Function Graph_DeleteEdges

src/graph/graph.c:1090–1156

removes edges from Graph and updates graph relevant matrices

// removes edges from Graph and updates graph relevant matrices
void Graph_DeleteEdges
(
	Graph *g,
	Edge *edges,
	uint64_t n
) {
	ASSERT(g != NULL);
	ASSERT(n > 0);
	ASSERT(edges != NULL);

	uint64_t    x;
	RG_Matrix   R;
	RG_Matrix   M;
	GrB_Info    info;
	bool        entry_deleted;

	MATRIX_POLICY policy = Graph_SetMatrixPolicy(g, SYNC_POLICY_NOP);

	for (uint i = 0; i < n; i++) {
		Edge       *e         =  edges + i;
		int         r         =  Edge_GetRelationID(e);
		NodeID      src_id    =  Edge_GetSrcNodeID(e);
		NodeID      dest_id   =  Edge_GetDestNodeID(e);

		ASSERT(!DataBlock_ItemIsDeleted((void *)e->attributes));

		// an edge of type r has just been deleted, update statistics
		GraphStatistics_DecEdgeCount(&g->stats, r, 1);

		R = Graph_GetRelationMatrix(g, r, false);

		// single edge of type R connecting src to dest, delete entry
		info = RG_Matrix_removeEntry_UINT64(R, src_id, dest_id, ENTITY_GET_ID(e), &entry_deleted);
		ASSERT(info == GrB_SUCCESS);

		if(entry_deleted) {
			// TODO: consider making ADJ UINT64_T where ADJ[i,j] = #connections
			// drop the entry once it reaches 0
			//
			// see if source is connected to destination with additional edges
			bool connected = false;
			int relationCount = Graph_RelationTypeCount(g);
			for(int i = 0; i < relationCount; i++) {
				if(i == r) continue;
				M = Graph_GetRelationMatrix(g, i, false);
				info = RG_Matrix_extractElement_UINT64(&x, M, src_id, dest_id);
				if(info == GrB_SUCCESS) {
					connected = true;
					break;
				}
			}

			// there are no additional edges connecting source to destination
			// remove edge from THE adjacency matrix
			if(!connected) {
				M = Graph_GetAdjacencyMatrix(g, false);
				info = RG_Matrix_removeElement_BOOL(M, src_id, dest_id);
				ASSERT(info == GrB_SUCCESS);