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Comparing BDB/BDB.pm (file contents):
Revision 1.42 by root, Wed Jul 9 12:53:46 2008 UTC vs.
Revision 1.67 by root, Tue Feb 2 04:07:06 2016 UTC

… …
27 db_sync $db; 27 db_sync $db;
28 28
29 # when you also use Coro, management is easy: 29 # when you also use Coro, management is easy:
30 use Coro::BDB; 30 use Coro::BDB;
31 31
32 # automatic event loop intergration with AnyEvent: 32 # automatic event loop integration with AnyEvent:
33 use AnyEvent::BDB; 33 use AnyEvent::BDB;
34 34
35 # automatic result processing with EV: 35 # automatic result processing with EV:
36 my $WATCHER = EV::io BDB::poll_fileno, EV::READ, \&BDB::poll_cb; 36 my $WATCHER = EV::io BDB::poll_fileno, EV::READ, \&BDB::poll_cb;
37 37
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103 103
104=cut 104=cut
105 105
106package BDB; 106package BDB;
107 107
108no warnings; 108use common::sense;
109use strict 'vars';
110 109
111use base 'Exporter'; 110use base 'Exporter';
112 111
112our $VERSION;
113
113BEGIN { 114BEGIN {
114 our $VERSION = '1.7'; 115 $VERSION = '1.91';
115 116
116 our @BDB_REQ = qw( 117 our @BDB_REQ = qw(
117 db_env_open db_env_close db_env_txn_checkpoint db_env_lock_detect 118 db_env_open db_env_close db_env_txn_checkpoint db_env_lock_detect
118 db_env_memp_sync db_env_memp_trickle db_env_dbrename db_env_dbremove 119 db_env_memp_sync db_env_memp_trickle db_env_dbrename db_env_dbremove
120 db_env_log_archive db_env_reset_lsn
119 db_open db_close db_compact db_sync db_upgrade 121 db_open db_close db_compact db_sync db_verify db_upgrade
120 db_put db_get db_pget db_del db_key_range 122 db_put db_exists db_get db_pget db_del db_key_range
121 db_txn_commit db_txn_abort db_txn_finish 123 db_txn_commit db_txn_abort db_txn_finish
122 db_c_close db_c_count db_c_put db_c_get db_c_pget db_c_del 124 db_c_close db_c_count db_c_put db_c_get db_c_pget db_c_del
123 db_sequence_open db_sequence_close 125 db_sequence_open db_sequence_close
124 db_sequence_get db_sequence_remove 126 db_sequence_get db_sequence_remove
125 ); 127 );
… …
133 135
134 require XSLoader; 136 require XSLoader;
135 XSLoader::load ("BDB", $VERSION); 137 XSLoader::load ("BDB", $VERSION);
136} 138}
137 139
138=head2 WIN32 FILENAMES/DATABASE NAME MESS
139
140Perl on Win32 supports only ASCII filenames (the reason is that it abuses
141an internal flag to store wether a filename is Unicode or ANSI, but that
142flag is used for somethign else in the perl core, so there is no way to
143detect wether a filename is ANSI or Unicode-encoded). The BDB module
144tries to work around this issue by assuming that the filename is an ANSI
145filename and BDB was built for unicode support.
