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/>.
28 #include "system/filesys.h"
29 #include "system/time.h"
30 #include "system/shmem.h"
31 #include "system/select.h"
32 #include "system/wait.h"
34 #define _XOPEN_SOURCE 500
48 #ifndef HAVE_GETPAGESIZE
49 #define getpagesize() 0x2000
52 typedef uint32_t tdb_len_t;
53 typedef uint32_t tdb_off_t;
56 #define offsetof(t,f) ((unsigned int)&((t *)0)->f)
59 #define TDB_MAGIC_FOOD "TDB file\n"
60 #define TDB_VERSION (0x26011967 + 6)
61 #define TDB_MAGIC (0x26011999U)
62 #define TDB_FREE_MAGIC (~TDB_MAGIC)
63 #define TDB_DEAD_MAGIC (0xFEE1DEAD)
64 #define TDB_RECOVERY_MAGIC (0xf53bc0e7U)
65 #define TDB_ALIGNMENT 4
66 #define DEFAULT_HASH_SIZE 131
67 #define FREELIST_TOP (sizeof(struct tdb_header))
68 #define TDB_ALIGN(x,a) (((x) + (a)-1) & ~((a)-1))
69 #define TDB_BYTEREV(x) (((((x)&0xff)<<24)|((x)&0xFF00)<<8)|(((x)>>8)&0xFF00)|((x)>>24))
70 #define TDB_DEAD(r) ((r)->magic == TDB_DEAD_MAGIC)
71 #define TDB_BAD_MAGIC(r) ((r)->magic != TDB_MAGIC && !TDB_DEAD(r))
72 #define TDB_HASH_TOP(hash) (FREELIST_TOP + (BUCKET(hash)+1)*sizeof(tdb_off_t))
73 #define TDB_HASHTABLE_SIZE(tdb) ((tdb->header.hash_size+1)*sizeof(tdb_off_t))
74 #define TDB_DATA_START(hash_size) (TDB_HASH_TOP(hash_size-1) + sizeof(tdb_off_t))
75 #define TDB_RECOVERY_HEAD offsetof(struct tdb_header, recovery_start)
76 #define TDB_SEQNUM_OFS offsetof(struct tdb_header, sequence_number)
77 #define TDB_PAD_BYTE 0x42
78 #define TDB_PAD_U32 0x42424242
80 /* NB assumes there is a local variable called "tdb" that is the
81 * current context, also takes doubly-parenthesized print-style
83 #define TDB_LOG(x) tdb->log.log_fn x
88 #define TRANSACTION_LOCK 8
90 /* free memory if the pointer is valid and zero the pointer */
92 #define SAFE_FREE(x) do { if ((x) != NULL) {free(x); (x)=NULL;} } while(0)
95 #define BUCKET(hash) ((hash) % tdb->header.hash_size)
97 #define DOCONV() (tdb->flags & TDB_CONVERT)
98 #define CONVERT(x) (DOCONV() ? tdb_convert(&x, sizeof(x)) : &x)
101 /* the body of the database is made of one list_struct for the free space
102 plus a separate data list for each hash value */
104 tdb_off_t next; /* offset of the next record in the list */
105 tdb_len_t rec_len; /* total byte length of record */
106 tdb_len_t key_len; /* byte length of key */
107 tdb_len_t data_len; /* byte length of data */
108 uint32_t full_hash; /* the full 32 bit hash of the key */
109 uint32_t magic; /* try to catch errors */
110 /* the following union is implied:
112 char record[rec_len];
117 uint32_t totalsize; (tailer)
123 /* this is stored at the front of every database */
125 char magic_food[32]; /* for /etc/magic */
126 uint32_t version; /* version of the code */
127 uint32_t hash_size; /* number of hash entries */
128 tdb_off_t rwlocks; /* obsolete - kept to detect old formats */
129 tdb_off_t recovery_start; /* offset of transaction recovery region */
130 tdb_off_t sequence_number; /* used when TDB_SEQNUM is set */
131 tdb_off_t reserved[29];
134 struct tdb_lock_type {
140 struct tdb_traverse_lock {
141 struct tdb_traverse_lock *next;
149 int (*tdb_read)(struct tdb_context *, tdb_off_t , void *, tdb_len_t , int );
150 int (*tdb_write)(struct tdb_context *, tdb_off_t, const void *, tdb_len_t);
151 void (*next_hash_chain)(struct tdb_context *, uint32_t *);
152 int (*tdb_oob)(struct tdb_context *, tdb_off_t , int );
153 int (*tdb_expand_file)(struct tdb_context *, tdb_off_t , tdb_off_t );
154 int (*tdb_brlock)(struct tdb_context *, tdb_off_t , int, int, int, size_t);
158 char *name; /* the name of the database */
