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      1 /*	$NetBSD: db.h,v 1.27 2016/09/24 20:11:43 christos Exp $	*/
      2 
      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 /*
     73  * Recursive sequential scan.
     74  *
     75  * This avoids using sibling pointers, permitting (possibly partial)
     76  * recovery from some kinds of btree corruption.  Start a sequential
     77  * scan as usual, but use R_RNEXT or R_RPREV to move forward or
     78  * backward.
     79  *
     80  * This probably doesn't work with btrees that allow duplicate keys.
     81  * Database modifications during the scan can also modify the parent
     82  * page stack needed for correct functioning.  Intermixing
     83  * non-recursive traversal by using R_NEXT or R_PREV can also make the
     84  * page stack inconsistent with the cursor and cause problems.
     85  */
     86 #define R_RNEXT		128		/* seq (BTREE, RECNO) */
     87 #define R_RPREV		129		/* seq (BTREE, RECNO) */
     88 
     89 typedef enum { DB_BTREE, DB_HASH, DB_RECNO } DBTYPE;
     90 
     91 /*
     92  * !!!
     93  * The following flags are included in the dbopen(3) call as part of the
     94  * open(2) flags.  In order to avoid conflicts with the open flags, start
     95  * at the top of the 16 or 32-bit number space and work our way down.  If
     96  * the open flags were significantly expanded in the future, it could be
     97  * a problem.  Wish I'd left another flags word in the dbopen call.
     98  *
     99  * !!!
    100  * None of this stuff is implemented yet.  The only reason that it's here
    101  * is so that the access methods can skip copying the key/data pair when
    102  * the DB_LOCK flag isn't set.
    103  */
    104 #if UINT_MAX > 65535
    105 #define	DB_LOCK		0x20000000	/* Do locking. */
    106 #define	DB_SHMEM	0x40000000	/* Use shared memory. */
    107 #define	DB_TXN		0x80000000	/* Do transactions. */
    108 #else
    109 #define	DB_LOCK		    0x2000	/* Do locking. */
    110 #define	DB_SHMEM	    0x4000	/* Use shared memory. */
    111 #define	DB_TXN		    0x8000	/* Do transactions. */
    112 #endif
    113 
    114 /* Access method description structure. */
    115 typedef struct __db {
    116 	DBTYPE type;			/* Underlying db type. */
    117 	int (*close)	(struct __db *);
    118 	int (*del)	(const struct __db *, const DBT *, unsigned int);
    119 	int (*get)	(const struct __db *, const DBT *, DBT *, unsigned int);
    120 	int (*put)	(const struct __db *, DBT *, const DBT *, unsigned int);
    121 	int (*seq)	(const struct __db *, DBT *, DBT *, unsigned int);
    122 	int (*sync)	(const struct __db *, unsigned int);
    123 	void *internal;			/* Access method private. */
    124 	int (*fd)	(const struct __db *);
    125 } DB;
    126 
    127 #define	BTREEMAGIC	0x053162
    128 #define	BTREEVERSION	3
    129 
    130 /* Structure used to pass parameters to the btree routines. */
    131 typedef struct {
    132 #define	R_DUP		0x01	/* duplicate keys */
    133 	unsigned long	flags;
    134 	unsigned int	cachesize;	/* bytes to cache */
    135 	int		maxkeypage;	/* maximum keys per page */
    136 	int		minkeypage;	/* minimum keys per page */
    137 	unsigned int	psize;		/* page size */
    138 	int	(*compare)	/* comparison function */
    139 		(const DBT *, const DBT *);
    140 	size_t	(*prefix)	/* prefix function */
    141 		(const DBT *, const DBT *);
    142 	int	lorder;		/* byte order */
    143 } BTREEINFO;
    144 
    145 #define	HASHMAGIC	0x061561
    146 #define	HASHVERSION	2
    147 
    148 /* Structure used to pass parameters to the hashing routines. */
    149 typedef struct {
    150 	unsigned int	bsize;		/* bucket size */
    151 	unsigned int	ffactor;	/* fill factor */
    152 	unsigned int	nelem;		/* number of elements */
    153 	unsigned int	cachesize;	/* bytes to cache */
    154 	uint32_t		/* hash function */
    155 		(*hash)(const void *, size_t);
    156 	int	lorder;		/* byte order */
    157 } HASHINFO;
    158 
    159 /* Structure used to pass parameters to the record routines. */
    160 typedef struct {
    161 #define	R_FIXEDLEN	0x01	/* fixed-length records */
    162 #define	R_NOKEY		0x02	/* key not required */
    163 #define	R_SNAPSHOT	0x04	/* snapshot the input */
    164 	unsigned long	flags;
    165 	unsigned int	cachesize;	/* bytes to cache */
    166 	unsigned int	psize;		/* page size */
    167 	int		lorder;		/* byte order */
    168 	size_t		reclen;		/* record length (fixed-length records) */
    169 	uint8_t		bval;		/* delimiting byte (variable-length records */
    170 	char		*bfname;	/* btree file name */
    171 } RECNOINFO;
    172 
    173 #ifdef __DBINTERFACE_PRIVATE
    174 /*
    175  * Little endian <==> big endian 32-bit swap macros.
