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
  37 #if defined(LIBC_SCCS) && !defined(lint)
  38 static char sccsid[] = "@(#)bt_conv.c   8.5 (Berkeley) 8/17/94";
  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 (!F_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 (!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 *)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);           /* magic */
 210         p += sizeof(u_int32_t);
 211         P_32_SWAP(p);           /* version */
 212         p += sizeof(u_int32_t);
 213         P_32_SWAP(p);           /* psize */
 214         p += sizeof(u_int32_t);
 215         P_32_SWAP(p);           /* free */
 216         p += sizeof(u_int32_t);
 217         P_32_SWAP(p);           /* nrecs */
 218         p += sizeof(u_int32_t);
 219         P_32_SWAP(p);           /* flags */
 220         p += sizeof(u_int32_t);
 221 }