When I looked at the code, I assumed that it wasn't intended for international use I'll have to go back and look to give you details, but it doesn't work for international use or unicode. It would be ok for 8859-1.
> -----Original Message----- > From: Scott MacVicar [mailto:[EMAIL PROTECTED] > Sent: Monday, June 09, 2008 6:58 AM > To: Nuno Lopes > Cc: internals@lists.php.net; Michal Dziemianko > Subject: Re: [PHP-DEV] Algorithm Optimizations - string search > > There is rabin-karp too but its worse case is O(nm) so that > might not be ideal, perhaps we should try to compare all of them. > > Scott > > Nuno Lopes wrote: > > Hi, > > > > So some comments: > > - you have some problems with the indentation. We only use tabs, so > > please stick to that. Also, there are some lines that are > not indented > > correctly > > - Have you considered the Boyer-Moore algorithm? I think > it's a little > > faster than KMP (take a look at e.g. > > http://www.cs.utexas.edu/users/moore/best-ideas/string-searching/) > > - please remove the //TUTAJ SKONCZYLEM comment > > - revert this change (as well as a few other that are similar): > > - for (r_end = r + Z_STRLEN_P(return_value) - 1; r < > r_end; ) { > > + for ( r_end = r + Z_STRLEN_P( return_value ) - 1; r > < r_end; > > ){ (we like small diffs, not long diffs with changes that > also break > > our coding standards. e.g. we don't use space after the '(' char. > > Philip wrote a nice article about diffs at > > http://wiki.php.net/doc/articles/whitespace) > > - in strrpos_reverse_kmp() I think you allocate 4 bytes > less that you > > want > > - I think you've too many comments.. We don't need 1 > comment per line > > :) > > > > After fixing all these points and after running the test suite (with > > valgrind) and make sure there are no regressions, I think it's safe > > for you to commit. Still, I would like to see some > performance figures > > comparing the KMP and the Boyer-Moore (or point me some > papers about > > the subject). > > > > Thanks for your work and good luck for the rest of the SoC > project :) > > > > Nuno > > > > > > ----- Original Message ----- From: "Michal Dziemianko" > > <[EMAIL PROTECTED]> > > To: <internals@lists.php.net> > > Sent: Monday, June 09, 2008 12:39 PM > > Subject: [PHP-DEV] Algorithm Optimizations - string search > > > > > >> Hello, > >> Here: http://212.85.117.53/DIFF.txt is small patch that > will speed > >> up following functions: > >> strpos, > >> stripos, > >> strrpos > >> strripos, > >> and probably some others (all that use zend_memnstr/php_memnstr > >> function) > >> > >> The speedup of zend_memnstr is about 8% on average (about > 30% in case > >> of artificial strings). > >> Functions strrpos and strripos are about 25% faster on average. > >> > >> The only drawback - it needs some additional space (size > of the needle). > >> > >> All functions pass all the tests. > >> > >> If it looks fine than I will apply for cvs account. > >> > >> Cheers, > >> Michal > > > > > > -- > PHP Internals - PHP Runtime Development Mailing List To > unsubscribe, visit: http://www.php.net/unsub.php > > -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
