Function to locate collation weight information for wide characters.

2025-01-03 08:11:08 +00:00 · 1999-12-30 23:59:06 +00:00 · 1999-12-30 23:59:06 +00:00 · 9eb157c875
commit 9eb157c875
parent 4efb5faf8c
1 changed files with 136 additions and 0 deletions
--- a/locale/weightwc.h
+++ b/locale/weightwc.h
@ -0,0 +1,136 @@
+/* Copyright (C) 1996, 1997, 1998, 1999 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Written by Ulrich Drepper, <drepper@cygnus.com>.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+/* Find index of weight.  */
+static inline int32_t
+findidx (const wint_t **cpp)
+{
+  int_fast32_t i;
+  const wint_t *cp;
+  wint_t ch;
+  size_t idx;
+  size_t cnt = 0;
+
+  ch = *(*cpp)++;
+  idx = ch % size;
+  while (names[idx] != ch)
+    {
+      if (++cnt == layers)
+	/* We didn't find the name.  It is case for UNDEFINED.  */
+	return 0;
+      idx += size;
+    }
+  i = table[idx];
+
+  if (i >= 0)
+    /* This is an index into the weight table.  Cool.  */
+    return i;
+
+  /* Oh well, more than one sequence starting with this byte.
+     Search for the correct one.  */
+  cp = &extra[-i];
+  while (1)
+    {
+      size_t nhere;
+      const wint_t *usrc = *cpp;
+
+      /* The first thing is the index.  */
+      i = *((int32_t *) cp);
+      cp += sizeof (int32_t);
+
+      /* Next is the length of the byte sequence.  These are always
+	 short byte sequences so there is no reason to call any
+	 function (even if they are inlined).  */
+      nhere = *cp++;
+
+      if (i >= 0)
+	{
+	  /* It is a single character.  If it matches we found our
+	     index.  Note that at the end of each list there is an
+	     entry of length zero which represents the single byte
+	     sequence.  The first (and here only) byte was tested
+	     already.  */
+	  size_t cnt;
+
+	  for (cnt = 0; cnt < nhere; ++cnt)
+	    if (cp[cnt] != usrc[cnt])
+	      break;
+
+	  if (cnt == nhere)
+	    {
+	      /* Found it.  */
+	      *cpp += nhere;
+	      return i;
+	    }
+
+	  /* Up to the next entry.  */
+	  cp += nhere;
+	}
+      else
+	{
+	  /* This is a range of characters.  First decide whether the
+	     current byte sequence lies in the range.  */
+	  size_t cnt;
+	  size_t offset = 0;
+
+	  for (cnt = 0; cnt < nhere; ++cnt)
+	    if (cp[cnt] != usrc[cnt])
+	      break;
+
+	  if (cnt != nhere)
+	    {
+	      if (cp[cnt] > usrc[cnt])
+		{
+		  /* Cannot be in this range.  */
+		  cp += 2 * nhere;
+		  continue;
+		}
+
+	      /* Test against the end of the range.  */
+	      for (cnt = 0; cnt < nhere; ++cnt)
+		if (cp[nhere + cnt] != usrc[cnt])
+		  break;
+
+	      if (cnt != nhere && cp[nhere + cnt] < usrc[cnt])
+		{
+		  /* Cannot be in this range.  */
+		  cp += 2 * nhere;
+		  continue;
+		}
+
+	      /* This range matches the next characters.  Now find
+		 the offset in the indirect table.  */
+	      for (cnt = 0; cp[cnt] == usrc[cnt]; ++cnt);
+
+	      do
+		{
+		  offset <<= 8;
+		  offset += usrc[cnt] - cp[cnt];
+		}
+	      while (++cnt < nhere);
+	    }
+
+	  *cpp += nhere;
+	  return offset;
+	}
+    }
+
+  /* NOTREACHED */
+  return 0x43219876;
+}