db.subproj/btree.subproj/bt_conv.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * Copyright (c) 1990, 1993
  24  *      The Regents of the University of California.  All rights reserved.
  25  *
  26  * This code is derived from software contributed to Berkeley by
  27  * Mike Olson.
  28  *
  29  * Redistribution and use in source and binary forms, with or without
  30  * modification, are permitted provided that the following conditions
  31  * are met:
  32  * 1. Redistributions of source code must retain the above copyright
  33  *    notice, this list of conditions and the following disclaimer.
  34  * 2. Redistributions in binary form must reproduce the above copyright
  35  *    notice, this list of conditions and the following disclaimer in the
  36  *    documentation and/or other materials provided with the distribution.
  37  * 3. All advertising materials mentioning features or use of this software
  38  *    must display the following acknowledgement:
  39  *      This product includes software developed by the University of
  40  *      California, Berkeley and its contributors.
  41  * 4. Neither the name of the University nor the names of its contributors
  42  *    may be used to endorse or promote products derived from this software
  43  *    without specific prior written permission.
  44  *
  45  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  46  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  47  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  48  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  49  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  50  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  51  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  52  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  53  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  54  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  55  * SUCH DAMAGE.
  56  */
  57
  58
  59 #include <sys/param.h>
  60
  61 #include <stdio.h>
  62
  63 #include <db.h>
  64 #include "btree.h"
  65
  66 static void mswap __P((PAGE *));
  67
  68 /*
  69  * __BT_BPGIN, __BT_BPGOUT --
  70  *      Convert host-specific number layout to/from the host-independent
  71  *      format stored on disk.
  72  *
  73  * Parameters:
  74  *      t:      tree
  75  *      pg:     page number
  76  *      h:      page to convert
  77  */
  78 void
  79 __bt_pgin(t, pg, pp)
  80         void *t;
  81         pgno_t pg;
  82         void *pp;
  83 {
  84         PAGE *h;
  85         indx_t i, top;
  86         u_char flags;
  87         char *p;
  88
  89         if (!ISSET(((BTREE *)t), B_NEEDSWAP))
  90                 return;
  91         if (pg == P_META) {
  92                 mswap(pp);
  93                 return;
  94         }
  95
  96         h = pp;
  97         M_32_SWAP(h->pgno);
  98         M_32_SWAP(h->prevpg);
  99         M_32_SWAP(h->nextpg);
 100         M_32_SWAP(h->flags);
 101         M_16_SWAP(h->lower);
 102         M_16_SWAP(h->upper);
 103
 104         top = NEXTINDEX(h);
 105         if ((h->flags & P_TYPE) == P_BINTERNAL)
 106                 for (i = 0; i < top; i++) {
 107                         M_16_SWAP(h->linp[i]);
 108                         p = (char *)GETBINTERNAL(h, i);
 109                         P_32_SWAP(p);
 110                         p += sizeof(size_t);
 111                         P_32_SWAP(p);
 112                         p += sizeof(pgno_t);
 113                         if (*(u_char *)p & P_BIGKEY) {
 114                                 p += sizeof(u_char);
 115                                 P_32_SWAP(p);
 116                                 p += sizeof(pgno_t);
 117                                 P_32_SWAP(p);
 118                         }
 119                 }
 120         else if ((h->flags & P_TYPE) == P_BLEAF)
 121                 for (i = 0; i < top; i++) {
 122                         M_16_SWAP(h->linp[i]);
 123                         p = (char *)GETBLEAF(h, i);
 124                         P_32_SWAP(p);
 125                         p += sizeof(size_t);
 126                         P_32_SWAP(p);
 127                         p += sizeof(size_t);
 128                         flags = *(u_char *)p;
