xref: /titanic_52/usr/src/cmd/sendmail/db/btree/bt_conv.c (revision 7c478bd95313f5f23a4c958a745db2134aa03244)
1 /*-
2  * See the file LICENSE for redistribution information.
3  *
4  * Copyright (c) 1996, 1997, 1998
5  *	Sleepycat Software.  All rights reserved.
6  */
7 
8 #include "config.h"
9 
10 #ifndef lint
11 static const char sccsid[] = "@(#)bt_conv.c	10.7 (Sleepycat) 9/20/98";
12 #endif /* not lint */
13 
14 #ifndef NO_SYSTEM_INCLUDES
15 #include <sys/types.h>
16 #endif
17 
18 #include "db_int.h"
19 #include "db_page.h"
20 #include "db_swap.h"
21 #include "btree.h"
22 
23 /*
24  * __bam_pgin --
25  *	Convert host-specific page layout from the host-independent format
26  *	stored on disk.
27  *
28  * PUBLIC: int __bam_pgin __P((db_pgno_t, void *, DBT *));
29  */
30 int
31 __bam_pgin(pg, pp, cookie)
32 	db_pgno_t pg;
33 	void *pp;
34 	DBT *cookie;
35 {
36 	DB_PGINFO *pginfo;
37 
38 	pginfo = (DB_PGINFO *)cookie->data;
39 	if (!pginfo->needswap)
40 		return (0);
41 	return (pg == PGNO_METADATA ?
42 	    __bam_mswap(pp) : __db_pgin(pg, pginfo->db_pagesize, pp));
43 }
44 
45 /*
46  * __bam_pgout --
47  *	Convert host-specific page layout to the host-independent format
48  *	stored on disk.
49  *
50  * PUBLIC: int __bam_pgout __P((db_pgno_t, void *, DBT *));
51  */
52 int
53 __bam_pgout(pg, pp, cookie)
54 	db_pgno_t pg;
55 	void *pp;
56 	DBT *cookie;
57 {
58 	DB_PGINFO *pginfo;
59 
60 	pginfo = (DB_PGINFO *)cookie->data;
61 	if (!pginfo->needswap)
62 		return (0);
63 	return (pg == PGNO_METADATA ?
64 	    __bam_mswap(pp) : __db_pgout(pg, pginfo->db_pagesize, pp));
65 }
66 
67 /*
68  * __bam_mswap --
69  *	Swap the bytes on the btree metadata page.
70  *
71  * PUBLIC: int __bam_mswap __P((PAGE *));
72  */
73 int
74 __bam_mswap(pg)
75 	PAGE *pg;
76 {
77 	u_int8_t *p;
78 
79 	p = (u_int8_t *)pg;
80 
81 	/* Swap the meta-data information. */
82 	SWAP32(p);		/* lsn.file */
83 	SWAP32(p);		/* lsn.offset */
84 	SWAP32(p);		/* pgno */
85 	SWAP32(p);		/* magic */
86 	SWAP32(p);		/* version */
87 	SWAP32(p);		/* pagesize */
88 	SWAP32(p);		/* maxkey */
89 	SWAP32(p);		/* minkey */
90 	SWAP32(p);		/* free */
91 	SWAP32(p);		/* flags */
92 
93 	return (0);
94 }
95