lib/ntdb/private.h

   1 #ifndef NTDB_PRIVATE_H
   2 #define NTDB_PRIVATE_H
   3 /*
   4   Trivial Database 2: private types and prototypes
   5   Copyright (C) Rusty Russell 2010
   6
   7   This library is free software; you can redistribute it and/or
   8   modify it under the terms of the GNU Lesser General Public
   9   License as published by the Free Software Foundation; either
  10   version 3 of the License, or (at your option) any later version.
  11
  12   This library is distributed in the hope that it will be useful,
  13   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15   Lesser General Public License for more details.
  16
  17   You should have received a copy of the GNU Lesser General Public
  18   License along with this library; if not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include "config.h"
  22 #ifndef HAVE_CCAN
  23 #error You need ccan to build ntdb!
  24 #endif
  25 #include "ntdb.h"
  26 #include <ccan/compiler/compiler.h>
  27 #include <ccan/likely/likely.h>
  28 #include <ccan/endian/endian.h>
  29
  30 #ifdef HAVE_LIBREPLACE
  31 #include "replace.h"
  32 #include "system/filesys.h"
  33 #include "system/time.h"
  34 #include "system/shmem.h"
  35 #include "system/select.h"
  36 #include "system/wait.h"
  37 #else
  38 #include <stdarg.h>
  39 #include <stdint.h>
  40 #include <stdbool.h>
  41 #include <stdlib.h>
  42 #include <stddef.h>
  43 #include <sys/time.h>
  44 #include <sys/mman.h>
  45 #include <unistd.h>
  46 #include <fcntl.h>
  47 #include <errno.h>
  48 #include <stdio.h>
  49 #include <utime.h>
  50 #include <unistd.h>
  51 #include <ctype.h>
  52 #include <string.h>
  53 #include <sys/wait.h>
  54 #include <time.h>
  55 #endif
  56 #include <assert.h>
  57
  58 #ifndef TEST_IT
  59 #define TEST_IT(cond)
  60 #endif
  61
  62 /* #define NTDB_TRACE 1 */
  63
  64 #ifndef __STRING
  65 #define __STRING(x)    #x
  66 #endif
  67
  68 #ifndef __STRINGSTRING
  69 #define __STRINGSTRING(x) __STRING(x)
  70 #endif
  71
  72 #ifndef __location__
  73 #define __location__ __FILE__ ":" __STRINGSTRING(__LINE__)
  74 #endif
  75
  76 typedef uint64_t ntdb_len_t;
  77 typedef uint64_t ntdb_off_t;
  78
  79 #define NTDB_MAGIC_FOOD "NTDB file\n"
  80 #define NTDB_VERSION ((uint64_t)(0x26011967 + 7))
  81 #define NTDB_USED_MAGIC ((uint64_t)0x1999)
  82 #define NTDB_HTABLE_MAGIC ((uint64_t)0x1888)
  83 #define NTDB_CHAIN_MAGIC ((uint64_t)0x1777)
  84 #define NTDB_FTABLE_MAGIC ((uint64_t)0x1666)
  85 #define NTDB_CAP_MAGIC ((uint64_t)0x1555)
  86 #define NTDB_FREE_MAGIC ((uint64_t)0xFE)
  87 #define NTDB_HASH_MAGIC (0xA1ABE11A01092008ULL)
  88 #define NTDB_RECOVERY_MAGIC (0xf53bc0e7ad124589ULL)
  89 #define NTDB_RECOVERY_INVALID_MAGIC (0x0ULL)
  90
  91 /* Capability bits. */
  92 #define NTDB_CAP_TYPE_MASK      0x1FFFFFFFFFFFFFFFULL
  93 #define NTDB_CAP_NOCHECK                0x8000000000000000ULL
  94 #define NTDB_CAP_NOWRITE                0x4000000000000000ULL
  95 #define NTDB_CAP_NOOPEN         0x2000000000000000ULL
  96
  97 #define NTDB_OFF_IS_ERR(off) unlikely(off >= (ntdb_off_t)(long)NTDB_ERR_LAST)
  98 #define NTDB_OFF_TO_ERR(off) ((enum NTDB_ERROR)(long)(off))
  99 #define NTDB_ERR_TO_OFF(ecode) ((ntdb_off_t)(long)(ecode))
 100
 101 /* Packing errors into pointers and v.v. */
 102 #define NTDB_PTR_IS_ERR(ptr)                                            \
