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  * 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  * @(#)bt_conv.c        8.5 (Berkeley) 8/17/94
  37  */
  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 __P((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(t, pg, pp)
  60         void *t;
  61         pgno_t pg;
  62         void *pp;
  63 {
  64         PAGE *h;
  65         indx_t i, top;
  66         u_char flags;
  67         char *p;
  68
  69         if (!F_ISSET(((BTREE *)t), B_NEEDSWAP))
  70                 return;
  71         if (pg == P_META) {
  72                 mswap(pp);
  73                 return;
  74         }
  75
  76         h = pp;
  77         M_32_SWAP(h->pgno);
  78         M_32_SWAP(h->prevpg);
  79         M_32_SWAP(h->nextpg);
  80         M_32_SWAP(h->flags);
  81         M_16_SWAP(h->lower);
  82         M_16_SWAP(h->upper);
  83
  84         top = NEXTINDEX(h);
  85         if ((h->flags & P_TYPE) == P_BINTERNAL)
  86                 for (i = 0; i < top; i++) {
  87                         M_16_SWAP(h->linp[i]);
  88                         p = (char *)GETBINTERNAL(h, i);
  89                         P_32_SWAP(p);
  90                         p += sizeof(u_int32_t);
  91                         P_32_SWAP(p);
  92                         p += sizeof(pgno_t);
  93                         if (*(u_char *)p & P_BIGKEY) {
  94                                 p += sizeof(u_char);
  95                                 P_32_SWAP(p);
  96                                 p += sizeof(pgno_t);
  97                                 P_32_SWAP(p);
  98                         }
  99                 }
 100         else if ((h->flags & P_TYPE) == P_BLEAF)
 101                 for (i = 0; i < top; i++) {
 102                         M_16_SWAP(h->linp[i]);
 103                         p = (char *)GETBLEAF(h, i);
 104                         P_32_SWAP(p);
 105                         p += sizeof(u_int32_t);
 106                         P_32_SWAP(p);
 107                         p += sizeof(u_int32_t);
 108                         flags = *(u_char *)p;
 109                         if (flags & (P_BIGKEY | P_BIGDATA)) {
 110                                 p += sizeof(u_char);
 111                                 if (flags & P_BIGKEY) {
 112                                         P_32_SWAP(p);
 113                                         p += sizeof(pgno_t);
 114                                         P_32_SWAP(p);
 115                                 }
 116                                 if (flags & P_BIGDATA) {
 117                                         p += sizeof(u_int32_t);
 118                                         P_32_SWAP(p);
 119                                         p += sizeof(pgno_t);
 120                                         P_32_SWAP(p);
 121                                 }
 122                         }
 123                 }
 124 }
 125
 126 void
 127 __bt_pgout(t, pg, pp)
 128         void *t;
 129         pgno_t pg;
 130         void *pp;
 131 {
 132         PAGE *h;
 133         indx_t i, top;
 134         u_char flags;
 135         char *p;
 136
 137         if (!F_ISSET(((BTREE *)t), B_NEEDSWAP))
 138                 return;
 139         if (pg == P_META) {
 140                 mswap(pp);
 141                 return;
 142         }
 143
 144         h = pp;
 145         top = NEXTINDEX(h);
 146         if ((h->flags & P_TYPE) == P_BINTERNAL)
 147                 for (i = 0; i < top; i++) {
 148                         p = (char *)GETBINTERNAL(h, i);
 149                         P_32_SWAP(p);
 150                         p += sizeof(u_int32_t);
 151                         P_32_SWAP(p);
 152                         p += sizeof(pgno_t);
 153                         if (*(u_char *)p & P_BIGKEY) {
 154                                 p += sizeof(u_char);
 155                                 P_32_SWAP(p);
 156                                 p += sizeof(pgno_t);
 157                                 P_32_SWAP(p);
 158                         }
 159                         M_16_SWAP(h->linp[i]);
 160                 }
 161         else if ((h->flags & P_TYPE) == P_BLEAF)
 162                 for (i = 0; i < top; i++) {
 163                         p = (char *)GETBLEAF(h, i);
 164                         P_32_SWAP(p);
 165                         p += sizeof(u_int32_t);
 166                         P_32_SWAP(p);
 167                         p += sizeof(u_int32_t);
 168                         flags = *(u_char *)p;
 169                         if (flags & (P_BIGKEY | P_BIGDATA)) {
 170                                 p += sizeof(u_char);
 171                                 if (flags & P_BIGKEY) {
 172                                         P_32_SWAP(p);
 173                                         p += sizeof(pgno_t);
 174                                         P_32_SWAP(p);
 175                                 }
 176                                 if (flags & P_BIGDATA) {
 177                                         p += sizeof(u_int32_t);
 178                                         P_32_SWAP(p);
 179                                         p += sizeof(pgno_t);
 180                                         P_32_SWAP(p);
 181                                 }
 182                         }
 183                         M_16_SWAP(h->linp[i]);
 184                 }
 185
 186         M_32_SWAP(h->pgno);
 187         M_32_SWAP(h->prevpg);
 188         M_32_SWAP(h->nextpg);
 189         M_32_SWAP(h->flags);
 190         M_16_SWAP(h->lower);
 191         M_16_SWAP(h->upper);
 192 }
 193
 194 /*
 195  * MSWAP -- Actually swap the bytes on the meta page.
 196  *
 197  * Parameters:
 198  *      p:      page to convert
 199  */
 200 static void
 201 mswap(pg)
 202         PAGE *pg;
 203 {
 204         char *p;
 205
 206         p = (char *)pg;
 207         P_32_SWAP(p);           /* magic */
 208         p += sizeof(u_int32_t);
 209         P_32_SWAP(p);           /* version */
 210         p += sizeof(u_int32_t);
 211         P_32_SWAP(p);           /* psize */
 212         p += sizeof(u_int32_t);
 213         P_32_SWAP(p);           /* free */
 214         p += sizeof(u_int32_t);
 215         P_32_SWAP(p);           /* nrecs */
 216         p += sizeof(u_int32_t);
 217         P_32_SWAP(p);           /* flags */
 218         p += sizeof(u_int32_t);
 219 }