xref: /freebsd/include/db.h (revision 5a1d14419a5b620430949a46cb6ee63148a43cb9)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1990, 1993, 1994
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #ifndef _DB_H_
33 #define	_DB_H_
34 
35 #include <sys/types.h>
36 #include <sys/cdefs.h>
37 
38 #include <limits.h>
39 
40 #define	RET_ERROR	-1		/* Return values. */
41 #define	RET_SUCCESS	 0
42 #define	RET_SPECIAL	 1
43 
44 #define	MAX_PAGE_NUMBER	0xffffffff	/* >= # of pages in a file */
45 typedef uint32_t	pgno_t;
46 #define	MAX_PAGE_OFFSET	65535		/* >= # of bytes in a page */
47 typedef uint16_t	indx_t;
48 #define	MAX_REC_NUMBER	0xffffffff	/* >= # of records in a tree */
49 typedef uint32_t	recno_t;
50 
51 /* Key/data structure -- a Data-Base Thang. */
52 typedef struct {
53 	void	*data;			/* data */
54 	size_t	 size;			/* data length */
55 } DBT;
56 
57 /* Routine flags. */
58 #define	R_CURSOR	1		/* del, put, seq */
59 #define	__R_UNUSED	2		/* UNUSED */
60 #define	R_FIRST		3		/* seq */
61 #define	R_IAFTER	4		/* put (RECNO) */
62 #define	R_IBEFORE	5		/* put (RECNO) */
63 #define	R_LAST		6		/* seq (BTREE, RECNO) */
64 #define	R_NEXT		7		/* seq */
65 #define	R_NOOVERWRITE	8		/* put */
66 #define	R_PREV		9		/* seq (BTREE, RECNO) */
67 #define	R_SETCURSOR	10		/* put (RECNO) */
68 #define	R_RECNOSYNC	11		/* sync (RECNO) */
69 
70 typedef enum { DB_BTREE, DB_HASH, DB_RECNO } DBTYPE;
71 
72 /*
73  * !!!
74  * The following flags are included in the dbopen(3) call as part of the
75  * open(2) flags.  In order to avoid conflicts with the open flags, start
76  * at the top of the 16 or 32-bit number space and work our way down.  If
77  * the open flags were significantly expanded in the future, it could be
78  * a problem.  Wish I'd left another flags word in the dbopen call.
79  *
80  * !!!
81  * None of this stuff is implemented yet.  The only reason that it's here
82  * is so that the access methods can skip copying the key/data pair when
83  * the DB_LOCK flag isn't set.
84  */
85 #if UINT_MAX > 65535
86 #define	DB_LOCK		0x20000000	/* Do locking. */
87 #define	DB_SHMEM	0x40000000	/* Use shared memory. */
88 #define	DB_TXN		0x80000000	/* Do transactions. */
89 #else
90 #define	DB_LOCK		    0x2000	/* Do locking. */
91 #define	DB_SHMEM	    0x4000	/* Use shared memory. */
92 #define	DB_TXN		    0x8000	/* Do transactions. */
93 #endif
94 
95 /* Access method description structure. */
96 typedef struct __db {
97 	DBTYPE type;			/* Underlying db type. */
98 	int (*close)(struct __db *);
99 	int (*del)(const struct __db *, const DBT *, unsigned int);
100 	int (*get)(const struct __db *, const DBT *, DBT *, unsigned int);
101 	int (*put)(const struct __db *, DBT *, const DBT *, unsigned int);
102 	int (*seq)(const struct __db *, DBT *, DBT *, unsigned int);
103 	int (*sync)(const struct __db *, unsigned int);
104 	void *internal;			/* Access method private. */
105 	int (*fd)(const struct __db *);
106 } DB;
107 
108 #define	BTREEMAGIC	0x053162
109 #define	BTREEVERSION	3
110 
111 /* Structure used to pass parameters to the btree routines. */
112 typedef struct {
113 #define	R_DUP		0x01	/* duplicate keys */
114 	unsigned long	flags;
115 	unsigned int	cachesize;	/* bytes to cache */
116 	int		maxkeypage;	/* maximum keys per page */
117 	int		minkeypage;	/* minimum keys per page */
118 	unsigned int	psize;		/* page size */
119 	int		(*compare)	/* comparison function */
