Method extend

src/jrd/pag.cpp:2416–2483

}

bool PageSpace::extend(thread_db* tdbb, const ULONG pageNum, const bool forceSize)
{
/**************************************
 *
 * Functional description
 *	Extend database file(s) up to at least pageNum pages. Number of pages to
 *	extend can't be less than hardcoded value MIN_EXTEND_BYTES and more than
 *	configured value "DatabaseGrowthIncrement" (both values in bytes).
 *
 *	If "DatabaseGrowthIncrement" is less than MIN_EXTEND_BYTES then don't
 *	extend file(s)
 *
 *  If forceSize is true, extend file up to pageNum pages (despite of value
 *  of "DatabaseGrowthIncrement") and don't make attempts to extend by less
 *	pages.
 *
 **************************************/
	fb_assert(dbb == tdbb->getDatabase());

	const int MAX_EXTEND_BYTES = dbb->dbb_config->getDatabaseGrowthIncrement();

	if (pageNum < maxPageNumber || MAX_EXTEND_BYTES < MIN_EXTEND_BYTES && !forceSize)
		return true;

	if (pageNum >= maxAlloc())
	{
		const ULONG minExtendPages = MIN_EXTEND_BYTES / dbb->dbb_page_size;
		const ULONG maxExtendPages = MAX_EXTEND_BYTES / dbb->dbb_page_size;
		const ULONG reqPages = pageNum - maxPageNumber + 1;

		ULONG extPages;
		extPages = MIN(MAX(maxPageNumber / 16, minExtendPages), maxExtendPages);
		extPages = MAX(reqPages, extPages);

		while (true)
		{
			const ULONG oldMaxPageNumber = maxPageNumber;
			try
			{
				PIO_extend(tdbb, file, extPages, dbb->dbb_page_size);
				break;
			}
			catch (const status_exception&)
			{
				if (extPages > reqPages && !forceSize)
				{
					fb_utils::init_status(tdbb->tdbb_status_vector);

					// if file was extended, return, else try to extend by less pages

					if (oldMaxPageNumber < maxAlloc())
						return true;

					extPages = MAX(reqPages, extPages / 2);
				}
				else
				{
					gds__log("Error extending file \"%s\" by %lu page(s).\nCurrently allocated %lu pages, requested page number %lu",