 103         unlikely((unsigned long)(ptr) >= (unsigned long)NTDB_ERR_LAST)
 104 #define NTDB_PTR_ERR(p) ((enum NTDB_ERROR)(long)(p))
 105 #define NTDB_ERR_PTR(err) ((void *)(long)(err))
 106
 107 /* This doesn't really need to be pagesize, but we use it for similar
 108  * reasons. */
 109 #define NTDB_PGSIZE 16384
 110
 111 /* Common case of returning true, false or -ve error. */
 112 typedef int ntdb_bool_err;
 113
 114 /* Prevent others from opening the file. */
 115 #define NTDB_OPEN_LOCK 0
 116 /* Expanding file. */
 117 #define NTDB_EXPANSION_LOCK 2
 118 /* Doing a transaction. */
 119 #define NTDB_TRANSACTION_LOCK 8
 120 /* Hash chain locks. */
 121 #define NTDB_HASH_LOCK_START 64
 122
 123 /* Extend file by least 100 times larger than needed. */
 124 #define NTDB_EXTENSION_FACTOR 100
 125
 126 /* We steal this many upper bits, giving a maximum offset of 64 exabytes. */
 127 #define NTDB_OFF_UPPER_STEAL 8
 128
 129 /* And we use the lower bit, too. */
 130 #define NTDB_OFF_CHAIN_BIT      0
 131
 132 /* Hash table sits just after the header. */
 133 #define NTDB_HASH_OFFSET (sizeof(struct ntdb_header))
 134
 135 /* Additional features we understand.  Currently: none. */
 136 #define NTDB_FEATURE_MASK ((uint64_t)0)
 137
 138 /* The bit number where we store the extra hash bits. */
 139 /* Convenience mask to get actual offset. */
 140 #define NTDB_OFF_MASK                                                   \
 141         (((1ULL << (64 - NTDB_OFF_UPPER_STEAL)) - 1) - (1<<NTDB_OFF_CHAIN_BIT))
 142
 143 /* How many buckets in a free list: see size_to_bucket(). */
 144 #define NTDB_FREE_BUCKETS (64 - NTDB_OFF_UPPER_STEAL)
 145
 146 /* We have to be able to fit a free record here. */
 147 #define NTDB_MIN_DATA_LEN                                               \
 148         (sizeof(struct ntdb_free_record) - sizeof(struct ntdb_used_record))
 149
 150 /* Indicates this entry is not on an flist (can happen during coalescing) */
 151 #define NTDB_FTABLE_NONE ((1ULL << NTDB_OFF_UPPER_STEAL) - 1)
 152
 153 /* By default, hash is 64k bytes */
 154 #define NTDB_DEFAULT_HBITS 13
 155
 156 struct ntdb_used_record {
 157         /* For on-disk compatibility, we avoid bitfields:
 158            magic: 16,        (highest)
 159            key_len_bits: 5,
 160            extra_padding: 32
 161         */
 162         uint64_t magic_and_meta;
 163         /* The bottom key_len_bits*2 are key length, rest is data length. */
 164         uint64_t key_and_data_len;
 165 };
 166
 167 static inline unsigned rec_key_bits(const struct ntdb_used_record *r)
 168 {
 169         return ((r->magic_and_meta >> 43) & ((1 << 5)-1)) * 2;
 170 }
 171
 172 static inline uint64_t rec_key_length(const struct ntdb_used_record *r)
 173 {
 174         return r->key_and_data_len & ((1ULL << rec_key_bits(r)) - 1);
 175 }
 176
 177 static inline uint64_t rec_data_length(const struct ntdb_used_record *r)
 178 {
 179         return r->key_and_data_len >> rec_key_bits(r);
 180 }
 181
 182 static inline uint64_t rec_extra_padding(const struct ntdb_used_record *r)
 183 {
 184         return (r->magic_and_meta >> 11) & 0xFFFFFFFF;
 185 }
 186
 187 static inline uint16_t rec_magic(const struct ntdb_used_record *r)
 188 {
 189         return (r->magic_and_meta >> 48);
 190 }
 191
 192 struct ntdb_free_record {
