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