lib/libc/db/btree/bt_close.c

/*-
 * Copyright (c) 1990, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Mike Olson.
 *
 * 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_close.c  8.1 (Berkeley) 6/4/93";
#endif /* LIBC_SCCS and not lint */

#include <sys/param.h>

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include <db.h>
#include "btree.h"

static int bt_meta __P((BTREE *));

/*
 * BT_CLOSE -- Close a btree.
 *
 * Parameters:
 *      dbp:    pointer to access method
 *
 * Returns:
 *      RET_ERROR, RET_SUCCESS
 */
int
__bt_close(dbp)
        DB *dbp;
{
        BTREE *t;
        int fd;

        t = dbp->internal;

        /*
         * Delete any already deleted record that we've been saving
         * because the cursor pointed to it.
         */
        if (ISSET(t, B_DELCRSR) && __bt_crsrdel(t, &t->bt_bcursor))
                return (RET_ERROR);

        if (__bt_sync(dbp, 0) == RET_ERROR)
                return (RET_ERROR);

        if (mpool_close(t->bt_mp) == RET_ERROR)
                return (RET_ERROR);

        if (t->bt_stack)
                free(t->bt_stack);
        if (t->bt_kbuf)
                free(t->bt_kbuf);
        if (t->bt_dbuf)
                free(t->bt_dbuf);

        fd = t->bt_fd;
        free(t);
        free(dbp);
        return (close(fd) ? RET_ERROR : RET_SUCCESS);
}

/*
 * BT_SYNC -- sync the btree to disk.
 *
 * Parameters:
 *      dbp:    pointer to access method
 *
 * Returns:
 *      RET_SUCCESS, RET_ERROR.
 */
int
__bt_sync(dbp, flags)
        const DB *dbp;
        u_int flags;
{
        BTREE *t;
        int status;
        PAGE *h;
        void *p;

        if (flags != 0) {
                errno = EINVAL;
                return (RET_ERROR);
        }

        t = dbp->internal;

        if (ISSET(t, B_INMEM | B_RDONLY) || !ISSET(t, B_MODIFIED))
                return (RET_SUCCESS);

        if (ISSET(t, B_METADIRTY) && bt_meta(t) == RET_ERROR)
                return (RET_ERROR);

        /*
         * Nastiness.  If the cursor has been marked for deletion, but not
         * actually deleted, we have to make a copy of the page, delete the
         * key/data item, sync the file, and then restore the original page
         * contents.
         */
        if (ISSET(t, B_DELCRSR)) {
                if ((p = malloc(t->bt_psize)) == NULL)
                        return (RET_ERROR);
                if ((h = mpool_get(t->bt_mp, t->bt_bcursor.pgno, 0)) == NULL)
                        return (RET_ERROR);
                memmove(p, h, t->bt_psize);
                if ((status =
                    __bt_dleaf(t, h, t->bt_bcursor.index)) == RET_ERROR)
                        goto ecrsr;
                mpool_put(t->bt_mp, h, MPOOL_DIRTY);
        }

        if ((status = mpool_sync(t->bt_mp)) == RET_SUCCESS)
                CLR(t, B_MODIFIED);

ecrsr:  if (ISSET(t, B_DELCRSR)) {
                if ((h = mpool_get(t->bt_mp, t->bt_bcursor.pgno, 0)) == NULL)
                        return (RET_ERROR);
                memmove(h, p, t->bt_psize);
                free(p);
                mpool_put(t->bt_mp, h, MPOOL_DIRTY);
        }
        return (status);
}

/*
 * BT_META -- write the tree meta data to disk.
 *
 * Parameters:
 *      t:      tree
 *
 * Returns:
 *      RET_ERROR, RET_SUCCESS
 */
static int
bt_meta(t)
        BTREE *t;
{
        BTMETA m;
        void *p;

        if ((p = mpool_get(t->bt_mp, P_META, 0)) == NULL)
                return (RET_ERROR);

        /* Fill in metadata. */
        m.m_magic = BTREEMAGIC;
        m.m_version = BTREEVERSION;
        m.m_psize = t->bt_psize;
        m.m_free = t->bt_free;
        m.m_nrecs = t->bt_nrecs;
        m.m_flags = t->bt_flags & SAVEMETA;

        memmove(p, &m, sizeof(BTMETA));
        mpool_put(t->bt_mp, p, MPOOL_DIRTY);
        return (RET_SUCCESS);
}