/*- * Copyright (c) 1990, 1993 * 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 8.2 (Berkeley) 2/21/94"; #endif /* LIBC_SCCS and not lint */ #include #include #include #include "btree.h" /* * __BT_FREE -- Put a page on the freelist. * * Parameters: * t: tree * h: page to free * * Returns: * RET_ERROR, RET_SUCCESS */ int __bt_free(t, h) BTREE *t; PAGE *h; { /* Insert the page at the start of the free list. */ h->prevpg = P_INVALID; h->nextpg = t->bt_free; t->bt_free = h->pgno; /* 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; return (h); } return (mpool_new(t->bt_mp, npg)); }