nanopb -编码问题

Question

我正在尝试使用oneof对消息进行编码-但大小似乎不太好。这看起来像是忽略了oneof部分-并且没有将其编码到流中。编码函数都返回"TRUE“-这意味着它们按照我的请求进行了编码，这意味着我编码错误……我错过了一些非常愚蠢的东西。

static auto encode(const pb_msgdesc_t *fields, const void *msg) -> std::vector<pb_byte_t>
{
    size_t size = 0;
    bool ok;
    ok = pb_get_encoded_size(&size, fields, msg);
    printf("pb_get_encoded_size=%d, Encoding data as %lx bytes\n", ok, size);
    auto buff = std::vector<pb_byte_t>(size);
    auto stream = pb_ostream_from_buffer(buff.data(), buff.size());
    ok = pb_encode(&stream, fields, msg);
    printf("pb_encode=%d, Encoding data as %lx bytes\n", ok, stream.bytes_written);
    return buff;
}

auto nano_pb_test() -> void
{
    std::vector<pb_byte_t> pb_res;
    {
        WifiCredResult2 wifi_result;
        wifi_result.ip = (int32_t)3232235920; // https://www.browserling.com/tools/ip-to-dec -> 192.168.1.144
        wifi_result.mac = { 6, { 0x30, 0x31, 0x32, 0x33, 0x34, 0x35}};

        ToAppMessage2 toAppMessage2 = ToAppMessage2_init_zero;
        toAppMessage2.type = ToAppMessageType_CONNECT_WIFI_RESULT;
        toAppMessage2.result = ToAppResultType_NETWORK_IS_LOCAL_ONLY;
        toAppMessage2.esp_error = 0x7002;
        toAppMessage2.which_payload = WifiCredResult2_ip_tag;
        toAppMessage2.payload.wifi = wifi_result;
        pb_res = encode(ToAppMessage2_fields, &toAppMessage2);
    }
    {
        ToAppMessage2 toAppMessage3 = ToAppMessage2_init_zero;
        toAppMessage3.payload.wifi.ip = 12;
        pb_istream_t istream = pb_istream_from_buffer((const pb_byte_t *)pb_res.data(), pb_res.size());

        if (!pb_decode(&istream, ToAppMessage2_fields, &toAppMessage3)) {
            printf("nanopb failed parsing:\n");
        } else {
            printf("result = %d, esp: %x, ip=%d\n", toAppMessage3.result, toAppMessage3.esp_error, toAppMessage3.payload.wifi.ip);
        }
    }
}

协议缓冲区(部分..)

enum ToAppMessageType {
...
}

enum ToAppResultType {
...
}

message Details {
    string project_id = 1;
    string url1   = 2;
    string url2    = 5;
}

message Result2 {
    int32 ip = 1;
    bytes mac = 2;
}

message ToAppMessage2 {
    ToAppMessageType type = 1;
    ToAppResultType result = 2;
    int32 error = 3;

    oneof payload {
        WifiCredResult2 wifi = 4;
        PairResult pair = 5;
    }
}

选项文件：

WifiCredResult2.mac max_size:6

Answer 1

我想你的问题出在这里：

toAppMessage2.which_payload = WifiCredResult2_ip_tag;

这将表明您的payload of包含一个WifiCredResult2.ip类型的项，但该of中没有这样的项，因此不会进行任何编码。看来你想要的是：

toAppMessage2.which_payload = ToAppMessage2_wifi_tag;