1 /* $XConsortium: bt_page.c /main/3 1996/06/11 17:12:50 cde-hal $ */
3 * Copyright (c) 1990, 1993
4 * The Regents of the University of California. All rights reserved.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. All advertising materials mentioning features or use of this software
15 * must display the following acknowledgement:
16 * This product includes software developed by the University of
17 * California, Berkeley and its contributors.
18 * 4. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 #if defined(LIBC_SCCS) && !defined(lint)
36 static char sccsid[] = "@(#)bt_page.c 8.1 (Berkeley) 6/4/93";
37 #endif /* LIBC_SCCS and not lint */
39 #include <sys/types.h>
41 #define __DBINTERFACE_PRIVATE
48 * __BT_FREE -- Put a page on the freelist.
55 * RET_ERROR, RET_SUCCESS
62 /* Insert the page at the start of the free list. */
63 h->prevpg = P_INVALID;
64 h->nextpg = t->bt_free;
67 /* Make sure the page gets written back. */
68 return (mpool_put(t->bt_mp, h, MPOOL_DIRTY));
72 * __BT_NEW -- Get a new page, preferably from the freelist.
76 * npg: storage for page number.
79 * Pointer to a page, NULL on error.
88 if (t->bt_free != P_INVALID &&
89 (h = mpool_get(t->bt_mp, t->bt_free, 0)) != NULL) {
91 t->bt_free = h->nextpg;
94 return (mpool_new(t->bt_mp, npg));