/*-
 * Copyright (c) 1990, 1993, 1994
 *      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. 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.
 *
 * @(#)bt_conv.c        8.5 (Berkeley) 8/17/94
 * $FreeBSD: head/lib/libc/db/btree/bt_conv.c 189291 2009-03-02 23:47:18Z delphij $
 */

#include <sys/param.h>

#include <stdio.h>

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

static void mswap(PAGE *);

/*
 * __BT_BPGIN, __BT_BPGOUT --
 *      Convert host-specific number layout to/from the host-independent
 *      format stored on disk.
 *
 * Parameters:
 *      t:      tree
 *      pg:     page number
 *      h:      page to convert
 */
void
__bt_pgin(void *t, pgno_t pg, void *pp)
{
        PAGE *h;
        indx_t i, top;
        unsigned char flags;
        char *p;

        if (!F_ISSET(((BTREE *)t), B_NEEDSWAP))
                return;
        if (pg == P_META) {
                mswap(pp);
                return;
        }

        h = pp;
        M_32_SWAP(h->pgno);
        M_32_SWAP(h->prevpg);
        M_32_SWAP(h->nextpg);
        M_32_SWAP(h->flags);
        M_16_SWAP(h->lower);
        M_16_SWAP(h->upper);

        top = NEXTINDEX(h);
        if ((h->flags & P_TYPE) == P_BINTERNAL)
                for (i = 0; i < top; i++) {
                        M_16_SWAP(h->linp[i]);
                        p = (char *)GETBINTERNAL(h, i);
                        P_32_SWAP(p);
                        p += sizeof(uint32_t);
                        P_32_SWAP(p);
                        p += sizeof(pgno_t);
                        if (*(unsigned char *)p & P_BIGKEY) {
                                p += sizeof(unsigned char);
                                P_32_SWAP(p);
                                p += sizeof(pgno_t);
                                P_32_SWAP(p);
                        }
                }
        else if ((h->flags & P_TYPE) == P_BLEAF)
                for (i = 0; i < top; i++) {
                        M_16_SWAP(h->linp[i]);
                        p = (char *)GETBLEAF(h, i);
                        P_32_SWAP(p);
                        p += sizeof(uint32_t);
                        P_32_SWAP(p);
                        p += sizeof(uint32_t);
                        flags = *(unsigned char *)p;
                        if (flags & (P_BIGKEY | P_BIGDATA)) {
                                p += sizeof(unsigned char);
                                if (flags & P_BIGKEY) {
                                        P_32_SWAP(p);
                                        p += sizeof(pgno_t);
                                        P_32_SWAP(p);
                                }
                                if (flags & P_BIGDATA) {
                                        p += sizeof(uint32_t);
                                        P_32_SWAP(p);
                                        p += sizeof(pgno_t);
                                        P_32_SWAP(p);
                                }
                        }
                }
}

void
__bt_pgout(void *t, pgno_t pg, void *pp)
{
        PAGE *h;
        indx_t i, top;
        unsigned char flags;
        char *p;

        if (!F_ISSET(((BTREE *)t), B_NEEDSWAP))
                return;
        if (pg == P_META) {
                mswap(pp);
                return;
        }

        h = pp;
        top = NEXTINDEX(h);
        if ((h->flags & P_TYPE) == P_BINTERNAL)
                for (i = 0; i < top; i++) {
                        p = (char *)GETBINTERNAL(h, i);
                        P_32_SWAP(p);
                        p += sizeof(uint32_t);
                        P_32_SWAP(p);
                        p += sizeof(pgno_t);
                        if (*(unsigned char *)p & P_BIGKEY) {
                                p += sizeof(unsigned char);
                                P_32_SWAP(p);
                                p += sizeof(pgno_t);
                                P_32_SWAP(p);
                        }
                        M_16_SWAP(h->linp[i]);
                }
        else if ((h->flags & P_TYPE) == P_BLEAF)
                for (i = 0; i < top; i++) {
                        p = (char *)GETBLEAF(h, i);
                        P_32_SWAP(p);
                        p += sizeof(uint32_t);
                        P_32_SWAP(p);
                        p += sizeof(uint32_t);
                        flags = *(unsigned char *)p;
                        if (flags & (P_BIGKEY | P_BIGDATA)) {
                                p += sizeof(unsigned char);
                                if (flags & P_BIGKEY) {
                                        P_32_SWAP(p);
                                        p += sizeof(pgno_t);
                                        P_32_SWAP(p);
                                }
                                if (flags & P_BIGDATA) {
                                        p += sizeof(uint32_t);
                                        P_32_SWAP(p);
                                        p += sizeof(pgno_t);
                                        P_32_SWAP(p);
                                }
                        }
                        M_16_SWAP(h->linp[i]);
                }

        M_32_SWAP(h->pgno);
        M_32_SWAP(h->prevpg);
        M_32_SWAP(h->nextpg);
        M_32_SWAP(h->flags);
        M_16_SWAP(h->lower);
        M_16_SWAP(h->upper);
}

/*
 * MSWAP -- Actually swap the bytes on the meta page.
 *
 * Parameters:
 *      p:      page to convert
 */
static void
mswap(PAGE *pg)
{
        char *p;

        p = (char *)pg;
        P_32_SWAP(p);           /* magic */
        p += sizeof(uint32_t);
        P_32_SWAP(p);           /* version */
        p += sizeof(uint32_t);
        P_32_SWAP(p);           /* psize */
        p += sizeof(uint32_t);
        P_32_SWAP(p);           /* free */
        p += sizeof(uint32_t);
        P_32_SWAP(p);           /* nrecs */
        p += sizeof(uint32_t);
        P_32_SWAP(p);           /* flags */
        p += sizeof(uint32_t);
}