120 			    (const DBT *, const DBT *);
121 	size_t		(*prefix)	/* prefix function */
122 			    (const DBT *, const DBT *);
123 	int		lorder;		/* byte order */
124 } BTREEINFO;
125 
126 #define	HASHMAGIC	0x061561
127 #define	HASHVERSION	2
128 
129 /* Structure used to pass parameters to the hashing routines. */
130 typedef struct {
131 	unsigned int	bsize;		/* bucket size */
132 	unsigned int	ffactor;	/* fill factor */
133 	unsigned int	nelem;		/* number of elements */
134 	unsigned int	cachesize;	/* bytes to cache */
135 	uint32_t			/* hash function */
136 		(*hash)(const void *, size_t);
137 	int	lorder;		/* byte order */
138 } HASHINFO;
139 
140 /* Structure used to pass parameters to the record routines. */
141 typedef struct {
142 #define	R_FIXEDLEN	0x01	/* fixed-length records */
143 #define	R_NOKEY		0x02	/* key not required */
144 #define	R_SNAPSHOT	0x04	/* snapshot the input */
145 	unsigned long	flags;
146 	unsigned int	cachesize; /* bytes to cache */
147 	unsigned int	psize;	/* page size */
148 	int		lorder;	/* byte order */
149 	size_t		reclen;	/* record length (fixed-length records) */
150 	unsigned char	bval;	/* delimiting byte (variable-length records */
151 	char	*bfname;	/* btree file name */
152 } RECNOINFO;
153 
154 #ifdef __DBINTERFACE_PRIVATE
155 /*
156  * Little endian <==> big endian 32-bit swap macros.
157  *	M_32_SWAP	swap a memory location
158  *	P_32_SWAP	swap a referenced memory location
159  *	P_32_COPY	swap from one location to another
160  */
161 #define	M_32_SWAP(a) {							\
162 	uint32_t _tmp = a;						\
163 	((char *)&a)[0] = ((char *)&_tmp)[3];				\
164 	((char *)&a)[1] = ((char *)&_tmp)[2];				\
165 	((char *)&a)[2] = ((char *)&_tmp)[1];				\
166 	((char *)&a)[3] = ((char *)&_tmp)[0];				\
167 }
168 #define	P_32_SWAP(a) {							\
169 	uint32_t _tmp = *(uint32_t *)a;					\
170 	((char *)a)[0] = ((char *)&_tmp)[3];				\
171 	((char *)a)[1] = ((char *)&_tmp)[2];				\
172 	((char *)a)[2] = ((char *)&_tmp)[1];				\
173 	((char *)a)[3] = ((char *)&_tmp)[0];				\
174 }
175 #define	P_32_COPY(a, b) {						\
176 	((char *)&(b))[0] = ((char *)&(a))[3];				\
177 	((char *)&(b))[1] = ((char *)&(a))[2];				\
178 	((char *)&(b))[2] = ((char *)&(a))[1];				\
179 	((char *)&(b))[3] = ((char *)&(a))[0];				\
180 }
181 
182 /*
183  * Little endian <==> big endian 16-bit swap macros.
184  *	M_16_SWAP	swap a memory location
185  *	P_16_SWAP	swap a referenced memory location
186  *	P_16_COPY	swap from one location to another
187  */
188 #define	M_16_SWAP(a) {							\
189 	uint16_t _tmp = a;						\
190 	((char *)&a)[0] = ((char *)&_tmp)[1];				\
191 	((char *)&a)[1] = ((char *)&_tmp)[0];				\
192 }
193 #define	P_16_SWAP(a) {							\
194 	uint16_t _tmp = *(uint16_t *)a;					\
195 	((char *)a)[0] = ((char *)&_tmp)[1];				\
196 	((char *)a)[1] = ((char *)&_tmp)[0];				\
197 }
198 #define	P_16_COPY(a, b) {						\
199 	((char *)&(b))[0] = ((char *)&(a))[1];				\
200 	((char *)&(b))[1] = ((char *)&(a))[0];				\
201 }
202 #endif
203 
204 __BEGIN_DECLS
205 #if __BSD_VISIBLE
206 DB *dbopen(const char *, int, int, DBTYPE, const void *);
207 #endif
208 
209 #ifdef __DBINTERFACE_PRIVATE
210 DB	*__bt_open(const char *, int, int, const BTREEINFO *, int);
211 DB	*__hash_open(const char *, int, int, const HASHINFO *, int);
212 DB	*__rec_open(const char *, int, int, const RECNOINFO *, int);
213 void	 __dbpanic(DB *dbp);
214 #endif
215 __END_DECLS
216 #endif /* !_DB_H_ */
217