db/btree/bt_conv.c

	bt_conv.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*-
 * See the file LICENSE for redistribution information.
 *
 * Copyright (c) 1996, 1997, 1998
 *  Sleepycat Software.  All rights reserved.
 */

#include "config.h"

#ifndef lint
static const char sccsid[] = "@(#)bt_conv.c 10.7 (Sleepycat) 9/20/98";
#endif /* not lint */

#ifndef NO_SYSTEM_INCLUDES
#include <sys/types.h>
#endif

#include "db_int.h"
#include "db_page.h"
#include "db_swap.h"
#include "btree.h"

/*
 * __bam_pgin --
 *  Convert host-specific page layout from the host-independent format
 *  stored on disk.
 *
 * PUBLIC: int __bam_pgin __P((db_pgno_t, void *, DBT *));
 */
int
__bam_pgin(pg, pp, cookie)
    db_pgno_t pg;
    void *pp;
    DBT *cookie;
{
    DB_PGINFO *pginfo;

    pginfo = (DB_PGINFO *)cookie->data;
    if (!pginfo->needswap)
        return (0);
    return (pg == PGNO_METADATA ?
        __bam_mswap(pp) : __db_pgin(pg, pginfo->db_pagesize, pp));
}

/*
 * __bam_pgout --
 *  Convert host-specific page layout to the host-independent format
 *  stored on disk.
 *
 * PUBLIC: int __bam_pgout __P((db_pgno_t, void *, DBT *));
 */
int
__bam_pgout(pg, pp, cookie)
    db_pgno_t pg;
    void *pp;
    DBT *cookie;
{
    DB_PGINFO *pginfo;

    pginfo = (DB_PGINFO *)cookie->data;
    if (!pginfo->needswap)
        return (0);
    return (pg == PGNO_METADATA ?
        __bam_mswap(pp) : __db_pgout(pg, pginfo->db_pagesize, pp));
}

/*
 * __bam_mswap --
 *  Swap the bytes on the btree metadata page.
 *
 * PUBLIC: int __bam_mswap __P((PAGE *));
 */
int
__bam_mswap(pg)
    PAGE *pg;
{
    u_int8_t *p;

    p = (u_int8_t *)pg;

    /* Swap the meta-data information. */
    SWAP32(p);      /* lsn.file */
    SWAP32(p);      /* lsn.offset */
    SWAP32(p);      /* pgno */
    SWAP32(p);      /* magic */
    SWAP32(p);      /* version */
    SWAP32(p);      /* pagesize */
    SWAP32(p);      /* maxkey */
    SWAP32(p);      /* minkey */
    SWAP32(p);      /* free */
    SWAP32(p);      /* flags */

    return (0);
}