101 lines
2.9 KiB
C
101 lines
2.9 KiB
C
/*-
|
|
* Copyright (c) 1990, 1993, 1994
|
|
* The Regents of the University of California. All rights reserved.
|
|
*
|
|
* 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[] = "@(#)bt_page.c 8.3 (Berkeley) 7/14/94";
|
|
#endif /* LIBC_SCCS and not lint */
|
|
|
|
#include <sys/types.h>
|
|
|
|
#include <stdio.h>
|
|
|
|
#include "../include/db.h"
|
|
#include "btree.h"
|
|
|
|
/*
|
|
* __bt_free --
|
|
* Put a page on the freelist.
|
|
*
|
|
* Parameters:
|
|
* t: tree
|
|
* h: page to free
|
|
*
|
|
* Returns:
|
|
* RET_ERROR, RET_SUCCESS
|
|
*
|
|
* Side-effect:
|
|
* mpool_put's the page.
|
|
*/
|
|
int
|
|
__bt_free(t, h)
|
|
BTREE *t;
|
|
PAGE *h;
|
|
{
|
|
/* Insert the page at the head of the free list. */
|
|
h->prevpg = P_INVALID;
|
|
h->nextpg = t->bt_free;
|
|
t->bt_free = h->pgno;
|
|
F_SET(t, B_METADIRTY);
|
|
|
|
/* Make sure the page gets written back. */
|
|
return (mpool_put(t->bt_mp, h, MPOOL_DIRTY));
|
|
}
|
|
|
|
/*
|
|
* __bt_new --
|
|
* Get a new page, preferably from the freelist.
|
|
*
|
|
* Parameters:
|
|
* t: tree
|
|
* npg: storage for page number.
|
|
*
|
|
* Returns:
|
|
* Pointer to a page, NULL on error.
|
|
*/
|
|
PAGE *
|
|
__bt_new(t, npg)
|
|
BTREE *t;
|
|
pgno_t *npg;
|
|
{
|
|
PAGE *h;
|
|
|
|
if (t->bt_free != P_INVALID &&
|
|
(h = mpool_get(t->bt_mp, t->bt_free, 0)) != NULL) {
|
|
*npg = t->bt_free;
|
|
t->bt_free = h->nextpg;
|
|
F_SET(t, B_METADIRTY);
|
|
return (h);
|
|
}
|
|
return (mpool_new(t->bt_mp, npg));
|
|
}
|