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
32 #define _XOPEN_SOURCE 500
49 #ifndef HAVE_PREAD_DECL
50 ssize_t pread(int fd, void *buf, size_t count, off_t offset);
52 #ifndef HAVE_PWRITE_DECL
53 ssize_t pwrite(int fd, const void *buf, size_t count, off_t offset);
58 #include "lib/tdb/include/tdb.h"
59 #include "system/time.h"
60 #include "system/shmem.h"
61 #include "system/filesys.h"
68 #ifndef HAVE_GETPAGESIZE
69 #define getpagesize() 0x2000
72 typedef u32 tdb_len_t;
73 typedef u32 tdb_off_t;
76 #define offsetof(t,f) ((unsigned int)&((t *)0)->f)
79 #define TDB_MAGIC_FOOD "TDB file\n"
80 #define TDB_VERSION (0x26011967 + 6)
81 #define TDB_MAGIC (0x26011999U)
82 #define TDB_FREE_MAGIC (~TDB_MAGIC)
83 #define TDB_DEAD_MAGIC (0xFEE1DEAD)
84 #define TDB_RECOVERY_MAGIC (0xf53bc0e7U)
85 #define TDB_ALIGNMENT 4
86 #define MIN_REC_SIZE (2*sizeof(struct list_struct) + TDB_ALIGNMENT)
87 #define DEFAULT_HASH_SIZE 131
88 #define FREELIST_TOP (sizeof(struct tdb_header))
89 #define TDB_ALIGN(x,a) (((x) + (a)-1) & ~((a)-1))
90 #define TDB_BYTEREV(x) (((((x)&0xff)<<24)|((x)&0xFF00)<<8)|(((x)>>8)&0xFF00)|((x)>>24))
91 #define TDB_DEAD(r) ((r)->magic == TDB_DEAD_MAGIC)
92 #define TDB_BAD_MAGIC(r) ((r)->magic != TDB_MAGIC && !TDB_DEAD(r))
93 #define TDB_HASH_TOP(hash) (FREELIST_TOP + (BUCKET(hash)+1)*sizeof(tdb_off_t))
94 #define TDB_HASHTABLE_SIZE(tdb) ((tdb->header.hash_size+1)*sizeof(tdb_off_t))
95 #define TDB_DATA_START(hash_size) TDB_HASH_TOP(hash_size-1)
96 #define TDB_RECOVERY_HEAD offsetof(struct tdb_header, recovery_start)
97 #define TDB_PAD_BYTE 0x42
98 #define TDB_PAD_U32 0x42424242
100 /* NB assumes there is a local variable called "tdb" that is the
101 * current context, also takes doubly-parenthesized print-style
103 #define TDB_LOG(x) tdb->log_fn x
106 #define GLOBAL_LOCK 0
107 #define ACTIVE_LOCK 4
108 #define TRANSACTION_LOCK 8
115 #define MAP_FAILED ((void *)-1)
118 #ifndef discard_const_p
119 # if defined(__intptr_t_defined) || defined(HAVE_INTPTR_T)
120 # define discard_const(ptr) ((void *)((intptr_t)(ptr)))
122 # define discard_const(ptr) ((void *)(ptr))
124 # define discard_const_p(type, ptr) ((type *)discard_const(ptr))
127 /* free memory if the pointer is valid and zero the pointer */
129 #define SAFE_FREE(x) do { if ((x) != NULL) {free(discard_const_p(void *, (x))); (x)=NULL;} } while(0)
132 #define BUCKET(hash) ((hash) % tdb->header.hash_size)
134 #define DOCONV() (tdb->flags & TDB_CONVERT)
135 #define CONVERT(x) (DOCONV() ? tdb_convert(&x, sizeof(x)) : &x)
138 /* the body of the database is made of one list_struct for the free space
139 plus a separate data list for each hash value */
141 tdb_off_t next; /* offset of the next record in the list */
142 tdb_len_t rec_len; /* total byte length of record */
143 tdb_len_t key_len; /* byte length of key */
144 tdb_len_t data_len; /* byte length of data */
145 u32 full_hash; /* the full 32 bit hash of the key */
146 u32 magic; /* try to catch errors */
147 /* the following union is implied:
149 char record[rec_len];
154 u32 totalsize; (tailer)
160 /* this is stored at the front of every database */
162 char magic_food[32]; /* for /etc/magic */
163 u32 version; /* version of the code */
164 u32 hash_size; /* number of hash entries */
165 tdb_off_t rwlocks; /* obsolete - kept to detect old formats */
166 tdb_off_t recovery_start; /* offset of transaction recovery region */
167 tdb_off_t reserved[30];
170 struct tdb_lock_type {
175 struct tdb_traverse_lock {
