Function CCH_init

src/jrd/cch.cpp:1546–1630

void CCH_init(thread_db* tdbb, ULONG number)
{
/**************************************
 *
 *	C C H _ i n i t
 *
 **************************************
 *
 * Functional description
 *	Initialize the cache.  Allocate buffers control block,
 *	buffer descriptors, and actual buffers.
 *
 **************************************/
	SET_TDBB(tdbb);
	Database* const dbb = tdbb->getDatabase();
	const bool shared = (dbb->dbb_flags & DBB_shared);

	CCH_TRACE(("INIT    %s", dbb->dbb_filename.c_str()));

	// Check for database-specific page buffers

	if (dbb->dbb_page_buffers)
		number = dbb->dbb_page_buffers;

	// Enforce page buffer cache constraints

	if (number < MIN_PAGE_BUFFERS)
		number = MIN_PAGE_BUFFERS;

	if (number > MAX_PAGE_BUFFERS)
		number = MAX_PAGE_BUFFERS;

	const ULONG count = number;

	// Allocate and initialize buffers control block
	BufferControl* bcb = BufferControl::create(dbb);
	while (true)
	{
		try
		{
			bcb->bcb_hashTable = FB_NEW_POOL(*bcb->bcb_bufferpool)
				BCBHashTable(*bcb->bcb_bufferpool, number);
			break;
		}
		catch (const Firebird::Exception& ex)
		{
			ex.stuffException(tdbb->tdbb_status_vector);

			number -= number >> 2;

			if (number < MIN_PAGE_BUFFERS)
				ERR_post(Arg::Gds(isc_cache_too_small));
		}
	}

	dbb->dbb_bcb = bcb;
	bcb->bcb_page_size = dbb->dbb_page_size;
	bcb->bcb_database = dbb;