/*
* Returns:
* 0 => OK
* -1 => error
*/
int
__big_split(
HTAB *hashp,
BUFHEAD *op, /* Pointer to where to put keys that go in old bucket */
BUFHEAD *np, /* Pointer to new bucket page */
/* Pointer to first page containing the big key/data */
BUFHEAD *big_keyp,
int addr, /* Address of big_keyp */
uint32_t obucket,/* Old Bucket */
SPLIT_RETURN *ret
)
{
BUFHEAD *tmpp;
uint16_t *tp;
BUFHEAD *bp;
DBT key, val;
uint32_t change;
uint16_t free_space, n, off;
size_t temp;
bp = big_keyp;
/* Now figure out where the big key/data goes */
if (__big_keydata(hashp, big_keyp, &key, &val, 0))
return (-1);
change = (__call_hash(hashp, key.data, (int)key.size) != obucket);
if ((ret->next_addr = __find_last_page(hashp, &big_keyp)) != 0) {
if (!(ret->nextp =
__get_buf(hashp, (uint32_t)ret->next_addr, big_keyp, 0)))
return (-1);
} else
ret->nextp = NULL;
/* Now make one of np/op point to the big key/data pair */
_DIAGASSERT(np->ovfl == NULL);
if (change)
tmpp = np;
else
tmpp = op;
tmpp->flags |= BUF_MOD;
#ifdef DEBUG1
(void)fprintf(stderr,
"BIG_SPLIT: %d->ovfl was %d is now %d\n", tmpp->addr,
(tmpp->ovfl ? tmpp->ovfl->addr : 0), (bp ? bp->addr : 0));
#endif
tmpp->ovfl = bp; /* one of op/np point to big_keyp */
tp = (uint16_t *)(void *)tmpp->page;
_DIAGASSERT(FREESPACE(tp) >= OVFLSIZE);
n = tp[0];
off = OFFSET(tp);
free_space = FREESPACE(tp);
tp[++n] = (uint16_t)addr;
tp[++n] = OVFLPAGE;
tp[0] = n;
OFFSET(tp) = off;
temp = free_space - OVFLSIZE;
_DBFIT(temp, uint16_t);
FREESPACE(tp) = (uint16_t)temp;
/*
* Finally, set the new and old return values. BIG_KEYP contains a
* pointer to the last page of the big key_data pair. Make sure that
* big_keyp has no following page (2 elements) or create an empty
* following page.
*/
ret->newp = np;
ret->oldp = op;
tp = (uint16_t *)(void *)big_keyp->page;
big_keyp->flags |= BUF_MOD;
if (tp[0] > 2) {
/*
* There may be either one or two offsets on this page. If
* there is one, then the overflow page is linked on normally
* and tp[4] is OVFLPAGE. If there are two, tp[4] contains
* the second offset and needs to get stuffed in after the
* next overflow page is added.
*/
n = tp[4];
free_space = FREESPACE(tp);
off = OFFSET(tp);
tp[0] -= 2;
temp = free_space + OVFLSIZE;
_DBFIT(temp, uint16_t);
FREESPACE(tp) = (uint16_t)temp;
OFFSET(tp) = off;
tmpp = __add_ovflpage(hashp, big_keyp);
if (!tmpp)
return (-1);
tp[4] = n;
} else
tmpp = big_keyp;
if (change)
ret->newp = tmpp;
else
ret->oldp = tmpp;
return (0);
}
/*
* Assume that hashp has been set in wrapper routine.
*/
static int
hash_access(HTAB *hashp, ACTION action, DBT *key, DBT *val)
{
BUFHEAD *rbufp;
BUFHEAD *bufp, *save_bufp;
u_int16_t *bp;
int n, ndx, off, size;
char *kp;
u_int16_t pageno;
#ifdef HASH_STATISTICS
hash_accesses++;
#endif
off = hashp->BSIZE;
size = key->size;
kp = (char *)key->data;
rbufp = __get_buf(hashp, __call_hash(hashp, kp, size), NULL, 0);
if (!rbufp)
return (ERROR);
save_bufp = rbufp;
/* Pin the bucket chain */
rbufp->flags |= BUF_PIN;
for (bp = (u_int16_t *)rbufp->page, n = *bp++, ndx = 1; ndx < n;)
if (bp[1] >= REAL_KEY) {
/* Real key/data pair */
if (size == off - *bp &&
memcmp(kp, rbufp->page + *bp, size) == 0)
goto found;
off = bp[1];
#ifdef HASH_STATISTICS
hash_collisions++;
#endif
bp += 2;
ndx += 2;
} else if (bp[1] == OVFLPAGE) {
rbufp = __get_buf(hashp, *bp, rbufp, 0);
if (!rbufp) {
save_bufp->flags &= ~BUF_PIN;
return (ERROR);
}
/* FOR LOOP INIT */
bp = (u_int16_t *)rbufp->page;
n = *bp++;
ndx = 1;
off = hashp->BSIZE;
} else if (bp[1] < REAL_KEY) {
if ((ndx =
__find_bigpair(hashp, rbufp, ndx, kp, size)) > 0)
goto found;
if (ndx == -2) {
bufp = rbufp;
if (!(pageno =
__find_last_page(hashp, &bufp))) {
ndx = 0;
rbufp = bufp;
break; /* FOR */
}
rbufp = __get_buf(hashp, pageno, bufp, 0);
if (!rbufp) {
save_bufp->flags &= ~BUF_PIN;
return (ERROR);
}
/* FOR LOOP INIT */
bp = (u_int16_t *)rbufp->page;
n = *bp++;
ndx = 1;
off = hashp->BSIZE;
} else {
save_bufp->flags &= ~BUF_PIN;
return (ERROR);
}
}
/* Not found */
switch (action) {
case HASH_PUT:
case HASH_PUTNEW:
if (__addel(hashp, rbufp, key, val)) {
save_bufp->flags &= ~BUF_PIN;
return (ERROR);
} else {
save_bufp->flags &= ~BUF_PIN;
return (SUCCESS);
}
case HASH_GET:
case HASH_DELETE:
default:
save_bufp->flags &= ~BUF_PIN;
return (ABNORMAL);
}
found:
switch (action) {
case HASH_PUTNEW:
save_bufp->flags &= ~BUF_PIN;
return (ABNORMAL);
case HASH_GET:
bp = (u_int16_t *)rbufp->page;
if (bp[ndx + 1] < REAL_KEY) {
if (__big_return(hashp, rbufp, ndx, val, 0))
return (ERROR);
} else {
val->data = (u_char *)rbufp->page + (int)bp[ndx + 1];
val->size = bp[ndx] - bp[ndx + 1];
}
break;
case HASH_PUT:
if ((__delpair(hashp, rbufp, ndx)) ||
(__addel(hashp, rbufp, key, val))) {
save_bufp->flags &= ~BUF_PIN;
return (ERROR);
}
break;
case HASH_DELETE:
if (__delpair(hashp, rbufp, ndx))
return (ERROR);
break;
default:
abort();
}
save_bufp->flags &= ~BUF_PIN;
return (SUCCESS);
}
/*
* Assume that hashp has been set in wrapper routine.
