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
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
|
/* $Id: cdb_findnext.c,v 1.9 2003/11/03 16:42:41 mjt Exp $
* sequential cdb_find routines
*
* This file is a part of tinycdb package by Michael Tokarev, mjt@corpit.ru.
* Public domain.
*/
/* see cdb_find.c for comments */
#include "cdb_int.h"
int
cdb_findinit(struct cdb_find *cdbfp, struct cdb *cdbp,
const void *key, unsigned klen)
{
unsigned n, pos;
cdbfp->cdb_cdbp = cdbp;
cdbfp->cdb_key = key;
cdbfp->cdb_klen = klen;
cdbfp->cdb_hval = cdb_hash(key, klen);
cdbfp->cdb_htp = cdbp->cdb_mem + ((cdbfp->cdb_hval << 3) & 2047);
n = cdb_unpack(cdbfp->cdb_htp + 4);
cdbfp->cdb_httodo = n << 3;
if (!n)
return 0;
pos = cdb_unpack(cdbfp->cdb_htp);
if (n > (cdbp->cdb_fsize >> 3)
|| pos < cdbp->cdb_dend
|| pos > cdbp->cdb_fsize
|| cdbfp->cdb_httodo > cdbp->cdb_fsize - pos)
return errno = EPROTO, -1;
cdbfp->cdb_htab = cdbp->cdb_mem + pos;
cdbfp->cdb_htend = cdbfp->cdb_htab + cdbfp->cdb_httodo;
cdbfp->cdb_htp = cdbfp->cdb_htab + (((cdbfp->cdb_hval >> 8) % n) << 3);
return 1;
}
int
cdb_findnext(struct cdb_find *cdbfp) {
struct cdb *cdbp = cdbfp->cdb_cdbp;
unsigned pos, n;
unsigned klen = cdbfp->cdb_klen;
while(cdbfp->cdb_httodo) {
pos = cdb_unpack(cdbfp->cdb_htp + 4);
if (!pos)
return 0;
n = cdb_unpack(cdbfp->cdb_htp) == cdbfp->cdb_hval;
if ((cdbfp->cdb_htp += 8) >= cdbfp->cdb_htend)
cdbfp->cdb_htp = cdbfp->cdb_htab;
cdbfp->cdb_httodo -= 8;
if (n) {
if (pos > cdbp->cdb_fsize - 8)
return errno = EPROTO, -1;
if (cdb_unpack(cdbp->cdb_mem + pos) == klen) {
if (cdbp->cdb_fsize - klen < pos + 8)
return errno = EPROTO, -1;
if (memcmp(cdbfp->cdb_key,
cdbp->cdb_mem + pos + 8, klen) == 0) {
n = cdb_unpack(cdbp->cdb_mem + pos + 4);
pos += 8;
if (cdbp->cdb_fsize < n ||
cdbp->cdb_fsize - n < pos + klen)
return errno = EPROTO, -1;
cdbp->cdb_kpos = pos;
cdbp->cdb_klen = klen;
cdbp->cdb_vpos = pos + klen;
cdbp->cdb_vlen = n;
return 1;
}
}
}
}
return 0;
}
|
