Merge pull request #35 from helium/adt/vss-optimization

When leader elections are disabled, ignore messages for unselected VSSes
helium · Mar 26, 2021 · 0260f48 · 0260f48
2 parents 303ccb8 + 687cff7
commit 0260f48
Showing 1 changed file with 78 additions and 55 deletions.
diff --git a/src/dkg_hybriddkg.erl b/src/dkg_hybriddkg.erl
@@ -117,65 +117,75 @@ start(DKG = #dkg{id=Id, u=G1}) ->
  {send, dkg_util:wrap({vss, Id}, ToSend)}}.
 
 handle_msg(DKG=#dkg{await_vss = true}, Sender, {{vss, SharesId}, SharesMsg}) ->
- case dkg_hybridvss:handle_msg(maps:get(SharesId, DKG#dkg.shares_map), Sender, SharesMsg) of
- {_Shares, ignore} ->
- {DKG, ignore};
- {NewShares, ok} ->
- {DKG#dkg{shares_map=maps:put(SharesId, NewShares, DKG#dkg.shares_map)}, ok};
- {NewShares, {send, ToSend}} ->
- {DKG#dkg{shares_map=maps:put(SharesId, NewShares, DKG#dkg.shares_map)},
- {send, dkg_util:wrap({vss, SharesId}, ToSend)}};
- {NewShares, {result, {_Session, Commitment, Si}}} ->
- NewDKG = DKG#dkg{shares_map = maps:put(SharesId, NewShares, DKG#dkg.shares_map),
- shares_results = maps:put(SharesId, {Commitment, Si}, DKG#dkg.shares_results),
- shares_seen = [SharesId | DKG#dkg.shares_seen]
- },
- case output_ready(NewDKG, NewDKG#dkg.shares_acked) of
- true ->
- {Shard, VerificationKey, PublicKeyShares} = output(NewDKG, NewDKG#dkg.shares_acked),
- {NewDKG, {result, {Shard, VerificationKey, PublicKeyShares}}};
- false ->
- {NewDKG, ok}
- end
+ case is_chosen_vss(SharesId, DKG) of
+ true ->
+ case dkg_hybridvss:handle_msg(maps:get(SharesId, DKG#dkg.shares_map), Sender, SharesMsg) of
+ {_Shares, ignore} ->
+ {DKG, ignore};
+ {NewShares, ok} ->
+ {DKG#dkg{shares_map=maps:put(SharesId, NewShares, DKG#dkg.shares_map)}, ok};
+ {NewShares, {send, ToSend}} ->
+ {DKG#dkg{shares_map=maps:put(SharesId, NewShares, DKG#dkg.shares_map)},
+ {send, dkg_util:wrap({vss, SharesId}, ToSend)}};
+ {NewShares, {result, {_Session, Commitment, Si}}} ->
+ NewDKG = DKG#dkg{shares_map = maps:put(SharesId, NewShares, DKG#dkg.shares_map),
+ shares_results = maps:put(SharesId, {Commitment, Si}, DKG#dkg.shares_results),
+ shares_seen = [SharesId | DKG#dkg.shares_seen]
+ },
+ case output_ready(NewDKG, NewDKG#dkg.shares_acked) of
+ true ->
+ {Shard, VerificationKey, PublicKeyShares} = output(NewDKG, NewDKG#dkg.shares_acked),
+ {NewDKG, {result, {Shard, VerificationKey, PublicKeyShares}}};
+ false ->
+ {NewDKG, ok}
+ end
+ end;
+ false ->
+ {DKG, ignore}
  end;
 handle_msg(DKG=#dkg{leader = Leader}, Sender, {{vss, SharesId}, SharesMsg}) ->
- case dkg_hybridvss:handle_msg(maps:get(SharesId, DKG#dkg.shares_map), Sender, SharesMsg) of
- {_Shares, ignore} ->
- {DKG, ignore};
- {NewShares, ok} ->
- {DKG#dkg{shares_map=maps:put(SharesId, NewShares, DKG#dkg.shares_map)}, ok};
- {NewShares, {send, ToSend}} ->
- {DKG#dkg{shares_map=maps:put(SharesId, NewShares, DKG#dkg.shares_map)}, {send, dkg_util:wrap({vss, SharesId}, ToSend)}};
- {NewShares, {result, {_Session, Commitment, Si}}} ->
- %% upon (Pd, τ, out, shared, Cd , si,d , Rd ) (first time):
