81 lines
2 KiB
C
81 lines
2 KiB
C
/* cdb_findnext.c: 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;
|
|
|
|
}
|