Function json_get_object_nkey

strings/json_lib.c:2226–2284

enum json_types json_get_object_nkey(const char *js __attribute__((unused)),
                                     const char *js_end __attribute__((unused)),
                                     int nkey __attribute__((unused)),
                                     const char **keyname __attribute__((unused)),
                                     const char **keyname_end __attribute__((unused)),
                                     const char **value __attribute__((unused)),
                                     int *value_len __attribute__((unused)))
{
  json_engine_t je;
  int keys_found= 0;
  MEM_ROOT current_mem_root;
  enum json_types return_value;

  init_alloc_root(PSI_INSTRUMENT_MEM, &current_mem_root,
                  BLOCK_SIZE_JSON_DYN_ARRAY, 0, MYF(0));

  mem_root_dynamic_array_init(&current_mem_root, PSI_INSTRUMENT_MEM,
                              &je.stack, sizeof(int), NULL,
                              JSON_DEPTH_DEFAULT, JSON_DEPTH_INC, MYF(0));

  json_scan_start(&je, &my_charset_utf8mb4_bin,(const uchar *) js,
                  (const uchar *) js_end);

  if (json_read_value(&je) ||
      je.value_type != JSON_VALUE_OBJECT)
    goto err_return;

  while (!json_scan_next(&je))
  {
    switch (je.state)
    {
    case JST_KEY:
      if (nkey == keys_found)
      {
        *keyname= (char *) je.s.c_str;
        while (json_read_keyname_chr(&je) == 0)
          *keyname_end= (char *) je.s.c_str;

        return_value= smart_read_value(&je, value, value_len);
        free_root(&current_mem_root, MYF(0));
        return return_value;
      }

      keys_found++;
      if (json_skip_key(&je))
        goto err_return;

      break;

    case JST_OBJ_END:
      free_root(&current_mem_root, MYF(0));
      return JSV_NOTHING;
    }
  }

err_return:
  free_root(&current_mem_root, MYF(0));
  return JSV_BAD_JSON;