Hi, Check this:
A wish a day 11: Perl Compatible Regular Expressions in CMake http://www.elpauer.org/?p=684 Unfortunately the student turned out to be a total fraud: he knew nothing about CMake, regular expressions (much less PCRE!), git, and could barely manage with C/C++. After months of explaining *really* basic stuff (such as the difference between a static and a shared library), he silently gave up. I do have an initial implementation and extensive information on how to implement PCRE in CMake. It's just I don't have enough spare time to do that, and at work I cannot justify investing so many time in CMake for free (for now, we don't need advanced regular expressions) On Mon, Nov 14, 2011 at 6:57 PM, Alexandru Ciobanu <a...@rogue-research.com>wrote: > Hi, > > Our team is affected by issue 0012381, that causes extremely poor > performance by CTest. Details here: > http://public.kitware.com/Bug/view.php?id=12381 > > I've created a small test case that demonstrates the problem. Please find > the .cpp file attached. > > From what I see, the RegularExpression class uses Henry Spencer regex > implementation, which is known to be slow for some cases. > > On my machine, the attached example runs in 0.8 sec. Just to process one > string! > $ time ./repr > real 0m0.865s > user 0m0.862s > sys 0m0.002s > > Grep can process 100k such strings in 0.5 sec (which includes reading a > 570MB file from disk): > $ wc -l big.str.txt > 100000 big.str.txt > $ ls -lh big.str.txt > -rw-r--r-- 1 alex staff 572M 14 Nov 12:30 big.str.txt > $ time grep "([^:]+): warning[ \t]*[0-9]+[ \t]*:" big.str.txt > real 0m0.525s > user 0m0.255s > sys 0m0.269s > > I see three ways to fix this problem: > A) use a trusted 3rd party regex library, like re2 or pcre > B) find another self-contained regex implementation > C) try to use the standard POSIX regex available in regex.h on most > systems > > I tried to find another self-contained regex implementation, that we could > use. I found Tiny REX, but it is as slow, in this case, as Henry Spencer's > implementation. > > So what do you think is the best way to proceed about this problem? > > sincerely, > Alex Ciobanu > > > > > -- > > Powered by www.kitware.com > > Visit other Kitware open-source projects at > http://www.kitware.com/opensource/opensource.html > > Please keep messages on-topic and check the CMake FAQ at: > http://www.cmake.org/Wiki/CMake_FAQ > > Follow this link to subscribe/unsubscribe: > http://public.kitware.com/cgi-bin/mailman/listinfo/cmake-developers > -- Pau Garcia i Quiles http://www.elpauer.org (Due to my workload, I may need 10 days to answer)
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