Net2/usr/src/lib/libc/db/btree/insert.c
/*-
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Mike Olson.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)insert.c 5.3 (Berkeley) 2/22/91";
#endif /* LIBC_SCCS and not lint */
#include <sys/types.h>
#include <db.h>
#include <stdlib.h>
#include <string.h>
#include "btree.h"
/*
* _BT_INSERT -- Insert a new user datum in the btree.
*
* This routine is called by bt_put, the public interface, once the
* location for the new item is known. We do the work here, and
* handle splits if necessary.
*
* Parameters:
* t -- btree in which to do the insertion.
* item -- BTITEM describing location of new datum
* key -- key to insert
* data -- data associated with key
* flag -- magic cookie passed recursively to bt_put if we
* have to do a split
*
* Returns:
* RET_SUCCESS, RET_ERROR.
*/
int
_bt_insert(t, item, key, data, flag)
BTREE_P t;
BTITEM *item;
DBT *key;
DBT *data;
int flag;
{
index_t index;
BTHEADER *h;
DATUM *d;
int nbytes;
int status;
pgno_t pgno;
int keysize, datasize;
int bigkey, bigdata;
if (_bt_getpage(t, item->bti_pgno) == RET_ERROR)
return (RET_ERROR);
h = t->bt_curpage;
if (TOOBIG(t, data->size)) {
bigdata = TRUE;
datasize = sizeof(pgno_t);
} else {
bigdata = FALSE;
datasize = data->size;
}
if (TOOBIG(t, key->size)) {
bigkey = TRUE;
keysize = sizeof(pgno_t);
} else {
bigkey = FALSE;
keysize = key->size;
}
nbytes = keysize + datasize + (sizeof(DATUM) - sizeof(char));
nbytes = LONGALIGN(nbytes) + sizeof(index_t);
/* if there's not enough room here, split the page */
if ((h->h_upper - h->h_lower) < nbytes) {
if (_bt_split(t) == RET_ERROR)
return (RET_ERROR);
/* okay, try again (empty the stack first, though) */
while (_bt_pop((BTREE) t) != P_NONE)
continue;
return (bt_put((BTREE) t, key, data, flag));
}
/* put together a leaf page datum from the key/data pair */
index = item->bti_index;
nbytes = keysize + datasize + (sizeof(DATUM) - sizeof(char));
if ((d = (DATUM *) malloc((unsigned) nbytes)) == (DATUM *) NULL)
return (RET_ERROR);
d->d_ksize = keysize;
d->d_dsize = datasize;
d->d_flags = 0;
if (bigkey) {
if (_bt_indirect(t, key, &pgno) == RET_ERROR)
return (RET_ERROR);
(void) bcopy((char *) &pgno, &(d->d_bytes[0]), sizeof(pgno));
d->d_flags |= D_BIGKEY;
if (_bt_getpage(t, item->bti_pgno) == RET_ERROR)
return (RET_ERROR);
} else {
if (d->d_ksize > 0) {
(void) bcopy((char *) key->data,
(char *) &(d->d_bytes[0]),
(int) d->d_ksize);
}
}
if (bigdata) {
if (_bt_indirect(t, data, &pgno) == RET_ERROR)
return (RET_ERROR);
(void) bcopy((char *) &pgno,
&(d->d_bytes[keysize]),
sizeof(pgno));
d->d_flags |= D_BIGDATA;
if (_bt_getpage(t, item->bti_pgno) == RET_ERROR)
return (RET_ERROR);
} else {
if (d->d_dsize > 0) {
(void) bcopy((char *) data->data,
(char *) &(d->d_bytes[keysize]),
(int) d->d_dsize);
}
}
/* do the insertion */
status = _bt_insertat(t, (char *) d, index);
(void) free((char *) d);
return (status);
}
/*
* _BT_INSERTI -- Insert IDATUM on current page in the btree.
