xref: /netbsd-src/lib/libc/db/btree/bt_conv.c (revision 86147b1c32e531f1f17ed1be66e6f9ae2dcb37be)
1 /*	$NetBSD: bt_conv.c,v 1.15 2016/09/24 20:11:12 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 __RCSID("$NetBSD: bt_conv.c,v 1.15 2016/09/24 20:11:12 christos Exp $");
41 
42 #include <assert.h>
43 #include <stdio.h>
44 #include <memory.h>
45 
46 #include <db.h>
47 #include "btree.h"
48 
49 static void mswap(PAGE *);
50 
51 /*
52  * __BT_BPGIN, __BT_BPGOUT --
53  *	Convert host-specific number layout to/from the host-independent
54  *	format stored on disk.
55  *
56  * Parameters:
57  *	t:	tree
58  *	pg:	page number
59  *	h:	page to convert
60  */
61 void
__bt_pgin(void * t,pgno_t pg,void * pp)62 __bt_pgin(void *t, pgno_t pg, void *pp)
63 {
64 	PAGE *h;
65 	indx_t i, top;
66 	uint8_t flags;
67 	char *p;
68 	uint32_t ksize;
69 
70 	if (!F_ISSET(((BTREE *)t), B_NEEDSWAP))
71 		return;
72 	if (pg == P_META) {
73 		mswap(pp);
74 		return;
75 	}
76 
77 	h = pp;
78 	M_32_SWAP(h->pgno);
79 	M_32_SWAP(h->prevpg);
80 	M_32_SWAP(h->nextpg);
81 	M_32_SWAP(h->flags);
82 	M_16_SWAP(h->lower);
83 	M_16_SWAP(h->upper);
84 
85 	top = NEXTINDEX(h);
86 	if ((h->flags & P_TYPE) == P_BINTERNAL)
87 		for (i = 0; i < top; i++) {
88 			M_16_SWAP(h->linp[i]);
89 			p = (char *)(void *)GETBINTERNAL(h, i);
90 			P_32_SWAP(p);
91 			p += sizeof(uint32_t);
92 			P_32_SWAP(p);
93 			p += sizeof(pgno_t);
94 			if (*(uint8_t *)p & P_BIGKEY) {
95 				p += sizeof(uint8_t);
96 				P_32_SWAP(p);
97 				p += sizeof(pgno_t);
98 				P_32_SWAP(p);
99 			}
100 		}
101 	else if ((h->flags & P_TYPE) == P_BLEAF)
102 		for (i = 0; i < top; i++) {
103 			M_16_SWAP(h->linp[i]);
104 			p = (char *)(void *)GETBLEAF(h, i);
105 			P_32_SWAP(p);
106 			memcpy(&ksize, p, sizeof(ksize));
107 			p += sizeof(uint32_t);
108 			P_32_SWAP(p);
109 			p += sizeof(uint32_t);
110 			flags = *(uint8_t *)p;
111 			if (flags & (P_BIGKEY | P_BIGDATA)) {
112 				p += sizeof(uint8_t);
113 				if (flags & P_BIGKEY) {
114 					P_32_SWAP(p);
115 					p += sizeof(pgno_t);
116 					P_32_SWAP(p);
117 				}
118 				if (flags & P_BIGDATA) {
119 					p += ksize;
120 					P_32_SWAP(p);
121 					p += sizeof(pgno_t);
122 					P_32_SWAP(p);
123 				}
124 			}
125 		}
126 }
127 
128 void
__bt_pgout(void * t,pgno_t pg,void * pp)129 __bt_pgout(void *t, pgno_t pg, void *pp)
130 {
131 	PAGE *h;
132 	indx_t i, top;
133 	uint8_t flags;
134 	char *p;
135 	uint32_t ksize;
136 
137 	if (!F_ISSET(((BTREE *)t), B_NEEDSWAP))
138 		return;
139 	if (pg == P_META) {
140 		mswap(pp);
141 		return;
142 	}
143 
144 	h = pp;
145 	top = NEXTINDEX(h);
146 	if ((h->flags & P_TYPE) == P_BINTERNAL)
147 		for (i = 0; i < top; i++) {
148 			p = (char *)(void *)GETBINTERNAL(h, i);
149 			P_32_SWAP(p);
150 			p += sizeof(uint32_t);
151 			P_32_SWAP(p);
152 			p += sizeof(pgno_t);
153 			if (*(uint8_t *)p & P_BIGKEY) {
154 				p += sizeof(uint8_t);
155 				P_32_SWAP(p);
156 				p += sizeof(pgno_t);
157 				P_32_SWAP(p);
158 			}
159 			M_16_SWAP(h->linp[i]);
160 		}
161 	else if ((h->flags & P_TYPE) == P_BLEAF)
162 		for (i = 0; i < top; i++) {
163 			p = (char *)(void *)GETBLEAF(h, i);
164 			ksize = GETBLEAF(h, i)->ksize;
165 			P_32_SWAP(p);
166 			p += sizeof(uint32_t);
167 			P_32_SWAP(p);
168 			p += sizeof(uint32_t);
169 			flags = *(uint8_t *)p;
170 			if (flags & (P_BIGKEY | P_BIGDATA)) {
171 				p += sizeof(uint8_t);
172 				if (flags & P_BIGKEY) {
173 					P_32_SWAP(p);
174 					p += sizeof(pgno_t);
175 					P_32_SWAP(p);
176 				}
177 				if (flags & P_BIGDATA) {
178 					p += ksize;
179 					P_32_SWAP(p);
180 					p += sizeof(pgno_t);
181 					P_32_SWAP(p);
182 				}
183 			}
184 			M_16_SWAP(h->linp[i]);
185 		}
186 
187 	M_32_SWAP(h->pgno);
188 	M_32_SWAP(h->prevpg);
189 	M_32_SWAP(h->nextpg);
190 	M_32_SWAP(h->flags);
191 	M_16_SWAP(h->lower);
192 	M_16_SWAP(h->upper);
193 }
194 
195 /*
196  * MSWAP -- Actually swap the bytes on the meta page.
197  *
198  * Parameters:
199  *	p:	page to convert
200  */
201 static void
mswap(PAGE * pg)202 mswap(PAGE *pg)
203 {
204 	char *p;
205 
206 	p = (char *)(void *)pg;
207 	P_32_SWAP(p);		/* magic */
208 	p += sizeof(uint32_t);
209 	P_32_SWAP(p);		/* version */
210 	p += sizeof(uint32_t);
211 	P_32_SWAP(p);		/* psize */
212 	p += sizeof(uint32_t);
213 	P_32_SWAP(p);		/* free */
214 	p += sizeof(uint32_t);
215 	P_32_SWAP(p);		/* nrecs */
216 	p += sizeof(uint32_t);
217 	P_32_SWAP(p);		/* flags */
218 	p += sizeof(uint32_t);
219 }
220