1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1990, 1993, 1994
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Mike Olson.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35 #include <sys/param.h>
36
37 #include <stdio.h>
38
39 #include <db.h>
40 #include "btree.h"
41
42 static void mswap(PAGE *);
43
44 /*
45 * __BT_BPGIN, __BT_BPGOUT --
46 * Convert host-specific number layout to/from the host-independent
47 * format stored on disk.
48 *
49 * Parameters:
50 * t: tree
51 * pg: page number
52 * h: page to convert
53 */
54 void
__bt_pgin(void * t,pgno_t pg,void * pp)55 __bt_pgin(void *t, pgno_t pg, void *pp)
56 {
57 PAGE *h;
58 indx_t i, top;
59 u_char flags;
60 char *p;
61
62 if (!F_ISSET(((BTREE *)t), B_NEEDSWAP))
63 return;
64 if (pg == P_META) {
65 mswap(pp);
66 return;
67 }
68
69 h = pp;
70 M_32_SWAP(h->pgno);
71 M_32_SWAP(h->prevpg);
72 M_32_SWAP(h->nextpg);
73 M_32_SWAP(h->flags);
74 M_16_SWAP(h->lower);
75 M_16_SWAP(h->upper);
76
77 top = NEXTINDEX(h);
78 if ((h->flags & P_TYPE) == P_BINTERNAL)
79 for (i = 0; i < top; i++) {
80 M_16_SWAP(h->linp[i]);
81 p = (char *)GETBINTERNAL(h, i);
82 P_32_SWAP(p);
83 p += sizeof(u_int32_t);
84 P_32_SWAP(p);
85 p += sizeof(pgno_t);
86 if (*(u_char *)p & P_BIGKEY) {
87 p += sizeof(u_char);
88 P_32_SWAP(p);
89 p += sizeof(pgno_t);
90 P_32_SWAP(p);
91 }
92 }
93 else if ((h->flags & P_TYPE) == P_BLEAF)
94 for (i = 0; i < top; i++) {
95 M_16_SWAP(h->linp[i]);
96 p = (char *)GETBLEAF(h, i);
97 P_32_SWAP(p);
98 p += sizeof(u_int32_t);
99 P_32_SWAP(p);
100 p += sizeof(u_int32_t);
101 flags = *(u_char *)p;
102 if (flags & (P_BIGKEY | P_BIGDATA)) {
103 p += sizeof(u_char);
104 if (flags & P_BIGKEY) {
105 P_32_SWAP(p);
106 p += sizeof(pgno_t);
107 P_32_SWAP(p);
108 }
109 if (flags & P_BIGDATA) {
110 p += sizeof(u_int32_t);
111 P_32_SWAP(p);
112 p += sizeof(pgno_t);
113 P_32_SWAP(p);
114 }
115 }
116 }
117 }
118
119 void
__bt_pgout(void * t,pgno_t pg,void * pp)120 __bt_pgout(void *t, pgno_t pg, void *pp)
121 {
122 PAGE *h;
123 indx_t i, top;
124 u_char flags;
125 char *p;
126
127 if (!F_ISSET(((BTREE *)t), B_NEEDSWAP))
128 return;
129 if (pg == P_META) {
130 mswap(pp);
131 return;
132 }
133
134 h = pp;
135 top = NEXTINDEX(h);
136 if ((h->flags & P_TYPE) == P_BINTERNAL)
137 for (i = 0; i < top; i++) {
138 p = (char *)GETBINTERNAL(h, i);
139 P_32_SWAP(p);
140 p += sizeof(u_int32_t);
141 P_32_SWAP(p);
142 p += sizeof(pgno_t);
143 if (*(u_char *)p & P_BIGKEY) {
144 p += sizeof(u_char);
145 P_32_SWAP(p);
146 p += sizeof(pgno_t);
147 P_32_SWAP(p);
148 }
149 M_16_SWAP(h->linp[i]);
150 }
151 else if ((h->flags & P_TYPE) == P_BLEAF)
152 for (i = 0; i < top; i++) {
153 p = (char *)GETBLEAF(h, i);
154 P_32_SWAP(p);
155 p += sizeof(u_int32_t);
156 P_32_SWAP(p);
157 p += sizeof(u_int32_t);
158 flags = *(u_char *)p;
159 if (flags & (P_BIGKEY | P_BIGDATA)) {
160 p += sizeof(u_char);
161 if (flags & P_BIGKEY) {
162 P_32_SWAP(p);
163 p += sizeof(pgno_t);
164 P_32_SWAP(p);
165 }
166 if (flags & P_BIGDATA) {
167 p += sizeof(u_int32_t);
168 P_32_SWAP(p);
169 p += sizeof(pgno_t);
170 P_32_SWAP(p);
171 }
172 }
173 M_16_SWAP(h->linp[i]);
174 }
175
176 M_32_SWAP(h->pgno);
177 M_32_SWAP(h->prevpg);
178 M_32_SWAP(h->nextpg);
179 M_32_SWAP(h->flags);
180 M_16_SWAP(h->lower);
181 M_16_SWAP(h->upper);
182 }
183
184 /*
185 * MSWAP -- Actually swap the bytes on the meta page.
186 *
187 * Parameters:
188 * p: page to convert
189 */
190 static void
mswap(PAGE * pg)191 mswap(PAGE *pg)
192 {
193 char *p;
194
195 p = (char *)pg;
196 P_32_SWAP(p); /* magic */
197 p += sizeof(u_int32_t);
198 P_32_SWAP(p); /* version */
199 p += sizeof(u_int32_t);
200 P_32_SWAP(p); /* psize */
201 p += sizeof(u_int32_t);
202 P_32_SWAP(p); /* free */
203 p += sizeof(u_int32_t);
204 P_32_SWAP(p); /* nrecs */
205 p += sizeof(u_int32_t);
206 P_32_SWAP(p); /* flags */
207 p += sizeof(u_int32_t);
208 }
209