2 Unix SMB/CIFS implementation.
4 trivial database library - private includes
6 Copyright (C) Andrew Tridgell 2005
8 ** NOTE! The following LGPL license applies to the tdb
9 ** library. This does NOT imply that all of Samba is released
12 This library is free software; you can redistribute it and/or
13 modify it under the terms of the GNU Lesser General Public
14 License as published by the Free Software Foundation; either
15 version 2 of the License, or (at your option) any later version.
17 This library is distributed in the hope that it will be useful,
18 but WITHOUT ANY WARRANTY; without even the implied warranty of
19 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
20 Lesser General Public License for more details.
22 You should have received a copy of the GNU Lesser General Public
23 License along with this library; if not, write to the Free Software
24 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
28 #include "system/filesys.h"
29 #include "system/time.h"
30 #include "system/shmem.h"
31 #include "system/select.h"
34 #ifndef HAVE_GETPAGESIZE
35 #define getpagesize() 0x2000
38 typedef uint32_t tdb_len_t
;
39 typedef uint32_t tdb_off_t
;
41 #define TDB_MAGIC_FOOD "TDB file\n"
42 #define TDB_VERSION (0x26011967 + 6)
43 #define TDB_MAGIC (0x26011999U)
44 #define TDB_FREE_MAGIC (~TDB_MAGIC)
45 #define TDB_DEAD_MAGIC (0xFEE1DEAD)
46 #define TDB_RECOVERY_MAGIC (0xf53bc0e7U)
47 #define TDB_ALIGNMENT 4
48 #define MIN_REC_SIZE (2*sizeof(struct list_struct) + TDB_ALIGNMENT)
49 #define DEFAULT_HASH_SIZE 131
50 #define FREELIST_TOP (sizeof(struct tdb_header))
51 #define TDB_ALIGN(x,a) (((x) + (a)-1) & ~((a)-1))
52 #define TDB_BYTEREV(x) (((((x)&0xff)<<24)|((x)&0xFF00)<<8)|(((x)>>8)&0xFF00)|((x)>>24))
53 #define TDB_DEAD(r) ((r)->magic == TDB_DEAD_MAGIC)
54 #define TDB_BAD_MAGIC(r) ((r)->magic != TDB_MAGIC && !TDB_DEAD(r))
55 #define TDB_HASH_TOP(hash) (FREELIST_TOP + (BUCKET(hash)+1)*sizeof(tdb_off_t))
56 #define TDB_HASHTABLE_SIZE(tdb) ((tdb->header.hash_size+1)*sizeof(tdb_off_t))
57 #define TDB_DATA_START(hash_size) TDB_HASH_TOP(hash_size-1)
58 #define TDB_RECOVERY_HEAD offsetof(struct tdb_header, recovery_start)
59 #define TDB_SEQNUM_OFS offsetof(struct tdb_header, sequence_number)
60 #define TDB_PAD_BYTE 0x42
61 #define TDB_PAD_U32 0x42424242
63 /* NB assumes there is a local variable called "tdb" that is the
64 * current context, also takes doubly-parenthesized print-style
66 #define TDB_LOG(x) tdb->log.log_fn x
71 #define TRANSACTION_LOCK 8
73 /* free memory if the pointer is valid and zero the pointer */
75 #define SAFE_FREE(x) do { if ((x) != NULL) {free(x); (x)=NULL;} } while(0)
78 #define BUCKET(hash) ((hash) % tdb->header.hash_size)
80 #define DOCONV() (tdb->flags & TDB_CONVERT)
81 #define CONVERT(x) (DOCONV() ? tdb_convert(&x, sizeof(x)) : &x)
84 /* the body of the database is made of one list_struct for the free space
85 plus a separate data list for each hash value */
87 tdb_off_t next
; /* offset of the next record in the list */
88 tdb_len_t rec_len
; /* total byte length of record */
89 tdb_len_t key_len
; /* byte length of key */
90 tdb_len_t data_len
; /* byte length of data */
91 uint32_t full_hash
; /* the full 32 bit hash of the key */
92 uint32_t magic
; /* try to catch errors */
93 /* the following union is implied:
100 uint32_t totalsize; (tailer)
106 /* this is stored at the front of every database */
108 char magic_food
[32]; /* for /etc/magic */
109 uint32_t version
; /* version of the code */
110 uint32_t hash_size
; /* number of hash entries */
111 tdb_off_t rwlocks
; /* obsolete - kept to detect old formats */
112 tdb_off_t recovery_start
; /* offset of transaction recovery region */
113 tdb_off_t sequence_number
; /* used when TDB_SEQNUM is set */
114 tdb_off_t reserved
[29];
117 struct tdb_lock_type
{
123 struct tdb_traverse_lock
