db/hash/hash_conv.c

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

#include "config.h"

#pragma ident   "%Z%%M% %I% %E% SMI"

#ifndef lint
static const char sccsid[] = "@(#)hash_conv.c   10.4 (Sleepycat) 9/15/97";
static const char sccsi2[] = "%W% (Sun) %G%";
#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 "hash.h"

/*
 * __ham_pgin --
 *  Convert host-specific page layout from the host-independent format
 *  stored on disk.
 *
 * PUBLIC: int __ham_pgin __P((db_pgno_t, void *, DBT *));
 */
int
__ham_pgin(pg, pp, cookie)
    db_pgno_t pg;
    void *pp;
    DBT *cookie;
{
    DB_PGINFO *pginfo;
    u_int32_t tpgno;

    pginfo = (DB_PGINFO *)cookie->data;
    tpgno = PGNO((PAGE *)pp);
    if (pginfo->needswap)
        M_32_SWAP(tpgno);

    if (pg != PGNO_METADATA && pg != tpgno) {
        P_INIT(pp, pginfo->db_pagesize,
            pg, PGNO_INVALID, PGNO_INVALID, 0, P_HASH);
        return (0);
    }

    if (!pginfo->needswap)
        return (0);
    return (pg == PGNO_METADATA ?
        __ham_mswap(pp) : __db_pgin(pg, pginfo->db_pagesize, pp));
}

/*
 * __ham_pgout --
 *  Convert host-specific page layout to the host-independent format
 *  stored on disk.
 *
 * PUBLIC: int __ham_pgout __P((db_pgno_t, void *, DBT *));
 */
int
__ham_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 ?
        __ham_mswap(pp) : __db_pgout(pg, pginfo->db_pagesize, pp));
}

/*
 * __ham_mswap --
 *  Swap the bytes on the hash metadata page.
 *
 * PUBLIC: int __ham_mswap __P((void *));
 */
int
__ham_mswap(pg)
    void *pg;
{
    u_int8_t *p;
    int i;

    p = (u_int8_t *)pg;
    SWAP32(p);      /* lsn part 1 */
    SWAP32(p);      /* lsn part 2 */
    SWAP32(p);      /* pgno */
    SWAP32(p);      /* magic */
    SWAP32(p);      /* version */
    SWAP32(p);      /* pagesize */
    SWAP32(p);      /* ovfl_point */
    SWAP32(p);      /* last_freed */
    SWAP32(p);      /* max_bucket */
    SWAP32(p);      /* high_mask */
    SWAP32(p);      /* low_mask */
    SWAP32(p);      /* ffactor */
    SWAP32(p);      /* nelem */
    SWAP32(p);      /* h_charkey */
    SWAP32(p);      /* flags */
    for (i = 0; i < NCACHED; ++i)
        SWAP32(p);  /* spares */
    return (0);
}