master
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 */
47typedef uint32_t pgno_t;
48#define MAX_PAGE_OFFSET 65535 /* >= # of bytes in a page */
49typedef uint16_t indx_t;
50#define MAX_REC_NUMBER 0xffffffff /* >= # of records in a tree */
51typedef uint32_t recno_t;
52
53/* Key/data structure -- a Data-Base Thang. */
54typedef 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
89typedef 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. */
115typedef 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. */
131typedef 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. */
149typedef 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. */
160typedef 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
230DB *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
236DB *__bt_open(const char *, int, mode_t, const BTREEINFO *, int);
237DB *__hash_open(const char *, int, mode_t, const HASHINFO *, int);
238DB *__rec_open(const char *, int, mode_t, const RECNOINFO *, int);
239void __dbpanic(DB *);
240struct stat;
241int __dbopen(const char *, int, mode_t, struct stat *);
242int __dbtemp(const char *, struct stat *);
243#endif
244__END_DECLS
245#endif /* !_DB_H_ */