 193         uint64_t magic_and_prev; /* NTDB_OFF_UPPER_STEAL bits magic, then prev */
 194         uint64_t ftable_and_len; /* Len not counting these two fields. */
 195         /* This is why the minimum record size is 8 bytes.  */
 196         uint64_t next;
 197 };
 198
 199 static inline uint64_t frec_prev(const struct ntdb_free_record *f)
 200 {
 201         return f->magic_and_prev & ((1ULL << (64 - NTDB_OFF_UPPER_STEAL)) - 1);
 202 }
 203
 204 static inline uint64_t frec_magic(const struct ntdb_free_record *f)
 205 {
 206         return f->magic_and_prev >> (64 - NTDB_OFF_UPPER_STEAL);
 207 }
 208
 209 static inline uint64_t frec_len(const struct ntdb_free_record *f)
 210 {
 211         return f->ftable_and_len & ((1ULL << (64 - NTDB_OFF_UPPER_STEAL))-1);
 212 }
 213
 214 static inline unsigned frec_ftable(const struct ntdb_free_record *f)
 215 {
 216         return f->ftable_and_len >> (64 - NTDB_OFF_UPPER_STEAL);
 217 }
 218
 219 struct ntdb_recovery_record {
 220         uint64_t magic;
 221         /* Length of record (add this header to get total length). */
 222         uint64_t max_len;
 223         /* Length used. */
 224         uint64_t len;
 225         /* Old length of file before transaction. */
 226         uint64_t eof;
 227 };
 228
 229 /* this is stored at the front of every database */
 230 struct ntdb_header {
 231         char magic_food[64]; /* for /etc/magic */
 232         /* FIXME: Make me 32 bit? */
 233         uint64_t version; /* version of the code */
 234         uint64_t hash_bits; /* bits for toplevel hash table. */
 235         uint64_t hash_test; /* result of hashing HASH_MAGIC. */
 236         uint64_t hash_seed; /* "random" seed written at creation time. */
 237         ntdb_off_t free_table; /* (First) free table. */
 238         ntdb_off_t recovery; /* Transaction recovery area. */
 239
 240         uint64_t features_used; /* Features all writers understand */
 241         uint64_t features_offered; /* Features offered */
 242
 243         uint64_t seqnum; /* Sequence number for NTDB_SEQNUM */
 244
 245         ntdb_off_t capabilities; /* Optional linked list of capabilities. */
 246         ntdb_off_t reserved[22];
 247
 248         /*
 249          * Hash table is next:
 250          *
 251          * struct ntdb_used_record htable_hdr;
 252          * ntdb_off_t htable[1 << hash_bits];
 253          */
 254 };
 255
 256 struct ntdb_freetable {
 257         struct ntdb_used_record hdr;
 258         ntdb_off_t next;
 259         ntdb_off_t buckets[NTDB_FREE_BUCKETS];
 260 };
 261
 262 struct ntdb_capability {
 263         struct ntdb_used_record hdr;
 264         ntdb_off_t type;
 265         ntdb_off_t next;
 266         /* ... */
 267 };
 268
 269 /* Information about a particular (locked) hash entry. */
 270 struct hash_info {
 271         /* Full hash value of entry. */
 272         uint32_t h;
 273         /* Start of hash table / chain. */
 274         ntdb_off_t table;
 275         /* Number of entries in this table/chain. */
 276         ntdb_off_t table_size;
 277         /* Bucket we (or an empty space) were found in. */
 278         ntdb_off_t bucket;
 279         /* Old value that was in that entry (if not found) */
 280         ntdb_off_t old_val;
 281 };
 282
 283 enum ntdb_lock_flags {
 284         /* WAIT == F_SETLKW, NOWAIT == F_SETLK */
