#include "apr_sdbm.h"
#include "sdbm_tune.h"
#include "sdbm_pair.h"
#include "sdbm_private.h"
#include <string.h>
#define exhash(item) sdbm_hash((item).dptr, (item).dsize)
static int seepair(char *, int, char *, int);
int
fitpair(pag, need)
char *pag;
int need;
{
register int n;
register int off;
register int avail;
register short *ino = (short *) pag;
off = ((n = ino[0]) > 0) ? ino[n] : PBLKSIZ;
avail = off - (n + 1) * sizeof(short);
need += 2 * sizeof(short);
debug(("avail %d need %d\n", avail, need));
return need <= avail;
}
void
putpair(pag, key, val)
char *pag;
apr_sdbm_datum_t key;
apr_sdbm_datum_t val;
{
register int n;
register int off;
register short *ino = (short *) pag;
off = ((n = ino[0]) > 0) ? ino[n] : PBLKSIZ;
off -= key.dsize;
(void) memcpy(pag + off, key.dptr, key.dsize);
ino[n + 1] = off;
off -= val.dsize;
(void) memcpy(pag + off, val.dptr, val.dsize);
ino[n + 2] = off;
ino[0] += 2;
}
apr_sdbm_datum_t
getpair(pag, key)
char *pag;
apr_sdbm_datum_t key;
{
register int i;
register int n;
apr_sdbm_datum_t val;
register short *ino = (short *) pag;
if ((n = ino[0]) == 0)
return sdbm_nullitem;
if ((i = seepair(pag, n, key.dptr, key.dsize)) == 0)
return sdbm_nullitem;
val.dptr = pag + ino[i + 1];
val.dsize = ino[i] - ino[i + 1];
return val;
}
int
duppair(pag, key)
char *pag;
apr_sdbm_datum_t key;
{
register short *ino = (short *) pag;
return ino[0] > 0 && seepair(pag, ino[0], key.dptr, key.dsize) > 0;
}
apr_sdbm_datum_t
getnkey(pag, num)
char *pag;
int num;
{
apr_sdbm_datum_t key;
register int off;
register short *ino = (short *) pag;
num = num * 2 - 1;
if (ino[0] == 0 || num > ino[0])
return sdbm_nullitem;
off = (num > 1) ? ino[num - 1] : PBLKSIZ;
key.dptr = pag + ino[num];
key.dsize = off - ino[num];
return key;
}
int
delpair(pag, key)
char *pag;
apr_sdbm_datum_t key;
{
register int n;
register int i;
register short *ino = (short *) pag;
if ((n = ino[0]) == 0)
return 0;
if ((i = seepair(pag, n, key.dptr, key.dsize)) == 0)
return 0;
if (i < n - 1) {
register int m;
register char *dst = pag + (i == 1 ? PBLKSIZ : ino[i - 1]);
register char *src = pag + ino[i + 1];
register short zoo = (short) (dst - src);
debug(("free-up %d ", zoo));
m = ino[i + 1] - ino[n];
#undef DUFF
#ifdef DUFF
#define MOVB *--dst = *--src
if (m > 0) {
register int loop = (m + 8 - 1) >> 3;
switch (m & (8 - 1)) {
case 0: do {
MOVB; case 7: MOVB;
case 6: MOVB; case 5: MOVB;
case 4: MOVB; case 3: MOVB;
case 2: MOVB; case 1: MOVB;
} while (--loop);
}
}
#else
dst -= m;
src -= m;
memmove(dst, src, m);
#endif
while (i < n - 1) {
ino[i] = ino[i + 2] + zoo;
i++;
}
}
ino[0] -= 2;
return 1;
}
static int
seepair(pag, n, key, siz)
char *pag;
register int n;
register char *key;
register int siz;
{
register int i;
register int off = PBLKSIZ;
register short *ino = (short *) pag;
for (i = 1; i < n; i += 2) {
if (siz == off - ino[i] &&
memcmp(key, pag + ino[i], siz) == 0)
return i;
off = ino[i + 1];
}
return 0;
}
void
splpage(pag, new, sbit)
char *pag;
char *new;
long sbit;
{
apr_sdbm_datum_t key;
apr_sdbm_datum_t val;
register int n;
register int off = PBLKSIZ;
char cur[PBLKSIZ];
register short *ino = (short *) cur;
(void) memcpy(cur, pag, PBLKSIZ);
(void) memset(pag, 0, PBLKSIZ);
(void) memset(new, 0, PBLKSIZ);
n = ino[0];
for (ino++; n > 0; ino += 2) {
key.dptr = cur + ino[0];
key.dsize = off - ino[0];
val.dptr = cur + ino[1];
val.dsize = ino[0] - ino[1];
(void) putpair((exhash(key) & sbit) ? new : pag, key, val);
off = ino[1];
n -= 2;
}
debug(("%d split %d/%d\n", ((short *) cur)[0] / 2,
((short *) new)[0] / 2,
((short *) pag)[0] / 2));
}
int
chkpage(pag)
char *pag;
{
register int n;
register int off;
register short *ino = (short *) pag;
if ((n = ino[0]) < 0 || n > PBLKSIZ / sizeof(short))
return 0;
if (n > 0) {
off = PBLKSIZ;
for (ino++; n > 0; ino += 2) {
if (ino[0] > off || ino[1] > off ||
ino[1] > ino[0])
return 0;
off = ino[1];
n -= 2;
}
}
return 1;
}