archery/cpp_ext/msg_handler.cpp

#include <nlohmann/json.hpp>
#include <string>
#include <cstring>
#include <cstdint>
#include <vector>
#include "native_logger.hpp"
#include "msg_handler.hpp"
#include "utils.hpp"

namespace py = pybind11;
using json = nlohmann::json;

namespace netcore {
    // 打包 TCP 数据包
    py::bytes make_packet(int msg_type, py::dict body_dict) {
        netcore::log_debug(std::string("make_packet msg_type=") + std::to_string(msg_type));
        // 1) 将 py::dict 转为 JSON 字符串
        json j = netcore::py_dict_to_json(body_dict);
        std::string body_str = j.dump();

        // 2) 计算 body_len 和 checksum
        uint32_t body_len = body_str.size();
        uint32_t checksum = body_len + msg_type;

        // 3) 打包头部（大端序）
        std::vector<uint8_t> packet;
        packet.reserve(12 + body_len);

        // body_len (big-endian, 4 bytes)
        packet.push_back((body_len >> 24) & 0xFF);
        packet.push_back((body_len >> 16) & 0xFF);
        packet.push_back((body_len >> 8) & 0xFF);
        packet.push_back(body_len & 0xFF);

        // msg_type (big-endian, 4 bytes)
        packet.push_back((msg_type >> 24) & 0xFF);
        packet.push_back((msg_type >> 16) & 0xFF);
        packet.push_back((msg_type >> 8) & 0xFF);
        packet.push_back(msg_type & 0xFF);

        // checksum (big-endian, 4 bytes)
        packet.push_back((checksum >> 24) & 0xFF);
        packet.push_back((checksum >> 16) & 0xFF);
        packet.push_back((checksum >> 8) & 0xFF);
        packet.push_back(checksum & 0xFF);

        // 4) 追加 body
        packet.insert(packet.end(), body_str.begin(), body_str.end());

        netcore::log_debug(std::string("make_packet done bytes=") + std::to_string(packet.size()));
        return py::bytes(reinterpret_cast<const char*>(packet.data()), packet.size());
    }

    // 解析 TCP 数据包
    py::tuple parse_packet(py::bytes data) {
        // 1) 转换为 bytes view
        py::buffer_info buf = py::buffer(data).request();
        if (buf.size < 12) {
            netcore::log_error(std::string("parse_packet too_short len=") + std::to_string(buf.size));
            return py::make_tuple(py::none(), py::none());
        }

        const uint8_t* ptr = static_cast<const uint8_t*>(buf.ptr);

        // 2) 解析头部（大端序）
        uint32_t body_len = (ptr[0] << 24) | (ptr[1] << 16) | (ptr[2] << 8) | ptr[3];
        uint32_t msg_type = (ptr[4] << 24) | (ptr[5] << 16) | (ptr[6] << 8) | ptr[7];
        uint32_t checksum = (ptr[8] << 24) | (ptr[9] << 16) | (ptr[10] << 8) | ptr[11];

        // 3) 校验 checksum（可选，你现有代码不强制校验）
        // if (checksum != (body_len + msg_type)) {
        //     return py::make_tuple(py::none(), py::none());
        // }

        // 4) 检查长度
        uint32_t expected_len = 12 + body_len;
        if (buf.size < expected_len) {
            // 半包
            netcore::log_warn(std::string("parse_packet incomplete got=") + std::to_string(buf.size) +
                              " expected=" + std::to_string(expected_len));
            return py::make_tuple(py::none(), py::none());
        }

        // 5) 防御性检查：如果 data 比预期长，说明可能有粘包
        // （只解析第一个包，忽略多余数据）
        if (buf.size > expected_len) {
            netcore::log_warn(std::string("parse_packet concat got=") + std::to_string(buf.size) +
                              " expected=" + std::to_string(expected_len) +
                              " body_len=" + std::to_string(body_len) +
                              " msg_type=" + std::to_string(msg_type));
        }

        // 6) 提取 body 并解析 JSON
        std::string body_str(reinterpret_cast<const char*>(ptr + 12), body_len);

        try {
            json j = json::parse(body_str);
            py::dict body_dict = netcore::json_to_py_dict(j);
            return py::make_tuple(py::int_(msg_type), body_dict);
        } catch (const json::parse_error& e) {
            // JSON 解析失败，返回 raw（兼容你现有的逻辑）
            netcore::log_error(std::string("parse_packet json_parse_error: ") + e.what());
            py::dict raw_dict;
            raw_dict["raw"] = body_str;
            return py::make_tuple(py::int_(msg_type), raw_dict);
        } catch (const std::exception& e) {
            netcore::log_error(std::string("parse_packet json_parse_error: ") + e.what());
            py::dict raw_dict;
            raw_dict["raw"] = body_str;
            return py::make_tuple(py::int_(msg_type), raw_dict);
        }
    }
}