xref: /freebsd/include/db.h (revision 2008043f386721d58158e37e0d7e50df8095942d)
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  *	@(#)db.h	8.7 (Berkeley) 6/16/94
32  */
33 
34 #ifndef _DB_H_
35 #define	_DB_H_
36 
37 #include <sys/types.h>
38 #include <sys/cdefs.h>
39 
40 #include <limits.h>
41 
42 #define	RET_ERROR	-1		/* Return values. */
43 #define	RET_SUCCESS	 0
44 #define	RET_SPECIAL	 1
45 
46 #define	MAX_PAGE_NUMBER	0xffffffff	/* >= # of pages in a file */
47 typedef uint32_t	pgno_t;
48 #define	MAX_PAGE_OFFSET	65535		/* >= # of bytes in a page */
49 typedef uint16_t	indx_t;
50 #define	MAX_REC_NUMBER	0xffffffff	/* >= # of records in a tree */
51 typedef uint32_t	recno_t;
52 
53 /* Key/data structure -- a Data-Base Thang. */
54 typedef struct {
55 	void	*data;			/* data */
56 	size_t	 size;			/* data length */
57 } DBT;
58 
59 /* Routine flags. */
60 #define	R_CURSOR	1		/* del, put, seq */
61 #define	__R_UNUSED	2		/* UNUSED */
62 #define	R_FIRST		3		/* seq */
63 #define	R_IAFTER	4		/* put (RECNO) */
64 #define	R_IBEFORE	5		/* put (RECNO) */
65 #define	R_LAST		6		/* seq (BTREE, RECNO) */
66 #define	R_NEXT		7		/* seq */
67 #define	R_NOOVERWRITE	8		/* put */
68 #define	R_PREV		9		/* seq (BTREE, RECNO) */
69 #define	R_SETCURSOR	10		/* put (RECNO) */
70 #define	R_RECNOSYNC	11		/* sync (RECNO) */
71 
72 typedef enum { DB_BTREE, DB_HASH, DB_RECNO } DBTYPE;
73 
74 /*
75  * !!!
76  * The following flags are included in the dbopen(3) call as part of the
77  * open(2) flags.  In order to avoid conflicts with the open flags, start
78  * at the top of the 16 or 32-bit number space and work our way down.  If
79  * the open flags were significantly expanded in the future, it could be
80  * a problem.  Wish I'd left another flags word in the dbopen call.
81  *
82  * !!!
83  * None of this stuff is implemented yet.  The only reason that it's here
84  * is so that the access methods can skip copying the key/data pair when
85  * the DB_LOCK flag isn't set.
86  */
87 #if UINT_MAX > 65535
88 #define	DB_LOCK		0x20000000	/* Do locking. */
89 #define	DB_SHMEM	0x40000000	/* Use shared memory. */
90 #define	DB_TXN		0x80000000	/* Do transactions. */
91 #else
92 #define	DB_LOCK		    0x2000	/* Do locking. */
93 #define	DB_SHMEM	    0x4000	/* Use shared memory. */
94 #define	DB_TXN		    0x8000	/* Do transactions. */
95 #endif
96 
97 /* Access method description structure. */
98 typedef struct __db {
99 	DBTYPE type;			/* Underlying db type. */
100 	int (*close)(struct __db *);
101 	int (*del)(const struct __db *, const DBT *, unsigned int);
102 	int (*get)(const struct __db *, const DBT *, DBT *, unsigned int);
103 	int (*put)(const struct __db *, DBT *, const DBT *, unsigned int);
104 	int (*seq)(const struct __db *, DBT *, DBT *, unsigned int);
105 	int (*sync)(const struct __db *, unsigned int);
106 	void *internal;			/* Access method private. */
107 	int (*fd)(const struct __db *);
108 } DB;
109 
110 #define	BTREEMAGIC	0x053162
111 #define	BTREEVERSION	3
112 
113 /* Structure used to pass parameters to the btree routines. */
114 typedef struct {
115 #define	R_DUP		0x01	/* duplicate keys */
116 	unsigned long	flags;
117 	unsigned int	cachesize;	/* bytes to cache */
118 	int		maxkeypage;	/* maximum keys per page */
119 	int		minkeypage;	/* minimum keys per page */
120 	unsigned int	psize;		/* page size */
121 	int		(*compare)	/* comparison function */
