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/* $OpenBSD: bt_page.c,v 1.9 2005/08/05 13:02:59 espie Exp $ */ |
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/*- |
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* Copyright (c) 1990, 1993, 1994 |
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* The Regents of the University of California. All rights reserved. |
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* |
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* Redistribution and use in source and binary forms, with or without |
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* modification, are permitted provided that the following conditions |
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* are met: |
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* 1. Redistributions of source code must retain the above copyright |
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* notice, this list of conditions and the following disclaimer. |
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* 2. Redistributions in binary form must reproduce the above copyright |
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* notice, this list of conditions and the following disclaimer in the |
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* documentation and/or other materials provided with the distribution. |
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* 3. Neither the name of the University nor the names of its contributors |
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* may be used to endorse or promote products derived from this software |
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* without specific prior written permission. |
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* |
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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* SUCH DAMAGE. |
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*/ |
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#include <sys/types.h> |
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#include <stdio.h> |
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#include <db.h> |
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#include "btree.h" |
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/* |
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* __bt_free -- |
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* Put a page on the freelist. |
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* |
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* Parameters: |
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* t: tree |
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* h: page to free |
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* |
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* Returns: |
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* RET_ERROR, RET_SUCCESS |
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* |
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* Side-effect: |
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* mpool_put's the page. |
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*/ |
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int |
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__bt_free(BTREE *t, PAGE *h) |
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{ |
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/* Insert the page at the head of the free list. */ |
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h->prevpg = P_INVALID; |
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h->nextpg = t->bt_free; |
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t->bt_free = h->pgno; |
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F_SET(t, B_METADIRTY); |
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/* Make sure the page gets written back. */ |
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return (mpool_put(t->bt_mp, h, MPOOL_DIRTY)); |
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} |
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/* |
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* __bt_new -- |
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* Get a new page, preferably from the freelist. |
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* |
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* Parameters: |
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* t: tree |
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* npg: storage for page number. |
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* |
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* Returns: |
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* Pointer to a page, NULL on error. |
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*/ |
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PAGE * |
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__bt_new(BTREE *t, pgno_t *npg) |
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{ |
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PAGE *h; |
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if (t->bt_free != P_INVALID && |
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(h = mpool_get(t->bt_mp, t->bt_free, 0)) != NULL) { |
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*npg = t->bt_free; |
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t->bt_free = h->nextpg; |
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F_SET(t, B_METADIRTY); |
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return (h); |
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} |
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return (mpool_new(t->bt_mp, npg, MPOOL_PAGE_NEXT)); |
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} |