*
* This routine handles insertions to internal pages after splits
* lower in the tree. On entry, t->bt_curpage is the page to get
* the new IDATUM. We are also given pgno, the page number of the
* IDATUM that is immediately left of the new IDATUM's position.
* This guarantees that the IDATUM for the right half of the page
* after a split goes next to the IDATUM for its left half.
*
* Parameters:
* t -- tree in which to do insertion.
* id -- new IDATUM to insert
* pgno -- page number of IDATUM left of id's position
*
* Returns:
* RET_SUCCESS, RET_ERROR.
*/
int
_bt_inserti(t, id, pgno)
BTREE_P t;
IDATUM *id;
pgno_t pgno;
{
BTHEADER *h = t->bt_curpage;
index_t next, i;
IDATUM *idx;
char *key;
pgno_t chain;
int free_key;
int ignore;
if (id->i_flags & D_BIGKEY) {
free_key = TRUE;
bcopy(&(id->i_bytes[0]), (char *) &chain, sizeof(chain));
if (_bt_getbig(t, chain, &key, &ignore) == RET_ERROR)
return (RET_ERROR);
} else {
free_key = FALSE;
key = &(id->i_bytes[0]);
}
i = _bt_binsrch(t, key);
next = NEXTINDEX(h);
while (i < next && _bt_cmp(t, key, i) >= 0)
i++;
if (free_key)
(void) free(key);
/* okay, now we're close; find adjacent IDATUM */
for (;;) {
idx = (IDATUM *) GETDATUM(h,i);
if (idx->i_pgno == pgno) {
i++;
break;
}
--i;
}
/* correctly positioned, do the insertion */
return (_bt_insertat(t, (char *) id, i));
}
/*
* _BT_INSERTAT -- Insert a datum at a given location on the current page.
*
* This routine does insertions on both leaf and internal pages.
*
* Parameters:
* t -- tree in which to do insertion.
* p -- DATUM or IDATUM to insert.
* index -- index in line pointer array to put this item.
*
* Returns:
* RET_SUCCESS, RET_ERROR.
*
* Side Effects:
* Will rearrange line pointers to make space for the new
* entry. This means that any scans currently active are
* invalid after this.
*
* Warnings:
* There must be sufficient room for the new item on the page.
*/
int
_bt_insertat(t, p, index)
BTREE_P t;
char *p;
index_t index;
{
IDATUM *id = (IDATUM *) p;
DATUM *d = (DATUM *) p;
BTHEADER *h;
CURSOR *c;
index_t nxtindex;
char *src, *dest;
int nbytes;
/* insertion may confuse an active scan. fix it. */
c = &(t->bt_cursor);
if (t->bt_flags & BTF_SEQINIT && t->bt_curpage->h_pgno == c->c_pgno)
if (_bt_fixscan(t, index, d, INSERT) == RET_ERROR)
return (RET_ERROR);
h = t->bt_curpage;
nxtindex = (index_t) NEXTINDEX(h);
/*
* If we're inserting at the middle of the line pointer array,
* copy pointers that will follow the new one up on the page.
*/
if (index < nxtindex) {
src = (char *) &(h->h_linp[index]);
dest = (char *) &(h->h_linp[index + 1]);
nbytes = (h->h_lower - (src - ((char *) h)))
+ sizeof(h->h_linp[0]);
(void) bcopy(src, dest, nbytes);
}
/* compute size and copy data to page */
if (h->h_flags & F_LEAF) {
nbytes = d->d_ksize + d->d_dsize
+ (sizeof(DATUM) - sizeof(char));
} else {
nbytes = id->i_size + (sizeof(IDATUM) - sizeof(char));
}
dest = (((char *) h) + h->h_upper) - LONGALIGN(nbytes);
(void) bcopy((char *) p, dest, nbytes);
/* update statistics */
dest -= (int) h;
h->h_linp[index] = (index_t) dest;
h->h_upper = (index_t) dest;
h->h_lower += sizeof(index_t);
/* we're done */
h->h_flags |= F_DIRTY;
return (RET_SUCCESS);
}