1 /*- 2 * Copyright (c) 1990 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Mike Olson. 7 * 8 * %sccs.include.redist.c% 9 */ 10 11 #if defined(LIBC_SCCS) && !defined(lint) 12 static char sccsid[] = "@(#)bt_conv.c 5.10 (Berkeley) 05/16/93"; 13 #endif /* LIBC_SCCS and not lint */ 14 15 #include <sys/param.h> 16 17 #include <stdio.h> 18 19 #include <db.h> 20 #include "btree.h" 21 22 static void mswap __P((PAGE *)); 23 24 /* 25 * __BT_BPGIN, __BT_BPGOUT -- 26 * Convert host-specific number layout to/from the host-independent 27 * format stored on disk. 28 * 29 * Parameters: 30 * t: tree 31 * pg: page number 32 * h: page to convert 33 */ 34 void 35 __bt_pgin(t, pg, pp) 36 void *t; 37 pgno_t pg; 38 void *pp; 39 { 40 PAGE *h; 41 int i, top; 42 u_char flags; 43 char *p; 44 45 if (!ISSET(((BTREE *)t), B_NEEDSWAP)) 46 return; 47 if (pg == P_META) { 48 mswap(pp); 49 return; 50 } 51 52 h = pp; 53 BLSWAP(h->pgno); 54 BLSWAP(h->prevpg); 55 BLSWAP(h->nextpg); 56 BLSWAP(h->flags); 57 BSSWAP(h->lower); 58 BSSWAP(h->upper); 59 60 top = NEXTINDEX(h); 61 if ((h->flags & P_TYPE) == P_BINTERNAL) 62 for (i = 0; i < top; i++) { 63 BSSWAP(h->linp[i]); 64 p = (char *)GETBINTERNAL(h, i); 65 BLPSWAP(p); 66 p += sizeof(size_t); 67 BLPSWAP(p); 68 p += sizeof(pgno_t); 69 if (*(u_char *)p & P_BIGKEY) { 70 p += sizeof(u_char); 71 BLPSWAP(p); 72 p += sizeof(pgno_t); 73 BLPSWAP(p); 74 } 75 } 76 else if ((h->flags & P_TYPE) == P_BLEAF) 77 for (i = 0; i < top; i++) { 78 BSSWAP(h->linp[i]); 79 p = (char *)GETBLEAF(h, i); 80 BLPSWAP(p); 81 p += sizeof(size_t); 82 BLPSWAP(p); 83 p += sizeof(size_t); 84 flags = *(u_char *)p; 85 if (flags & (P_BIGKEY | P_BIGDATA)) { 86 p += sizeof(u_char); 87 if (flags & P_BIGKEY) { 88 BLPSWAP(p); 89 p += sizeof(pgno_t); 90 BLPSWAP(p); 91 } 92 if (flags & P_BIGDATA) { 93 p += sizeof(size_t); 94 BLPSWAP(p); 95 p += sizeof(pgno_t); 96 BLPSWAP(p); 97 } 98 } 99 } 100 } 101 102 void 103 __bt_pgout(t, pg, pp) 104 void *t; 105 pgno_t pg; 106 void *pp; 107 { 108 PAGE *h; 109 int i, top; 110 u_char flags; 111 char *p; 112 113 if (!ISSET(((BTREE *)t), B_NEEDSWAP)) 114 return; 115 if (pg == P_META) { 116 mswap(pp); 117 return; 118 } 119 120 h = pp; 121 top = NEXTINDEX(h); 122 if ((h->flags & P_TYPE) == P_BINTERNAL) 123 for (i = 0; i < top; i++) { 124 p = (char *)GETBINTERNAL(h, i); 125 BLPSWAP(p); 126 p += sizeof(size_t); 127 BLPSWAP(p); 128 p += sizeof(pgno_t); 129 if (*(u_char *)p & P_BIGKEY) { 130 p += sizeof(u_char); 131 BLPSWAP(p); 132 p += sizeof(pgno_t); 133 BLPSWAP(p); 134 } 135 BSSWAP(h->linp[i]); 136 } 137 else if ((h->flags & P_TYPE) == P_BLEAF) 138 for (i = 0; i < top; i++) { 139 p = (char *)GETBLEAF(h, i); 140 BLPSWAP(p); 141 p += sizeof(size_t); 142 BLPSWAP(p); 143 p += sizeof(size_t); 144 flags = *(u_char *)p; 145 if (flags & (P_BIGKEY | P_BIGDATA)) { 146 p += sizeof(u_char); 147 if (flags & P_BIGKEY) { 148 BLPSWAP(p); 149 p += sizeof(pgno_t); 150 BLPSWAP(p); 151 } 152 if (flags & P_BIGDATA) { 153 p += sizeof(size_t); 154 BLPSWAP(p); 155 p += sizeof(pgno_t); 156 BLPSWAP(p); 157 } 158 } 159 BSSWAP(h->linp[i]); 160 } 161 162 BLSWAP(h->pgno); 163 BLSWAP(h->prevpg); 164 BLSWAP(h->nextpg); 165 BLSWAP(h->flags); 166 BSSWAP(h->lower); 167 BSSWAP(h->upper); 168 } 169 170 /* 171 * MSWAP -- Actually swap the bytes on the meta page. 172 * 173 * Parameters: 174 * p: page to convert 175 */ 176 static void 177 mswap(pg) 178 PAGE *pg; 179 { 180 char *p; 181 182 p = (char *)pg; 183 BLPSWAP(p); /* m_magic */ 184 p += sizeof(u_long); 185 BLPSWAP(p); /* m_version */ 186 p += sizeof(u_long); 187 BLPSWAP(p); /* m_psize */ 188 p += sizeof(u_long); 189 BLPSWAP(p); /* m_free */ 190 p += sizeof(u_long); 191 BLPSWAP(p); /* m_nrecs */ 192 p += sizeof(u_long); 193 BLPSWAP(p); /* m_flags */ 194 p += sizeof(u_long); 195 } 196