122 			    (const DBT *, const DBT *);
123 	size_t		(*prefix)	/* prefix function */
124 			    (const DBT *, const DBT *);
125 	int		lorder;		/* byte order */
126 } BTREEINFO;
127 
128 #define	HASHMAGIC	0x061561
129 #define	HASHVERSION	2
130 
131 /* Structure used to pass parameters to the hashing routines. */
132 typedef struct {
133 	unsigned int	bsize;		/* bucket size */
134 	unsigned int	ffactor;	/* fill factor */
135 	unsigned int	nelem;		/* number of elements */
136 	unsigned int	cachesize;	/* bytes to cache */
137 	uint32_t			/* hash function */
138 		(*hash)(const void *, size_t);
139 	int	lorder;		/* byte order */
140 } HASHINFO;
141 
142 /* Structure used to pass parameters to the record routines. */
143 typedef struct {
144 #define	R_FIXEDLEN	0x01	/* fixed-length records */
145 #define	R_NOKEY		0x02	/* key not required */
146 #define	R_SNAPSHOT	0x04	/* snapshot the input */
147 	unsigned long	flags;
148 	unsigned int	cachesize; /* bytes to cache */
149 	unsigned int	psize;	/* page size */
150 	int		lorder;	/* byte order */
151 	size_t		reclen;	/* record length (fixed-length records) */
152 	unsigned char	bval;	/* delimiting byte (variable-length records */
153 	char	*bfname;	/* btree file name */
154 } RECNOINFO;
155 
156 #ifdef __DBINTERFACE_PRIVATE
157 /*
158  * Little endian <==> big endian 32-bit swap macros.
159  *	M_32_SWAP	swap a memory location
160  *	P_32_SWAP	swap a referenced memory location
161  *	P_32_COPY	swap from one location to another
162  */
163 #define	M_32_SWAP(a) {							\
164 	uint32_t _tmp = a;						\
165 	((char *)&a)[0] = ((char *)&_tmp)[3];				\
166 	((char *)&a)[1] = ((char *)&_tmp)[2];				\
167 	((char *)&a)[2] = ((char *)&_tmp)[1];				\
168 	((char *)&a)[3] = ((char *)&_tmp)[0];				\
169 }
170 #define	P_32_SWAP(a) {							\
171 	uint32_t _tmp = *(uint32_t *)a;					\
172 	((char *)a)[0] = ((char *)&_tmp)[3];				\
173 	((char *)a)[1] = ((char *)&_tmp)[2];				\
174 	((char *)a)[2] = ((char *)&_tmp)[1];				\
175 	((char *)a)[3] = ((char *)&_tmp)[0];				\
176 }
177 #define	P_32_COPY(a, b) {						\
178 	((char *)&(b))[0] = ((char *)&(a))[3];				\
179 	((char *)&(b))[1] = ((char *)&(a))[2];				\
180 	((char *)&(b))[2] = ((char *)&(a))[1];				\
181 	((char *)&(b))[3] = ((char *)&(a))[0];				\
182 }
183 
184 /*
185  * Little endian <==> big endian 16-bit swap macros.
186  *	M_16_SWAP	swap a memory location
187  *	P_16_SWAP	swap a referenced memory location
188  *	P_16_COPY	swap from one location to another
189  */
190 #define	M_16_SWAP(a) {							\
191 	uint16_t _tmp = a;						\
192 	((char *)&a)[0] = ((char *)&_tmp)[1];				\
193 	((char *)&a)[1] = ((char *)&_tmp)[0];				\
194 }
195 #define	P_16_SWAP(a) {							\
196 	uint16_t _tmp = *(uint16_t *)a;					\
197 	((char *)a)[0] = ((char *)&_tmp)[1];				\
198 	((char *)a)[1] = ((char *)&_tmp)[0];				\
199 }
200 #define	P_16_COPY(a, b) {						\
201 	((char *)&(b))[0] = ((char *)&(a))[1];				\
202 	((char *)&(b))[1] = ((char *)&(a))[0];				\
203 }
204 #endif
205 
206 __BEGIN_DECLS
207 #if __BSD_VISIBLE
208 DB *dbopen(const char *, int, int, DBTYPE, const void *);
209 #endif
210 
211 #ifdef __DBINTERFACE_PRIVATE
212 DB	*__bt_open(const char *, int, int, const BTREEINFO *, int);
213 DB	*__hash_open(const char *, int, int, const HASHINFO *, int);
214 DB	*__rec_open(const char *, int, int, const RECNOINFO *, int);
215 void	 __dbpanic(DB *dbp);
216 #endif
217 __END_DECLS
218 #endif /* !_DB_H_ */
219