X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;ds=sidebyside;f=lib%2Fstrcasestr.c;h=3cca84ad67918b03c90949b783d9f8c77b4d671c;hb=43593319b31e6b0175b8eec4433bac744959822d;hp=e1f5952c7a9b1d119ba63a35a2fbab6c299a977b;hpb=9dcc0e05407833a59b84cb6b32460242ddc6ff98;p=gnulib.git

diff --git a/lib/strcasestr.c b/lib/strcasestr.c
index e1f5952c7..3cca84ad6 100644
--- a/lib/strcasestr.c
+++ b/lib/strcasestr.c
@@ -1,5 +1,5 @@
 /* Case-insensitive searching in a string.
-   Copyright (C) 2005-2007 Free Software Foundation, Inc.
+   Copyright (C) 2005-2013 Free Software Foundation, Inc.
    Written by Bruno Haible <bruno@clisp.org>, 2005.
 
    This program is free software; you can redistribute it and/or modify
@@ -13,8 +13,7 @@
    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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+   along with this program; if not, see <http://www.gnu.org/licenses/>.  */
 
 #include <config.h>
 
@@ -22,51 +21,62 @@
 #include <string.h>
 
 #include <ctype.h>
-#include <stddef.h>  /* for NULL, in case a nonstandard string.h lacks it */
+#include <stdbool.h>
+#include <strings.h>
 
 #define TOLOWER(Ch) (isupper (Ch) ? tolower (Ch) : (Ch))
 
-/* Find the first occurrence of NEEDLE in HAYSTACK, using case-insensitive
-   comparison.
-   Note: This function may, in multibyte locales, return success even if
-   strlen (haystack) < strlen (needle) !  */
+/* Two-Way algorithm.  */
+#define RETURN_TYPE char *
+#define AVAILABLE(h, h_l, j, n_l)                       \
+  (!memchr ((h) + (h_l), '\0', (j) + (n_l) - (h_l))     \
+   && ((h_l) = (j) + (n_l)))
+#define CANON_ELEMENT(c) TOLOWER (c)
+#define CMP_FUNC(p1, p2, l)                             \
+  strncasecmp ((const char *) (p1), (const char *) (p2), l)
+#include "str-two-way.h"
+
+/* Find the first occurrence of NEEDLE in HAYSTACK, using
+   case-insensitive comparison.  This function gives unspecified
+   results in multibyte locales.  */
 char *
-strcasestr (const char *haystack, const char *needle)
+strcasestr (const char *haystack_start, const char *needle_start)
 {
-  if (*needle != '\0')
-    {
-      /* Speed up the following searches of needle by caching its first
-	 character.  */
-      unsigned char b = TOLOWER ((unsigned char) *needle);
+  const char *haystack = haystack_start;
+  const char *needle = needle_start;
+  size_t needle_len; /* Length of NEEDLE.  */
+  size_t haystack_len; /* Known minimum length of HAYSTACK.  */
+  bool ok = true; /* True if NEEDLE is prefix of HAYSTACK.  */
 
+  /* Determine length of NEEDLE, and in the process, make sure
+     HAYSTACK is at least as long (no point processing all of a long
+     NEEDLE if HAYSTACK is too short).  */
+  while (*haystack && *needle)
+    {
+      ok &= (TOLOWER ((unsigned char) *haystack)
+             == TOLOWER ((unsigned char) *needle));
+      haystack++;
       needle++;
-      for (;; haystack++)
-	{
-	  if (*haystack == '\0')
-	    /* No match.  */
-	    return NULL;
-	  if (TOLOWER ((unsigned char) *haystack) == b)
-	    /* The first character matches.  */
-	    {
-	      const char *rhaystack = haystack + 1;
-	      const char *rneedle = needle;
-
-	      for (;; rhaystack++, rneedle++)
-		{
-		  if (*rneedle == '\0')
-		    /* Found a match.  */
-		    return (char *) haystack;
-		  if (*rhaystack == '\0')
-		    /* No match.  */
-		    return NULL;
-		  if (TOLOWER ((unsigned char) *rhaystack)
-		      != TOLOWER ((unsigned char) *rneedle))
-		    /* Nothing in this round.  */
-		    break;
-		}
-	    }
-	}
     }
-  else
-    return (char *) haystack;
+  if (*needle)
+    return NULL;
+  if (ok)
+    return (char *) haystack_start;
+  needle_len = needle - needle_start;
+  haystack = haystack_start + 1;
+  haystack_len = needle_len - 1;
+
+  /* Perform the search.  Abstract memory is considered to be an array
+     of 'unsigned char' values, not an array of 'char' values.  See
+     ISO C 99 section 6.2.6.1.  */
+  if (needle_len < LONG_NEEDLE_THRESHOLD)
+    return two_way_short_needle ((const unsigned char *) haystack,
+                                 haystack_len,
+                                 (const unsigned char *) needle_start,
+                                 needle_len);
+  return two_way_long_needle ((const unsigned char *) haystack, haystack_len,
+                              (const unsigned char *) needle_start,
+                              needle_len);
 }
+
+#undef LONG_NEEDLE_THRESHOLD