1#include <stdint.h>
2#include <string.h>
3
4static inline uint32_t swapc(uint32_t x, int c)
5{
6	return c ? x>>24 | x>>8&0xff00 | x<<8&0xff0000 | x<<24 : x;
7}
8
9const char *__mo_lookup(const void *p, size_t size, const char *s)
10{
11	const uint32_t *mo = p;
12	int sw = *mo - 0x950412de;
13	uint32_t b = 0, n = swapc(mo[2], sw);
14	uint32_t o = swapc(mo[3], sw);
15	uint32_t t = swapc(mo[4], sw);
16	if (n>=size/4 || o>=size-4*n || t>=size-4*n || ((o|t)%4))
17		return 0;
18	o/=4;
19	t/=4;
20	for (;;) {
21		uint32_t ol = swapc(mo[o+2*(b+n/2)], sw);
22		uint32_t os = swapc(mo[o+2*(b+n/2)+1], sw);
23		if (os >= size || ol >= size-os || ((char *)p)[os+ol])
24			return 0;
25		int sign = strcmp(s, (char *)p + os);
26		if (!sign) {
27			uint32_t tl = swapc(mo[t+2*(b+n/2)], sw);
28			uint32_t ts = swapc(mo[t+2*(b+n/2)+1], sw);
29			if (ts >= size || tl >= size-ts || ((char *)p)[ts+tl])
30				return 0;
31			return (char *)p + ts;
32		}
33		else if (n == 1) return 0;
34		else if (sign < 0)
35			n /= 2;
36		else {
37			b += n/2;
38			n -= n/2;
39		}
40	}
41	return 0;
42}
43