Concatenated incremental JSON stream parsing with nlohmann/json (somewhat 💩 code!)

Parser.cpp

//mtx_ is a Boost mutex

void Parser::put_into_internal_string_stream(std::string& str) {
    mtx_.lock();

    internal_ss_.clear();
    internal_ss_.str(internal_ss_.str() + str);
   
    mtx_.unlock();
}

//Parser.cpp contains internal_ss_ and last_parse_pos_
std::vector<json> Parser::extract_json_blobs_from_internal_string_stream_new() {

    mtx_.lock();
    std::cout << "in mutex\n";
    std::vector<json> return_vec;

    //std::cout << "string stream contents: " << internal_ss_.str() << std::endl << std::endl;
    internal_ss_.clear();

    bool prepended = false;

    while(internal_ss_.peek() != EOF) {
          

            json json_obj_buf;
            try {
                internal_ss_ >> json_obj_buf;
           
                return_vec.emplace_back(json_obj_buf);
              
                last_parse_pos_ = internal_ss_.tellg();
            } catch(json::parse_error &e) {

             

                internal_ss_.clear();
                internal_ss_.seekg(last_parse_pos_);
                if (internal_ss_.eof()) break; //IMPORTANT OR IF ITS EMPTY, WE GET EXC_BAD_ACCESS ON READ
                
                while(internal_ss_.peek() != EOF) {
                    prepend_string_.push_back(internal_ss_.get());
                }

       

                std::stringstream(prepend_string_).swap(internal_ss_); //Reset internal string stream
                prepend_string_ = ""; //Reset prepend
                last_parse_pos_ = 0;
                break;
            }
        }
    mtx_.unlock();
    return return_vec;
}