bt_conv.c revision 1.2
1 /*- 2 * Copyright (c) 1990, 1993 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[] = "from: @(#)bt_conv.c 8.1 (Berkeley) 6/4/93";*/ 39 static char rcsid[] = "$Id: bt_conv.c,v 1.2 1993/08/01 18:43:59 mycroft Exp $"; 40 #endif /* LIBC_SCCS and not lint */ 41 42 #include <sys/param.h> 43 44 #include <stdio.h> 45 46 #include <db.h> 47 #include "btree.h" 48 49 static void mswap __P((PAGE *)); 50 51 /* 52 * __BT_BPGIN, __BT_BPGOUT -- 53 * Convert host-specific number layout to/from the host-independent 54 * format stored on disk. 55 * 56 * Parameters: 57 * t: tree 58 * pg: page number 59 * h: page to convert 60 */ 61 void 62 __bt_pgin(t, pg, pp) 63 void *t; 64 pgno_t pg; 65 void *pp; 66 { 67 PAGE *h; 68 int i, top; 69 u_char flags; 70 char *p; 71 72 if (!ISSET(((BTREE *)t), B_NEEDSWAP)) 73 return; 74 if (pg == P_META) { 75 mswap(pp); 76 return; 77 } 78 79 h = pp; 80 BLSWAP(h->pgno); 81 BLSWAP(h->prevpg); 82 BLSWAP(h->nextpg); 83 BLSWAP(h->flags); 84 BSSWAP(h->lower); 85 BSSWAP(h->upper); 86 87 top = NEXTINDEX(h); 88 if ((h->flags & P_TYPE) == P_BINTERNAL) 89 for (i = 0; i < top; i++) { 90 BSSWAP(h->linp[i]); 91 p = (char *)GETBINTERNAL(h, i); 92 BLPSWAP(p); 93 p += sizeof(size_t); 94 BLPSWAP(p); 95 p += sizeof(pgno_t); 96 if (*(u_char *)p & P_BIGKEY) { 97 p += sizeof(u_char); 98 BLPSWAP(p); 99 p += sizeof(pgno_t); 100 BLPSWAP(p); 101 } 102 } 103 else if ((h->flags & P_TYPE) == P_BLEAF) 104 for (i = 0; i < top; i++) { 105 BSSWAP(h->linp[i]); 106 p = (char *)GETBLEAF(h, i); 107 BLPSWAP(p); 108 p += sizeof(size_t); 109 BLPSWAP(p); 110 p += sizeof(size_t); 111 flags = *(u_char *)p; 112 if (flags & (P_BIGKEY | P_BIGDATA)) { 113 p += sizeof(u_char); 114 if (flags & P_BIGKEY) { 115 BLPSWAP(p); 116 p += sizeof(pgno_t); 117 BLPSWAP(p); 118 } 119 if (flags & P_BIGDATA) { 120 p += sizeof(size_t); 121 BLPSWAP(p); 122 p += sizeof(pgno_t); 123 BLPSWAP(p); 124 } 125 } 126 } 127 } 128 129 void 130 __bt_pgout(t, pg, pp) 131 void *t; 132 pgno_t pg; 133 void *pp; 134 { 135 PAGE *h; 136 int i, top; 137 u_char flags; 138 char *p; 139 140 if (!ISSET(((BTREE *)t), B_NEEDSWAP)) 141 return; 142 if (pg == P_META) { 143 mswap(pp); 144 return; 145 } 146 147 h = pp; 148 top = NEXTINDEX(h); 149 if ((h->flags & P_TYPE) == P_BINTERNAL) 150 for (i = 0; i < top; i++) { 151 p = (char *)GETBINTERNAL(h, i); 152 BLPSWAP(p); 153 p += sizeof(size_t); 154 BLPSWAP(p); 155 p += sizeof(pgno_t); 156 if (*(u_char *)p & P_BIGKEY) { 157 p += sizeof(u_char); 158 BLPSWAP(p); 159 p += sizeof(pgno_t); 160 BLPSWAP(p); 161 } 162 BSSWAP(h->linp[i]); 163 } 164 else if ((h->flags & P_TYPE) == P_BLEAF) 165 for (i = 0; i < top; i++) { 166 p = (char *)GETBLEAF(h, i); 167 BLPSWAP(p); 168 p += sizeof(size_t); 169 BLPSWAP(p); 170 p += sizeof(size_t); 171 flags = *(u_char *)p; 172 if (flags & (P_BIGKEY | P_BIGDATA)) { 173 p += sizeof(u_char); 174 if (flags & P_BIGKEY) { 175 BLPSWAP(p); 176 p += sizeof(pgno_t); 177 BLPSWAP(p); 178 } 179 if (flags & P_BIGDATA) { 180 p += sizeof(size_t); 181 BLPSWAP(p); 182 p += sizeof(pgno_t); 183 BLPSWAP(p); 184 } 185 } 186 BSSWAP(h->linp[i]); 187 } 188 189 BLSWAP(h->pgno); 190 BLSWAP(h->prevpg); 191 BLSWAP(h->nextpg); 192 BLSWAP(h->flags); 193 BSSWAP(h->lower); 194 BSSWAP(h->upper); 195 } 196 197 /* 198 * MSWAP -- Actually swap the bytes on the meta page. 199 * 200 * Parameters: 201 * p: page to convert 202 */ 203 static void 204 mswap(pg) 205 PAGE *pg; 206 { 207 char *p; 208 209 p = (char *)pg; 210 BLPSWAP(p); /* m_magic */ 211 p += sizeof(u_long); 212 BLPSWAP(p); /* m_version */ 213 p += sizeof(u_long); 214 BLPSWAP(p); /* m_psize */ 215 p += sizeof(u_long); 216 BLPSWAP(p); /* m_free */ 217 p += sizeof(u_long); 218 BLPSWAP(p); /* m_nrecs */ 219 p += sizeof(u_long); 220 BLPSWAP(p); /* m_flags */ 221 p += sizeof(u_long); 222 } 223
Indexes created Thu Oct 02 01:09:59 GMT 2025