lib/libc/db/btree/bt_conv.c

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