146
147=head2 BERKELEYDB FUNCTIONS 140=head1 BERKELEYDB FUNCTIONS
148 141
149All of these are functions. The create functions simply return a new 142All of these are functions. The create functions simply return a new
150object and never block. All the remaining functions take an optional 143object and never block. All the remaining functions take an optional
151callback as last argument. If it is missing, then the function will be 144callback as last argument. If it is missing, then the function will be
152executed synchronously. In both cases, C<$!> will reflect the return value 145executed synchronously. In both cases, C<$!> will reflect the return value
… …
191 184
192 db_env_txn_checkpoint $db_env, 0, 0, 0, undef; 185 db_env_txn_checkpoint $db_env, 0, 0, 0, undef;
193 db_env_txn_checkpoint $db_env, 0, 0, 0; 186 db_env_txn_checkpoint $db_env, 0, 0, 0;
194 db_env_txn_checkpoint $db_env, 0; 187 db_env_txn_checkpoint $db_env, 0;
195 188
196=head3 BDB functions 189=head2 BDB functions
197 190
198Functions in the BDB namespace, exported by default: 191Functions in the BDB namespace, exported by default:
199 192
200 $env = db_env_create (U32 env_flags = 0) 193 $env = db_env_create (U32 env_flags = 0)
201 flags: RPCCLIENT 194 flags: RPCCLIENT
202 195
203 db_env_open (DB_ENV *env, bdb_filename db_home, U32 open_flags, int mode, SV *callback = &PL_sv_undef) 196 db_env_open (DB_ENV *env, bdb_filename db_home, U32 open_flags, int mode, SV *callback = 0)
204 open_flags: INIT_CDB INIT_LOCK INIT_LOG INIT_MPOOL INIT_REP INIT_TXN RECOVER RECOVER_FATAL USE_ENVIRON USE_ENVIRON_ROOT CREATE LOCKDOWN PRIVATE REGISTER SYSTEM_MEM 197 open_flags: INIT_CDB INIT_LOCK INIT_LOG INIT_MPOOL INIT_REP INIT_TXN RECOVER RECOVER_FATAL USE_ENVIRON USE_ENVIRON_ROOT CREATE LOCKDOWN PRIVATE REGISTER SYSTEM_MEM
205 db_env_close (DB_ENV *env, U32 flags = 0, SV *callback = &PL_sv_undef) 198 db_env_close (DB_ENV *env, U32 flags = 0, SV *callback = 0)
206 db_env_txn_checkpoint (DB_ENV *env, U32 kbyte = 0, U32 min = 0, U32 flags = 0, SV *callback = &PL_sv_undef) 199 db_env_txn_checkpoint (DB_ENV *env, U32 kbyte = 0, U32 min = 0, U32 flags = 0, SV *callback = 0)
207 flags: FORCE 200 flags: FORCE
208 db_env_lock_detect (DB_ENV *env, U32 flags = 0, U32 atype = DB_LOCK_DEFAULT, SV *dummy = 0, SV *callback = &PL_sv_undef) 201 db_env_lock_detect (DB_ENV *env, U32 flags = 0, U32 atype = DB_LOCK_DEFAULT, SV *dummy = 0, SV *callback = 0)
209 atype: LOCK_DEFAULT LOCK_EXPIRE LOCK_MAXLOCKS LOCK_MAXWRITE LOCK_MINLOCKS LOCK_MINWRITE LOCK_OLDEST LOCK_RANDOM LOCK_YOUNGEST 202 atype: LOCK_DEFAULT LOCK_EXPIRE LOCK_MAXLOCKS LOCK_MAXWRITE LOCK_MINLOCKS LOCK_MINWRITE LOCK_OLDEST LOCK_RANDOM LOCK_YOUNGEST
210 db_env_memp_sync (DB_ENV *env, SV *dummy = 0, SV *callback = &PL_sv_undef) 203 db_env_memp_sync (DB_ENV *env, SV *dummy = 0, SV *callback = 0)
211 db_env_memp_trickle (DB_ENV *env, int percent, SV *dummy = 0, SV *callback = &PL_sv_undef) 204 db_env_memp_trickle (DB_ENV *env, int percent, SV *dummy = 0, SV *callback = 0)
