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. 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  * @(#)bt_conv.c        8.5 (Berkeley) 8/17/94
  33  * $FreeBSD: head/lib/libc/db/btree/bt_conv.c 189291 2009-03-02 23:47:18Z delphij $
  34  */
  35
  36 #include <sys/param.h>
  37
  38 #include <stdio.h>
  39
  40 #include <db.h>
  41 #include "btree.h"
  42
  43 static void mswap(PAGE *);
  44
  45 /*
  46  * __BT_BPGIN, __BT_BPGOUT --
  47  *      Convert host-specific number layout to/from the host-independent
  48  *      format stored on disk.
  49  *
  50  * Parameters:
  51  *      t:      tree
  52  *      pg:     page number
  53  *      h:      page to convert
  54  */
  55 void
  56 __bt_pgin(void *t, pgno_t pg, void *pp)
  57 {
  58         PAGE *h;
  59         indx_t i, top;
  60         unsigned char flags;
  61         char *p;
  62
  63         if (!F_ISSET(((BTREE *)t), B_NEEDSWAP))
  64                 return;
  65         if (pg == P_META) {
  66                 mswap(pp);
  67                 return;
  68         }
  69
  70         h = pp;
  71         M_32_SWAP(h->pgno);
  72         M_32_SWAP(h->prevpg);
  73         M_32_SWAP(h->nextpg);
  74         M_32_SWAP(h->flags);
  75         M_16_SWAP(h->lower);
  76         M_16_SWAP(h->upper);
  77
  78         top = NEXTINDEX(h);
  79         if ((h->flags & P_TYPE) == P_BINTERNAL)
  80                 for (i = 0; i < top; i++) {
  81                         M_16_SWAP(h->linp[i]);
  82                         p = (char *)GETBINTERNAL(h, i);
  83                         P_32_SWAP(p);
  84                         p += sizeof(uint32_t);
  85                         P_32_SWAP(p);
  86                         p += sizeof(pgno_t);
  87                         if (*(unsigned char *)p & P_BIGKEY) {
  88                                 p += sizeof(unsigned char);
  89                                 P_32_SWAP(p);
  90                                 p += sizeof(pgno_t);
  91                                 P_32_SWAP(p);
  92                         }
  93                 }
  94         else if ((h->flags & P_TYPE) == P_BLEAF)
  95                 for (i = 0; i < top; i++) {
  96                         M_16_SWAP(h->linp[i]);
  97                         p = (char *)GETBLEAF(h, i);
  98                         P_32_SWAP(p);
  99                         p += sizeof(uint32_t);
 100                         P_32_SWAP(p);
 101                         p += sizeof(uint32_t);
 102                         flags = *(unsigned char *)p;
 103                         if (flags & (P_BIGKEY | P_BIGDATA)) {
 104                                 p += sizeof(unsigned char);
 105                                 if (flags & P_BIGKEY) {
 106                                         P_32_SWAP(p);
 107                                         p += sizeof(pgno_t);
 108                                         P_32_SWAP(p);
 109                                 }
 110                                 if (flags & P_BIGDATA) {
 111                                         p += sizeof(uint32_t);
 112                                         P_32_SWAP(p);
 113                                         p += sizeof(pgno_t);
 114                                         P_32_SWAP(p);
 115                                 }
 116                         }
 117                 }
 118 }
 119
 120 void
 121 __bt_pgout(void *t, pgno_t pg, void *pp)
 122 {
 123         PAGE *h;
 124         indx_t i, top;
 125         unsigned char flags;
 126         char *p;
 127
 128         if (!F_ISSET(((BTREE *)t), B_NEEDSWAP))
 129                 return;
 130         if (pg == P_META) {
 131                 mswap(pp);
 132                 return;
 133         }
 134
 135         h = pp;
 136         top = NEXTINDEX(h);
 137         if ((h->flags & P_TYPE) == P_BINTERNAL)
 138                 for (i = 0; i < top; i++) {
 139                         p = (char *)GETBINTERNAL(h, i);
 140                         P_32_SWAP(p);
 141                         p += sizeof(uint32_t);
 142                         P_32_SWAP(p);
 143                         p += sizeof(pgno_t);
 144                         if (*(unsigned char *)p & P_BIGKEY) {
 145                                 p += sizeof(unsigned char);
 146                                 P_32_SWAP(p);
 147                                 p += sizeof(pgno_t);
 148                                 P_32_SWAP(p);
 149                         }
 150                         M_16_SWAP(h->linp[i]);
 151                 }
 152         else if ((h->flags & P_TYPE) == P_BLEAF)
 153                 for (i = 0; i < top; i++) {
 154                         p = (char *)GETBLEAF(h, i);
 155                         P_32_SWAP(p);
 156                         p += sizeof(uint32_t);
 157                         P_32_SWAP(p);
 158                         p += sizeof(uint32_t);
 159                         flags = *(unsigned char *)p;
 160                         if (flags & (P_BIGKEY | P_BIGDATA)) {
 161                                 p += sizeof(unsigned char);
 162                                 if (flags & P_BIGKEY) {
 163                                         P_32_SWAP(p);
 164                                         p += sizeof(pgno_t);
 165                                         P_32_SWAP(p);
 166                                 }
 167                                 if (flags & P_BIGDATA) {
 168                                         p += sizeof(uint32_t);
 169                                         P_32_SWAP(p);
 170                                         p += sizeof(pgno_t);
 171                                         P_32_SWAP(p);
 172                                 }
 173                         }
 174                         M_16_SWAP(h->linp[i]);
 175                 }
 176
 177         M_32_SWAP(h->pgno);
 178         M_32_SWAP(h->prevpg);
 179         M_32_SWAP(h->nextpg);
 180         M_32_SWAP(h->flags);
 181         M_16_SWAP(h->lower);
 182         M_16_SWAP(h->upper);
 183 }
 184
 185 /*
 186  * MSWAP -- Actually swap the bytes on the meta page.
 187  *
 188  * Parameters:
 189  *      p:      page to convert
 190  */
 191 static void
 192 mswap(PAGE *pg)
 193 {
 194         char *p;
 195
 196         p = (char *)pg;
 197         P_32_SWAP(p);           /* magic */
 198         p += sizeof(uint32_t);
 199         P_32_SWAP(p);           /* version */
 200         p += sizeof(uint32_t);
 201         P_32_SWAP(p);           /* psize */
 202         p += sizeof(uint32_t);
 203         P_32_SWAP(p);           /* free */
 204         p += sizeof(uint32_t);
 205         P_32_SWAP(p);           /* nrecs */
 206         p += sizeof(uint32_t);
 207         P_32_SWAP(p);           /* flags */
 208         p += sizeof(uint32_t);
 209 }