/* Find the first occurrence of NEEDLE in HAYSTACK, using case-insensitive
comparison from the C locale, regardless of the current locale. */
char *
c_strcasestr (const char *haystack_start, const char *needle_start)
{
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 &= (c_tolower ((unsigned char) *haystack++)
== c_tolower ((unsigned char) *needle++));
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);
}
/* Return the first occurrence of NEEDLE in HAYSTACK. Return HAYSTACK
if NEEDLE is empty, otherwise NULL if NEEDLE is not found in
HAYSTACK. */
char *
STRSTR (const char *haystack_start, const char *needle_start)
{
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. */
#if 0
fprintf(stderr, "libc-arm-2012-03-fix strstr called\n");
#endif
/* 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 &= *haystack++ == *needle++;
if (*needle)
return NULL;
if (ok)
return (char *) haystack_start;
/* Reduce the size of haystack using strchr, since it has a smaller
linear coefficient than the Two-Way algorithm. */
needle_len = needle - needle_start;
haystack = strchr (haystack_start + 1, *needle_start);
if (!haystack || __builtin_expect (needle_len == 1, 0))
return (char *) haystack;
needle -= needle_len;
haystack_len = (haystack > haystack_start + needle_len ? 1
: needle_len + haystack_start - haystack);
/* 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, needle_len);
return two_way_long_needle ((const unsigned char *) haystack, haystack_len,
(const unsigned char *) needle, needle_len);
}
void *
twoway_memmem (const void *haystack_start, size_t haystack_len,
const void *needle_start, size_t needle_len)
{
/* 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. */
const unsigned char *haystack = (const unsigned char *) haystack_start;
const unsigned char *needle = (const unsigned char *) needle_start;
if (needle_len == 0)
/* The first occurrence of the empty string is deemed to occur at
the beginning of the string. */
return (void *) haystack;
/* Sanity check, otherwise the loop might search through the whole
memory. */
if (__glibc_unlikely (haystack_len < needle_len))
return NULL;
/* Use optimizations in memchr when possible, to reduce the search
size of haystack using a linear algorithm with a smaller
coefficient. However, avoid memchr for long needles, since we
can often achieve sublinear performance. */
if (needle_len < LONG_NEEDLE_THRESHOLD)
{
haystack = memchr (haystack, *needle, haystack_len);
if (!haystack || __builtin_expect (needle_len == 1, 0))
return (void *) haystack;
haystack_len -= haystack - (const unsigned char *) haystack_start;
if (haystack_len < needle_len)
return NULL;
/* Check whether we have a match. This improves performance since we
avoid the initialization overhead of the two-way algorithm. */
if (memcmp (haystack, needle, needle_len) == 0)
return (void *) haystack;
return two_way_short_needle (haystack, haystack_len, needle, needle_len);
}
else
return two_way_long_needle (haystack, haystack_len, needle, needle_len);
}
