Method walk_chain

src/jrd/validation.cpp:1530–1589

}

Validation::RTN Validation::walk_chain(jrd_rel* relation, const rhd* header,
	RecordNumber head_number)
{
/**************************************
 *
 *	w a l k _ c h a i n
 *
 **************************************
 *
 * Functional description
 *	Make sure chain of record versions is completely intact.
 *
 **************************************/
#ifdef DEBUG_VAL_VERBOSE
	USHORT counter = 0;
#endif

	ULONG page_number = header->rhd_b_page;
	USHORT line_number = header->rhd_b_line;
	WIN window(DB_PAGE_SPACE, -1);
	window.win_flags = WIN_garbage_collector;

	while (page_number)
	{
		const bool delta_flag = (header->rhd_flags & rhd_delta) ? true : false;
#ifdef DEBUG_VAL_VERBOSE
		if (VAL_debug_level)
			fprintf(stdout, "  BV %02d: ", ++counter);
#endif
		vdr_rel_chain_counter++;
		data_page* page = 0;
		fetch_page(true, page_number, pag_data, &window, &page);

		if (page->dpg_relation != relation->rel_id)
		{
			release_page(&window);
			return corrupt(VAL_DATA_PAGE_CONFUSED, relation, page_number, page->dpg_sequence);
		}

		vdr_rel_chain_counter++;
		PBM_SET(vdr_tdbb->getDefaultPool(), &vdr_chain_pages, page_number);

		const data_page::dpg_repeat* line = &page->dpg_rpt[line_number];
		header = (const rhd*) ((UCHAR*) page + line->dpg_offset);
		if (page->dpg_count <= line_number || !line->dpg_length ||
			(header->rhd_flags & (rhd_blob | rhd_fragment)) ||
			!(header->rhd_flags & rhd_chain) ||
			walk_record(relation, header, line->dpg_length,
						head_number, delta_flag) != rtn_ok)
		{
			release_page(&window);
			return corrupt(VAL_REC_CHAIN_BROKEN, relation, head_number.getValue());
		}
		page_number = header->rhd_b_page;
		line_number = header->rhd_b_line;
		release_page(&window);
	}