[unix-history] / usr / src / lib / libc / db / btree / bt_close.c

/*-
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Mike Olson.
*
* %sccs.include.redist.c%
*/

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)bt_close.c  5.7 (Berkeley) %G%";
#endif /* LIBC_SCCS and not lint */

#include <sys/param.h>

#include <db.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.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, BTF_DELCRSR) && __bt_crsrdel(t, &t->bt_bcursor))
               return (RET_ERROR);

       if (__bt_sync(dbp) == 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)
       const DB *dbp;
{
       BTREE *t;
       int status;
       PAGE *h;
       void *p;

       t = dbp->internal;

       if (ISSET(t, BTF_INMEM | BTF_RDONLY) || !ISSET(t, BTF_MODIFIED))
               return (RET_SUCCESS);

       if (ISSET(t, BTF_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, BTF_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);
               bcopy(h, p, t->bt_psize);
               if (status =
                   __bt_dleaf(t, h, t->bt_bcursor.index) == RET_ERROR)
                       goto ecrsr;
       }
               
       if ((status = mpool_sync(t->bt_mp)) == RET_SUCCESS)
               CLR(t, BTF_MODIFIED);

ecrsr:  if (ISSET(t, BTF_DELCRSR)) {
               bcopy(p, h, t->bt_psize);
               free(p);
               mpool_put(t->bt_mp, h, 0);
       }
       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 -- lorder is host-independent. */
       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;
       m.m_lorder = htonl((u_long)t->bt_lorder);

       if (t->bt_lorder != BYTE_ORDER) {
               BLSWAP(m.m_magic);
               BLSWAP(m.m_version);
               BLSWAP(m.m_psize);
               BLSWAP(m.m_free);
               BLSWAP(m.m_nrecs);
               BLSWAP(m.m_flags);
       }

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