root/libdb/db.h

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/*-
 * Copyright (c) 1990, 1993, 1994
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      @(#)db.h        8.7 (Berkeley) 6/16/94
 */

#ifndef _DB_H_
#define _DB_H_

#include <sys/types.h>

#ifdef HAVE_LIMITS_H
#include <limits.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

#include "compat.h"

#define RET_ERROR       -1              /* Return values. */
#define RET_SUCCESS      0
#define RET_SPECIAL      1

#define MAX_PAGE_NUMBER 0xffffffff      /* >= # of pages in a file */
#define pgno_t          u_int32_t
#define MAX_PAGE_OFFSET 65535           /* >= # of bytes in a page */
#define indx_t          u_int16_t
#define MAX_REC_NUMBER  0xffffffff      /* >= # of records in a tree */
#define recno_t         u_int32_t

/* Key/data structure -- a Data-Base Thang. */
typedef struct {
        void    *data;                  /* data */
        size_t   size;                  /* data length */
} DBT;

/* Routine flags. */
#define R_CURSOR        1               /* del, put, seq */
#define __R_UNUSED      2               /* UNUSED */
#define R_FIRST         3               /* seq */
#define R_IAFTER        4               /* put (RECNO) */
#define R_IBEFORE       5               /* put (RECNO) */
#define R_LAST          6               /* seq (BTREE, RECNO) */
#define R_NEXT          7               /* seq */
#define R_NOOVERWRITE   8               /* put */
#define R_PREV          9               /* seq (BTREE, RECNO) */
#define R_SETCURSOR     10              /* put (RECNO) */
#define R_RECNOSYNC     11              /* sync (RECNO) */

typedef enum { DB_BTREE, DB_HASH, DB_RECNO } DBTYPE;

/*
 * !!!
 * The following flags are included in the dbopen(3) call as part of the
 * open(2) flags.  In order to avoid conflicts with the open flags, start
 * at the top of the 16 or 32-bit number space and work our way down.  If
 * the open flags were significantly expanded in the future, it could be
 * a problem.  Wish I'd left another flags word in the dbopen call.
 *
 * !!!
 * None of this stuff is implemented yet.  The only reason that it's here
 * is so that the access methods can skip copying the key/data pair when
 * the DB_LOCK flag isn't set.
 */
#if UINT_MAX > 65535
#define DB_LOCK         0x20000000      /* Do locking. */
#define DB_SHMEM        0x40000000      /* Use shared memory. */
#define DB_TXN          0x80000000      /* Do transactions. */
#else
#define DB_LOCK             0x2000      /* Do locking. */
#define DB_SHMEM            0x4000      /* Use shared memory. */
#define DB_TXN              0x8000      /* Do transactions. */
#endif

/* Access method description structure. */
typedef struct __db {
        DBTYPE type;                    /* Underlying db type. */
        /* The 2nd argument was added in order to
           avoid useless writing just before unlink. */
        int (*close)    (struct __db *, int);
        int (*del)      (const struct __db *, const DBT *, u_int);
        int (*get)      (const struct __db *, const DBT *, DBT *, u_int);
        int (*put)      (const struct __db *, DBT *, const DBT *, u_int);
        int (*seq)      (const struct __db *, DBT *, DBT *, u_int);
        int (*sync)     (const struct __db *, u_int);
        void *internal;                 /* Access method private. */
        int (*fd)       (const struct __db *);
} DB;

#define BTREEMAGIC      0x053162
#define BTREEVERSION    3
#define R_DUP           0x01    /* duplicate keys */

/* Structure used to pass parameters to the btree routines. */
typedef struct {
        u_long  flags;
        u_int   cachesize;      /* bytes to cache */
        int     maxkeypage;     /* maximum keys per page */
        int     minkeypage;     /* minimum keys per page */
        u_int   psize;          /* page size */
        int     (*compare)      /* comparison function */
           (const DBT *, const DBT *);
        size_t  (*prefix)       /* prefix function */
           (const DBT *, const DBT *);
        int     lorder;         /* byte order */
} BTREEINFO;

