Method update_virtual_fields

sql/table.cc:9299–9435

*/

int TABLE::update_virtual_fields(handler *h, enum_vcol_update_mode update_mode)
{
  DBUG_ENTER("TABLE::update_virtual_fields");
  DBUG_PRINT("enter", ("update_mode: %d  is_error: %d", update_mode,
                       in_use->is_error()));
  Field **vfield_ptr, *vf;
  Query_arena backup_arena;
  Turn_errors_to_warnings_handler Suppress_errors;
  bool handler_pushed= 0, update_all_columns= 1;
  DBUG_ASSERT(vfield);

  /*
    TODO: this imposes memory leak until table flush when save_in_field()
          does expr_arena allocation. F.ex. case in
          gcol.gcol_supported_sql_funcs_innodb (see CONVERT_TZ):

          create table t1 (
            a datetime, b datetime generated always as
            (convert_tz(a, 'MET', 'UTC')) virtual);
          insert into t1 values ('2008-08-31', default);
  */
  in_use->set_n_backup_active_arena(expr_arena, &backup_arena);

  /* When reading or deleting row, ignore errors from virtual columns */
  if (update_mode == VCOL_UPDATE_FOR_READ ||
      update_mode == VCOL_UPDATE_FOR_DELETE ||
      update_mode == VCOL_UPDATE_INDEXED)
  {
    in_use->push_internal_handler(&Suppress_errors);
    handler_pushed= 1;
  }
  else if (update_mode == VCOL_UPDATE_FOR_REPLACE &&
           in_use->is_current_stmt_binlog_format_row() &&
           in_use->variables.binlog_row_image != BINLOG_ROW_IMAGE_MINIMAL)
  {
    /*
      If we are doing a replace with not minimal binary logging, we have to
      calculate all virtual columns.
    */
    update_all_columns= 1;
  }

  /* Iterate over virtual fields in the table */
  for (vfield_ptr= vfield; *vfield_ptr ; vfield_ptr++)
  {
    vf= (*vfield_ptr);
    Virtual_column_info *vcol_info= vf->vcol_info;
    DBUG_ASSERT(vcol_info);
    DBUG_ASSERT(vcol_info->expr);

    bool update= 0, swap_values= 0;
    switch (update_mode) {
    case VCOL_UPDATE_FOR_READ:
      if (!bitmap_is_set(read_set, vf->field_index))
        update= false;
      else if (h->keyread_enabled())
      {
        /*