{
124 struct tdb_traverse_lock
*next
;
132 int (*tdb_read
)(struct tdb_context
*, tdb_off_t
, void *, tdb_len_t
, int );
133 int (*tdb_write
)(struct tdb_context
*, tdb_off_t
, const void *, tdb_len_t
);
134 void (*next_hash_chain
)(struct tdb_context
*, uint32_t *);
135 int (*tdb_oob
)(struct tdb_context
*, tdb_off_t
, int );
136 int (*tdb_expand_file
)(struct tdb_context
*, tdb_off_t
, tdb_off_t
);
137 int (*tdb_brlock
)(struct tdb_context
*, tdb_off_t
, int, int, int, size_t);
141 char *name
; /* the name of the database */
142 void *map_ptr
; /* where it is currently mapped */
143 int fd
; /* open file descriptor for the database */
144 tdb_len_t map_size
; /* how much space has been mapped */
145 int read_only
; /* opened read-only */
146 int traverse_read
; /* read-only traversal */
147 struct tdb_lock_type global_lock
;
149 struct tdb_lock_type
*lockrecs
; /* only real locks, all with count>0 */
150 enum TDB_ERROR ecode
; /* error code for last tdb error */
151 struct tdb_header header
; /* a cached copy of the header */
152 uint32_t flags
; /* the flags passed to tdb_open */
153 struct tdb_traverse_lock travlocks
; /* current traversal locks */
154 struct tdb_context
*next
; /* all tdbs to avoid multiple opens */
155 dev_t device
; /* uniquely identifies this tdb */
156 ino_t inode
; /* uniquely identifies this tdb */
157 struct tdb_logging_context log
;
158 unsigned int (*hash_fn
)(TDB_DATA
*key
);
159 int open_flags
; /* flags used in the open - needed by reopen */
160 unsigned int num_locks
; /* number of chain locks held */
161 const struct tdb_methods
*methods
;
162 struct tdb_transaction
*transaction
;
164 int max_dead_records
;
171 int tdb_munmap(struct tdb_context
*tdb
);
172 void tdb_mmap(struct tdb_context
*tdb
);
173 int tdb_lock(struct tdb_context
*tdb
, int list
, int ltype
);
174 int tdb_unlock(struct tdb_context
*tdb
, int list
, int ltype
);
175 int tdb_brlock(struct tdb_context
*tdb
, tdb_off_t offset
, int rw_type
, int lck_type
, int probe
, size_t len
);
176 int tdb_brlock_upgrade(struct tdb_context
*tdb
, tdb_off_t offset
, size_t len
);
177 int tdb_write_lock_record(struct tdb_context
*tdb
, tdb_off_t off
);
178 int tdb_write_unlock_record(struct tdb_context
*tdb
, tdb_off_t off
);
179 int tdb_ofs_read(struct tdb_context
*tdb
, tdb_off_t offset
, tdb_off_t
*d
);
180 int tdb_ofs_write(struct tdb_context
*tdb
, tdb_off_t offset
, tdb_off_t
*d
);
181 void *tdb_convert(void *buf
, uint32_t size
);
182 int tdb_free(struct tdb_context
*tdb
, tdb_off_t offset
, struct list_struct
*rec
);
183 tdb_off_t
tdb_allocate(struct tdb_context
*tdb
, tdb_len_t length
, struct list_struct
*rec
);
184 int tdb_ofs_read(struct tdb_context
*tdb
, tdb_off_t offset
, tdb_off_t
*d
);
185 int tdb_ofs_write(struct tdb_context
*tdb
, tdb_off_t offset
, tdb_off_t
*d
);
186 int tdb_lock_record(struct tdb_context
*tdb
, tdb_off_t off
);
187 int tdb_unlock_record(struct tdb_context
*tdb
, tdb_off_t off
);
188 int tdb_rec_read(struct tdb_context
*tdb
, tdb_off_t offset
, struct list_struct
*rec
);
189 int tdb_rec_write(struct tdb_context
*tdb
, tdb_off_t offset
, struct list_struct
*rec
);
190 int tdb_do_delete(struct tdb_context
*tdb
, tdb_off_t rec_ptr
, struct list_struct
*rec
);
191 unsigned char *tdb_alloc_read(struct tdb_context
*tdb
, tdb_off_t offset
, tdb_len_t len
);
192 int tdb_parse_data(struct tdb_context
*tdb
, TDB_DATA key
,
193 tdb_off_t offset
, tdb_len_t len
,
194 int (*parser
)(TDB_DATA key
, TDB_DATA data
,
197 tdb_off_t
tdb_find_lock_hash(struct tdb_context
*tdb
, TDB_DATA key
, uint32_t hash
, int locktype
,
198 struct list_struct
*rec
);
199 void tdb_io_init(struct tdb_context
*tdb
);
200 int tdb_expand(struct tdb_context
*tdb
, tdb_off_t size
);
201 int tdb_rec_free_read(struct tdb_context
*tdb
, tdb_off_t off
,
202 struct list_struct
*rec
);