clusterl_dedup.erl

-module(clusterl_dedup).

-export([init/0, first/1]).

-define(TABLE, ?MODULE).

-define(DELETION_TIMEOUT, 3600000). % 1 hour

init() ->
  ets:new(?TABLE, [public, named_table]).

first(Frame) ->
  Result = ets:insert_new(?TABLE, {Frame}),
  schedule_deletion(Result, Frame),
  Result.

schedule_deletion(false, _Frame) ->
  ignore;
schedule_deletion(true, Frame) ->
  F = fun() ->
          receive after ?DELETION_TIMEOUT ->
                      ets:delete(?TABLE, Frame)
                  end
      end,
  proc_lib:spawn_link(F).

clusterl_network.erl

handle_info({signal, Link, Ip, Frame}, StateName, State) ->
  case clusterl_dedup:first(Frame) of
    false ->
      ignore;
    true ->
      ?FRAME(Time, ?HEADER(From, To, Hops), Data) = Frame,
      RealFrom = case From of
                   origin -> {ip, Ip};
                   _ -> From
                 end,
      handle_frame(Link, Time, RealFrom, To, Hops, Data, State)
  end,
  {next_state, StateName, State};