212 db_env_dbremove (DB_ENV *env, DB_TXN_ornull *txnid, bdb_filename file, bdb_filename database, U32 flags = 0, SV *callback = &PL_sv_undef) 205 db_env_dbremove (DB_ENV *env, DB_TXN_ornull *txnid, bdb_filename file, bdb_filename database, U32 flags = 0, SV *callback = 0)
213 db_env_dbrename (DB_ENV *env, DB_TXN_ornull *txnid, bdb_filename file, bdb_filename database, bdb_filename newname, U32 flags = 0, SV *callback = &PL_sv_undef) 206 db_env_dbrename (DB_ENV *env, DB_TXN_ornull *txnid, bdb_filename file, bdb_filename database, bdb_filename newname, U32 flags = 0, SV *callback = 0)
207 db_env_log_archive (DB_ENV *env, SV *listp, U32 flags = 0, SV *callback = 0)
208 db_env_lsn_reset (DB_ENV *env, bdb_filename db, U32 flags = 0, SV *callback = 0)
214 209
215 $db = db_create (DB_ENV *env = 0, U32 flags = 0) 210 $db = db_create (DB_ENV *env = 0, U32 flags = 0)
216 flags: XA_CREATE 211 flags: XA_CREATE
217 212
218 db_open (DB *db, DB_TXN_ornull *txnid, bdb_filename file, bdb_filename database, int type, U32 flags, int mode, SV *callback = &PL_sv_undef) 213 db_open (DB *db, DB_TXN_ornull *txnid, bdb_filename file, bdb_filename database, int type, U32 flags, int mode, SV *callback = 0)
219 flags: AUTO_COMMIT CREATE EXCL MULTIVERSION NOMMAP RDONLY READ_UNCOMMITTED THREAD TRUNCATE 214 flags: AUTO_COMMIT CREATE EXCL MULTIVERSION NOMMAP RDONLY READ_UNCOMMITTED THREAD TRUNCATE
220 db_close (DB *db, U32 flags = 0, SV *callback = &PL_sv_undef) 215 db_close (DB *db, U32 flags = 0, SV *callback = 0)
221 flags: DB_NOSYNC 216 flags: DB_NOSYNC
217 db_verify (DB *db, bdb_filename file, bdb_filename database = 0, SV *dummy = 0, U32 flags = 0, SV *callback = 0)
222 db_upgrade (DB *db, bdb_filename file, U32 flags = 0, SV *callback = &PL_sv_undef) 218 db_upgrade (DB *db, bdb_filename file, U32 flags = 0, SV *callback = 0)
223 db_compact (DB *db, DB_TXN_ornull *txn = 0, SV *start = 0, SV *stop = 0, SV *unused1 = 0, U32 flags = DB_FREE_SPACE, SV *unused2 = 0, SV *callback = &PL_sv_undef) 219 db_compact (DB *db, DB_TXN_ornull *txn = 0, SV *start = 0, SV *stop = 0, SV *unused1 = 0, U32 flags = DB_FREE_SPACE, SV *unused2 = 0, SV *callback = 0)
224 flags: FREELIST_ONLY FREE_SPACE 220 flags: FREELIST_ONLY FREE_SPACE
225 db_sync (DB *db, U32 flags = 0, SV *callback = &PL_sv_undef) 221 db_sync (DB *db, U32 flags = 0, SV *callback = 0)
226 db_key_range (DB *db, DB_TXN_ornull *txn, SV *key, SV *key_range, U32 flags = 0, SV *callback = &PL_sv_undef) 222 db_key_range (DB *db, DB_TXN_ornull *txn, SV *key, SV *key_range, U32 flags = 0, SV *callback = 0)
227 db_put (DB *db, DB_TXN_ornull *txn, SV *key, SV *data, U32 flags = 0, SV *callback = &PL_sv_undef) 223 db_put (DB *db, DB_TXN_ornull *txn, SV *key, SV *data, U32 flags = 0, SV *callback = 0)
228 flags: APPEND NODUPDATA NOOVERWRITE 224 flags: APPEND NODUPDATA NOOVERWRITE
225 db_exists (DB *db, DB_TXN_ornull *txn, SV *key, U32 flags = 0, SV *callback = 0) (v4.6)
