X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fmemcoll.c;h=23f6f79d9da77fdbc14d826826c8d6e82b2197b5;hb=6add58a9a1e2531ac96079cc063201ef3b3c2b98;hp=09f9f2dd133040dc0288c2552c2ed93fa9967ef8;hpb=89f2b4892655a929a506eff123c9126a88e2c8eb;p=gnulib.git

diff --git a/lib/memcoll.c b/lib/memcoll.c
index 09f9f2dd1..23f6f79d9 100644
--- a/lib/memcoll.c
+++ b/lib/memcoll.c
@@ -1,10 +1,12 @@
 /* Locale-specific memory comparison.
-   Copyright 1999 Free Software Foundation, Inc.
 
-   This program is free software; you can redistribute it and/or modify
+   Copyright (C) 1999, 2002-2004, 2006, 2009-2011 Free Software Foundation,
+   Inc.
+
+   This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 2, or (at your option)
-   any later version.
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
 
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ -12,60 +14,98 @@
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software Foundation,
-   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 /* Contributed by Paul Eggert <eggert@twinsun.com>.  */
 
-#if HAVE_CONFIG_H
-# include <config.h>
-#endif
+#include <config.h>
 
-#if HAVE_STRING_H
-# include <string.h>
-#endif
+#include "memcoll.h"
 
-/* Compare S1 (with length S1LEN) and S2 (with length S2LEN) according
-   to the LC_COLLATE locale.  S1 and S2 do not overlap, and are not
-   adjacent.  Temporarily modify the bytes after S1 and S2, but
-   restore their original contents before returning.  */
-int
-memcoll (char *s1, size_t s1len, char *s2, size_t s2len)
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+
+/* Compare S1 (with size S1SIZE) and S2 (with length S2SIZE) according
+   to the LC_COLLATE locale.  S1 and S2 are both blocks of memory with
+   nonzero sizes, and the last byte in each block must be a null byte.
+   Set errno to an error number if there is an error, and to zero
+   otherwise.  */
+static inline int
+strcoll_loop (char const *s1, size_t s1size, char const *s2, size_t s2size)
 {
   int diff;
-  char n1 = s1[s1len];
-  char n2 = s2[s2len];
 
-  s1[s1len++] = '\0';
-  s2[s2len++] = '\0';
-
-  while (! (diff = strcoll (s1, s2)))
+  while (! (errno = 0, (diff = strcoll (s1, s2)) || errno))
     {
       /* strcoll found no difference, but perhaps it was fooled by NUL
-	 characters in the data.  Work around this problem by advancing
-	 past the NUL chars.  */
+         characters in the data.  Work around this problem by advancing
+         past the NUL chars.  */
       size_t size1 = strlen (s1) + 1;
       size_t size2 = strlen (s2) + 1;
       s1 += size1;
       s2 += size2;
-      s1len -= size1;
-      s2len -= size2;
-
-      if (s1len == 0)
-	{
-	  if (s2len != 0)
-	    diff = -1;
-	  break;
-	}
-      else if (s2len == 0)
-	{
-	  diff = 1;
-	  break;
-	}
+      s1size -= size1;
+      s2size -= size2;
+
+      if (s1size == 0)
+        return - (s2size != 0);
+      if (s2size == 0)
+        return 1;
+    }
+
+  return diff;
+}
+
+/* Compare S1 (with length S1LEN) and S2 (with length S2LEN) according
+   to the LC_COLLATE locale.  S1 and S2 do not overlap, and are not
+   adjacent.  Perhaps temporarily modify the bytes after S1 and S2,
+   but restore their original contents before returning.  Set errno to an
+   error number if there is an error, and to zero otherwise.  */
+int
+memcoll (char *s1, size_t s1len, char *s2, size_t s2len)
+{
+  int diff;
+
+  /* strcoll is slow on many platforms, so check for the common case
+     where the arguments are bytewise equal.  Otherwise, walk through
+     the buffers using strcoll on each substring.  */
+
+  if (s1len == s2len && memcmp (s1, s2, s1len) == 0)
+    {
+      errno = 0;
+      diff = 0;
     }
+  else
+    {
+      char n1 = s1[s1len];
+      char n2 = s2[s2len];
+
+      s1[s1len] = '\0';
+      s2[s2len] = '\0';
 
-  s1[s1len - 1] = n1;
-  s2[s2len - 1] = n2;
+      diff = strcoll_loop (s1, s1len + 1, s2, s2len + 1);
+
+      s1[s1len] = n1;
+      s2[s2len] = n2;
+    }
 
   return diff;
 }
+
+/* Compare S1 (a memory block of size S1SIZE, with a NUL as last byte)
+   and S2 (a memory block of size S2SIZE, with a NUL as last byte)
+   according to the LC_COLLATE locale.  S1SIZE and S2SIZE must be > 0.
+   Set errno to an error number if there is an error, and to zero
+   otherwise.  */
+int
+memcoll0 (char const *s1, size_t s1size, char const *s2, size_t s2size)
+{
+  if (s1size == s2size && memcmp (s1, s2, s1size) == 0)
+    {
+      errno = 0;
+      return 0;
+    }
+  else
+    return strcoll_loop (s1, s1size, s2, s2size);
+}