 285         NTDB_LOCK_NOWAIT = 0,
 286         NTDB_LOCK_WAIT = 1,
 287         /* If set, don't log an error on failure. */
 288         NTDB_LOCK_PROBE = 2,
 289         /* If set, don't check for recovery (used by recovery code). */
 290         NTDB_LOCK_NOCHECK = 4,
 291 };
 292
 293 struct ntdb_lock {
 294         struct ntdb_context *owner;
 295         off_t off;
 296         uint32_t count;
 297         uint32_t ltype;
 298 };
 299
 300 /* This is only needed for ntdb_access_commit, but used everywhere to
 301  * simplify. */
 302 struct ntdb_access_hdr {
 303         struct ntdb_access_hdr *next;
 304         ntdb_off_t off;
 305         ntdb_len_t len;
 306         bool convert;
 307 };
 308
 309 /* mmaps we are keeping around because they are still direct accessed */
 310 struct ntdb_old_mmap {
 311         struct ntdb_old_mmap *next;
 312
 313         void *map_ptr;
 314         ntdb_len_t map_size;
 315 };
 316
 317 struct ntdb_file {
 318         /* How many are sharing us? */
 319         unsigned int refcnt;
 320
 321         /* Mmap (if any), or malloc (for NTDB_INTERNAL). */
 322         void *map_ptr;
 323
 324         /* How much space has been mapped (<= current file size) */
 325         ntdb_len_t map_size;
 326
 327         /* The file descriptor (-1 for NTDB_INTERNAL). */
 328         int fd;
 329
 330         /* How many are accessing directly? */
 331         unsigned int direct_count;
 332
 333         /* Old maps, still direct accessed. */
 334         struct ntdb_old_mmap *old_mmaps;
 335
 336         /* Lock information */
 337         pid_t locker;
 338         struct ntdb_lock allrecord_lock;
 339         size_t num_lockrecs;
 340         struct ntdb_lock *lockrecs;
 341
 342         /* Identity of this file. */
 343         dev_t device;
 344         ino_t inode;
 345 };
 346
 347 struct ntdb_methods {
 348         enum NTDB_ERROR (*tread)(struct ntdb_context *, ntdb_off_t, void *,
 349                                  ntdb_len_t);
 350         enum NTDB_ERROR (*twrite)(struct ntdb_context *, ntdb_off_t, const void *,
 351                                   ntdb_len_t);
 352         enum NTDB_ERROR (*oob)(struct ntdb_context *, ntdb_off_t, ntdb_len_t, bool);
 353         enum NTDB_ERROR (*expand_file)(struct ntdb_context *, ntdb_len_t);
 354         void *(*direct)(struct ntdb_context *, ntdb_off_t, size_t, bool);
 355         ntdb_off_t (*read_off)(struct ntdb_context *ntdb, ntdb_off_t off);
 356         enum NTDB_ERROR (*write_off)(struct ntdb_context *ntdb, ntdb_off_t off,
 357                                      ntdb_off_t val);
 358 };
 359
 360 /*
 361   internal prototypes
 362 */
 363 /* Get bits from a value. */
 364 static inline uint32_t bits_from(uint64_t val, unsigned start, unsigned num)
 365 {
 366         assert(num <= 32);
 367         return (val >> start) & ((1U << num) - 1);
 368 }
 369
 370
 371 /* hash.c: */
 372 uint32_t ntdb_jenkins_hash(const void *key, size_t length, uint32_t seed,
 373                            void *unused);
 374
 375 enum NTDB_ERROR first_in_hash(struct ntdb_context *ntdb,
 376                               struct hash_info *h,
 377                               NTDB_DATA *kbuf, size_t *dlen);
 378
 379 enum NTDB_ERROR next_in_hash(struct ntdb_context *ntdb,
 380                              struct hash_info *h,
