include/db.h

   1 /*      $NetBSD: db.h,v 1.24 2008/08/26 21:18:38 joerg 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 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         uint8_t         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 *)(void *)&a)[0] = ((char *)(void *)&_tmp)[3];           \
 166         ((char *)(void *)&a)[1] = ((char *)(void *)&_tmp)[2];           \
 167         ((char *)(void *)&a)[2] = ((char *)(void *)&_tmp)[1];           \
 168         ((char *)(void *)&a)[3] = ((char *)(void *)&_tmp)[0];           \
 169 }
 170 #define P_32_SWAP(a) {                                                  \
 171         char  _tmp[4];                                                  \
 172         _tmp[0] = ((char *)(void *)a)[0];                               \
 173         _tmp[1] = ((char *)(void *)a)[1];                               \
 174         _tmp[2] = ((char *)(void *)a)[2];                               \
 175         _tmp[3] = ((char *)(void *)a)[3];                               \
 176         ((char *)(void *)a)[0] = _tmp[3];                               \
 177         ((char *)(void *)a)[1] = _tmp[2];                               \
 178         ((char *)(void *)a)[2] = _tmp[1];                               \
 179         ((char *)(void *)a)[3] = _tmp[0];                               \
 180 }
 181 #define P_32_COPY(a, b) {                                               \
 182         ((char *)(void *)&(b))[0] = ((char *)(void *)&(a))[3];          \
 183         ((char *)(void *)&(b))[1] = ((char *)(void *)&(a))[2];          \
 184         ((char *)(void *)&(b))[2] = ((char *)(void *)&(a))[1];          \
 185         ((char *)(void *)&(b))[3] = ((char *)(void *)&(a))[0];          \
 186 }
 187
 188 /*
 189  * Little endian <==> big endian 16-bit swap macros.
 190  *      M_16_SWAP       swap a memory location
 191  *      P_16_SWAP       swap a referenced memory location
 192  *      P_16_COPY       swap from one location to another
 193  */
 194 #define M_16_SWAP(a) {                                                  \
 195         uint16_t _tmp = a;                                              \
 196         ((char *)(void *)&a)[0] = ((char *)(void *)&_tmp)[1];           \
 197         ((char *)(void *)&a)[1] = ((char *)(void *)&_tmp)[0];           \
 198 }
 199 #define P_16_SWAP(a) {                                                  \
 200         char  _tmp[2];                                                  \
 201         _tmp[0] = ((char *)(void *)a)[0];                               \
 202         _tmp[1] = ((char *)(void *)a)[1];                               \
 203         ((char *)(void *)a)[0] = _tmp[1];                               \
 204         ((char *)(void *)a)[1] = _tmp[0];                               \
 205 }
 206 #define P_16_COPY(a, b) {                                               \
 207         ((char *)(void *)&(b))[0] = ((char *)(void *)&(a))[1];          \
 208         ((char *)(void *)&(b))[1] = ((char *)(void *)&(a))[0];          \
 209 }
 210 #endif
 211
 212 __BEGIN_DECLS
 213 DB *dbopen(const char *, int, mode_t, DBTYPE, const void *);
 214
 215 #ifdef __DBINTERFACE_PRIVATE
 216
 217 #define _DBMASK(a) (~((1ULL << (sizeof(a) * NBBY)) - 1))
 218 #define _DBFIT(a, t) _DIAGASSERT(((a) & _DBMASK(t)) == 0)
 219
 220 DB      *__bt_open(const char *, int, mode_t, const BTREEINFO *, int);
 221 DB      *__hash_open(const char *, int, mode_t, const HASHINFO *, int);
 222 DB      *__rec_open(const char *, int, mode_t, const RECNOINFO *, int);
 223 void     __dbpanic(DB *);
 224 #endif
 225 __END_DECLS
 226 #endif /* !_DB_H_ */