229 db_get (DB *db, DB_TXN_ornull *txn, SV *key, SV *data, U32 flags = 0, SV *callback = &PL_sv_undef) 226 db_get (DB *db, DB_TXN_ornull *txn, SV *key, SV *data, U32 flags = 0, SV *callback = 0)
230 flags: CONSUME CONSUME_WAIT GET_BOTH SET_RECNO MULTIPLE READ_COMMITTED READ_UNCOMMITTED RMW 227 flags: CONSUME CONSUME_WAIT GET_BOTH SET_RECNO MULTIPLE READ_COMMITTED READ_UNCOMMITTED RMW
231 db_pget (DB *db, DB_TXN_ornull *txn, SV *key, SV *pkey, SV *data, U32 flags = 0, SV *callback = &PL_sv_undef) 228 db_pget (DB *db, DB_TXN_ornull *txn, SV *key, SV *pkey, SV *data, U32 flags = 0, SV *callback = 0)
232 flags: CONSUME CONSUME_WAIT GET_BOTH SET_RECNO MULTIPLE READ_COMMITTED READ_UNCOMMITTED RMW 229 flags: CONSUME CONSUME_WAIT GET_BOTH SET_RECNO MULTIPLE READ_COMMITTED READ_UNCOMMITTED RMW
233 db_del (DB *db, DB_TXN_ornull *txn, SV *key, U32 flags = 0, SV *callback = &PL_sv_undef) 230 db_del (DB *db, DB_TXN_ornull *txn, SV *key, U32 flags = 0, SV *callback = 0)
234 db_txn_commit (DB_TXN *txn, U32 flags = 0, SV *callback = &PL_sv_undef) 231 db_txn_commit (DB_TXN *txn, U32 flags = 0, SV *callback = 0)
235 flags: TXN_NOSYNC TXN_SYNC 232 flags: TXN_NOSYNC TXN_SYNC
236 db_txn_abort (DB_TXN *txn, SV *callback = &PL_sv_undef) 233 db_txn_abort (DB_TXN *txn, SV *callback = 0)
237 234
238 db_c_close (DBC *dbc, SV *callback = &PL_sv_undef) 235 db_c_close (DBC *dbc, SV *callback = 0)
239 db_c_count (DBC *dbc, SV *count, U32 flags = 0, SV *callback = &PL_sv_undef) 236 db_c_count (DBC *dbc, SV *count, U32 flags = 0, SV *callback = 0)
240 db_c_put (DBC *dbc, SV *key, SV *data, U32 flags = 0, SV *callback = &PL_sv_undef) 237 db_c_put (DBC *dbc, SV *key, SV *data, U32 flags = 0, SV *callback = 0)
241 flags: AFTER BEFORE CURRENT KEYFIRST KEYLAST NODUPDATA 238 flags: AFTER BEFORE CURRENT KEYFIRST KEYLAST NODUPDATA
242 db_c_get (DBC *dbc, SV *key, SV *data, U32 flags = 0, SV *callback = &PL_sv_undef) 239 db_c_get (DBC *dbc, SV *key, SV *data, U32 flags = 0, SV *callback = 0)
243 flags: CURRENT FIRST GET_BOTH GET_BOTH_RANGE GET_RECNO JOIN_ITEM LAST NEXT NEXT_DUP NEXT_NODUP PREV PREV_DUP PREV_NODUP SET SET_RANGE SET_RECNO READ_UNCOMMITTED MULTIPLE MULTIPLE_KEY RMW 240 flags: CURRENT FIRST GET_BOTH GET_BOTH_RANGE GET_RECNO JOIN_ITEM LAST NEXT NEXT_DUP NEXT_NODUP PREV PREV_DUP PREV_NODUP SET SET_RANGE SET_RECNO READ_UNCOMMITTED MULTIPLE MULTIPLE_KEY RMW
244 db_c_pget (DBC *dbc, SV *key, SV *pkey, SV *data, U32 flags = 0, SV *callback = &PL_sv_undef) 241 db_c_pget (DBC *dbc, SV *key, SV *pkey, SV *data, U32 flags = 0, SV *callback = 0)
245 db_c_del (DBC *dbc, U32 flags = 0, SV *callback = &PL_sv_undef) 242 db_c_del (DBC *dbc, U32 flags = 0, SV *callback = 0)
246 243
247 db_sequence_open (DB_SEQUENCE *seq, DB_TXN_ornull *txnid, SV *key, U32 flags = 0, SV *callback = &PL_sv_undef) 244 db_sequence_open (DB_SEQUENCE *seq, DB_TXN_ornull *txnid, SV *key, U32 flags = 0, SV *callback = 0)
248 flags: CREATE EXCL 245 flags: CREATE EXCL
