mirror of
https://github.com/git/git
synced 2024-10-30 14:03:28 +00:00
b21b9f1de3
memmem() is a nice GNU extension for searching a length limited string in another one. This compat version is based on the version found in glibc 2.2 (GPL 2); I only removed the optimization of checking the first char by hand, and generally tried to keep the code simple. We can add it back if memcmp shows up high in a profile, but for now I prefer to keep it (almost trivially) simple. Since I don't really know which platforms beside those with a glibc have their own memmem(), I used a heuristic: if NO_STRCASESTR is set, then NO_MEMMEM is set, too. Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx> Signed-off-by: Junio C Hamano <gitster@pobox.com>
29 lines
668 B
C
29 lines
668 B
C
#include "../git-compat-util.h"
|
|
|
|
void *gitmemmem(const void *haystack, size_t haystack_len,
|
|
const void *needle, size_t needle_len)
|
|
{
|
|
const char *begin = haystack;
|
|
const char *last_possible = begin + haystack_len - needle_len;
|
|
|
|
/*
|
|
* The first occurrence of the empty string is deemed to occur at
|
|
* the beginning of the string.
|
|
*/
|
|
if (needle_len == 0)
|
|
return (void *)begin;
|
|
|
|
/*
|
|
* Sanity check, otherwise the loop might search through the whole
|
|
* memory.
|
|
*/
|
|
if (haystack_len < needle_len)
|
|
return NULL;
|
|
|
|
for (; begin <= last_possible; begin++) {
|
|
if (!memcmp(begin, needle, needle_len))
|
|
return (void *)begin;
|
|
}
|
|
|
|
return NULL;
|
|
}
|