 129                         if (flags & (P_BIGKEY | P_BIGDATA)) {
 130                                 p += sizeof(u_char);
 131                                 if (flags & P_BIGKEY) {
 132                                         P_32_SWAP(p);
 133                                         p += sizeof(pgno_t);
 134                                         P_32_SWAP(p);
 135                                 }
 136                                 if (flags & P_BIGDATA) {
 137                                         p += sizeof(size_t);
 138                                         P_32_SWAP(p);
 139                                         p += sizeof(pgno_t);
 140                                         P_32_SWAP(p);
 141                                 }
 142                         }
 143                 }
 144 }
 145
 146 void
 147 __bt_pgout(t, pg, pp)
 148         void *t;
 149         pgno_t pg;
 150         void *pp;
 151 {
 152         PAGE *h;
 153         indx_t i, top;
 154         u_char flags;
 155         char *p;
 156
 157         if (!ISSET(((BTREE *)t), B_NEEDSWAP))
 158                 return;
 159         if (pg == P_META) {
 160                 mswap(pp);
 161                 return;
 162         }
 163
 164         h = pp;
 165         top = NEXTINDEX(h);
 166         if ((h->flags & P_TYPE) == P_BINTERNAL)
 167                 for (i = 0; i < top; i++) {
 168                         p = (char *)GETBINTERNAL(h, i);
 169                         P_32_SWAP(p);
 170                         p += sizeof(size_t);
 171                         P_32_SWAP(p);
 172                         p += sizeof(pgno_t);
 173                         if (*(u_char *)p & P_BIGKEY) {
 174                                 p += sizeof(u_char);
 175                                 P_32_SWAP(p);
 176                                 p += sizeof(pgno_t);
 177                                 P_32_SWAP(p);
 178                         }
 179                         M_16_SWAP(h->linp[i]);
 180                 }
 181         else if ((h->flags & P_TYPE) == P_BLEAF)
 182                 for (i = 0; i < top; i++) {
 183                         p = (char *)GETBLEAF(h, i);
 184                         P_32_SWAP(p);
 185                         p += sizeof(size_t);
 186                         P_32_SWAP(p);
 187                         p += sizeof(size_t);
 188                         flags = *(u_char *)p;
 189                         if (flags & (P_BIGKEY | P_BIGDATA)) {
 190                                 p += sizeof(u_char);
 191                                 if (flags & P_BIGKEY) {
 192                                         P_32_SWAP(p);
 193                                         p += sizeof(pgno_t);
 194                                         P_32_SWAP(p);
 195                                 }
 196                                 if (flags & P_BIGDATA) {
 197                                         p += sizeof(size_t);
 198                                         P_32_SWAP(p);
 199                                         p += sizeof(pgno_t);
 200                                         P_32_SWAP(p);
 201                                 }
 202                         }
 203                         M_16_SWAP(h->linp[i]);
 204                 }
 205
 206         M_32_SWAP(h->pgno);
 207         M_32_SWAP(h->prevpg);
 208         M_32_SWAP(h->nextpg);
 209         M_32_SWAP(h->flags);
 210         M_16_SWAP(h->lower);
 211         M_16_SWAP(h->upper);
 212 }
 213
 214 /*
 215  * MSWAP -- Actually swap the bytes on the meta page.
 216  *
 217  * Parameters:
 218  *      p:      page to convert
 219  */
 220 static void
 221 mswap(pg)
 222         PAGE *pg;
 223 {
 224         char *p;
 225
 226         p = (char *)pg;
 227         P_32_SWAP(p);           /* m_magic */
 228         p += sizeof(u_int32_t);
 229         P_32_SWAP(p);           /* m_version */
 230         p += sizeof(u_int32_t);
 231         P_32_SWAP(p);           /* m_psize */
 232         p += sizeof(u_int32_t);
 233         P_32_SWAP(p);           /* m_free */
 234         p += sizeof(u_int32_t);
 235         P_32_SWAP(p);           /* m_nrecs */
 236         p += sizeof(u_int32_t);
 237         P_32_SWAP(p);           /* m_flags */
 238         p += sizeof(u_int32_t);
 239 }