Method fetch_data

test/network_tests/fake_socket_tests/helpers/data_pipe.cpp:60–87

}

[[nodiscard]] size_t data_pipe::fetch_data(boost::asio::mutable_buffer _out) {
    std::scoped_lock lock{mtx_};
    if (data_to_forward_.size() == 0) {
        return 0;
    }

    size_t len{0};
    auto data_it = data_to_forward_.begin();
    while (data_it != data_to_forward_.end()) {
        // Number of bytes we can write from the current segment without exceeding the output buffer size.
        auto const segment_writable = std::min(_out.size() - len, data_it->buffer_.size());
        std::copy(data_it->buffer_.begin(), data_it->buffer_.begin() + static_cast<std::ptrdiff_t>(segment_writable),
                  static_cast<unsigned char*>(_out.data()) + len);
        len += segment_writable;
        if (segment_writable == data_it->buffer_.size()) {
            // Fully consumed the current segment, move to the next one.
            ++data_it;
        } else {
            // Partially consumed the current segment, erase the consumed part and stop.
            data_it->buffer_.erase(data_it->buffer_.begin(), data_it->buffer_.begin() + static_cast<std::ptrdiff_t>(segment_writable));
            break;
        }
    }
    // Remove all fully consumed segments from the forward queue.
    data_to_forward_.erase(data_to_forward_.begin(), data_it);

    return len;
}

[[nodiscard]] bool data_pipe::fetch_data(control_data_t& _out) {
    std::scoped_lock lock{mtx_};