1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1990, 1993, 1994
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#if defined(LIBC_SCCS) && !defined(lint)
33static char sccsid[] = "@(#)bt_page.c	8.3 (Berkeley) 7/14/94";
34#endif /* LIBC_SCCS and not lint */
35#include <sys/cdefs.h>
36__FBSDID("$FreeBSD$");
37
38#include <sys/types.h>
39
40#include <stdio.h>
41
42#include <db.h>
43#include "btree.h"
44
45/*
46 * __bt_free --
47 *	Put a page on the freelist.
48 *
49 * Parameters:
50 *	t:	tree
51 *	h:	page to free
52 *
53 * Returns:
54 *	RET_ERROR, RET_SUCCESS
55 *
56 * Side-effect:
57 *	mpool_put's the page.
58 */
59int
60__bt_free(BTREE *t, PAGE *h)
61{
62	/* Insert the page at the head of the free list. */
63	h->prevpg = P_INVALID;
64	h->nextpg = t->bt_free;
65	t->bt_free = h->pgno;
66	F_SET(t, B_METADIRTY);
67
68	/* Make sure the page gets written back. */
69	return (mpool_put(t->bt_mp, h, MPOOL_DIRTY));
70}
71
72/*
73 * __bt_new --
74 *	Get a new page, preferably from the freelist.
75 *
76 * Parameters:
77 *	t:	tree
78 *	npg:	storage for page number.
79 *
80 * Returns:
81 *	Pointer to a page, NULL on error.
82 */
83PAGE *
84__bt_new(BTREE *t, pgno_t *npg)
85{
86	PAGE *h;
87
88	if (t->bt_free != P_INVALID &&
89	    (h = mpool_get(t->bt_mp, t->bt_free, 0)) != NULL) {
90		*npg = t->bt_free;
91		t->bt_free = h->nextpg;
92		F_SET(t, B_METADIRTY);
93		return (h);
94	}
95	return (mpool_new(t->bt_mp, npg, MPOOL_PAGE_NEXT));
96}
97