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bt_conv.c revision 1.1.1.1
      1 /*-
      2  * Copyright (c) 1990, 1993, 1994
      3  *	The Regents of the University of California.  All rights reserved.
      4  *
      5  * This code is derived from software contributed to Berkeley by
      6  * Mike Olson.
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  * 1. Redistributions of source code must retain the above copyright
     12  *    notice, this list of conditions and the following disclaimer.
     13  * 2. Redistributions in binary form must reproduce the above copyright
     14  *    notice, this list of conditions and the following disclaimer in the
     15  *    documentation and/or other materials provided with the distribution.
     16  * 3. All advertising materials mentioning features or use of this software
     17  *    must display the following acknowledgement:
     18  *	This product includes software developed by the University of
     19  *	California, Berkeley and its contributors.
     20  * 4. Neither the name of the University nor the names of its contributors
     21  *    may be used to endorse or promote products derived from this software
     22  *    without specific prior written permission.
     23  *
     24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     34  * SUCH DAMAGE.
     35  */
     36 
     37 #if defined(LIBC_SCCS) && !defined(lint)
     38 static char sccsid[] = "@(#)bt_conv.c	8.3 (Berkeley) 5/31/94";
     39 #endif /* LIBC_SCCS and not lint */
     40 
     41 #include <sys/param.h>
     42 
     43 #include <stdio.h>
     44 
     45 #include <db.h>
     46 #include "btree.h"
     47 
     48 static void mswap __P((PAGE *));
     49 
     50 /*
     51  * __BT_BPGIN, __BT_BPGOUT --
     52  *	Convert host-specific number layout to/from the host-independent
     53  *	format stored on disk.
     54  *
     55  * Parameters:
     56  *	t:	tree
     57  *	pg:	page number
     58  *	h:	page to convert
     59  */
     60 void
     61 __bt_pgin(t, pg, pp)
     62 	void *t;
     63 	pgno_t pg;
     64 	void *pp;
     65 {
     66 	PAGE *h;
     67 	indx_t i, top;
     68 	u_char flags;
     69 	char *p;
     70 
     71 	if (!ISSET(((BTREE *)t), B_NEEDSWAP))
     72 		return;
     73 	if (pg == P_META) {
     74 		mswap(pp);
     75 		return;
     76 	}
     77 
     78 	h = pp;
     79 	M_32_SWAP(h->pgno);
     80 	M_32_SWAP(h->prevpg);
     81 	M_32_SWAP(h->nextpg);
     82 	M_32_SWAP(h->flags);
     83 	M_16_SWAP(h->lower);
     84 	M_16_SWAP(h->upper);
     85 
     86 	top = NEXTINDEX(h);
     87 	if ((h->flags & P_TYPE) == P_BINTERNAL)
     88 		for (i = 0; i < top; i++) {
     89 			M_16_SWAP(h->linp[i]);
     90 			p = (char *)GETBINTERNAL(h, i);
     91 			P_32_SWAP(p);
     92 			p += sizeof(u_int32_t);
     93 			P_32_SWAP(p);
     94 			p += sizeof(pgno_t);
     95 			if (*(u_char *)p & P_BIGKEY) {
     96 				p += sizeof(u_char);
     97 				P_32_SWAP(p);
     98 				p += sizeof(pgno_t);
     99 				P_32_SWAP(p);
    100 			}
    101 		}
    102 	else if ((h->flags & P_TYPE) == P_BLEAF)
    103 		for (i = 0; i < top; i++) {
    104 			M_16_SWAP(h->linp[i]);
    105 			p = (char *)GETBLEAF(h, i);
    106 			P_32_SWAP(p);
    107 			p += sizeof(u_int32_t);
    108 			P_32_SWAP(p);
    109 			p += sizeof(u_int32_t);
    110 			flags = *(u_char *)p;
    111 			if (flags & (P_BIGKEY | P_BIGDATA)) {
    112 				p += sizeof(u_char);
    113 				if (flags & P_BIGKEY) {
    114 					P_32_SWAP(p);
    115 					p += sizeof(pgno_t);
    116 					P_32_SWAP(p);
    117 				}
    118 				if (flags & P_BIGDATA) {
    119 					p += sizeof(u_int32_t);
    120 					P_32_SWAP(p);
    121 					p += sizeof(pgno_t);
    122 					P_32_SWAP(p);
    123 				}
    124 			}
    125 		}
    126 }
    127 
    128 void
    129 __bt_pgout(t, pg, pp)
    130 	void *t;
    131 	pgno_t pg;
    132 	void *pp;
    133 {
    134 	PAGE *h;
    135 	indx_t i, top;
    136 	u_char flags;
    137 	char *p;
    138 
    139 	if (!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 *)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 *)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(pg)
    204 	PAGE *pg;
    205 {
    206 	char *p;
    207 
    208 	p = (char *)pg;
    209 	P_32_SWAP(p);		/* m_magic */
    210 	p += sizeof(u_int32_t);
    211 	P_32_SWAP(p);		/* m_version */
    212 	p += sizeof(u_int32_t);
    213 	P_32_SWAP(p);		/* m_psize */
    214 	p += sizeof(u_int32_t);
    215 	P_32_SWAP(p);		/* m_free */
    216 	p += sizeof(u_int32_t);
    217 	P_32_SWAP(p);		/* m_nrecs */
    218 	p += sizeof(u_int32_t);
    219 	P_32_SWAP(p);		/* m_flags */
    220 	p += sizeof(u_int32_t);
    221 }
    222