159 void *map_ptr; /* where it is currently mapped */
160 int fd; /* open file descriptor for the database */
161 tdb_len_t map_size; /* how much space has been mapped */
162 int read_only; /* opened read-only */
163 int traverse_read; /* read-only traversal */
164 int traverse_write; /* read-write traversal */
165 struct tdb_lock_type global_lock;
167 struct tdb_lock_type *lockrecs; /* only real locks, all with count>0 */
168 enum TDB_ERROR ecode; /* error code for last tdb error */
169 struct tdb_header header; /* a cached copy of the header */
170 uint32_t flags; /* the flags passed to tdb_open */
171 struct tdb_traverse_lock travlocks; /* current traversal locks */
172 struct tdb_context *next; /* all tdbs to avoid multiple opens */
173 dev_t device; /* uniquely identifies this tdb */
174 ino_t inode; /* uniquely identifies this tdb */
175 struct tdb_logging_context log;
176 unsigned int (*hash_fn)(TDB_DATA *key);
177 int open_flags; /* flags used in the open - needed by reopen */
178 unsigned int num_locks; /* number of chain locks held */
179 const struct tdb_methods *methods;
180 struct tdb_transaction *transaction;
182 int max_dead_records;
183 bool have_transaction_lock;
184 volatile sig_atomic_t *interrupt_sig_ptr;
191 int tdb_munmap(struct tdb_context *tdb);
192 void tdb_mmap(struct tdb_context *tdb);
193 int tdb_lock(struct tdb_context *tdb, int list, int ltype);
194 int tdb_lock_nonblock(struct tdb_context *tdb, int list, int ltype);
195 int tdb_unlock(struct tdb_context *tdb, int list, int ltype);
196 int tdb_brlock(struct tdb_context *tdb, tdb_off_t offset, int rw_type, int lck_type, int probe, size_t len);
197 int tdb_transaction_lock(struct tdb_context *tdb, int ltype);
198 int tdb_transaction_unlock(struct tdb_context *tdb);
199 int tdb_brlock_upgrade(struct tdb_context *tdb, tdb_off_t offset, size_t len);
200 int tdb_write_lock_record(struct tdb_context *tdb, tdb_off_t off);
201 int tdb_write_unlock_record(struct tdb_context *tdb, tdb_off_t off);
202 int tdb_ofs_read(struct tdb_context *tdb, tdb_off_t offset, tdb_off_t *d);
203 int tdb_ofs_write(struct tdb_context *tdb, tdb_off_t offset, tdb_off_t *d);
204 void *tdb_convert(void *buf, uint32_t size);
205 int tdb_free(struct tdb_context *tdb, tdb_off_t offset, struct list_struct *rec);
206 tdb_off_t tdb_allocate(struct tdb_context *tdb, tdb_len_t length, struct list_struct *rec);
207 int tdb_ofs_read(struct tdb_context *tdb, tdb_off_t offset, tdb_off_t *d);
208 int tdb_ofs_write(struct tdb_context *tdb, tdb_off_t offset, tdb_off_t *d);
209 int tdb_lock_record(struct tdb_context *tdb, tdb_off_t off);
210 int tdb_unlock_record(struct tdb_context *tdb, tdb_off_t off);
211 int tdb_rec_read(struct tdb_context *tdb, tdb_off_t offset, struct list_struct *rec);
212 int tdb_rec_write(struct tdb_context *tdb, tdb_off_t offset, struct list_struct *rec);
213 int tdb_do_delete(struct tdb_context *tdb, tdb_off_t rec_ptr, struct list_struct *rec);
214 unsigned char *tdb_alloc_read(struct tdb_context *tdb, tdb_off_t offset, tdb_len_t len);
215 int tdb_parse_data(struct tdb_context *tdb, TDB_DATA key,
216 tdb_off_t offset, tdb_len_t len,
217 int (*parser)(TDB_DATA key, TDB_DATA data,
220 tdb_off_t tdb_find_lock_hash(struct tdb_context *tdb, TDB_DATA key, uint32_t hash, int locktype,
221 struct list_struct *rec);
222 void tdb_io_init(struct tdb_context *tdb);
223 int tdb_expand(struct tdb_context *tdb, tdb_off_t size);
224 int tdb_rec_free_read(struct tdb_context *tdb, tdb_off_t off,
225 struct list_struct *rec);