Hi Simon, You should never confuse Java byte code with compiled byte code. I understand there are a few superfluous byte codes, but in the end the JVM determines how to compile it to CPU instructions. Unfortunately I am not aware of what the JVM actually does with unused values. Does it do escape analysis already?
Regards, Erik. Simon Kitching schreef: > Erik van Oosten schrieb: > >> Christopher, >> >> As I wrote already on Feb 17: >> There is another aproach, as taken by http://code.google.com/p/log5j/. >> It is >> a wrapper around log4j. I wish they had made it for SLF4J! >> >> I am still waiting for someone to this for SLF4J. It should not be hard. I >> did not yet find the time myself :( >> >> > > Sigh. Broken broken broken. > > Re the "feature" for determining which category to create a logger for, > see the documentation for Exception.getStackTrace. There is no guarantee > that valid info about the callstack is available. So this code will work > fine under unit testing, then may start emitting messages to the wrong > categories when run in a high-performance environment. That will be fun > to debug... > > Re the printf-style formatting: > > log.debug("format str", arg0, arg1, arg2); > > is exactly equivalent to: > > push "format str" onto stack > tmp = new Object[3]; > tmp[0] = arg0; > tmp[1] = arg1; > tmp[2] = arg2; > push tmp onto stack > invoke log.debug > (and of course garbage-collect the tmp object later..) > > So in practice, for good performance you need > if (log.isDebugEnabled()) > around each call anyway. In which case, the printf-style stuff gives no > performance benefits at all; if something is going to be logged then the > formatting is nowhere near the bottleneck step. > > The SLF4J fake-varargs approach, where the api allows 0,1 or 2 params is > slightly better, as it avoids the "new Object[]" call. But for best > performance, isDebugEnabled should be used anyway. > > Regards, > Simon > > _______________________________________________ > user mailing list > user@slf4j.org > http://www.slf4j.org/mailman/listinfo/user > -- -- Erik van Oosten http://day-to-day-stuff.blogspot.com/ _______________________________________________ user mailing list user@slf4j.org http://www.slf4j.org/mailman/listinfo/user