xref: /netbsd-src/lib/libc/db/btree/bt_conv.c (revision 8b0f9554ff8762542c4defc4f70e1eb76fb508fa)
1 /*	$NetBSD: bt_conv.c,v 1.12 2007/02/03 23:46:09 christos Exp $	*/
2 
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 #if HAVE_NBTOOL_CONFIG_H
36 #include "nbtool_config.h"
37 #endif
38 
39 #include <sys/cdefs.h>
40 #if defined(LIBC_SCCS) && !defined(lint)
41 #if 0
42 static char sccsid[] = "@(#)bt_conv.c	8.5 (Berkeley) 8/17/94";
43 #else
44 __RCSID("$NetBSD: bt_conv.c,v 1.12 2007/02/03 23:46:09 christos Exp $");
45 #endif
46 #endif /* LIBC_SCCS and not lint */
47 
48 #include <assert.h>
49 #include <stdio.h>
50 
51 #include <db.h>
52 #include "btree.h"
53 
54 static void mswap(PAGE *);
55 
56 /*
57  * __BT_BPGIN, __BT_BPGOUT --
58  *	Convert host-specific number layout to/from the host-independent
59  *	format stored on disk.
60  *
61  * Parameters:
62  *	t:	tree
63  *	pg:	page number
64  *	h:	page to convert
65  */
66 void
67 __bt_pgin(void *t, pgno_t pg, void *pp)
68 {
69 	PAGE *h;
70 	indx_t i, top;
71 	u_char flags;
72 	char *p;
73 
74 	if (!F_ISSET(((BTREE *)t), B_NEEDSWAP))
75 		return;
76 	if (pg == P_META) {
77 		mswap(pp);
78 		return;
79 	}
80 
81 	h = pp;
82 	M_32_SWAP(h->pgno);
83 	M_32_SWAP(h->prevpg);
84 	M_32_SWAP(h->nextpg);
85 	M_32_SWAP(h->flags);
86 	M_16_SWAP(h->lower);
87 	M_16_SWAP(h->upper);
88 
89 	top = NEXTINDEX(h);
90 	if ((h->flags & P_TYPE) == P_BINTERNAL)
91 		for (i = 0; i < top; i++) {
92 			M_16_SWAP(h->linp[i]);
93 			p = (char *)(void *)GETBINTERNAL(h, i);
94 			P_32_SWAP(p);
95 			p += sizeof(u_int32_t);
96 			P_32_SWAP(p);
97 			p += sizeof(pgno_t);
98 			if (*(u_char *)p & P_BIGKEY) {
99 				p += sizeof(u_char);
100 				P_32_SWAP(p);
101 				p += sizeof(pgno_t);
102 				P_32_SWAP(p);
103 			}
104 		}
105 	else if ((h->flags & P_TYPE) == P_BLEAF)
106 		for (i = 0; i < top; i++) {
107 			M_16_SWAP(h->linp[i]);
108 			p = (char *)(void *)GETBLEAF(h, i);
109 			P_32_SWAP(p);
110 			p += sizeof(u_int32_t);
111 			P_32_SWAP(p);
112 			p += sizeof(u_int32_t);
113 			flags = *(u_char *)p;
114 			if (flags & (P_BIGKEY | P_BIGDATA)) {
115 				p += sizeof(u_char);
116 				if (flags & P_BIGKEY) {
117 					P_32_SWAP(p);
118 					p += sizeof(pgno_t);
119 					P_32_SWAP(p);
120 				}
121 				if (flags & P_BIGDATA) {
122 					p += sizeof(u_int32_t);
123 					P_32_SWAP(p);
124 					p += sizeof(pgno_t);
125 					P_32_SWAP(p);
126 				}
127 			}
128 		}
129 }
130 
131 void
132 __bt_pgout(void *t, pgno_t pg, 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 *)(void *)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 *)(void *)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  */
202 static void
203 mswap(PAGE *pg)
204 {
205 	char *p;
206 
207 	p = (char *)(void *)pg;
208 	P_32_SWAP(p);		/* magic */
209 	p += sizeof(u_int32_t);
210 	P_32_SWAP(p);		/* version */
211 	p += sizeof(u_int32_t);
212 	P_32_SWAP(p);		/* psize */
213 	p += sizeof(u_int32_t);
214 	P_32_SWAP(p);		/* free */
215 	p += sizeof(u_int32_t);
216 	P_32_SWAP(p);		/* nrecs */
217 	p += sizeof(u_int32_t);
218 	P_32_SWAP(p);		/* flags */
219 	p += sizeof(u_int32_t);
220 }
221