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btree
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bt_conv.c
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C/C++ Source or Header
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1994-08-18
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5KB
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222 lines
/*-
* 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. 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_conv.c 8.5 (Berkeley) 8/17/94";
#endif /* LIBC_SCCS and not lint */
#include <sys/param.h>
#include <stdio.h>
#include <db.h>
#include "btree.h"
static void mswap __P((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(t, pg, pp)
void *t;
pgno_t pg;
void *pp;
{
PAGE *h;
indx_t i, top;
u_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(u_int32_t);
P_32_SWAP(p);
p += sizeof(pgno_t);
if (*(u_char *)p & P_BIGKEY) {
p += sizeof(u_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(u_int32_t);
P_32_SWAP(p);
p += sizeof(u_int32_t);
flags = *(u_char *)p;
if (flags & (P_BIGKEY | P_BIGDATA)) {
p += sizeof(u_char);
if (flags & P_BIGKEY) {
P_32_SWAP(p);
p += sizeof(pgno_t);
P_32_SWAP(p);
}
if (flags & P_BIGDATA) {
p += sizeof(u_int32_t);
P_32_SWAP(p);
p += sizeof(pgno_t);
P_32_SWAP(p);
}
}
}
}
void
__bt_pgout(t, pg, pp)
void *t;
pgno_t pg;
void *pp;
{
PAGE *h;
indx_t i, top;
u_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(u_int32_t);
P_32_SWAP(p);
p += sizeof(pgno_t);
if (*(u_char *)p & P_BIGKEY) {
p += sizeof(u_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(u_int32_t);
P_32_SWAP(p);
p += sizeof(u_int32_t);
flags = *(u_char *)p;
if (flags & (P_BIGKEY | P_BIGDATA)) {
p += sizeof(u_char);
if (flags & P_BIGKEY) {
P_32_SWAP(p);
p += sizeof(pgno_t);
P_32_SWAP(p);
}
if (flags & P_BIGDATA) {
p += sizeof(u_int32_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(pg)
PAGE *pg;
{
char *p;
p = (char *)pg;
P_32_SWAP(p); /* magic */
p += sizeof(u_int32_t);
P_32_SWAP(p); /* version */
p += sizeof(u_int32_t);
P_32_SWAP(p); /* psize */
p += sizeof(u_int32_t);
P_32_SWAP(p); /* free */
p += sizeof(u_int32_t);
P_32_SWAP(p); /* nrecs */
p += sizeof(u_int32_t);
P_32_SWAP(p); /* flags */
p += sizeof(u_int32_t);
}