/*
* Called when bufp's page contains a partial key (index should be 1)
*
* All pages in the big key/data pair except bufp are freed. We cannot
* free bufp because the page pointing to it is lost and we can't get rid
* of its pointer.
*
* Returns:
* 0 => OK
*-1 => ERROR
*/
int
__big_delete(HTAB *hashp, BUFHEAD *bufp)
{
BUFHEAD *last_bfp, *rbufp;
uint16_t *bp, pageno;
int key_done, n;
size_t temp;
rbufp = bufp;
last_bfp = NULL;
bp = (uint16_t *)(void *)bufp->page;
pageno = 0;
key_done = 0;
while (!key_done || (bp[2] != FULL_KEY_DATA)) {
if (bp[2] == FULL_KEY || bp[2] == FULL_KEY_DATA)
key_done = 1;
/*
* If there is freespace left on a FULL_KEY_DATA page, then
* the data is short and fits entirely on this page, and this
* is the last page.
*/
if (bp[2] == FULL_KEY_DATA && FREESPACE(bp))
break;
pageno = bp[bp[0] - 1];
rbufp->flags |= BUF_MOD;
rbufp = __get_buf(hashp, (uint32_t)pageno, rbufp, 0);
if (last_bfp)
__free_ovflpage(hashp, last_bfp);
last_bfp = rbufp;
if (!rbufp)
return (-1); /* Error. */
bp = (uint16_t *)(void *)rbufp->page;
}
/*
* If we get here then rbufp points to the last page of the big
* key/data pair. Bufp points to the first one -- it should now be
* empty pointing to the next page after this pair. Can't free it
* because we don't have the page pointing to it.
*/
/* This is information from the last page of the pair. */
n = bp[0];
pageno = bp[n - 1];
/* Now, bp is the first page of the pair. */
bp = (uint16_t *)(void *)bufp->page;
if (n > 2) {
/* There is an overflow page. */
bp[1] = pageno;
bp[2] = OVFLPAGE;
bufp->ovfl = rbufp->ovfl;
} else
/* This is the last page. */
bufp->ovfl = NULL;
n -= 2;
bp[0] = n;
temp = hashp->BSIZE - PAGE_META(n);
_DBFIT(temp, uint16_t);
FREESPACE(bp) = (uint16_t)temp;
OFFSET(bp) = hashp->BSIZE;
bufp->flags |= BUF_MOD;
if (rbufp)
__free_ovflpage(hashp, rbufp);
if (last_bfp && last_bfp != rbufp)
__free_ovflpage(hashp, last_bfp);
hashp->NKEYS--;
return (0);
}
/*
* Called when we encounter an overflow or big key/data page during split
* handling. This is special cased since we have to begin checking whether
* the key/data pairs fit on their respective pages and because we may need
* overflow pages for both the old and new pages.
*
* The first page might be a page with regular key/data pairs in which case
* we have a regular overflow condition and just need to go on to the next
* page or it might be a big key/data pair in which case we need to fix the
* big key/data pair.
*
* Returns:
* 0 ==> success
* -1 ==> failure
*/
static int
ugly_split(
HTAB *hashp,
uint32_t obucket, /* Same as __split_page. */
BUFHEAD *old_bufp,
BUFHEAD *new_bufp,
int copyto, /* First byte on page which contains key/data values. */
int moved /* Number of pairs moved to new page. */
)
{
BUFHEAD *bufp; /* Buffer header for ino */
uint16_t *ino; /* Page keys come off of */
uint16_t *np; /* New page */
uint16_t *op; /* Page keys go on to if they aren't moving */
size_t temp;
BUFHEAD *last_bfp; /* Last buf header OVFL needing to be freed */
DBT key, val;
SPLIT_RETURN ret;
uint16_t n, off, ov_addr, scopyto;
char *cino; /* Character value of ino */
bufp = old_bufp;
ino = (uint16_t *)(void *)old_bufp->page;
np = (uint16_t *)(void *)new_bufp->page;
op = (uint16_t *)(void *)old_bufp->page;
last_bfp = NULL;
scopyto = (uint16_t)copyto; /* ANSI */
n = ino[0] - 1;
while (n < ino[0]) {
if (ino[2] < REAL_KEY && ino[2] != OVFLPAGE) {
if (__big_split(hashp, old_bufp,
new_bufp, bufp, (int)bufp->addr, obucket, &ret))
return (-1);
old_bufp = ret.oldp;
if (!old_bufp)
return (-1);
op = (uint16_t *)(void *)old_bufp->page;
new_bufp = ret.newp;
if (!new_bufp)
return (-1);
np = (uint16_t *)(void *)new_bufp->page;
bufp = ret.nextp;
if (!bufp)
return (0);
cino = (char *)bufp->page;
ino = (uint16_t *)(void *)cino;
last_bfp = ret.nextp;
} else if (ino[n + 1] == OVFLPAGE) {
ov_addr = ino[n];
/*
* Fix up the old page -- the extra 2 are the fields
* which contained the overflow information.
