Function DecodeXLogTuple

src/backend/replication/logical/decode.c:1207–1239

* Read a HeapTuple as WAL logged by heap_insert, heap_update and heap_delete * (but not by heap_multi_insert) into a tuplebuf. * * The size 'len' and the pointer 'data' in the record need to be * computed outside as they are record specific. */

 * computed outside as they are record specific.
 */
static void
DecodeXLogTuple(char *data, Size len, ReorderBufferTupleBuf *tuple)
{
	xl_heap_header xlhdr;
	int			datalen = len - SizeOfHeapHeader;
	HeapTupleHeader header;

	Assert(datalen >= 0);

	tuple->tuple.t_len = datalen + SizeofHeapTupleHeader;
	header = tuple->tuple.t_data;

	/* not a disk based tuple */
	ItemPointerSetInvalid(&tuple->tuple.t_self);

	/* we can only figure this out after reassembling the transactions */
	tuple->tuple.t_tableOid = InvalidOid;

	/* data is not stored aligned, copy to aligned storage */
	memcpy((char *) &xlhdr,
		   data,
		   SizeOfHeapHeader);

	memset(header, 0, SizeofHeapTupleHeader);

	memcpy(((char *) tuple->tuple.t_data) + SizeofHeapTupleHeader,
		   data + SizeOfHeapHeader,
		   datalen);

	header->t_infomask = xlhdr.t_infomask;
	header->t_infomask2 = xlhdr.t_infomask2;
	header->t_hoff = xlhdr.t_hoff;
}

/*
 * Check whether we are interested in this specific transaction.