blob: d18ab7744246bd286fbc8a67117c320a29169700 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
|
#include <stdint.h>
#include <string.h>
static inline uint32_t swapc(uint32_t x, int c)
{
return c ? x>>24 | x>>8&0xff00 | x<<8&0xff0000 | x<<24 : x;
}
const char *__mo_lookup(const void *p, size_t size, const char *s)
{
const uint32_t *mo = p;
int sw = *mo - 0x950412de;
uint32_t b = 0, n = swapc(mo[2], sw);
uint32_t o = swapc(mo[3], sw);
uint32_t t = swapc(mo[4], sw);
if (n>=size/4 || o>=size-4*n || t>=size-4*n || ((o|t)%4))
return 0;
o/=4;
t/=4;
for (;;) {
uint32_t ol = swapc(mo[o+2*(b+n/2)], sw);
uint32_t os = swapc(mo[o+2*(b+n/2)+1], sw);
if (os >= size || ol >= size-os || ((char *)p)[os+ol])
return 0;
int sign = strcmp(s, (char *)p + os);
if (!sign) {
uint32_t tl = swapc(mo[t+2*(b+n/2)], sw);
uint32_t ts = swapc(mo[t+2*(b+n/2)+1], sw);
if (ts >= size || tl >= size-ts || ((char *)p)[ts+tl])
return 0;
return (char *)p + ts;
}
else if (n == 1) return 0;
else if (sign < 0)
n /= 2;
else {
b += n/2;
n -= n/2;
}
}
return 0;
}
|
