[erlang-questions] tcp data in a gen_fsm

Frans Schneider schneider@REDACTED
Sun Nov 29 14:27:27 CET 2015

Dear list,

I have a gen_fsm representing the tcp connection to a remote server with 
6 states defined. Tcp data is handled by handle_info with active = 
once.Tcp packets can contain more than one commands/data items.
I would like to feed the data into the different FSM states in the same 
manner as with send_event() and not handle the different states in 
separate handle_info clauses for the different states or a massive 
handle_info clause with a huge case statement.
Question is, can I call the state clauses like this or do I brake OTP 
behavior?This is a client and blocking incoming data is not an issue.

handle_info({tcp, Socket, Raw_data}, State_name, #state{buffer = Buffer} 
= State) ->
     {Datas, Buffer1} = unpack(<<Buffer/binary, Raw_data/binary>>),
     lists:foldl(fun(Data, {StateName_in, State_in}) ->
                         {next_state, StateName_out, State_out} = 
?MODULE:StateName_in({recv, Data}, State_in),
             {StateName_out, State_out}
         end, {State_name, State}, Datas),
     inet:setopts(Socket, [{active, once}]),
     {next_state, active, State#state{buffer = Buffer1}};

I can of course use a seperate process for handling the tcp stuff which 
makes the gen_fsm calls, but was just wondering if this could work as well.



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