Method parse_bucket

sql/opt_histogram_json.cc:526–680

@brief Parse a JSON representation for one histogram bucket @param je The JSON parser object @param field Table field we are using histogram (used to convert endpoints from text representation to binary) @param total_size INOUT Fraction of the table rows in the buckets parsed so far. @param assigned_last_end OUT TRUE<=>

   -1  EOF
*/
int Histogram_json_hb::parse_bucket(json_engine_t *je, Field *field,
                                    double *total_size,
                                    bool *assigned_last_end,
                                    const char **err)
{
  *assigned_last_end= false;
  if (json_scan_next(je))
    return 1;
  if (je->state != JST_VALUE)
  {
    if (je->state == JST_ARRAY_END)
      return -1; // EOF
    else
      return 1; // An error
  }

  if (json_scan_next(je) || je->state != JST_OBJ_START)
  {
    *err= "Expected an object in the buckets array";
    return 1;
  }

  bool have_start= false;
  bool have_size= false;
  bool have_ndv= false;
  CHARSET_INFO *cs;

  if (!(cs= field->charset()))
    cs= &my_charset_bin;

  double size_d;
  longlong ndv_ll= 0;
  StringBuffer<128> value_buf(cs);
  int rc;

  while (!(rc= json_scan_next(je)) && je->state != JST_OBJ_END)
  {
    Json_saved_parser_state save1(je);
    Json_string start_str("start");
    if (json_key_matches(je, start_str.get()))
    {
      if (read_bucket_endpoint(je, field, &value_buf, err))
        return 1;

      have_start= true;
      continue;
    }
    save1.restore_to(je);

    Json_string size_str("size");
    if (json_key_matches(je, size_str.get()))
    {
      if (json_read_value(je))
        return 1;

      const char *size= (const char*)je->value_begin;
      char *size_end= (char*)je->value_end;
      int conv_err;