*/
static int
hash_access(
HTAB *hashp,
ACTION action,
DBT *key, DBT *val)
{
register BUFHEAD *rbufp;
BUFHEAD *bufp, *save_bufp;
register uint16 *bp;
register long n, ndx, off;
register size_t size;
register char *kp;
uint16 pageno;
uint32 ovfl_loop_count=0;
int32 last_overflow_page_no = -1;
#ifdef HASH_STATISTICS
hash_accesses++;
#endif
off = hashp->BSIZE;
size = key->size;
kp = (char *)key->data;
rbufp = __get_buf(hashp, __call_hash(hashp, kp, size), NULL, 0);
if (!rbufp)
return (DATABASE_CORRUPTED_ERROR);
save_bufp = rbufp;
/* Pin the bucket chain */
rbufp->flags |= BUF_PIN;
for (bp = (uint16 *)rbufp->page, n = *bp++, ndx = 1; ndx < n;)
{
if (bp[1] >= REAL_KEY) {
/* Real key/data pair */
if (size == (unsigned long)(off - *bp) &&
memcmp(kp, rbufp->page + *bp, size) == 0)
goto found;
off = bp[1];
#ifdef HASH_STATISTICS
hash_collisions++;
#endif
bp += 2;
ndx += 2;
} else if (bp[1] == OVFLPAGE) {
/* database corruption: overflow loop detection */
if(last_overflow_page_no == (int32)*bp)
return (DATABASE_CORRUPTED_ERROR);
last_overflow_page_no = *bp;
rbufp = __get_buf(hashp, *bp, rbufp, 0);
if (!rbufp) {
save_bufp->flags &= ~BUF_PIN;
return (DBM_ERROR);
}
ovfl_loop_count++;
if(ovfl_loop_count > MAX_OVERFLOW_HASH_ACCESS_LOOPS)
return (DATABASE_CORRUPTED_ERROR);
/* FOR LOOP INIT */
bp = (uint16 *)rbufp->page;
n = *bp++;
ndx = 1;
off = hashp->BSIZE;
} else if (bp[1] < REAL_KEY) {
if ((ndx =
__find_bigpair(hashp, rbufp, ndx, kp, (int)size)) > 0)
goto found;
if (ndx == -2) {
bufp = rbufp;
if (!(pageno =
__find_last_page(hashp, &bufp))) {
ndx = 0;
rbufp = bufp;
break; /* FOR */
}
rbufp = __get_buf(hashp, pageno, bufp, 0);
if (!rbufp) {
save_bufp->flags &= ~BUF_PIN;
return (DBM_ERROR);
}
/* FOR LOOP INIT */
bp = (uint16 *)rbufp->page;
n = *bp++;
ndx = 1;
off = hashp->BSIZE;
} else {
save_bufp->flags &= ~BUF_PIN;
return (DBM_ERROR);
}
}
}
/* Not found */
switch (action) {
case HASH_PUT:
case HASH_PUTNEW:
if (__addel(hashp, rbufp, key, val)) {
save_bufp->flags &= ~BUF_PIN;
return (DBM_ERROR);
} else {
save_bufp->flags &= ~BUF_PIN;
return (SUCCESS);
}
case HASH_GET:
case HASH_DELETE:
default:
save_bufp->flags &= ~BUF_PIN;
return (ABNORMAL);
}
found:
switch (action) {
case HASH_PUTNEW:
save_bufp->flags &= ~BUF_PIN;
return (ABNORMAL);
case HASH_GET:
bp = (uint16 *)rbufp->page;
if (bp[ndx + 1] < REAL_KEY) {
if (__big_return(hashp, rbufp, ndx, val, 0))
return (DBM_ERROR);
} else {
val->data = (uint8 *)rbufp->page + (int)bp[ndx + 1];
val->size = bp[ndx] - bp[ndx + 1];
}
break;
case HASH_PUT:
if ((__delpair(hashp, rbufp, ndx)) ||
(__addel(hashp, rbufp, key, val))) {
save_bufp->flags &= ~BUF_PIN;
return (DBM_ERROR);
}
break;
case HASH_DELETE:
if (__delpair(hashp, rbufp, ndx))
return (DBM_ERROR);
break;
default:
abort();
}
save_bufp->flags &= ~BUF_PIN;
return (SUCCESS);
}
