ZMQ lazy pirate pattern - client - erlzmq2

lpc.es

#!/usr/bin/env escript
-module(lpc).

-mode(compile).

-define(request_timeout,2500). %% msecs, (> 1000!)
-define(request_retries,3). %% before we abandon
-define(recv_timeout_enable,true).
-define(recv_timeout,2500). %% msecs

main(_Args) ->
    %% Append project ebin to path
    true = code:add_pathz(filename:dirname(escript:script_name()) ++ "/../ebin"),

    loop(1,connect(),[{retries,?request_retries},{timeout,?request_timeout},{connect,fun connect/0}]).

connect() ->
    %% Create ZMQ client with REQ client socket pattern and connect
    {ok, Ctx} = erlzmq:context(),
    {ok, Sock} = erlzmq:socket(Ctx, req),
    ok = erlzmq:connect(Sock, "tcp://localhost:4321"),

    case ?recv_timeout_enable of
        true -> erlzmq:setsockopt(Sock, rcvtimeo, ?recv_timeout);
        _ -> ignore
    end,

    %% Configure socket to not wait at close
    %% czmq:zctx_set_linger(Ctx, 0),

    {Ctx,Sock}.


loop(Sequence,{Ctx,Sock},Options) ->
    {value,{_,Retries}} = lists:keysearch(retries,1,Options),
    {value,{_,Timeout}} = lists:keysearch(timeout,1,Options),
    loop(0,{Ctx,Sock},Retries,Timeout).

loop(Sequence,{Ctx,Sock},Retries,Timeout) ->
    {_,_,Connection} = send(Sequence,{Ctx,Sock},lazy_pirate,Retries,Timeout),
    timer:sleep(1000),
    loop(Sequence+1,Connection,Retries,Timeout).

send(Sequence,_,lazy_pirate,0,Timeout) ->
    io:format("Fail: ~p~n", [Sequence]),        
    {error, Sequence, connect()};
send(Sequence,{Ctx,Sock},lazy_pirate,Retries,Timeout) ->
    io:format("Trying ~p ~p~n", [Sequence,(4 - Retries)]),
    case erlzmq:send(Sock,integer_to_binary(Sequence)) of
        ok -> case erlzmq:recv(Sock) of
                {ok,Reply} -> io:format("Pass: ~p~n", [Sequence]), {ok,Reply,{Ctx,Sock}};
                {error, eagain} -> send(Sequence,connect(),lazy_pirate,Retries-1,Timeout)
            end;
        error -> send(Sequence,connect(),lazy_pirate,Retries-1,Timeout)
    end.