 381                              NTDB_DATA *kbuf, size_t *dlen);
 382
 383 /* Hash random memory. */
 384 uint32_t ntdb_hash(struct ntdb_context *ntdb, const void *ptr, size_t len);
 385
 386 /* Find and lock a hash entry (or where it would be). */
 387 ntdb_off_t find_and_lock(struct ntdb_context *ntdb,
 388                          NTDB_DATA key,
 389                          int ltype,
 390                          struct hash_info *h,
 391                          struct ntdb_used_record *rec,
 392                          const char **rkey);
 393
 394 enum NTDB_ERROR replace_in_hash(struct ntdb_context *ntdb,
 395                                 const struct hash_info *h,
 396                                 ntdb_off_t new_off);
 397
 398 enum NTDB_ERROR add_to_hash(struct ntdb_context *ntdb,
 399                             const struct hash_info *h,
 400                             ntdb_off_t new_off);
 401
 402 enum NTDB_ERROR delete_from_hash(struct ntdb_context *ntdb,
 403                                  const struct hash_info *h);
 404
 405 /* For ntdb_check */
 406 bool is_subhash(ntdb_off_t val);
 407 enum NTDB_ERROR unknown_capability(struct ntdb_context *ntdb, const char *caller,
 408                                    ntdb_off_t type);
 409
 410 /* free.c: */
 411 enum NTDB_ERROR ntdb_ftable_init(struct ntdb_context *ntdb);
 412
 413 /* check.c needs these to iterate through free lists. */
 414 ntdb_off_t first_ftable(struct ntdb_context *ntdb);
 415 ntdb_off_t next_ftable(struct ntdb_context *ntdb, ntdb_off_t ftable);
 416
 417 /* This returns space or -ve error number. */
 418 ntdb_off_t alloc(struct ntdb_context *ntdb, size_t keylen, size_t datalen,
 419                  unsigned magic, bool growing);
 420
 421 /* Put this record in a free list. */
 422 enum NTDB_ERROR add_free_record(struct ntdb_context *ntdb,
 423                                 ntdb_off_t off, ntdb_len_t len_with_header,
 424                                 enum ntdb_lock_flags waitflag,
 425                                 bool coalesce_ok);
 426
 427 /* Set up header for a used/ftable/htable/chain/capability record. */
 428 enum NTDB_ERROR set_header(struct ntdb_context *ntdb,
 429                            struct ntdb_used_record *rec,
 430                            unsigned magic, uint64_t keylen, uint64_t datalen,
 431                            uint64_t actuallen);
 432
 433 /* Used by ntdb_check to verify. */
 434 unsigned int size_to_bucket(ntdb_len_t data_len);
 435 ntdb_off_t bucket_off(ntdb_off_t ftable_off, unsigned bucket);
 436
 437 /* Used by ntdb_summary */
 438 ntdb_off_t dead_space(struct ntdb_context *ntdb, ntdb_off_t off);
 439
 440 /* Adjust expansion, used by create_recovery_area */
 441 ntdb_off_t ntdb_expand_adjust(ntdb_off_t map_size, ntdb_off_t size);
 442
 443 /* io.c: */
 444 /* Initialize ntdb->methods. */
 445 void ntdb_io_init(struct ntdb_context *ntdb);
 446
 447 /* Convert endian of the buffer if required. */
 448 void *ntdb_convert(const struct ntdb_context *ntdb, void *buf, ntdb_len_t size);
 449
 450 /* Unmap and try to map the ntdb. */
 451 enum NTDB_ERROR ntdb_munmap(struct ntdb_context *ntdb);
 452 enum NTDB_ERROR ntdb_mmap(struct ntdb_context *ntdb);
 453
 454 /* Either alloc a copy, or give direct access.  Release frees or noop. */
