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 * 3. 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 * @(#)bt_page.c 8.3 (Berkeley) 7/14/94 30 * $DragonFly: src/lib/libc/db/btree/bt_page.c,v 1.4 2005/11/12 23:01:54 swildner Exp $ 31 */ 32 33 #include <sys/types.h> 34 35 #include <stdio.h> 36 37 #include <db.h> 38 #include "btree.h" 39 40 /* 41 * __bt_free -- 42 * Put a page on the freelist. 43 * 44 * Parameters: 45 * t: tree 46 * h: page to free 47 * 48 * Returns: 49 * RET_ERROR, RET_SUCCESS 50 * 51 * Side-effect: 52 * mpool_put's the page. 53 */ 54 int 55 __bt_free(BTREE *t, PAGE *h) 56 { 57 /* Insert the page at the head of the free list. */ 58 h->prevpg = P_INVALID; 59 h->nextpg = t->bt_free; 60 t->bt_free = h->pgno; 61 F_SET(t, B_METADIRTY); 62 63 /* Make sure the page gets written back. */ 64 return (mpool_put(t->bt_mp, h, MPOOL_DIRTY)); 65 } 66 67 /* 68 * __bt_new -- 69 * Get a new page, preferably from the freelist. 70 * 71 * Parameters: 72 * t: tree 73 * npg: storage for page number. 74 * 75 * Returns: 76 * Pointer to a page, NULL on error. 77 */ 78 PAGE * 79 __bt_new(BTREE *t, pgno_t *npg) 80 { 81 PAGE *h; 82 83 if (t->bt_free != P_INVALID && 84 (h = mpool_get(t->bt_mp, t->bt_free, 0)) != NULL) { 85 *npg = t->bt_free; 86 t->bt_free = h->nextpg; 87 F_SET(t, B_METADIRTY); 88 return (h); 89 } 90 return (mpool_new(t->bt_mp, npg)); 91 } 92