/*
* NAME: node->insert()
* DESCRIPTION: insert a new record into a node; return a record for parent
*/
int n_insert(node *np, byte *record, unsigned int *reclen)
{
/* check for free space */
if (np->nd.ndNRecs >= HFS_MAX_NRECS ||
*reclen + 2 > NODEFREE(*np))
return split(np, record, reclen);
n_insertx(np, record, *reclen);
*reclen = 0;
return bt_putnode(np);
}
/*
* NAME: node->insert()
* DESCRIPTION: insert a new record into a node; return a record for parent
*/
int n_insert(node *np, unsigned char *record, int *reclen)
{
n_compact(np);
/* check for free space */
if (np->nd.ndNRecs >= HFS_MAXRECS ||
*reclen + 2 > (int)NODESPACE(*np))
return n_split(np, record, reclen);
n_insertx(np, record, *reclen);
*reclen = 0;
return bt_putnode(np);
}
/*
* NAME: split()
* DESCRIPTION: divide a node into two and insert a record
*/
static
int split(node *left, byte *record, unsigned int *reclen)
{
btree *bt = left->bt;
node n, *right = &n, *side = 0;
int mark, i;
/* create a second node by cloning the first */
*right = *left;
if (n_new(right) == -1)
goto fail;
left->nd.ndFLink = right->nnum;
right->nd.ndBLink = left->nnum;
/* divide all records evenly between the two nodes */
mark = (NODEUSED(*left) + 2 * left->nd.ndNRecs + *reclen + 2) >> 1;
if (left->rnum == -1)
{
side = left;
mark -= *reclen + 2;
}
for (i = 0; i < left->nd.ndNRecs; ++i)
{
node *np;
byte *rec;
np = (mark > 0) ? right : left;
rec = HFS_NODEREC(*np, i);
mark -= HFS_RECLEN(*np, i) + 2;
HFS_SETKEYLEN(rec, 0);
if (left->rnum == i)
{
side = (mark > 0) ? left : right;
mark -= *reclen + 2;
}
}
compact(left);
compact(right);
/* insert the new record and store the modified nodes */
ASSERT(side);
n_search(side, record);
n_insertx(side, record, *reclen);
if (bt_putnode(left) == -1 ||
bt_putnode(right) == -1)
goto fail;
/* create an index record in the parent for the new node */
n_index(right, record, reclen);
/* update link pointers */
if (bt->hdr.bthLNode == left->nnum)
{
bt->hdr.bthLNode = right->nnum;
bt->flags |= HFS_BT_UPDATE_HDR;
}
if (right->nd.ndFLink > 0)
{
node sib;
if (bt_getnode(&sib, right->bt, right->nd.ndFLink) == -1)
goto fail;
sib.nd.ndBLink = right->nnum;
if (bt_putnode(&sib) == -1)
goto fail;
}
return 0;
fail:
return -1;
}
/*
* NAME: node->split()
* DESCRIPTION: divide a node into two and insert a record
*/
int n_split(node *left, unsigned char *record, int *reclen)
{
node right;
int nrecs, i, mid;
unsigned char *rec;
right = *left;
right.nd.ndBLink = left->nnum;
if (n_new(&right) < 0)
return -1;
left->nd.ndFLink = right.nnum;
nrecs = left->nd.ndNRecs;
/*
* Ensure node split leaves enough room for new record.
* The size calculations used are based on the NODESPACE() macro, but
* I don't know what the extra 2's and 1's are needed for.
* John Witford <*****@*****.**>
*/
n_search(&right, record);
mid = nrecs/2;
for(;;)
{
if (right.rnum < mid)
{
if ( mid > 0
&& (int)left->roff[mid] + *reclen + 2 > HFS_BLOCKSZ - 2 * (mid + 1))
{
--mid;
if (mid > 0)
continue;
}
}
else
{
if ( mid < nrecs
&& (int)right.roff[nrecs] - (int)right.roff[mid] + (int)left->roff[0] + *reclen + 2 > HFS_BLOCKSZ - 2 * (mid + 1))
{
++mid;
if (mid < nrecs)
continue;
}
}
break;
}
for (i = 0; i < nrecs; ++i)
{
if (i < mid)
rec = HFS_NODEREC(right, i);
else
rec = HFS_NODEREC(*left, i);
HFS_RECKEYLEN(rec) = 0;
}
/* original code ...
for (i = 0; i < nrecs; ++i)
{
if (i < nrecs / 2)
rec = HFS_NODEREC(right, i);
else
rec = HFS_NODEREC(*left, i);
HFS_RECKEYLEN(rec) = 0;
}
*/
n_compact(left);
n_compact(&right);
n_search(&right, record);
if (right.rnum >= 0)
n_insertx(&right, record, *reclen);
else
{
n_search(left, record);
n_insertx(left, record, *reclen);
}
/* store the new/modified nodes */
if (bt_putnode(left) < 0 ||
bt_putnode(&right) < 0)
return -1;
/* create an index record for the new node in the parent */
n_index(right.bt, HFS_NODEREC(right, 0), right.nnum, record, reclen);
/* update link pointers */
if (left->bt->hdr.bthLNode == left->nnum)
{
left->bt->hdr.bthLNode = right.nnum;
left->bt->flags |= HFS_UPDATE_BTHDR;
}
if (right.nd.ndFLink)
{
node n;
n.bt = right.bt;
n.nnum = right.nd.ndFLink;
if (bt_getnode(&n) < 0)
return -1;
n.nd.ndBLink = right.nnum;
if (bt_putnode(&n) < 0)
return -1;
}
return 0;
}
/*
* NAME: node->split()
* DESCRIPTION: divide a node into two and insert a record
*/
int n_split(node *left, unsigned char *record, int *reclen)
{
node right;
int nrecs, i;
unsigned char *rec;
right = *left;
right.nd.ndBLink = left->nnum;
if (n_new(&right) < 0)
return -1;
left->nd.ndFLink = right.nnum;
nrecs = left->nd.ndNRecs;
for (i = 0; i < nrecs; ++i)
{
if (i < nrecs / 2)
rec = HFS_NODEREC(right, i);
else
rec = HFS_NODEREC(*left, i);
HFS_RECKEYLEN(rec) = 0;
}
n_compact(left);
n_compact(&right);
n_search(&right, record);
if (right.rnum >= 0)
n_insertx(&right, record, *reclen);
else
{
n_search(left, record);
n_insertx(left, record, *reclen);
}
/* store the new/modified nodes */
if (bt_putnode(left) < 0 ||
bt_putnode(&right) < 0)
return -1;
/* create an index record for the new node in the parent */
n_index(right.bt, HFS_NODEREC(right, 0), right.nnum, record, reclen);
/* update link pointers */
if (left->bt->hdr.bthLNode == left->nnum)
{
left->bt->hdr.bthLNode = right.nnum;
left->bt->flags |= HFS_UPDATE_BTHDR;
}
if (right.nd.ndFLink)
{
node n;
n.bt = right.bt;
n.nnum = right.nd.ndFLink;
if (bt_getnode(&n) < 0)
return -1;
n.nd.ndBLink = right.nnum;
if (bt_putnode(&n) < 0)
return -1;
}
return 0;
}
