Function AR_SHORTEST_PATH

src/arithmetic/path_funcs/path_funcs.c:127–266

}

SIValue AR_SHORTEST_PATH(SIValue *argv, int argc, void *private_data) {
	if(SI_TYPE(argv[0]) == T_NULL) return SI_NullVal();
	if(SI_TYPE(argv[1]) == T_NULL) return SI_NullVal();

	Node             *srcNode   =  argv[0].ptrval;
	Node             *destNode  =  argv[1].ptrval;
	ShortestPathCtx  *ctx       =  private_data;
	GrB_Index src_id            =  ENTITY_GET_ID(srcNode);
	GrB_Index dest_id           =  ENTITY_GET_ID(destNode);

	GrB_Info res;
	UNUSED(res);
	Edge *edges = NULL;
	GrB_Vector V = GrB_NULL;  // vector of results
	GrB_Vector PI = GrB_NULL; // vector backtracking results to their parents
	GraphContext *gc = QueryCtx_GetGraphCtx();

	GrB_Index max_level = (ctx->maxHops == EDGE_LENGTH_INF) ? 0 : ctx->maxHops;

	if(ctx->R == GrB_NULL) {
		// First invocation, initialize unset context members.
		if(ctx->reltype_count > 0) {
			// Retrieve IDs of traversed relationship types.
			ctx->reltypes = array_new(int, ctx->reltype_count);
			for(uint i = 0; i < ctx->reltype_count; i ++) {
				Schema *s = GraphContext_GetSchema(gc, ctx->reltype_names[i], SCHEMA_EDGE);
				// Skip missing schemas
				if(s) array_append(ctx->reltypes, Schema_GetID(s));
			}

			// Update the reltype count, as it may have changed due to missing schemas
			ctx->reltype_count = array_len(ctx->reltypes);
		}

		// Get edge matrix and transpose matrix, if available.
		if(ctx->reltypes == NULL) {
			// No edge types were specified, use the overall adjacency matrix.
			ctx->free_matrices = true;
			res = RG_Matrix_export(&ctx->R, Graph_GetAdjacencyMatrix(gc->g,
						false));
			ASSERT(res == GrB_SUCCESS);
		} else if(ctx->reltype_count == 0) {
			// If edge types were specified but none were valid,
			// use the zero matrix
			ctx->free_matrices = true;
			res = RG_Matrix_export(&ctx->R, Graph_GetZeroMatrix(gc->g));
			ASSERT(res == GrB_SUCCESS);
		} else if(ctx->reltype_count == 1) {
			ctx->free_matrices = true;
			res = RG_Matrix_export(&ctx->R, Graph_GetRelationMatrix(gc->g,
						ctx->reltypes[0], false));
			ASSERT(res == GrB_SUCCESS);
		} else {
			// we have multiple edge types, combine them into a boolean matrix
			ctx->free_matrices = true;
			GrB_Index dims = Graph_RequiredMatrixDim(gc->g);
			res = GrB_Matrix_new(&ctx->R, GrB_BOOL, dims, dims);
			ASSERT(res == GrB_SUCCESS);