 455 const void *ntdb_access_read(struct ntdb_context *ntdb,
 456                              ntdb_off_t off, ntdb_len_t len, bool convert);
 457 void *ntdb_access_write(struct ntdb_context *ntdb,
 458                         ntdb_off_t off, ntdb_len_t len, bool convert);
 459
 460 /* Release result of ntdb_access_read/write. */
 461 void ntdb_access_release(struct ntdb_context *ntdb, const void *p);
 462 /* Commit result of ntdb_acces_write. */
 463 enum NTDB_ERROR ntdb_access_commit(struct ntdb_context *ntdb, void *p);
 464
 465 /* Clear an ondisk area. */
 466 enum NTDB_ERROR zero_out(struct ntdb_context *ntdb, ntdb_off_t off, ntdb_len_t len);
 467
 468 /* Return a non-zero offset between >= start < end in this array (or end). */
 469 ntdb_off_t ntdb_find_nonzero_off(struct ntdb_context *ntdb,
 470                                  ntdb_off_t base,
 471                                  uint64_t start,
 472                                  uint64_t end);
 473
 474 /* Return a zero offset in this array, or num. */
 475 ntdb_off_t ntdb_find_zero_off(struct ntdb_context *ntdb, ntdb_off_t off,
 476                               uint64_t num);
 477
 478 /* Allocate and make a copy of some offset. */
 479 void *ntdb_alloc_read(struct ntdb_context *ntdb, ntdb_off_t offset, ntdb_len_t len);
 480
 481 /* Writes a converted copy of a record. */
 482 enum NTDB_ERROR ntdb_write_convert(struct ntdb_context *ntdb, ntdb_off_t off,
 483                                    const void *rec, size_t len);
 484
 485 /* Reads record and converts it */
 486 enum NTDB_ERROR ntdb_read_convert(struct ntdb_context *ntdb, ntdb_off_t off,
 487                                   void *rec, size_t len);
 488
 489 /* Bump the seqnum (caller checks for ntdb->flags & NTDB_SEQNUM) */
 490 void ntdb_inc_seqnum(struct ntdb_context *ntdb);
 491
 492 /* lock.c: */
 493 /* Print message because another ntdb owns a lock we want. */
 494 enum NTDB_ERROR owner_conflict(struct ntdb_context *ntdb, const char *call);
 495
 496 /* If we fork, we no longer really own locks. */
 497 bool check_lock_pid(struct ntdb_context *ntdb, const char *call, bool log);
 498
 499 /* Lock/unlock a hash bucket. */
 500 enum NTDB_ERROR ntdb_lock_hash(struct ntdb_context *ntdb,
 501                                unsigned int hbucket,
 502                                int ltype);
 503 enum NTDB_ERROR ntdb_unlock_hash(struct ntdb_context *ntdb,
 504                                  unsigned int hash, int ltype);
 505
 506 /* For closing the file. */
 507 void ntdb_lock_cleanup(struct ntdb_context *ntdb);
 508
 509 /* Lock/unlock a particular free bucket. */
 510 enum NTDB_ERROR ntdb_lock_free_bucket(struct ntdb_context *ntdb, ntdb_off_t b_off,
 511                                       enum ntdb_lock_flags waitflag);
 512 void ntdb_unlock_free_bucket(struct ntdb_context *ntdb, ntdb_off_t b_off);
 513
 514 /* Serialize transaction start. */
 515 enum NTDB_ERROR ntdb_transaction_lock(struct ntdb_context *ntdb, int ltype);
 516 void ntdb_transaction_unlock(struct ntdb_context *ntdb, int ltype);
 517
 518 /* Do we have any hash locks (ie. via ntdb_chainlock) ? */
 519 bool ntdb_has_hash_locks(struct ntdb_context *ntdb);
 520
 521 /* Lock entire database. */
 522 enum NTDB_ERROR ntdb_allrecord_lock(struct ntdb_context *ntdb, int ltype,
 523                                     enum ntdb_lock_flags flags, bool upgradable);
