Introduzco una serie de texto en mi analizador SIP. El primero toma el tiempo más largo, no importa cuál sea el primero. Me pregunto si hay algún trabajo de inicialización cuando spirit :: lex realiza el primer análisis.

template <typename Lexer>
struct sip_token : lex::lexer<Lexer>
{
    sip_token()
    {
        this->self.add_pattern
            ("KSIP", "sip:")
            ("KSIPS", "sips:")
            ("USERINFO", "[0-9a-zA-Z-_.!~*'()]+(:[0-9a-zA-Z-_.!~*'()&=+$,]*)?@")
            ("DOMAINLBL", "([0-9a-zA-Z]|([0-9a-zA-Z][0-9a-zA-Z-]*[0-9a-zA-Z]))")
            ("TOPLBL", "[a-zA-Z]|([a-zA-Z][0-9a-zA-Z-]*[0-9a-zA-Z-])")
            ("INVITE", "INVITE")
            ("ACK", "ACK")
            ("OPTIONS", "OPTIONS")
            ("BYE", "BYE")
            ("CANCEL", "CANCEL")
            ("REGISTER", "REGISTER")
            ("METHOD", "({INVITE}|{ACK}|{OPTIONS}|{BYE}|{CANCEL}|{REGISTER})")
            ("SIPVERSION", "SIP\\/[0-9]\\.[0-9]")
            ("PROTOCOAL", "SIP\\/[^/]+\\/UDP")
            ("IPV4ADDR", "(\\d{1,3}\\.){3}\\d{1,3}")                
            ("HOSTNAME", "[^ \t\r\n]+")            
            ("SIPURL", "{KSIP}{USERINFO}?{HOSTNAME}(:[0-9]+)?")
            ("SIPSURL", "{KSIPS}{USERINFO}?{HOSTNAME}(:[0-9]+)?")
            ("SENTBY", "({HOSTNAME}|{IPV4ADDR})(:[0-9]+)?")
            ("GENPARM", "[^ ;\\n]+=[^ ;\r\\n]+")
            ("TOKEN", "[0-9a-zA-Z-.!%*_+~`']+")
            ("NAMEADDR", "({TOKEN} )?<({SIPURL}|{SIPSURL})>")
            ("STATUSCODE", "\\d{3}")
            ("REASONPHRASE", "[0-9a-zA-Z-_.!~*'()&=+$,]*")
            ("CR", "\\r")
            ("LF", "\\n")
        ;

        this->self.add
            ("{METHOD} {SIPURL} {SIPVERSION}", T_REQ_LINE)
            ("{SIPVERSION} {STATUSCODE} {REASONPHRASE}", T_STAT_LINE)
            ("{CR}?{LF}", T_CRLF)
            ("Via: {PROTOCOAL} {SENTBY}(;{GENPARM})*", T_VIA)
            ("To: {NAMEADDR}(;{GENPARM})*", T_TO)
            ("From: {NAMEADDR}(;{GENPARM})*", T_FROM)
            ("[0-9a-zA-Z -_.!~*'()&=+$,;/?:@]+", T_OTHER)

        ;
    }
};

gramática:

template <typename Iterator>
struct sip_grammar : qi::grammar<Iterator>
{
  template <typename TokenDef>
  sip_grammar(TokenDef const& tok)
    : sip_grammar::base_type(start)     
  {
    using boost::phoenix::ref;
    using boost::phoenix::size;
    using boost::spirit::qi::eol;

    start = request  | response;
    response = stat_line >> *(msg_header) >> qi::token(T_CRLF);
    request = req_line >> *(msg_header) >> qi::token(T_CRLF);
    stat_line = qi::token(T_STAT_LINE) >> qi::token(T_CRLF);
    req_line = qi::token(T_REQ_LINE) >> qi::token(T_CRLF);
    msg_header = (qi::token(T_VIA) | qi::token(T_TO) | qi::token(T_FROM) | qi::token(T_OTHER))
      >> qi::token(T_CRLF);    
  }

  std::size_t c, w, l;
  qi::rule<Iterator> start, response, request, stat_line, req_line, msg_header; 
};

sincronización:

gettimeofday(&t1, NULL);
bool r = lex::tokenize_and_parse(first, last, siplexer, g);
gettimeofday(&t2, NULL);    

resultado:

pkt1 time=40945(us)
pkt2 time=140
pkt3 time=60
pkt4 time=74
pkt5 time=58
pkt6 time=51