As mentioned above, the SGraph supports bulk updates (inserting of new vertices/edges, and efficient update of individual fields).
I am not sure what you mean by "computation/recomputation". Do you mean, for instance, the computation of PageRank? We do not have, builtin, the ability to perform incremental computation of PageRank after a graph modification. The PageRank computation will have to restart from scratch (or at best, a warm start).
Techniques for doing this do exist in certain cases though. For instance, it is easy to see that shortest path can support such incremental computation as long as you are only adding vertices/edges; never removing. (More generally there is a certain contraction property that has to be proved.)