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