[PING^3][PATCH v3] Improve fnmatch performance.

[Ondřej Bílka]

ping
On Wed, Aug 12, 2015 at 07:41:20AM +0200, Ondřej Bílka wrote:
> ping
> On Tue, Jun 16, 2015 at 07:30:17PM +0200, Ondřej Bílka wrote:
> > On Tue, Jun 09, 2015 at 04:27:48PM +0200, Ondřej Bílka wrote:
> > > On Wed, May 13, 2015 at 09:48:27AM -0700, Paul Eggert wrote:
> > > > Ondřej Bílka wrote:
> > > > >How to synchronize this with gnulib? Only implementation specific detail
> > > > >is utf8 detection.
> > > > 
> > > > It could be something like this:
> > > > 
> > > >  #if _LIBC
> > > >   struct __locale_data *current = _NL_CURRENT_LOCALE->__locales[LC_COLLATE];
> > > >   uint_fast32_t encoding =
> > > >     current->values[_NL_ITEM_INDEX (_NL_COLLATE_ENCODING_TYPE)].word;
> > > >   bool is_utf8 = encoding == !__cet_other;
> > > >  #else
> > > >   bool is_utf8 = STRCASEEQ (locale_charset (),
> > > >                             "UTF-8", 'U','T','F','-','8',0,0,0,0)
> > > >  #endif
> > > > 
> > > > We should package this sort of thing up and make it easier to use,
> > > > but that could be another day.
> > > 
> > > Yes I will use that pattern, it needs to change details like that it
> > > also works for single-byte encodings.
> > > 
> > > I also removed expect on MB_CUR_MAX as unicode is widespread.
> > > 
> > > Also I now return directly match when entire pattern is normal and
> > > FNM_PERIOD or FNM_FILE_NAME wasn't set which could also help performance
> > > a bit.
> > > 
> > > Then I could allow nonascii characters to start pattern unless its utf8
> > > and you have FNM_CASEFOLD, would it be better to add two tables or check
> > > for testing these?
> > > 
> > > 	* posix/fnmatch.c (fnmatch): Improve performance.
> > > 
> > > diff --git a/posix/fnmatch.c b/posix/fnmatch.c
> > > index fd85efa..4c32992 100644
> > > --- a/posix/fnmatch.c
> > > +++ b/posix/fnmatch.c
> > > @@ -131,6 +131,13 @@ extern int fnmatch (const char *pattern, const char *string, int flags);
> > >  #   define ISWCTYPE(WC, WT)	iswctype (WC, WT)
> > >  #  endif
> > >  
> > > +#  ifdef _LIBC
> > > +#   define STRCASESTR		__strcasestr
> > > +#  else
> > > +#   define STRCASESTR		strcasestr
> > > +#  endif
> > > +
> > > +
> > >  #  if (HAVE_MBSTATE_T && HAVE_MBSRTOWCS) || _LIBC
> > >  /* In this case we are implementing the multibyte character handling.  */
> > >  #   define HANDLE_MULTIBYTE	1
> > > @@ -332,8 +339,62 @@ fnmatch (pattern, string, flags)
> > >       const char *string;
> > >       int flags;
> > >  {
> > > +
> > > +  /* ASCII with \+/.*?[{(@! excluded.  */
> > > +  static unsigned char normal[256] = {
> > > + 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
> > > + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
> > > + 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 0, 0, 
> > > + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0,
> > > + 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
> > > + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1,
> > > + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
> > > + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1,
> > > + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
> > > + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
> > > + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
> > > + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
> > > + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
> > > + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
> > > + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
> > > + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
> > > + };
> > > +#  if _LIBC
> > > +   struct __locale_data *current = _NL_CURRENT_LOCALE->__locales[LC_COLLATE];
> > > +   uint_fast32_t encoding =
> > > +     current->values[_NL_ITEM_INDEX (_NL_COLLATE_ENCODING_TYPE)].word;
> > > +   bool fast_encoding = (encoding != __cet_other);
> > > +#  else
> > > +#   if HANDLE_MULTIBYTE
> > > +   bool is_utf8 = STRCASEEQ (locale_charset (),
> > > +                             "UTF-8", 'U','T','F','-','8',0,0,0,0);
> > > +   bool fast_encoding = (MB_CUR_MAX == 1) || is_utf;
> > > +#   else
> > > +   bool fast_encoding = true;
> > > +#   endif
> > > +#  endif
> > > +
> > > +  if (fast_encoding)
> > > +    {
> > > +      char start[8];
> > > +      char *string2;
> > > +      size_t i;
> > > +      for (i = 0; i < 7 && normal[(unsigned char) pattern[i]]; i++)
> > > +        start[i] = pattern[i];
> > > +      start[i] = 0;
> > > +      if (flags & FNM_CASEFOLD)
> > > +        string2 = STRCASESTR (string, start);
> > > +      else  
> > > +        string2 = strstr (string, start);
> > > +      if (!string2)
> > > +        return FNM_NOMATCH;
> > > + 
> > > +      if (pattern[i] == '\0' && (flags & (FNM_FILE_NAME | FNM_PERIOD)) == 0)
> > > +        return 0; 
> > > +    }
> > > +
> > >  # if HANDLE_MULTIBYTE
> > > -  if (__builtin_expect (MB_CUR_MAX, 1) != 1)
> > > +  if (MB_CUR_MAX != 1)
> > >      {
> > >        mbstate_t ps;
> > >        size_t n;
> > 

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