Function VIO_backout

src/jrd/vio.cpp:800–1108

}

void VIO_backout(thread_db* tdbb, record_param* rpb, const jrd_tra* transaction)
{
/**************************************
 *
 *	V I O _ b a c k o u t
 *
 **************************************
 *
 * Functional description
 *	Backout the current version of a record.  This may called
 *	either because of transaction death or because the record
 *	violated a unique index.  In either case, get rid of the
 *	current version and back an old version.
 *
 *	This routine is called with an inactive record_param, and has to
 *	take great pains to avoid conflicting with another process
 *	which is also trying to backout the same record.  On exit
 *	there is no active record_param, and the record may or may not have
 *	been backed out, depending on whether we encountered conflict.
 *	But this record is doomed, and if we don't get it somebody
 *	will.
 *
 **************************************/
	SET_TDBB(tdbb);
	Database* dbb = tdbb->getDatabase();
	CHECK_DBB(dbb);

	fb_assert(assert_gc_enabled(transaction, rpb->rpb_relation));

	jrd_rel* const relation = rpb->rpb_relation;

#ifdef VIO_DEBUG
	VIO_trace(DEBUG_WRITES,
		"VIO_backout (rel_id %u, record_param %" SQUADFORMAT", transaction %" SQUADFORMAT")\n",
		relation->rel_id, rpb->rpb_number.getValue(), transaction ? transaction->tra_number : 0);
#endif

	// If there is data in the record, fetch it now.  If the old version
	// is a differences record, we will need it sooner.  In any case, we
	// will need it eventually to clean up blobs and indices. If the record
	// has changed in between, stop now before things get worse.

	record_param temp = *rpb;
	if (!DPM_get(tdbb, &temp, LCK_read))
		return;

#ifdef VIO_DEBUG
	VIO_trace(DEBUG_WRITES_INFO,
		"   record  %" SLONGFORMAT":%d, rpb_trans %" SQUADFORMAT
		", flags %d, back %" SLONGFORMAT":%d, fragment %" SLONGFORMAT":%d\n",
		temp.rpb_page, temp.rpb_line, temp.rpb_transaction_nr,
		temp.rpb_flags, temp.rpb_b_page, temp.rpb_b_line,
		temp.rpb_f_page, temp.rpb_f_line);

	if (temp.rpb_b_page != rpb->rpb_b_page || temp.rpb_b_line != rpb->rpb_b_line ||
		temp.rpb_transaction_nr != rpb->rpb_transaction_nr)
	{
		VIO_trace(DEBUG_WRITES_INFO,