176 struct tdb_traverse_lock *next;
184 int (*tdb_read)(struct tdb_context *, tdb_off_t , void *, tdb_len_t , int );
185 int (*tdb_write)(struct tdb_context *, tdb_off_t, const void *, tdb_len_t);
186 void (*next_hash_chain)(struct tdb_context *, u32 *);
187 int (*tdb_oob)(struct tdb_context *, tdb_off_t , int );
188 int (*tdb_expand_file)(struct tdb_context *, tdb_off_t , tdb_off_t );
189 int (*tdb_brlock)(struct tdb_context *, tdb_off_t , int, int, int);
193 char *name; /* the name of the database */
194 void *map_ptr; /* where it is currently mapped */
195 int fd; /* open file descriptor for the database */
196 tdb_len_t map_size; /* how much space has been mapped */
197 int read_only; /* opened read-only */
198 int traverse_read; /* read-only traversal */
199 struct tdb_lock_type *locked; /* array of chain locks */
200 enum TDB_ERROR ecode; /* error code for last tdb error */
201 struct tdb_header header; /* a cached copy of the header */
202 u32 flags; /* the flags passed to tdb_open */
203 struct tdb_traverse_lock travlocks; /* current traversal locks */
204 struct tdb_context *next; /* all tdbs to avoid multiple opens */
205 dev_t device; /* uniquely identifies this tdb */
206 ino_t inode; /* uniquely identifies this tdb */
207 void (*log_fn)(struct tdb_context *tdb, int level, const char *, ...) PRINTF_ATTRIBUTE(3,4); /* logging function */
208 unsigned int (*hash_fn)(TDB_DATA *key);
209 int open_flags; /* flags used in the open - needed by reopen */
210 unsigned int num_locks; /* number of chain locks held */
211 const struct tdb_methods *methods;
212 struct tdb_transaction *transaction;
220 int tdb_munmap(struct tdb_context *tdb);
221 void tdb_mmap(struct tdb_context *tdb);
222 int tdb_lock(struct tdb_context *tdb, int list, int ltype);
223 int tdb_unlock(struct tdb_context *tdb, int list, int ltype);
224 int tdb_brlock(struct tdb_context *tdb, tdb_off_t offset, int rw_type, int lck_type, int probe);
225 int tdb_brlock_len(struct tdb_context *tdb, tdb_off_t offset,
226 int rw_type, int lck_type, int probe, size_t len);
227 int tdb_write_lock_record(struct tdb_context *tdb, tdb_off_t off);
228 int tdb_write_unlock_record(struct tdb_context *tdb, tdb_off_t off);
229 int tdb_ofs_read(struct tdb_context *tdb, tdb_off_t offset, tdb_off_t *d);
230 int tdb_ofs_write(struct tdb_context *tdb, tdb_off_t offset, tdb_off_t *d);
231 void *tdb_convert(void *buf, u32 size);
232 int tdb_free(struct tdb_context *tdb, tdb_off_t offset, struct list_struct *rec);
233 tdb_off_t tdb_allocate(struct tdb_context *tdb, tdb_len_t length, struct list_struct *rec);
234 int tdb_ofs_read(struct tdb_context *tdb, tdb_off_t offset, tdb_off_t *d);
235 int tdb_ofs_write(struct tdb_context *tdb, tdb_off_t offset, tdb_off_t *d);
236 int tdb_lock_record(struct tdb_context *tdb, tdb_off_t off);
237 int tdb_unlock_record(struct tdb_context *tdb, tdb_off_t off);
238 int tdb_rec_read(struct tdb_context *tdb, tdb_off_t offset, struct list_struct *rec);
239 int tdb_rec_write(struct tdb_context *tdb, tdb_off_t offset, struct list_struct *rec);
240 int tdb_do_delete(struct tdb_context *tdb, tdb_off_t rec_ptr, struct list_struct *rec);
241 unsigned char *tdb_alloc_read(struct tdb_context *tdb, tdb_off_t offset, tdb_len_t len);
242 tdb_off_t tdb_find_lock_hash(struct tdb_context *tdb, TDB_DATA key, u32 hash, int locktype,
243 struct list_struct *rec);
244 void tdb_io_init(struct tdb_context *tdb);
245 int tdb_expand(struct tdb_context *tdb, tdb_off_t size);