Function _bitmap_xlog_insert_meta

src/backend/access/bitmap/bitmapxlog.c:108–138

* _bitmap_xlog_insert_meta() -- update a metapage. */

 * _bitmap_xlog_insert_meta() -- update a metapage.
 */
static void
_bitmap_xlog_insert_meta(XLogRecPtr lsn, XLogReaderState *record)
{
	xl_bm_metapage	*xlrec = (xl_bm_metapage *) XLogRecGetData(record);
	Buffer			metabuf;
	Page			mp;
	BMMetaPage		metapage;

	metabuf = XLogReadBufferExtended(xlrec->bm_node, xlrec->bm_fork, BM_METAPAGE, RBM_ZERO_AND_LOCK);
	Assert(BufferIsValid(metabuf));

	mp = BufferGetPage(metabuf);
	if (PageIsNew(mp))
		PageInit(mp, BufferGetPageSize(metabuf), 0);

	if (PageGetLSN(mp) < lsn)
	{
		metapage = (BMMetaPage)PageGetContents(mp);

		metapage->bm_magic = BITMAP_MAGIC;
		metapage->bm_version = BITMAP_VERSION;
		metapage->bm_lov_heapId = xlrec->bm_lov_heapId;
		metapage->bm_lov_indexId = xlrec->bm_lov_indexId;
		metapage->bm_lov_lastpage = xlrec->bm_lov_lastpage;

		PageSetLSN(mp, lsn);
		_bitmap_wrtbuf(metabuf);
	}
	else
		_bitmap_relbuf(metabuf);
}

/*
 * _bitmap_xlog_insert_bitmap_lastwords() -- update the last two words