bt_conv.c revision 14272
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) 38static 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 48static 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 */ 60void 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 128void 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 */ 202static void 203mswap(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} 222