 524 void ntdb_allrecord_unlock(struct ntdb_context *ntdb, int ltype);
 525 enum NTDB_ERROR ntdb_allrecord_upgrade(struct ntdb_context *ntdb, off_t start);
 526
 527 /* Serialize db open. */
 528 enum NTDB_ERROR ntdb_lock_open(struct ntdb_context *ntdb,
 529                                int ltype, enum ntdb_lock_flags flags);
 530 void ntdb_unlock_open(struct ntdb_context *ntdb, int ltype);
 531 bool ntdb_has_open_lock(struct ntdb_context *ntdb);
 532
 533 /* Serialize db expand. */
 534 enum NTDB_ERROR ntdb_lock_expand(struct ntdb_context *ntdb, int ltype);
 535 void ntdb_unlock_expand(struct ntdb_context *ntdb, int ltype);
 536 bool ntdb_has_expansion_lock(struct ntdb_context *ntdb);
 537
 538 /* If it needs recovery, grab all the locks and do it. */
 539 enum NTDB_ERROR ntdb_lock_and_recover(struct ntdb_context *ntdb);
 540
 541 /* Default lock and unlock functions. */
 542 int ntdb_fcntl_lock(int fd, int rw, off_t off, off_t len, bool waitflag, void *);
 543 int ntdb_fcntl_unlock(int fd, int rw, off_t off, off_t len, void *);
 544
 545 /* transaction.c: */
 546 enum NTDB_ERROR ntdb_transaction_recover(struct ntdb_context *ntdb);
 547 ntdb_bool_err ntdb_needs_recovery(struct ntdb_context *ntdb);
 548
 549 struct ntdb_context {
 550         /* Single list of all TDBs, to detect multiple opens. */
 551         struct ntdb_context *next;
 552
 553         /* Filename of the database. */
 554         const char *name;
 555
 556         /* Logging function */
 557         void (*log_fn)(struct ntdb_context *ntdb,
 558                        enum ntdb_log_level level,
 559                        enum NTDB_ERROR ecode,
 560                        const char *message,
 561                        void *data);
 562         void *log_data;
 563
 564         /* Open flags passed to ntdb_open. */
 565         int open_flags;
 566
 567         /* low level (fnctl) lock functions. */
 568         int (*lock_fn)(int fd, int rw, off_t off, off_t len, bool w, void *);
 569         int (*unlock_fn)(int fd, int rw, off_t off, off_t len, void *);
 570         void *lock_data;
 571
 572         /* the ntdb flags passed to ntdb_open. */
 573         uint32_t flags;
 574
 575         /* Our statistics. */
 576         struct ntdb_attribute_stats stats;
 577
 578         /* The actual file information */
 579         struct ntdb_file *file;
 580
 581         /* Hash function. */
 582         uint32_t (*hash_fn)(const void *key, size_t len, uint32_t seed, void *);
 583         void *hash_data;
 584         uint32_t hash_seed;
 585         /* Bits in toplevel hash table. */
 586         unsigned int hash_bits;
 587
 588         /* Allocate and free functions. */
 589         void *(*alloc_fn)(const void *owner, size_t len, void *priv_data);
 590         void *(*expand_fn)(void *old, size_t newlen, void *priv_data);
 591         void (*free_fn)(void *old, void *priv_data);
 592         void *alloc_data;
 593
 594         /* Our open hook, if any. */
 595         enum NTDB_ERROR (*openhook)(int fd, void *data);
 596         void *openhook_data;
 597
 598         /* Set if we are in a transaction. */
 599         struct ntdb_transaction *transaction;
 600
 601         /* What free table are we using? */
 602         ntdb_off_t ftable_off;
 603         unsigned int ftable;
 604
