32> : INT32_ARRAY


#二进制数据
typedef string : BIN_DATA


#结构体定义
datatype(CDesc)
{
int8 n_type = 0
string str_desc = ""
INT32_ARRAY arr_fd
INT8_ARRAY arr_status
}


#协议消息ID定义
var SAMPLE_MSGID = 0xff000001
#协议体和消息关联定义
message(CSamplePacket, SAMPLE_MSGID)
{
uint8 msg_type = 0
uint16 seq_id = 0
uint32 user_id = 0
uint64 guid = 0
Inet_Addr server_addr
BIN_DATA bin_data
CDesc msg_desc
}

以上是基本的def定义，如果要将协议翻译成c++框架能认识的协议,就需要通过revolver中提供的协议翻译器来进行翻译，协议翻译器在revolver项目中protocol_analysis工程编译得到，会生成一个make.exe。生成make程序后，可在命令行里输入make sample_msg.def c++，就可生成对应的C++接口协议。生成的C++接口文件如下:

namespace BASE {

#define SAMPLE_MSGID	0xff000001

typedef string		BIN_DATA;
typedef vector<int32_t>		INT32_ARRAY;
typedef vector<int8_t>		INT8_ARRAY;

class CDesc
{
public:
	CDesc()
	{
		n_type = 0;
		str_desc = "";
	}
	~CDesc()
	{
	}

public:
	int8_t		n_type;
	string		str_desc;
	INT32_ARRAY		arr_fd;
	INT8_ARRAY		arr_status;


	friend BinStream& operator<<(BinStream& strm, const CDesc& packet)
	{
		strm << packet.n_type;
		strm << packet.str_desc;

		int32_t count_0 = packet.arr_fd.size();
		strm << count_0;
		for (int32_t i = 0; i < count_0; i++)
		{
			strm << packet.arr_fd[i];
		}

		int32_t count_1 = packet.arr_status.size();
		strm << count_1;
		for (int32_t i = 0; i < count_1; i++)
		{
			strm << packet.arr_status[i];
		}
		return strm;
	}

	friend BinStream& operator>>(BinStream& strm, CDesc& packet)
	{
		strm >> packet.n_type;
		strm >> packet.str_desc;

		int32_t count_2 = 0;
		strm >> count_2;
		packet.arr_fd.resize(count_2);
		for (int32_t i = 0; i < count_2; i++)
		{
			strm >> packet.arr_fd[i];
		}

		int32_t count_3 = 0;
		strm >> count_3;
		packet.arr_status.resize(count_3);
		for (int32_t i = 0; i < count_3; i++)
		{
			strm >> packet.arr_status[i];
		}
		return strm;
	}

	void  Print(std::ostream& os) const
	{
		os << "CDesc, {";
		os << "n_type = " << (int16_t)n_type << ",";
		os << "str_desc = " << str_desc << ",";
		os << "arr_fd = ";
		for (uint32_t i = 0; i < arr_fd.size(); i++)
		{
			os << arr_fd[i] << ",";
		}
		os << "arr_status = ";
		for (uint32_t i = 0; i < arr_status.size(); i++)
		{
			os << (int16_t)arr_status[i] << ",";
		}
		os << "}";
	}

	friend ostream& operator<<(ostream& os, const CDesc& packet)
	{
		packet.Print(os);
		return os;
	}
};


class CSamplePacket : public CBasePacket
{
public:
	CSamplePacket()
	{
		msg_type = 0;
		seq_id = 0;
		user_id = 0;
		guid = 0;
	}
	~CSamplePacket()
	{
	}

public:
	uint8_t		msg_type;
	uint16_t		seq_id;
	uint32_t		user_id;
	uint64_t		guid;
	Inet_Addr		server_addr;
	BIN_DATA		bin_data;
	CDesc		msg_desc;

public:
	void	Pack(BinStream& strm) const
	{
		strm << msg_type;
		strm << seq_id;
		strm << user_id;
		strm << guid;
		strm << server_addr;
		strm << bin_data;
		strm << msg_desc;
	}
	void	UnPack(BinStream& strm)
	{
		strm >> msg_type;
		strm >> seq_id;
		strm >> user_id;
		strm >> guid;
		strm >> server_addr;
		strm >> bin_data;
		strm >> msg_desc;
	}

	void  Print(std::ostream& os) const
	{
		os << "CSamplePacket, {";
		os << "msg_type = " << (uint16_t)msg_type << ",";
		os << "seq_id = " << seq_id << ",";
		os << "user_id = " << user_id << ",";
		os << "guid = " << guid << ",";
		os << "server_addr = " << server_addr << ",";
		os << "bin_data's size = " << bin_data.size();
		os << "msg_desc = " << msg_desc << ",";
		os << "}";
	}
};

也可以生成lua 或者AS 等。命令make sample_msg.def lua 或者make sample_msg.def as。其他的语言类似，也可以根据项目中使用的语言修改协议翻译器，让它支持你所用的语言。

def协议接口介绍

基础数据类型:

int8 有符号单字节整型数

uint8 无符号单字节整型数

int16 有符号双字节整型数

uint16 无符号双字节整型数

int32 有符号4字节整型数

uint32 无符号4字节整型数

int64 有符号8字节整型数

uint64 无符号8字节整型数

string 字符串

BIN_DATA 二进制数组

Inet_Addr IP v4地址，包括端口

关键字:

var 数字定义关键字

array 数组关键字

datatype 数据结构定义关键字，类似结构体

message 协议定义关键字

typedef 重定义关键字

{ 结构的开始

} 结构的结束

# 注释关键字

综述

revolver提供协议接口编程，就是将自动化引入整个框架，减少因为协议带来的调试和差错，重在提高生产效率。这也是revolver框架的主要特性之一。