Remove unnecessary intermediate allocations

Summary: TSIA

Reviewed By: michalmuskala

Differential Revision: D69056710

fbshipit-source-id: 05e93bdcbd8dda8fdb99e1c52a2aeab039eef8d4

src/wa_raft_server.erl

@@ -1476,7 +1476,7 @@ candidate(cast, ?REMOTE(?IDENTITY_REQUIRES_MIGRATION(_, NodeId), ?VOTE(true)),
             Duration = erlang:monotonic_time(millisecond) - StateStartTs,
             LastIndex = wa_raft_log:last_index(View),
             {ok, LastTerm} = wa_raft_log:term(View, LastIndex),
-            EstablishedQuorum = [Peer || {Peer, true} <- maps:to_list(Votes1)],
+            EstablishedQuorum = [Peer || Peer := true <- Votes1],
             ?LOG_NOTICE("Server[~0p, term ~0p, candidate] is becoming leader after ~0p ms with log at ~0p:~0p and votes from ~0p.",
                 [Name, CurrentTerm, Duration, LastIndex, LastTerm, EstablishedQuorum], #{domain => [whatsapp, wa_raft]}),
             ?RAFT_GATHER('raft.candidate.election.duration', Duration),