*/
ino[0] -= (moved + 2);
temp = sizeof(uint16_t) * (ino[0] + 3);
_DIAGASSERT(scopyto >= temp);
FREESPACE(ino) = (uint16_t)(scopyto - temp);
OFFSET(ino) = scopyto;
bufp = __get_buf(hashp, (uint32_t)ov_addr, bufp, 0);
if (!bufp)
return (-1);
ino = (uint16_t *)(void *)bufp->page;
n = 1;
scopyto = hashp->BSIZE;
moved = 0;
if (last_bfp)
__free_ovflpage(hashp, last_bfp);
last_bfp = bufp;
}
/* Move regular sized pairs of there are any */
off = hashp->BSIZE;
for (n = 1; (n < ino[0]) && (ino[n + 1] >= REAL_KEY); n += 2) {
cino = (char *)(void *)ino;
key.data = (uint8_t *)cino + ino[n];
key.size = off - ino[n];
val.data = (uint8_t *)cino + ino[n + 1];
val.size = ino[n] - ino[n + 1];
off = ino[n + 1];
if (__call_hash(hashp, key.data, (int)key.size) == obucket) {
/* Keep on old page */
if (PAIRFITS(op, (&key), (&val)))
putpair((char *)(void *)op, &key, &val);
else {
old_bufp =
__add_ovflpage(hashp, old_bufp);
if (!old_bufp)
return (-1);
op = (uint16_t *)(void *)old_bufp->page;
putpair((char *)(void *)op, &key, &val);
}
old_bufp->flags |= BUF_MOD;
} else {
/* Move to new page */
if (PAIRFITS(np, (&key), (&val)))
putpair((char *)(void *)np, &key, &val);
else {
new_bufp =
__add_ovflpage(hashp, new_bufp);
if (!new_bufp)
return (-1);
np = (uint16_t *)(void *)new_bufp->page;
putpair((char *)(void *)np, &key, &val);
}
new_bufp->flags |= BUF_MOD;
}
}
}
if (last_bfp)
__free_ovflpage(hashp, last_bfp);
return (0);
}
static int
ugly_split(HTAB *hashp, uint32 obucket, BUFHEAD *old_bufp,
BUFHEAD *new_bufp, /* Same as __split_page. */ int copyto, int moved)
/* int copyto; First byte on page which contains key/data values. */
/* int moved; Number of pairs moved to new page. */
{
register BUFHEAD *bufp; /* Buffer header for ino */
register uint16 *ino; /* Page keys come off of */
register uint16 *np; /* New page */
register uint16 *op; /* Page keys go on to if they aren't moving */
uint32 loop_detection = 0;
BUFHEAD *last_bfp; /* Last buf header OVFL needing to be freed */
DBT key, val;
SPLIT_RETURN ret;
uint16 n, off, ov_addr, scopyto;
char *cino; /* Character value of ino */
int status;
bufp = old_bufp;
ino = (uint16 *)old_bufp->page;
np = (uint16 *)new_bufp->page;
op = (uint16 *)old_bufp->page;
last_bfp = NULL;
scopyto = (uint16)copyto; /* ANSI */
n = ino[0] - 1;
while (n < ino[0]) {
/* this function goes nuts sometimes and never returns.
* I havent found the problem yet but I need a solution
* so if we loop too often we assume a database curruption error
* :LJM
*/
loop_detection++;
if (loop_detection > MAX_UGLY_SPLIT_LOOPS)
return DATABASE_CORRUPTED_ERROR;
if (ino[2] < REAL_KEY && ino[2] != OVFLPAGE) {
if ((status = __big_split(hashp, old_bufp,
new_bufp, bufp, bufp->addr, obucket, &ret)))
return (status);
old_bufp = ret.oldp;
if (!old_bufp)
return (-1);
op = (uint16 *)old_bufp->page;
new_bufp = ret.newp;
if (!new_bufp)
return (-1);
np = (uint16 *)new_bufp->page;
bufp = ret.nextp;
if (!bufp)
return (0);
cino = (char *)bufp->page;
ino = (uint16 *)cino;
last_bfp = ret.nextp;
} else if (ino[n + 1] == OVFLPAGE) {
ov_addr = ino[n];
/*
* Fix up the old page -- the extra 2 are the fields
* which contained the overflow information.
*/
ino[0] -= (moved + 2);
FREESPACE(ino) =
scopyto - sizeof(uint16) * (ino[0] + 3);
OFFSET(ino) = scopyto;
bufp = __get_buf(hashp, ov_addr, bufp, 0);
if (!bufp)
return (-1);
ino = (uint16 *)bufp->page;
n = 1;
scopyto = hashp->BSIZE;
moved = 0;
if (last_bfp)
__free_ovflpage(hashp, last_bfp);
last_bfp = bufp;
}
/* Move regular sized pairs of there are any */
off = hashp->BSIZE;
for (n = 1; (n < ino[0]) && (ino[n + 1] >= REAL_KEY); n += 2) {
cino = (char *)ino;
key.data = (uint8 *)cino + ino[n];
key.size = off - ino[n];
val.data = (uint8 *)cino + ino[n + 1];
val.size = ino[n] - ino[n + 1];
off = ino[n + 1];
if (__call_hash(hashp, (char *)key.data, key.size) == obucket) {
/* Keep on old page */
if (PAIRFITS(op, (&key), (&val)))
putpair((char *)op, &key, &val);
else {
old_bufp =
__add_ovflpage(hashp, old_bufp);
if (!old_bufp)
return (-1);
op = (uint16 *)old_bufp->page;
putpair((char *)op, &key, &val);
}
old_bufp->flags |= BUF_MOD;
} else {
/* Move to new page */
if (PAIRFITS(np, (&key), (&val)))
putpair((char *)np, &key, &val);
else {
new_bufp =
__add_ovflpage(hashp, new_bufp);
if (!new_bufp)
return (-1);
np = (uint16 *)new_bufp->page;
putpair((char *)np, &key, &val);
}
new_bufp->flags |= BUF_MOD;
}
}
}
if (last_bfp)
__free_ovflpage(hashp, last_bfp);
return (0);
}