Function Graph_GetNodeDegree

src/graph/graph.c:946–1048

returns node incoming/outgoing degree

// returns node incoming/outgoing degree
uint64_t Graph_GetNodeDegree
(
	const Graph *g,      // graph to inquery
	const Node *n,       // node to get degree of
	GRAPH_EDGE_DIR dir,  // incoming/outgoing/both
	RelationID edgeType  // relation type
) {
	ASSERT(g != NULL);
	ASSERT(n != NULL);

	NodeID              srcID      = ENTITY_GET_ID(n);
	NodeID              destID     = INVALID_ENTITY_ID;
	EdgeID              edgeID     = INVALID_ENTITY_ID;
	uint64_t            edge_count = 0;
	RG_Matrix           M          = NULL;
	RG_Matrix           TM         = NULL;
	RG_MatrixTupleIter  it         = {0};

	if(edgeType == GRAPH_UNKNOWN_RELATION) {
		return 0;  // no edges
	}

	bool outgoing = (dir == GRAPH_EDGE_DIR_OUTGOING ||
					 dir == GRAPH_EDGE_DIR_BOTH);

	bool incoming = (dir == GRAPH_EDGE_DIR_INCOMING ||
					 dir == GRAPH_EDGE_DIR_BOTH);

	// relationships to consider
	int start_rel;
	int end_rel;

	if(edgeType != GRAPH_NO_RELATION) {
		// consider only specified relationship
		start_rel = edgeType;
		end_rel = start_rel + 1;
	} else {
		// consider all relationship types
		start_rel = 0;
		end_rel = Graph_RelationTypeCount(g);
	}

	// for each relationship type to consider
	for(edgeType = start_rel; edgeType < end_rel; edgeType++) {
		M = Graph_GetRelationMatrix(g, edgeType, false);

		//----------------------------------------------------------------------
		// outgoing edges
		//----------------------------------------------------------------------

		// TODO: revisit once we get rid of MULTI-EDGE hack
		if(outgoing) {
			// construct an iterator to traverse over the source node row,
			// containing all outgoing edges
			RG_MatrixTupleIter_AttachRange(&it, M, srcID, srcID);
			// scan row
			while(RG_MatrixTupleIter_next_UINT64(&it, NULL, &destID, &edgeID)
					== GrB_SUCCESS) {