To use this library for batch insertion when the amount of data is determined in runtime

[MelodicDrumstep]

Hi here! Firstly, thanks a lot for writing this awesome C++ client library for influxdb! It really helps a lot.
Currently, I'm faced up with a situation where the incoming data will be placed in a circular buffer. And I have to read a batch of data from the buffer and insert them in a batch into the database every certain seconds. The problem is that the amount of data I will read each turn is determined in runtime.

The example you mentioned about batch insertion is

influxdb_cpp::builder()
    .meas("foo")  // series 1
    .field("x", 10)

    .meas("bar")  // series 2
    .field("y", 10.3)
    .send_udp("127.0.0.1", 8091);

which is cool but not useful under this situation. Therefore, I wrote the piece of code below to resolve this in a non-graceful way:

    /** 
    @param data a vector of integer data that I want to insert into the database. 
    The bucket name and the measurement name are set before this function.
    */
    void Insert(std::vector<int> & data) 
    {
        influxdb_cpp::builder builder;
        influxdb_cpp::builder * temp_ts_caller = &builder;

        for(int i = 0; i < data.size(); i++)
        {
            temp_ts_caller =  &((temp_ts_caller -> meas(measurement_)).field("value", data[i]));
        }
        reinterpret_cast<influxdb_cpp::detail::ts_caller *>(temp_ts_caller) -> post_http(si_);
    }

However, it turns out that it doesn't work. This is due to the lack of newline character between insertions in the "lines_" variable.

Therefore, I have to convert "lines_" data member to be public and add this line to the code : temp_ts_caller -> lines_ << "\n";
After this, the piece of code would be:

    /** 
    @param data a vector of integer data that I want to insert into the database. 
    The bucket name and the measurement name are set before this function.
    */
    void Insert(std::vector<int> & data) 
    {
        influxdb_cpp::builder builder;
        influxdb_cpp::builder * temp_ts_caller = &builder;

        for(int i = 0; i < data.size(); i++)
        {
            temp_ts_caller =  &((temp_ts_caller -> meas(measurement_)).field("value", data[i]));
            temp_ts_caller -> lines_ << "\n";
        }
        reinterpret_cast<influxdb_cpp::detail::ts_caller *>(temp_ts_caller) -> post_http(si_);
    }

This solves the problem, but it's not graceful. I don't know if it's because I find the wrong way to use batch insertion under this situation. And I do not have time to see which piece goes wrong (if any) in the source code in my situation.

---

By the way, I find myself failing to use ".timestamp" function for timestamp customization under this situation.

For example, below is the errorous code:

        influxdb_cpp::builder builder;
        influxdb_cpp::builder * temp_ts_caller = &builder;

        for(int i = 0; i < data.size(); i++)
        {
            auto now = std::chrono::system_clock::now();
            auto duration_ns = std::chrono::duration_cast<std::chrono::nanoseconds>(now.time_since_epoch());
            temp_ts_caller =  &((temp_ts_caller -> meas(measurement_)).field("value", data[i]).timestamp(duration_ns.count()));
            temp_ts_caller -> lines_ << "\n";       // Fix for the bug of the library. 
        }
        reinterpret_cast<influxdb_cpp::detail::ts_caller *>(temp_ts_caller) -> post_http(si_);

If I try to add the timestamp in this way, I cannot get any insertion done. What's going wrong?

Sincerely waiting for your reply!