 605         /* IO methods: changes for transactions. */
 606         const struct ntdb_methods *io;
 607
 608         /* Direct access information */
 609         struct ntdb_access_hdr *access;
 610 };
 611
 612 /* ntdb.c: */
 613 enum NTDB_ERROR COLD PRINTF_FMT(4, 5)
 614         ntdb_logerr(struct ntdb_context *ntdb,
 615                     enum NTDB_ERROR ecode,
 616                     enum ntdb_log_level level,
 617                     const char *fmt, ...);
 618
 619 static inline enum NTDB_ERROR ntdb_oob(struct ntdb_context *ntdb,
 620                                        ntdb_off_t off, ntdb_len_t len,
 621                                        bool probe)
 622 {
 623         if (likely(off + len >= off)
 624             && likely(off + len <= ntdb->file->map_size)
 625             && likely(!probe)) {
 626                     return NTDB_SUCCESS;
 627         }
 628         return ntdb->io->oob(ntdb, off, len, probe);
 629 }
 630
 631 /* Convenience routine to get an offset. */
 632 static inline ntdb_off_t ntdb_read_off(struct ntdb_context *ntdb,
 633                                        ntdb_off_t off)
 634 {
 635         return ntdb->io->read_off(ntdb, off);
 636 }
 637
 638 /* Write an offset at an offset. */
 639 static inline enum NTDB_ERROR ntdb_write_off(struct ntdb_context *ntdb,
 640                                              ntdb_off_t off,
 641                                ntdb_off_t val)
 642 {
 643         return ntdb->io->write_off(ntdb, off, val);
 644 }
 645
 646 #ifdef NTDB_TRACE
 647 void ntdb_trace(struct ntdb_context *ntdb, const char *op);
 648 void ntdb_trace_seqnum(struct ntdb_context *ntdb, uint32_t seqnum, const char *op);
 649 void ntdb_trace_open(struct ntdb_context *ntdb, const char *op,
 650                      unsigned hash_size, unsigned ntdb_flags, unsigned open_flags);
 651 void ntdb_trace_ret(struct ntdb_context *ntdb, const char *op, int ret);
 652 void ntdb_trace_retrec(struct ntdb_context *ntdb, const char *op, NTDB_DATA ret);
 653 void ntdb_trace_1rec(struct ntdb_context *ntdb, const char *op,
 654                      NTDB_DATA rec);
 655 void ntdb_trace_1rec_ret(struct ntdb_context *ntdb, const char *op,
 656                          NTDB_DATA rec, int ret);
 657 void ntdb_trace_1rec_retrec(struct ntdb_context *ntdb, const char *op,
 658                             NTDB_DATA rec, NTDB_DATA ret);
 659 void ntdb_trace_2rec_flag_ret(struct ntdb_context *ntdb, const char *op,
 660                               NTDB_DATA rec1, NTDB_DATA rec2, unsigned flag,
 661                               int ret);
 662 void ntdb_trace_2rec_retrec(struct ntdb_context *ntdb, const char *op,
 663                             NTDB_DATA rec1, NTDB_DATA rec2, NTDB_DATA ret);
 664 #else
 665 #define ntdb_trace(ntdb, op)
 666 #define ntdb_trace_seqnum(ntdb, seqnum, op)
 667 #define ntdb_trace_open(ntdb, op, hash_size, ntdb_flags, open_flags)
 668 #define ntdb_trace_ret(ntdb, op, ret)
 669 #define ntdb_trace_retrec(ntdb, op, ret)
 670 #define ntdb_trace_1rec(ntdb, op, rec)
 671 #define ntdb_trace_1rec_ret(ntdb, op, rec, ret)
 672 #define ntdb_trace_1rec_retrec(ntdb, op, rec, ret)
 673 #define ntdb_trace_2rec_flag_ret(ntdb, op, rec1, rec2, flag, ret)
 674 #define ntdb_trace_2rec_retrec(ntdb, op, rec1, rec2, ret)
 675 #endif /* !NTDB_TRACE */
 676
 677 #endif