Today you sent me mail regarding Re: [rrd-developers] Re: Some minor...: *> > *> Tobi, you wrote about the "INT" operator being more general useful. *> > *> I do agree about that but I do think that if you only want operators *> > *> that fall in that category you should mention it now. I'm sure that *> > *> not only I will come up with other operators that are not-so-general :) *> > *> > I have no general opinion on these issues yet ... but we might have to do *> > some performance evaluations of rrd_graph to see if the CDEF language *> > verbosity has a siginificant impact ... *> > *> *> Am I right in assuming that parsing a line is only done once? *> (inside rrd_graph(), during "case GF_CDEF") *> *> If so: performance should not suffer a lot since the operators are *> looked up from an array. I could be wrong -I'm no programmer- but *> I think that "9,2,/,INT" will cost more than "9,2,DIV" even if DIV *> would not be programmed in that first case. *> *> I'm sure there are C-experts here who can do that test.
the parsing is only done once but there is a switch/case statement for evaluating the expressions. This sitts at the most inner loop of the CDEF function ... I am not sure what the performance implications with large switch statements are ... guess this can be optimized beautifully by the compiler ... cheers tobi *> -- ______ __ _ /_ __/_ / / (_) Oetiker, Timelord & SysMgr @ EE-Dept ETH-Zurich / // _ \/ _ \/ / TEL: +41(0)1-6325286 FAX:...1517 ICQ: 10419518 /_/ \.__/_.__/_/ [EMAIL PROTECTED] http://ee-staff.ethz.ch/~oetiker -- * To unsubscribe from the rrd-developers mailing list, send a message with the subject: unsubscribe to [EMAIL PROTECTED]