- %%  Qhat ← {Pd}; Rhat ← {Rd}
- %% if |Qhat| = t + 1 and Qbar = ∅ then
- %% if Pi = L then
- %%  send the message (L, τ, send, Qhat, Rhat) to each Pj
- %%  else
- %% delay ← delay(T); start timer(delay)
-
- NewDKG = DKG#dkg{shares_map = maps:put(SharesId, NewShares, DKG#dkg.shares_map),
- shares_results = maps:put(SharesId, {Commitment, Si}, DKG#dkg.shares_results),
-  shares_seen = [SharesId | DKG#dkg.shares_seen]
- },
- case length(NewDKG#dkg.shares_seen) == NewDKG#dkg.t + 1 andalso length(NewDKG#dkg.shares_acked) == 0 of
- true ->
- case NewDKG#dkg.id == Leader of
+ case is_chosen_vss(SharesId, DKG) of
+ true ->
+ case dkg_hybridvss:handle_msg(maps:get(SharesId, DKG#dkg.shares_map), Sender, SharesMsg) of
+  {_Shares, ignore} ->
+  {DKG, ignore};
+  {NewShares, ok} ->
+  {DKG#dkg{shares_map=maps:put(SharesId, NewShares, DKG#dkg.shares_map)}, ok};
+  {NewShares, {send, ToSend}} ->
+  {DKG#dkg{shares_map=maps:put(SharesId, NewShares, DKG#dkg.shares_map)}, {send, dkg_util:wrap({vss, SharesId}, ToSend)}};
+ {NewShares, {result, {_Session, Commitment, Si}}} ->
+  %% upon (Pd, τ, out, shared, Cd , si,d , Rd ) (first time):
+ %%  Qhat ← {Pd}; Rhat ← {Rd}
+ %% if |Qhat| = t + 1 and Qbar = ∅ then
+  %% if Pi = L then
+  %% send the message (L, τ, send, Qhat, Rhat) to each Pj
+ %% else
+  %% delay ← delay(T); start timer(delay)
+
+ NewDKG = DKG#dkg{shares_map = maps:put(SharesId, NewShares, DKG#dkg.shares_map),
+  shares_results = maps:put(SharesId, {Commitment, Si}, DKG#dkg.shares_results),
+  shares_seen = [SharesId | DKG#dkg.shares_seen]
+  },
+ case length(NewDKG#dkg.shares_seen) == NewDKG#dkg.t + 1 andalso length(NewDKG#dkg.shares_acked) == 0 of
  true ->
- {NewDKG, {send, [{multicast, {send, {vss_ready_proofs,
- [ {SId, dkg_commitment:ready_proofs(C)} || {SId, {C, _}} <- maps:to_list(NewDKG#dkg.shares_results)]
- }
- }
- }
- ]
- }};
+ case NewDKG#dkg.id == Leader of
+ true ->
+ {NewDKG, {send, [{multicast, {send, {vss_ready_proofs,
+ [ {SId, dkg_commitment:ready_proofs(C)} || {SId, {C, _}} <- maps:to_list(NewDKG#dkg.shares_results)]
+ }
+ }
+ }
+ ]
+ }};
+ false ->
+ {NewDKG, start_timer}
+ end;
  false ->
- {NewDKG, start_timer}
- end;
-  false ->
-  {NewDKG, ok}
- end
+ {NewDKG, ok}
+ end
+ end;
+ false ->
+ {DKG, ignore}
  end;
 
 %% upon a message (L, τ, send, Q, R/M) from L (first time):
@@ -646,6 +656,19 @@ result_name(Key) when is_atom(Key) ->
  "result_" ++ Int = L,
  list_to_integer(Int).
 
+is_chosen_vss(_, #dkg{elections_allowed=true}) ->
+ %% never optimize these VSSes away if we do elections
+ true;
+is_chosen_vss(VSSID, DKG) ->
+ case maps:size(DKG#dkg.echo_counts) + maps:size(DKG#dkg.ready_counts) of
+ 0 ->
+ %% no echoes/readies yet, so assume we need it
+ true;
+ _ ->
+ %% check if any echo or ready mentions this VSS ID
+ lists:any(fun({_Leader, SelectedShares}) -> lists:member(VSSID, SelectedShares) end, maps:keys(DKG#dkg.echo_counts) ++ maps:keys(DKG#dkg.ready_counts))
+ end.
+
 -spec status(dkg()) -> map().
 status(DKG) ->
  #{id => DKG#dkg.id,