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#include "cdbpriv.h"
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#ifndef SEEK_SET
#define SEEK_SET 0
#endif
RCSID("$Id: cdb_find.c,v 1.2 2000/02/29 19:31:33 shmit Exp $");
static int
cdb_bread(char **ptr, char *endptr, unsigned char *buf, unsigned int len)
{
if ((*ptr)+len > endptr) {
errno = EIO;
return -1;
}
memcpy(buf, *ptr, len);
*ptr += len;
return 0;
}
static int
match(char **ptr, char *endptr, const unsigned char *key, unsigned int len)
{
unsigned char buf[32];
int n;
int i;
n = sizeof(buf);
if (n > len)
n = len;
while (len > 0) {
if (cdb_bread(ptr, endptr, buf, n) == -1)
return -1;
for (i = 0; i < n; ++i)
if (buf[i] != key[i])
return 0;
key += n;
len -= n;
}
return 1;
}
int
cdb_find(char *buff, off_t bufflen, const unsigned char *key,
unsigned int len, char **ret, uint32_t *retlen)
{
char *cur, *end;
unsigned char packbuf[8];
uint32_t pos;
uint32_t h;
uint32_t lenhash;
uint32_t h2;
uint32_t loop;
uint32_t poskd;
cur = buff;
end = buff + bufflen;
h = cdb_hash(key, len);
pos = 8 * (h & 255);
cur += pos;
if (cur > end) {
errno = EIO;
return -1;
}
if (cdb_bread(&cur, end, packbuf, 8) == -1)
return -1;
pos = cdb_unpack(packbuf);
lenhash = cdb_unpack(packbuf + 4);
if (!lenhash) return 0;
h2 = (h >> 8) % lenhash;
for (loop = 0; loop < lenhash; ++loop) {
cur = buff + (pos + 8 * h2);
if (cur > end) {
errno = EIO;
return -1;
}
if (cdb_bread(&cur, end, packbuf, 8) == -1)
return -1;
poskd = cdb_unpack(packbuf + 4);
if (!poskd)
return 0;
if (cdb_unpack(packbuf) == h) {
cur = buff + poskd;
if (cur > end) {
errno = EIO;
return -1;
}
if (cdb_bread(&cur, end, packbuf, 8) == -1)
return -1;
if (cdb_unpack(packbuf) == len) {
switch(match(&cur, end, key, len)) {
case -1:
return -1;
case 1:
*retlen = cdb_unpack(&packbuf[4]);
*ret = cur;
return 1;
}
}
}
if (++h2 == lenhash)
h2 = 0;
}
return 0;
}
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