#define HASHMAGIC       0x061561
#define HASHVERSION     2

/* Structure used to pass parameters to the hashing routines. */
typedef struct {
        u_int   bsize;          /* bucket size */
        u_int   ffactor;        /* fill factor */
        u_int   nelem;          /* number of elements */
        u_int   cachesize;      /* bytes to cache */
        u_int32_t               /* hash function */
                (*hash)(const void *, size_t);
        int     lorder;         /* byte order */
} HASHINFO;

#define R_FIXEDLEN      0x01    /* fixed-length records */
#define R_NOKEY         0x02    /* key not required */
#define R_SNAPSHOT      0x04    /* snapshot the input */

/* Structure used to pass parameters to the record routines. */
typedef struct {
        u_long  flags;
        u_int   cachesize;      /* bytes to cache */
        u_int   psize;          /* page size */
        int     lorder;         /* byte order */
        size_t  reclen;         /* record length (fixed-length records) */
        u_char  bval;           /* delimiting byte (variable-length records */
        char    *bfname;        /* btree file name */ 
} RECNOINFO;

/*
 * Little endian <==> big endian 32-bit swap macros.
 *      M_32_SWAP       swap a memory location
 *      P_32_SWAP       swap a referenced memory location
 *      P_32_COPY       swap from one location to another
 */
#define M_32_SWAP(a) {                                                  \
        u_int32_t _tmp = a;                                             \
        ((char *)&a)[0] = ((char *)&_tmp)[3];                           \
        ((char *)&a)[1] = ((char *)&_tmp)[2];                           \
        ((char *)&a)[2] = ((char *)&_tmp)[1];                           \
        ((char *)&a)[3] = ((char *)&_tmp)[0];                           \
}
#define P_32_SWAP(a) {                                                  \
        u_int32_t _tmp = *(u_int32_t *)a;                               \
        ((char *)a)[0] = ((char *)&_tmp)[3];                            \
        ((char *)a)[1] = ((char *)&_tmp)[2];                            \
        ((char *)a)[2] = ((char *)&_tmp)[1];                            \
        ((char *)a)[3] = ((char *)&_tmp)[0];                            \
}
#define P_32_COPY(a, b) {                                               \
        ((char *)&(b))[0] = ((char *)&(a))[3];                          \
        ((char *)&(b))[1] = ((char *)&(a))[2];                          \
        ((char *)&(b))[2] = ((char *)&(a))[1];                          \
        ((char *)&(b))[3] = ((char *)&(a))[0];                          \
}

/*
 * Little endian <==> big endian 16-bit swap macros.
 *      M_16_SWAP       swap a memory location
 *      P_16_SWAP       swap a referenced memory location
 *      P_16_COPY       swap from one location to another
 */
#define M_16_SWAP(a) {                                                  \
        u_int16_t _tmp = a;                                             \
        ((char *)&a)[0] = ((char *)&_tmp)[1];                           \
        ((char *)&a)[1] = ((char *)&_tmp)[0];                           \
}
#define P_16_SWAP(a) {                                                  \
        u_int16_t _tmp = *(u_int16_t *)a;                               \
        ((char *)a)[0] = ((char *)&_tmp)[1];                            \
        ((char *)a)[1] = ((char *)&_tmp)[0];                            \
}
#define P_16_COPY(a, b) {                                               \
        ((char *)&(b))[0] = ((char *)&(a))[1];                          \
        ((char *)&(b))[1] = ((char *)&(a))[0];                          \
}

DB      *dbopen(const char *, int, int, DBTYPE, const void *);

DB      *__bt_open(const char *, int, int, const BTREEINFO *, int);
DB      *__hash_open(const char *, int, int, const HASHINFO *, int);
DB      *__rec_open(const char *, int, int, const RECNOINFO *, int);
void     __dbpanic(DB *dbp);
#endif /* !_DB_H_ */

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