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 3 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, see <http://www.gnu.org/licenses/>.
27 #include "system/filesys.h"
28 #include "system/time.h"
29 #include "system/shmem.h"
30 #include "system/select.h"
31 #include "system/wait.h"
34 #ifndef HAVE_GETPAGESIZE
35 #define getpagesize() 0x2000
38 typedef uint32_t tdb_len_t;
39 typedef uint32_t tdb_off_t;
42 #define offsetof(t,f) ((unsigned int)&((t *)0)->f)
45 #define TDB_MAGIC_FOOD "TDB file\n"
46 #define TDB_VERSION (0x26011967 + 6)
47 #define TDB_MAGIC (0x26011999U)
48 #define TDB_FREE_MAGIC (~TDB_MAGIC)
49 #define TDB_DEAD_MAGIC (0xFEE1DEAD)
50 #define TDB_RECOVERY_MAGIC (0xf53bc0e7U)
51 #define TDB_ALIGNMENT 4
52 #define DEFAULT_HASH_SIZE 131
53 #define FREELIST_TOP (sizeof(struct tdb_header))
54 #define TDB_ALIGN(x,a) (((x) + (a)-1) & ~((a)-1))
55 #define TDB_BYTEREV(x) (((((x)&0xff)<<24)|((x)&0xFF00)<<8)|(((x)>>8)&0xFF00)|((x)>>24))
56 #define TDB_DEAD(r) ((r)->magic == TDB_DEAD_MAGIC)
57 #define TDB_BAD_MAGIC(r) ((r)->magic != TDB_MAGIC && !TDB_DEAD(r))
58 #define TDB_HASH_TOP(hash) (FREELIST_TOP + (BUCKET(hash)+1)*sizeof(tdb_off_t))
59 #define TDB_HASHTABLE_SIZE(tdb) ((tdb->header.hash_size+1)*sizeof(tdb_off_t))
60 #define TDB_DATA_START(hash_size) (TDB_HASH_TOP(hash_size-1) + sizeof(tdb_off_t))
61 #define TDB_RECOVERY_HEAD offsetof(struct tdb_header, recovery_start)
62 #define TDB_SEQNUM_OFS offsetof(struct tdb_header, sequence_number)
63 #define TDB_PAD_BYTE 0x42
64 #define TDB_PAD_U32 0x42424242
66 /* NB assumes there is a local variable called "tdb" that is the
67 * current context, also takes doubly-parenthesized print-style
69 #define TDB_LOG(x) tdb->log.log_fn x
74 #define TRANSACTION_LOCK 8
76 /* free memory if the pointer is valid and zero the pointer */
78 #define SAFE_FREE(x) do { if ((x) != NULL) {free(x); (x)=NULL;} } while(0)
81 #define BUCKET(hash) ((hash) % tdb->header.hash_size)
83 #define DOCONV() (tdb->flags & TDB_CONVERT)
84 #define CONVERT(x) (DOCONV() ? tdb_convert(&x, sizeof(x)) : &x)
87 /* the body of the database is made of one list_struct for the free space
88 plus a separate data list for each hash value */
90 tdb_off_t next; /* offset of the next record in the list */
91 tdb_len_t rec_len; /* total byte length of record */
92 tdb_len_t key_len; /* byte length of key */
93 tdb_len_t data_len; /* byte length of data */
94 uint32_t full_hash; /* the full 32 bit hash of the key */
95 uint32_t magic; /* try to catch errors */
96 /* the following union is implied:
103 uint32_t totalsize; (tailer)
109 /* this is stored at the front of every database */
111 char magic_food[32]; /* for /etc/magic */
112 uint32_t version; /* version of the code */
113 uint32_t hash_size; /* number of hash entries */
114 tdb_off_t rwlocks; /* obsolete - kept to detect old formats */
115 tdb_off_t recovery_start; /* offset of transaction recovery region */
116 tdb_off_t sequence_number; /* used when TDB_SEQNUM is set */
117 tdb_off_t reserved[29];
120 struct tdb_lock_type {
126 struct tdb_traverse_lock {
127 struct tdb_traverse_lock *next;
135 int (*tdb_read)(struct tdb_context *, tdb_off_t , void *, tdb_len_t , int );
136 int (*tdb_write)(struct tdb_context *, tdb_off_t, const void *, tdb_len_t);
137 void (*next_hash_chain)(struct tdb_context *, uint32_t *);
138 int (*tdb_oob)(struct tdb_context *, tdb_off_t , int );
139 int (*tdb_expand_file)(struct tdb_context *, tdb_off_t , tdb_off_t );
140 int (*tdb_brlock)(struct tdb_context *, tdb_off_t , int, int, int, size_t);
