Method fetch_page

src/jrd/validation.cpp:1170–1294

}

Validation::FETCH_CODE Validation::fetch_page(bool mark, ULONG page_number,
	USHORT type, WIN* window, void* aPage_pointer)
{
/**************************************
 *
 *	f e t c h _ p a g e
 *
 **************************************
 *
 * Functional description
 *	Fetch page and return type of illness, if any.  If "mark" is true,
 *	check for doubly allocated pages and account for page use.
 *
 **************************************/
	Database* dbb = vdr_tdbb->getDatabase();

	if (JRD_reschedule(vdr_tdbb))
	{
		if (vdr_service && vdr_service->finished())
		{
			CCH_unwind(vdr_tdbb, false);
			Arg::Gds(isc_att_shutdown).raise();
		}
	}

	window->win_page = page_number;
	window->win_flags = 0;
	pag** page_pointer = reinterpret_cast<pag**>(aPage_pointer);

	FB_SIZE_T pos;
	if (vdr_used_bdbs.find(page_number, pos))
	{
		vdr_used_bdbs[pos].count++;

		BufferDesc* bdb = vdr_used_bdbs[pos].bdb;
		fb_assert(bdb->bdb_page == PageNumber(DB_PAGE_SPACE, page_number));

		window->win_bdb = bdb;
		*page_pointer = window->win_buffer = bdb->bdb_buffer;
	}
	else
	{
		*page_pointer = CCH_FETCH_NO_SHADOW(vdr_tdbb, window,
			(vdr_flags & VDR_online ? LCK_read : LCK_write),
			0);

		vdr_used_bdbs.add(UsedBdb(window->win_bdb));
	}

	if ((*page_pointer)->pag_type != type && type != pag_undefined)
	{
		corrupt(VAL_PAG_WRONG_TYPE, 0, page_number,
			pagtype(type).c_str(), pagtype((*page_pointer)->pag_type).c_str());
		return fetch_type;
	}

	if (!mark)
		return fetch_ok;