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bt_conv.c revision 1.12
      1 /*	$NetBSD: bt_conv.c,v 1.12 2007/02/03 23:46:09 christos Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1990, 1993, 1994
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * This code is derived from software contributed to Berkeley by
      8  * Mike Olson.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. Neither the name of the University nor the names of its contributors
     19  *    may be used to endorse or promote products derived from this software
     20  *    without specific prior written permission.
     21  *
     22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     32  * SUCH DAMAGE.
     33  */
     34 
     35 #if HAVE_NBTOOL_CONFIG_H
     36 #include "nbtool_config.h"
     37 #endif
     38 
     39 #include <sys/cdefs.h>
     40 #if defined(LIBC_SCCS) && !defined(lint)
     41 #if 0
     42 static char sccsid[] = "@(#)bt_conv.c	8.5 (Berkeley) 8/17/94";
     43 #else
     44 __RCSID("$NetBSD: bt_conv.c,v 1.12 2007/02/03 23:46:09 christos Exp $");
     45 #endif
     46 #endif /* LIBC_SCCS and not lint */
     47 
     48 #include <assert.h>
     49 #include <stdio.h>
     50 
     51 #include <db.h>
     52 #include "btree.h"
     53 
     54 static void mswap(PAGE *);
     55 
     56 /*
     57  * __BT_BPGIN, __BT_BPGOUT --
     58  *	Convert host-specific number layout to/from the host-independent
     59  *	format stored on disk.
     60  *
     61  * Parameters:
     62  *	t:	tree
     63  *	pg:	page number
     64  *	h:	page to convert
     65  */
     66 void
     67 __bt_pgin(void *t, pgno_t pg, void *pp)
     68 {
     69 	PAGE *h;
     70 	indx_t i, top;
     71 	u_char flags;
     72 	char *p;
     73 
     74 	if (!F_ISSET(((BTREE *)t), B_NEEDSWAP))
     75 		return;
     76 	if (pg == P_META) {
     77 		mswap(pp);
     78 		return;
     79 	}
     80 
     81 	h = pp;
     82 	M_32_SWAP(h->pgno);
     83 	M_32_SWAP(h->prevpg);
     84 	M_32_SWAP(h->nextpg);
     85 	M_32_SWAP(h->flags);
     86 	M_16_SWAP(h->lower);
     87 	M_16_SWAP(h->upper);
     88 
     89 	top = NEXTINDEX(h);
     90 	if ((h->flags & P_TYPE) == P_BINTERNAL)
     91 		for (i = 0; i < top; i++) {
     92 			M_16_SWAP(h->linp[i]);
     93 			p = (char *)(void *)GETBINTERNAL(h, i);
     94 			P_32_SWAP(p);
     95 			p += sizeof(u_int32_t);
     96 			P_32_SWAP(p);
     97 			p += sizeof(pgno_t);
     98 			if (*(u_char *)p & P_BIGKEY) {
     99 				p += sizeof(u_char);
    100 				P_32_SWAP(p);
    101 				p += sizeof(pgno_t);
    102 				P_32_SWAP(p);
    103 			}
    104 		}
    105 	else if ((h->flags & P_TYPE) == P_BLEAF)
    106 		for (i = 0; i < top; i++) {
    107 			M_16_SWAP(h->linp[i]);
    108 			p = (char *)(void *)GETBLEAF(h, i);
    109 			P_32_SWAP(p);
    110 			p += sizeof(u_int32_t);
    111 			P_32_SWAP(p);
    112 			p += sizeof(u_int32_t);
    113 			flags = *(u_char *)p;
    114 			if (flags & (P_BIGKEY | P_BIGDATA)) {
    115 				p += sizeof(u_char);
    116 				if (flags & P_BIGKEY) {
    117 					P_32_SWAP(p);
    118 					p += sizeof(pgno_t);
    119 					P_32_SWAP(p);
    120 				}
    121 				if (flags & P_BIGDATA) {
    122 					p += sizeof(u_int32_t);
    123 					P_32_SWAP(p);
    124 					p += sizeof(pgno_t);
    125 					P_32_SWAP(p);
    126 				}
    127 			}
    128 		}
    129 }
    130 
    131 void
    132 __bt_pgout(void *t, pgno_t pg, void *pp)
    133 {
    134 	PAGE *h;
    135 	indx_t i, top;
    136 	u_char flags;
    137 	char *p;
    138 
    139 	if (!F_ISSET(((BTREE *)t), B_NEEDSWAP))
    140 		return;
    141 	if (pg == P_META) {
    142 		mswap(pp);
    143 		return;
    144 	}
    145 
    146 	h = pp;
    147 	top = NEXTINDEX(h);
    148 	if ((h->flags & P_TYPE) == P_BINTERNAL)
    149 		for (i = 0; i < top; i++) {
    150 			p = (char *)(void *)GETBINTERNAL(h, i);
    151 			P_32_SWAP(p);
    152 			p += sizeof(u_int32_t);
    153 			P_32_SWAP(p);
    154 			p += sizeof(pgno_t);
    155 			if (*(u_char *)p & P_BIGKEY) {
    156 				p += sizeof(u_char);
    157 				P_32_SWAP(p);
    158 				p += sizeof(pgno_t);
    159 				P_32_SWAP(p);
    160 			}
    161 			M_16_SWAP(h->linp[i]);
    162 		}
    163 	else if ((h->flags & P_TYPE) == P_BLEAF)
    164 		for (i = 0; i < top; i++) {
    165 			p = (char *)(void *)GETBLEAF(h, i);
    166 			P_32_SWAP(p);
    167 			p += sizeof(u_int32_t);
    168 			P_32_SWAP(p);
    169 			p += sizeof(u_int32_t);
    170 			flags = *(u_char *)p;
    171 			if (flags & (P_BIGKEY | P_BIGDATA)) {
    172 				p += sizeof(u_char);
    173 				if (flags & P_BIGKEY) {
    174 					P_32_SWAP(p);
    175 					p += sizeof(pgno_t);
    176 					P_32_SWAP(p);
    177 				}
    178 				if (flags & P_BIGDATA) {
    179 					p += sizeof(u_int32_t);
    180 					P_32_SWAP(p);
    181 					p += sizeof(pgno_t);
    182 					P_32_SWAP(p);
    183 				}
    184 			}
    185 			M_16_SWAP(h->linp[i]);
    186 		}
    187 
    188 	M_32_SWAP(h->pgno);
    189 	M_32_SWAP(h->prevpg);
    190 	M_32_SWAP(h->nextpg);
    191 	M_32_SWAP(h->flags);
    192 	M_16_SWAP(h->lower);
    193 	M_16_SWAP(h->upper);
    194 }
    195 
    196 /*
    197  * MSWAP -- Actually swap the bytes on the meta page.
    198  *
    199  * Parameters:
    200  *	p:	page to convert
    201  */
    202 static void
    203 mswap(PAGE *pg)
    204 {
    205 	char *p;
    206 
    207 	p = (char *)(void *)pg;
    208 	P_32_SWAP(p);		/* magic */
    209 	p += sizeof(u_int32_t);
    210 	P_32_SWAP(p);		/* version */
    211 	p += sizeof(u_int32_t);
    212 	P_32_SWAP(p);		/* psize */
    213 	p += sizeof(u_int32_t);
    214 	P_32_SWAP(p);		/* free */
    215 	p += sizeof(u_int32_t);
    216 	P_32_SWAP(p);		/* nrecs */
    217 	p += sizeof(u_int32_t);
    218 	P_32_SWAP(p);		/* flags */
    219 	p += sizeof(u_int32_t);
    220 }
    221