/* Return the offset of one string within another.
- Copyright (C) 1994-2018 Free Software Foundation, Inc.
+ Copyright (C) 1994-2019 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
- <http://www.gnu.org/licenses/>. */
+ <https://www.gnu.org/licenses/>. */
/*
* My personal strstr() implementation that beats most other algorithms.
/* Two-Way algorithm. */
#define RETURN_TYPE char *
#define AVAILABLE(h, h_l, j, n_l) \
- (((j) + (n_l) <= (h_l)) || ((h_l) += __strnlen ((void*)((h) + (h_l)), 512), \
- (j) + (n_l) <= (h_l)))
+ (((j) + (n_l) <= (h_l)) \
+ || ((h_l) += __strnlen ((void*)((h) + (h_l)), (n_l) + 512), \
+ (j) + (n_l) <= (h_l)))
#define CHECK_EOL (1)
#define RET0_IF_0(a) if (!a) goto ret0
#define CANON_ELEMENT(c) TOLOWER (c)
case-insensitive comparison. This function gives unspecified
results in multibyte locales. */
char *
-STRCASESTR (const char *haystack_start, const char *needle_start)
+STRCASESTR (const char *haystack, const 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++;
- }
- if (*needle)
+
+ /* Handle empty NEEDLE special case. */
+ if (needle[0] == '\0')
+ return (char *) haystack;
+
+ /* Ensure HAYSTACK length is at least as long as NEEDLE length.
+ Since a match may occur early on in a huge HAYSTACK, use strnlen
+ and read ahead a few cachelines for improved performance. */
+ needle_len = strlen (needle);
+ haystack_len = __strnlen (haystack, needle_len + 256);
+ if (haystack_len < needle_len)
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
if (needle_len < LONG_NEEDLE_THRESHOLD)
return two_way_short_needle ((const unsigned char *) haystack,
haystack_len,
- (const unsigned char *) needle_start,
+ (const unsigned char *) needle,
needle_len);
return two_way_long_needle ((const unsigned char *) haystack, haystack_len,
- (const unsigned char *) needle_start,
+ (const unsigned char *) needle,
needle_len);
}