    176  *	M_32_SWAP	swap a memory location
    177  *	P_32_SWAP	swap a referenced memory location
    178  *	P_32_COPY	swap from one location to another
    179  */
    180 #define	M_32_SWAP(a) {							\
    181 	uint32_t _tmp = a;						\
    182 	((char *)(void *)&a)[0] = ((char *)(void *)&_tmp)[3];		\
    183 	((char *)(void *)&a)[1] = ((char *)(void *)&_tmp)[2];		\
    184 	((char *)(void *)&a)[2] = ((char *)(void *)&_tmp)[1];		\
    185 	((char *)(void *)&a)[3] = ((char *)(void *)&_tmp)[0];		\
    186 }
    187 #define	P_32_SWAP(a) {							\
    188 	char  _tmp[4];							\
    189 	_tmp[0] = ((char *)(void *)a)[0];				\
    190 	_tmp[1] = ((char *)(void *)a)[1];				\
    191 	_tmp[2] = ((char *)(void *)a)[2];				\
    192 	_tmp[3] = ((char *)(void *)a)[3];				\
    193 	((char *)(void *)a)[0] = _tmp[3];				\
    194 	((char *)(void *)a)[1] = _tmp[2];				\
    195 	((char *)(void *)a)[2] = _tmp[1];				\
    196 	((char *)(void *)a)[3] = _tmp[0];				\
    197 }
    198 #define	P_32_COPY(a, b) {						\
    199 	((char *)(void *)&(b))[0] = ((char *)(void *)&(a))[3];		\
    200 	((char *)(void *)&(b))[1] = ((char *)(void *)&(a))[2];		\
    201 	((char *)(void *)&(b))[2] = ((char *)(void *)&(a))[1];		\
    202 	((char *)(void *)&(b))[3] = ((char *)(void *)&(a))[0];		\
    203 }
    204 
    205 /*
    206  * Little endian <==> big endian 16-bit swap macros.
    207  *	M_16_SWAP	swap a memory location
    208  *	P_16_SWAP	swap a referenced memory location
    209  *	P_16_COPY	swap from one location to another
    210  */
    211 #define	M_16_SWAP(a) {							\
    212 	uint16_t _tmp = a;						\
    213 	((char *)(void *)&a)[0] = ((char *)(void *)&_tmp)[1];		\
    214 	((char *)(void *)&a)[1] = ((char *)(void *)&_tmp)[0];		\
    215 }
    216 #define	P_16_SWAP(a) {							\
    217 	char  _tmp[2];							\
    218 	_tmp[0] = ((char *)(void *)a)[0];				\
    219 	_tmp[1] = ((char *)(void *)a)[1];				\
    220 	((char *)(void *)a)[0] = _tmp[1];				\
    221 	((char *)(void *)a)[1] = _tmp[0];				\
    222 }
    223 #define	P_16_COPY(a, b) {						\
    224 	((char *)(void *)&(b))[0] = ((char *)(void *)&(a))[1];		\
    225 	((char *)(void *)&(b))[1] = ((char *)(void *)&(a))[0];		\
    226 }
    227 #endif
    228 
    229 __BEGIN_DECLS
    230 DB *dbopen(const char *, int, mode_t, DBTYPE, const void *);
    231 
    232 #ifdef __DBINTERFACE_PRIVATE
    233 
    234 #define _DBFIT(a, t) _DIAGASSERT(__type_fit(t, a))
    235 
    236 DB	*__bt_open(const char *, int, mode_t, const BTREEINFO *, int);
    237 DB	*__hash_open(const char *, int, mode_t, const HASHINFO *, int);
    238 DB	*__rec_open(const char *, int, mode_t, const RECNOINFO *, int);
    239 void	 __dbpanic(DB *);
    240 struct stat;
    241 int	 __dbopen(const char *, int, mode_t, struct stat *);
    242 int	 __dbtemp(const char *, struct stat *);
    243 #endif
    244 __END_DECLS
    245 #endif /* !_DB_H_ */
    246