xref: /openbsd-src/lib/libc/db/btree/bt_conv.c (revision b2ea75c1b17e1a9a339660e7ed45cd24946b230e)
1 /*	$OpenBSD: bt_conv.c,v 1.4 1999/02/15 05:11:22 millert 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. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the University of
21  *	California, Berkeley and its contributors.
22  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  */
38 
39 #if defined(LIBC_SCCS) && !defined(lint)
40 #if 0
41 static char sccsid[] = "@(#)bt_conv.c	8.5 (Berkeley) 8/17/94";
42 #else
43 static char rcsid[] = "$OpenBSD: bt_conv.c,v 1.4 1999/02/15 05:11:22 millert Exp $";
44 #endif
45 #endif /* LIBC_SCCS and not lint */
46 
47 #include <sys/param.h>
48 
49 #include <stdio.h>
50 
51 #include <db.h>
52 #include "btree.h"
53 
54 static void mswap __P((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(t, pg, pp)
68 	void *t;
69 	pgno_t pg;
70 	void *pp;
71 {
72 	PAGE *h;
73 	indx_t i, top;
74 	u_char flags;
75 	char *p;
76 
77 	if (!F_ISSET(((BTREE *)t), B_NEEDSWAP))
78 		return;
79 	if (pg == P_META) {
80 		mswap(pp);
81 		return;
82 	}
83 
84 	h = pp;
85 	M_32_SWAP(h->pgno);
86 	M_32_SWAP(h->prevpg);
87 	M_32_SWAP(h->nextpg);
88 	M_32_SWAP(h->flags);
89 	M_16_SWAP(h->lower);
90 	M_16_SWAP(h->upper);
91 
92 	top = NEXTINDEX(h);
93 	if ((h->flags & P_TYPE) == P_BINTERNAL)
94 		for (i = 0; i < top; i++) {
95 			M_16_SWAP(h->linp[i]);
96 			p = (char *)GETBINTERNAL(h, i);
97 			P_32_SWAP(p);
98 			p += sizeof(u_int32_t);
99 			P_32_SWAP(p);
100 			p += sizeof(pgno_t);
101 			if (*(u_char *)p & P_BIGKEY) {
102 				p += sizeof(u_char);
103 				P_32_SWAP(p);
104 				p += sizeof(pgno_t);
105 				P_32_SWAP(p);
106 			}
107 		}
108 	else if ((h->flags & P_TYPE) == P_BLEAF)
109 		for (i = 0; i < top; i++) {
110 			M_16_SWAP(h->linp[i]);
111 			p = (char *)GETBLEAF(h, i);
112 			P_32_SWAP(p);
113 			p += sizeof(u_int32_t);
114 			P_32_SWAP(p);
115 			p += sizeof(u_int32_t);
116 			flags = *(u_char *)p;
117 			if (flags & (P_BIGKEY | P_BIGDATA)) {
118 				p += sizeof(u_char);
119 				if (flags & P_BIGKEY) {
120 					P_32_SWAP(p);
121 					p += sizeof(pgno_t);
122 					P_32_SWAP(p);
123 				}
124 				if (flags & P_BIGDATA) {
125 					p += sizeof(u_int32_t);
126 					P_32_SWAP(p);
127 					p += sizeof(pgno_t);
128 					P_32_SWAP(p);
129 				}
130 			}
131 		}
132 }
133 
134 void
135 __bt_pgout(t, pg, pp)
136 	void *t;
137 	pgno_t pg;
138 	void *pp;
139 {
140 	PAGE *h;
141 	indx_t i, top;
142 	u_char flags;
143 	char *p;
144 
145 	if (!F_ISSET(((BTREE *)t), B_NEEDSWAP))
146 		return;
147 	if (pg == P_META) {
148 		mswap(pp);
149 		return;
150 	}
151 
152 	h = pp;
153 	top = NEXTINDEX(h);
154 	if ((h->flags & P_TYPE) == P_BINTERNAL)
155 		for (i = 0; i < top; i++) {
156 			p = (char *)GETBINTERNAL(h, i);
157 			P_32_SWAP(p);
158 			p += sizeof(u_int32_t);
159 			P_32_SWAP(p);
160 			p += sizeof(pgno_t);
161 			if (*(u_char *)p & P_BIGKEY) {
162 				p += sizeof(u_char);
163 				P_32_SWAP(p);
164 				p += sizeof(pgno_t);
165 				P_32_SWAP(p);
166 			}
167 			M_16_SWAP(h->linp[i]);
168 		}
169 	else if ((h->flags & P_TYPE) == P_BLEAF)
170 		for (i = 0; i < top; i++) {
171 			p = (char *)GETBLEAF(h, i);
172 			P_32_SWAP(p);
173 			p += sizeof(u_int32_t);
174 			P_32_SWAP(p);
175 			p += sizeof(u_int32_t);
176 			flags = *(u_char *)p;
177 			if (flags & (P_BIGKEY | P_BIGDATA)) {
178 				p += sizeof(u_char);
179 				if (flags & P_BIGKEY) {
180 					P_32_SWAP(p);
181 					p += sizeof(pgno_t);
182 					P_32_SWAP(p);
183 				}
184 				if (flags & P_BIGDATA) {
185 					p += sizeof(u_int32_t);
186 					P_32_SWAP(p);
187 					p += sizeof(pgno_t);
188 					P_32_SWAP(p);
189 				}
190 			}
191 			M_16_SWAP(h->linp[i]);
192 		}
193 
194 	M_32_SWAP(h->pgno);
195 	M_32_SWAP(h->prevpg);
196 	M_32_SWAP(h->nextpg);
197 	M_32_SWAP(h->flags);
198 	M_16_SWAP(h->lower);
199 	M_16_SWAP(h->upper);
200 }
201 
202 /*
203  * MSWAP -- Actually swap the bytes on the meta page.
204  *
205  * Parameters:
206  *	p:	page to convert
207  */
208 static void
209 mswap(pg)
210 	PAGE *pg;
211 {
212 	char *p;
213 
214 	p = (char *)pg;
215 	P_32_SWAP(p);		/* magic */
216 	p += sizeof(u_int32_t);
217 	P_32_SWAP(p);		/* version */
218 	p += sizeof(u_int32_t);
219 	P_32_SWAP(p);		/* psize */
220 	p += sizeof(u_int32_t);
221 	P_32_SWAP(p);		/* free */
222 	p += sizeof(u_int32_t);
223 	P_32_SWAP(p);		/* nrecs */
224 	p += sizeof(u_int32_t);
225 	P_32_SWAP(p);		/* flags */
226 	p += sizeof(u_int32_t);
227 }
228