144 char *name; /* the name of the database */
145 void *map_ptr; /* where it is currently mapped */
146 int fd; /* open file descriptor for the database */
147 tdb_len_t map_size; /* how much space has been mapped */
148 int read_only; /* opened read-only */
149 int traverse_read; /* read-only traversal */
150 int traverse_write; /* read-write traversal */
151 struct tdb_lock_type global_lock;
153 struct tdb_lock_type *lockrecs; /* only real locks, all with count>0 */
154 enum TDB_ERROR ecode; /* error code for last tdb error */
155 struct tdb_header header; /* a cached copy of the header */
156 uint32_t flags; /* the flags passed to tdb_open */
157 struct tdb_traverse_lock travlocks; /* current traversal locks */
158 struct tdb_context *next; /* all tdbs to avoid multiple opens */
159 dev_t device; /* uniquely identifies this tdb */
160 ino_t inode; /* uniquely identifies this tdb */
161 struct tdb_logging_context log;
162 unsigned int (*hash_fn)(TDB_DATA *key);
163 int open_flags; /* flags used in the open - needed by reopen */
164 unsigned int num_locks; /* number of chain locks held */
165 const struct tdb_methods *methods;
166 struct tdb_transaction *transaction;
168 int max_dead_records;
169 bool have_transaction_lock;
170 volatile sig_atomic_t *interrupt_sig_ptr;
177 int tdb_munmap(struct tdb_context *tdb);
178 void tdb_mmap(struct tdb_context *tdb);
179 int tdb_lock(struct tdb_context *tdb, int list, int ltype);
180 int tdb_lock_nonblock(struct tdb_context *tdb, int list, int ltype);
181 int tdb_unlock(struct tdb_context *tdb, int list, int ltype);
182 int tdb_brlock(struct tdb_context *tdb, tdb_off_t offset, int rw_type, int lck_type, int probe, size_t len);
183 int tdb_transaction_lock(struct tdb_context *tdb, int ltype);
184 int tdb_transaction_unlock(struct tdb_context *tdb);
185 int tdb_brlock_upgrade(struct tdb_context *tdb, tdb_off_t offset, size_t len);
186 int tdb_write_lock_record(struct tdb_context *tdb, tdb_off_t off);
187 int tdb_write_unlock_record(struct tdb_context *tdb, tdb_off_t off);
188 int tdb_ofs_read(struct tdb_context *tdb, tdb_off_t offset, tdb_off_t *d);
189 int tdb_ofs_write(struct tdb_context *tdb, tdb_off_t offset, tdb_off_t *d);
190 void *tdb_convert(void *buf, uint32_t size);
191 int tdb_free(struct tdb_context *tdb, tdb_off_t offset, struct list_struct *rec);
192 tdb_off_t tdb_allocate(struct tdb_context *tdb, tdb_len_t length, struct list_struct *rec);
193 int tdb_ofs_read(struct tdb_context *tdb, tdb_off_t offset, tdb_off_t *d);
194 int tdb_ofs_write(struct tdb_context *tdb, tdb_off_t offset, tdb_off_t *d);
195 int tdb_lock_record(struct tdb_context *tdb, tdb_off_t off);
196 int tdb_unlock_record(struct tdb_context *tdb, tdb_off_t off);
197 int tdb_rec_read(struct tdb_context *tdb, tdb_off_t offset, struct list_struct *rec);
198 int tdb_rec_write(struct tdb_context *tdb, tdb_off_t offset, struct list_struct *rec);
199 int tdb_do_delete(struct tdb_context *tdb, tdb_off_t rec_ptr, struct list_struct *rec);
200 unsigned char *tdb_alloc_read(struct tdb_context *tdb, tdb_off_t offset, tdb_len_t len);
201 int tdb_parse_data(struct tdb_context *tdb, TDB_DATA key,
202 tdb_off_t offset, tdb_len_t len,
203 int (*parser)(TDB_DATA key, TDB_DATA data,
206 tdb_off_t tdb_find_lock_hash(struct tdb_context *tdb, TDB_DATA key, uint32_t hash, int locktype,
207 struct list_struct *rec);
208 void tdb_io_init(struct tdb_context *tdb);
209 int tdb_expand(struct tdb_context *tdb, tdb_off_t size);
210 int tdb_rec_free_read(struct tdb_context *tdb, tdb_off_t off,
211 struct list_struct *rec);