Method walk_pip

src/jrd/validation.cpp:2438–2565

}

void Validation::walk_pip()
{
/**************************************
 *
 *	w a l k _ p i p
 *
 **************************************
 *
 * Functional description
 *	Walk the page inventory pages.
 *
 **************************************/
	Database* dbb = vdr_tdbb->getDatabase();

	PageManager& pageSpaceMgr = dbb->dbb_page_manager;
	const PageSpace* pageSpace = pageSpaceMgr.findPageSpace(DB_PAGE_SPACE);
	fb_assert(pageSpace);

	page_inv_page* page = 0;

	for (USHORT sequence = 0; true; sequence++)
	{
		const ULONG page_number =
			sequence ? sequence * pageSpaceMgr.pagesPerPIP - 1 : pageSpace->pipFirst;
#ifdef DEBUG_VAL_VERBOSE
		if (VAL_debug_level)
			fprintf(stdout, "walk_pip: page %d\n", page_number);
#endif
		WIN window(DB_PAGE_SPACE, -1);
		fetch_page(true, page_number, pag_pages, &window, &page);

		ULONG pipMin = MAX_ULONG;
		ULONG pipExtent = MAX_ULONG;
		ULONG pipUsed = 0;

		UCHAR* bytes = page->pip_bits;
		const UCHAR* end = (UCHAR*) page + dbb->dbb_page_size;
		for (; bytes < end; bytes++)
		{
			if (*bytes == 0)
			{
				pipUsed = (bytes - page->pip_bits + 1) * 8;
				continue;
			}

			if (*bytes == 0xFF && pipExtent == MAX_ULONG)
				pipExtent = (bytes - page->pip_bits) * 8;

			if (pipMin == MAX_ULONG)
			{
				UCHAR mask = 1;
				for (int i = 0; i < 8; i++, mask <<= 1)
				{
					if (*bytes & mask)
					{
						pipMin = (bytes - page->pip_bits) * 8 + i;
						break;
					}