xref: /dragonfly/lib/libc/db/btree/bt_conv.c (revision 0085a56d)
1 /*-
2  * Copyright (c) 1990, 1993, 1994
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. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  *
32  * @(#)bt_conv.c	8.5 (Berkeley) 8/17/94
33  * $FreeBSD: head/lib/libc/db/btree/bt_conv.c 189291 2009-03-02 23:47:18Z delphij $
34  */
35 
36 #include <sys/param.h>
37 
38 #include <stdio.h>
39 
40 #include <db.h>
41 #include "btree.h"
42 
43 static void mswap(PAGE *);
44 
45 /*
46  * __BT_BPGIN, __BT_BPGOUT --
47  *	Convert host-specific number layout to/from the host-independent
48  *	format stored on disk.
49  *
50  * Parameters:
51  *	t:	tree
52  *	pg:	page number
53  *	h:	page to convert
54  */
55 void
56 __bt_pgin(void *t, pgno_t pg, void *pp)
57 {
58 	PAGE *h;
59 	indx_t i, top;
60 	unsigned char flags;
61 	char *p;
62 
63 	if (!F_ISSET(((BTREE *)t), B_NEEDSWAP))
64 		return;
65 	if (pg == P_META) {
66 		mswap(pp);
67 		return;
68 	}
69 
70 	h = pp;
71 	M_32_SWAP(h->pgno);
72 	M_32_SWAP(h->prevpg);
73 	M_32_SWAP(h->nextpg);
74 	M_32_SWAP(h->flags);
75 	M_16_SWAP(h->lower);
76 	M_16_SWAP(h->upper);
77 
78 	top = NEXTINDEX(h);
79 	if ((h->flags & P_TYPE) == P_BINTERNAL)
80 		for (i = 0; i < top; i++) {
81 			M_16_SWAP(h->linp[i]);
82 			p = (char *)GETBINTERNAL(h, i);
83 			P_32_SWAP(p);
84 			p += sizeof(uint32_t);
85 			P_32_SWAP(p);
86 			p += sizeof(pgno_t);
87 			if (*(unsigned char *)p & P_BIGKEY) {
88 				p += sizeof(unsigned char);
89 				P_32_SWAP(p);
90 				p += sizeof(pgno_t);
91 				P_32_SWAP(p);
92 			}
93 		}
94 	else if ((h->flags & P_TYPE) == P_BLEAF)
95 		for (i = 0; i < top; i++) {
96 			M_16_SWAP(h->linp[i]);
97 			p = (char *)GETBLEAF(h, i);
98 			P_32_SWAP(p);
99 			p += sizeof(uint32_t);
100 			P_32_SWAP(p);
101 			p += sizeof(uint32_t);
102 			flags = *(unsigned char *)p;
103 			if (flags & (P_BIGKEY | P_BIGDATA)) {
104 				p += sizeof(unsigned char);
105 				if (flags & P_BIGKEY) {
106 					P_32_SWAP(p);
107 					p += sizeof(pgno_t);
108 					P_32_SWAP(p);
109 				}
110 				if (flags & P_BIGDATA) {
111 					p += sizeof(uint32_t);
112 					P_32_SWAP(p);
113 					p += sizeof(pgno_t);
114 					P_32_SWAP(p);
115 				}
116 			}
117 		}
118 }
119 
120 void
121 __bt_pgout(void *t, pgno_t pg, void *pp)
122 {
123 	PAGE *h;
124 	indx_t i, top;
125 	unsigned char flags;
126 	char *p;
127 
128 	if (!F_ISSET(((BTREE *)t), B_NEEDSWAP))
129 		return;
130 	if (pg == P_META) {
131 		mswap(pp);
132 		return;
133 	}
134 
135 	h = pp;
136 	top = NEXTINDEX(h);
137 	if ((h->flags & P_TYPE) == P_BINTERNAL)
138 		for (i = 0; i < top; i++) {
139 			p = (char *)GETBINTERNAL(h, i);
140 			P_32_SWAP(p);
141 			p += sizeof(uint32_t);
142 			P_32_SWAP(p);
143 			p += sizeof(pgno_t);
144 			if (*(unsigned char *)p & P_BIGKEY) {
145 				p += sizeof(unsigned char);
146 				P_32_SWAP(p);
147 				p += sizeof(pgno_t);
148 				P_32_SWAP(p);
149 			}
150 			M_16_SWAP(h->linp[i]);
151 		}
152 	else if ((h->flags & P_TYPE) == P_BLEAF)
153 		for (i = 0; i < top; i++) {
154 			p = (char *)GETBLEAF(h, i);
155 			P_32_SWAP(p);
156 			p += sizeof(uint32_t);
157 			P_32_SWAP(p);
158 			p += sizeof(uint32_t);
159 			flags = *(unsigned char *)p;
160 			if (flags & (P_BIGKEY | P_BIGDATA)) {
161 				p += sizeof(unsigned char);
162 				if (flags & P_BIGKEY) {
163 					P_32_SWAP(p);
164 					p += sizeof(pgno_t);
165 					P_32_SWAP(p);
166 				}
167 				if (flags & P_BIGDATA) {
168 					p += sizeof(uint32_t);
169 					P_32_SWAP(p);
170 					p += sizeof(pgno_t);
171 					P_32_SWAP(p);
172 				}
173 			}
174 			M_16_SWAP(h->linp[i]);
175 		}
176 
177 	M_32_SWAP(h->pgno);
178 	M_32_SWAP(h->prevpg);
179 	M_32_SWAP(h->nextpg);
180 	M_32_SWAP(h->flags);
181 	M_16_SWAP(h->lower);
182 	M_16_SWAP(h->upper);
183 }
184 
185 /*
186  * MSWAP -- Actually swap the bytes on the meta page.
187  *
188  * Parameters:
189  *	p:	page to convert
190  */
191 static void
192 mswap(PAGE *pg)
193 {
194 	char *p;
195 
196 	p = (char *)pg;
197 	P_32_SWAP(p);		/* magic */
198 	p += sizeof(uint32_t);
199 	P_32_SWAP(p);		/* version */
200 	p += sizeof(uint32_t);
201 	P_32_SWAP(p);		/* psize */
202 	p += sizeof(uint32_t);
203 	P_32_SWAP(p);		/* free */
204 	p += sizeof(uint32_t);
205 	P_32_SWAP(p);		/* nrecs */
206 	p += sizeof(uint32_t);
207 	P_32_SWAP(p);		/* flags */
208 	p += sizeof(uint32_t);
209 }
210