Datum create_complete_graph()

in src/backend/utils/graph_generation.c [53:203]

• 116 lines of code
• 13 McCabe index (conditional complexity)

Datum create_complete_graph(PG_FUNCTION_ARGS)
{
    Oid graph_oid;
    Name graph_name;

    int64 no_vertices;
    int64 i,j,vid = 1, eid, start_vid, end_vid;

    Name vtx_label_name = NULL;
    Name edge_label_name;
    int32 vtx_label_id;
    int32 edge_label_id;

    agtype *props = NULL;
    graphid object_graph_id;
    graphid start_vertex_graph_id;
    graphid end_vertex_graph_id;

    Oid vtx_seq_id;
    Oid edge_seq_id;

    char* graph_name_str;
    char* vtx_name_str;
    char* edge_name_str;

    graph_cache_data *graph_cache;
    label_cache_data *vertex_cache;
    label_cache_data *edge_cache;

    Oid nsp_id;
    Name vtx_seq_name;
    char *vtx_seq_name_str;

    Name edge_seq_name;
    char *edge_seq_name_str;

    int64 lid;

    if (PG_ARGISNULL(0))
    {
        ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                        errmsg("graph name can not be NULL")));
    }

    if (PG_ARGISNULL(1))
    {
        ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                        errmsg("number of nodes can not be NULL")));
    }

    if (PG_ARGISNULL(2))
    {
        ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                        errmsg("edge label can not be NULL")));
    }

    graph_name = PG_GETARG_NAME(0);
    no_vertices = (int64) PG_GETARG_INT64(1);
    edge_label_name = PG_GETARG_NAME(2);

    graph_name_str = NameStr(*graph_name);
    vtx_name_str = AG_DEFAULT_LABEL_VERTEX;
    edge_name_str = NameStr(*edge_label_name);

    if (!PG_ARGISNULL(3))
    {
        vtx_label_name = PG_GETARG_NAME(3);
        vtx_name_str = NameStr(*vtx_label_name);

        /* Check if vertex and edge label are same */
        if (strcmp(vtx_name_str, edge_name_str) == 0)
        {
            ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                    errmsg("vertex and edge label can not be same")));
        }
    }

    if (!graph_exists(graph_name_str))
    {
        DirectFunctionCall1(create_graph, CStringGetDatum(graph_name->data));
    }

    graph_oid = get_graph_oid(graph_name_str);

    if (!PG_ARGISNULL(3))
    {
        /* Check if label with the input name already exists */
        if (!label_exists(vtx_name_str, graph_oid))
        {
            DirectFunctionCall2(create_vlabel,
                                CStringGetDatum(graph_name->data),
                                CStringGetDatum(vtx_label_name->data));
        }
    }

    if (!label_exists(edge_name_str, graph_oid))
    {
        DirectFunctionCall2(create_elabel,
                            CStringGetDatum(graph_name->data),
                            CStringGetDatum(edge_label_name->data));
    }

    vtx_label_id = get_label_id(vtx_name_str, graph_oid);
    edge_label_id = get_label_id(edge_name_str, graph_oid);

    graph_cache = search_graph_name_cache(graph_name_str);
    vertex_cache = search_label_name_graph_cache(vtx_name_str, graph_oid);
    edge_cache = search_label_name_graph_cache(edge_name_str, graph_oid);

    nsp_id = graph_cache->namespace;
    vtx_seq_name = &(vertex_cache->seq_name);
    vtx_seq_name_str = NameStr(*vtx_seq_name);

    edge_seq_name = &(edge_cache->seq_name);
    edge_seq_name_str = NameStr(*edge_seq_name);

    vtx_seq_id = get_relname_relid(vtx_seq_name_str, nsp_id);
    edge_seq_id = get_relname_relid(edge_seq_name_str, nsp_id);

    props = create_empty_agtype();

    /* Creating vertices*/
    for (i=(int64)1; i<=no_vertices; i++)
    {
        vid = nextval_internal(vtx_seq_id, true);
        object_graph_id = make_graphid(vtx_label_id, vid);
        insert_vertex_simple(graph_oid, vtx_name_str, object_graph_id, props);
    }

    lid = vid;

    /* Creating edges*/
    for (i = 1; i<=no_vertices-1; i++)
    {
        start_vid = lid-no_vertices+i;
        for(j=i+1; j<=no_vertices; j++)
        {
            end_vid = lid-no_vertices+j;
            eid = nextval_internal(edge_seq_id, true);
            object_graph_id = make_graphid(edge_label_id, eid);

            start_vertex_graph_id = make_graphid(vtx_label_id, start_vid);
            end_vertex_graph_id = make_graphid(vtx_label_id, end_vid);

            insert_edge_simple(graph_oid, edge_name_str, object_graph_id,
                               start_vertex_graph_id, end_vertex_graph_id,
                               props);
        }
    }
    PG_RETURN_VOID();
}