Method garbage_collect

src/jrd/validation.cpp:1313–1400

}

void Validation::garbage_collect()
{
/**************************************
 *
 *	g a r b a g e _ c o l l e c t
 *
 **************************************
 *
 * Functional description
 *	The database has been walked; compare the page inventory against
 *	the bitmap of pages visited.
 *
 **************************************/
	Database* dbb = vdr_tdbb->getDatabase();

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

	WIN window(DB_PAGE_SPACE, -1);

	for (ULONG sequence = 0, number = 0; number < vdr_max_page; sequence++)
	{
		const ULONG page_number = sequence ? sequence * pageSpaceMgr.pagesPerPIP - 1 : pageSpace->pipFirst;
		page_inv_page* page = 0;
		fetch_page(false, page_number, pag_pages, &window, &page);
		UCHAR* p = page->pip_bits;
		const UCHAR* const end = p + pageSpaceMgr.bytesBitPIP;
		while (p < end && number < vdr_max_page)
		{
			UCHAR byte = *p++;
			for (int i = 8; i; --i, byte >>= 1, number++)
			{
				if (PageBitmap::test(vdr_page_bitmap, number))
				{
					if (byte & 1)
					{
						corrupt(VAL_PAG_IN_USE, 0, number);
						if (vdr_flags & VDR_update)
						{
							CCH_MARK(vdr_tdbb, &window);
							p[-1] &= ~(1 << (number & 7));
							vdr_fixed++;
						}
					}
				}
				else if (!(byte & 1) && (vdr_flags & VDR_records))
				{
					// Page is potentially an orphan - but don't declare it as such
					// unless we think we walked all pages

					corrupt(VAL_PAG_ORPHAN, 0, number);
					if (vdr_flags & VDR_update)
					{
						CCH_MARK(vdr_tdbb, &window);
						p[-1] |= 1 << (number & 7);
						vdr_fixed++;