Function LogLogicalInvalidations

src/backend/utils/cache/inval.c:1617–1654

* LogLogicalInvalidations * * Emit WAL for invalidations. This is currently only used for logging * invalidations at the command end or at commit time if any invalidations * are pending. */

 * are pending.
 */
void
LogLogicalInvalidations()
{
	xl_xact_invals xlrec;
	SharedInvalidationMessage *invalMessages;
	int			nmsgs = 0;

	/* Quick exit if we haven't done anything with invalidation messages. */
	if (transInvalInfo == NULL)
		return;

	ProcessInvalidationMessagesMulti(&transInvalInfo->CurrentCmdInvalidMsgs,
									 MakeSharedInvalidMessagesArray);

	Assert(!(numSharedInvalidMessagesArray > 0 &&
			 SharedInvalidMessagesArray == NULL));

	invalMessages = SharedInvalidMessagesArray;
	nmsgs = numSharedInvalidMessagesArray;
	SharedInvalidMessagesArray = NULL;
	numSharedInvalidMessagesArray = 0;

	if (nmsgs > 0)
	{
		/* prepare record */
		memset(&xlrec, 0, MinSizeOfXactInvals);
		xlrec.nmsgs = nmsgs;

		/* perform insertion */
		XLogBeginInsert();
		XLogRegisterData((char *) (&xlrec), MinSizeOfXactInvals);
		XLogRegisterData((char *) invalMessages,
						 nmsgs * sizeof(SharedInvalidationMessage));
		XLogInsert(RM_XACT_ID, XLOG_XACT_INVALIDATIONS);

		pfree(invalMessages);
	}
}