249 db_sequence_close (DB_SEQUENCE *seq, U32 flags = 0, SV *callback = &PL_sv_undef) 246 db_sequence_close (DB_SEQUENCE *seq, U32 flags = 0, SV *callback = 0)
250 db_sequence_get (DB_SEQUENCE *seq, DB_TXN_ornull *txnid, int delta, SV *seq_value, U32 flags = DB_TXN_NOSYNC, SV *callback = &PL_sv_undef) 247 db_sequence_get (DB_SEQUENCE *seq, DB_TXN_ornull *txnid, int delta, SV *seq_value, U32 flags = DB_TXN_NOSYNC, SV *callback = 0)
251 flags: TXN_NOSYNC 248 flags: TXN_NOSYNC
252 db_sequence_remove (DB_SEQUENCE *seq, DB_TXN_ornull *txnid = 0, U32 flags = 0, SV *callback = &PL_sv_undef) 249 db_sequence_remove (DB_SEQUENCE *seq, DB_TXN_ornull *txnid = 0, U32 flags = 0, SV *callback = 0)
253 flags: TXN_NOSYNC 250 flags: TXN_NOSYNC
254 251
255=head4 db_txn_finish (DB_TXN *txn, U32 flags = 0, SV *callback = &PL_sv_undef) 252=head3 db_txn_finish (DB_TXN *txn, U32 flags = 0, SV *callback = 0)
256 253
257This is not actually a Berkeley DB function but a BDB module 254This is not actually a Berkeley DB function but a BDB module
258extension. The background for this exytension is: It is very annoying to 255extension. The background for this exytension is: It is very annoying to
259have to check every single BDB function for error returns and provide a 256have to check every single BDB function for error returns and provide a
260codepath out of your transaction. While the BDB module still makes this 257codepath out of your transaction. While the BDB module still makes this
… …
286 283
287You can use the C<< $txn->failed >> method to check wether a transaction 284You can use the C<< $txn->failed >> method to check wether a transaction
288has failed in this way and abort further processing (excluding 285has failed in this way and abort further processing (excluding
289C<db_txn_finish>). 286C<db_txn_finish>).
290 287
288
291=head3 DB_ENV/database environment methods 289=head2 DB_ENV/database environment methods
292 290
293Methods available on DB_ENV/$env handles: 291Methods available on DB_ENV/$env handles:
294 292
295 DESTROY (DB_ENV_ornull *env) 293 DESTROY (DB_ENV_ornull *env)
296 CODE: 294 CODE:
… …
301 $int = $env->set_tmp_dir (const char *dir) 299 $int = $env->set_tmp_dir (const char *dir)
302 $int = $env->set_lg_dir (const char *dir) 300 $int = $env->set_lg_dir (const char *dir)
303 $int = $env->set_shm_key (long shm_key) 301 $int = $env->set_shm_key (long shm_key)
304 $int = $env->set_cachesize (U32 gbytes, U32 bytes, int ncache = 0) 302 $int = $env->set_cachesize (U32 gbytes, U32 bytes, int ncache = 0)
305 $int = $env->set_flags (U32 flags, int onoff = 1) 303 $int = $env->set_flags (U32 flags, int onoff = 1)
306 $int = $env->log_set_config (U32 flags, int onoff = 1) [v4.7] 304 $int = $env->log_set_config (U32 flags, int onoff = 1) (v4.7)
307 $int = $env->set_intermediate_dir_mode (const char *modestring) [v4.7] 305 $int = $env->set_intermediate_dir_mode (const char *modestring) (v4.7)
308 $env->set_errfile (FILE *errfile = 0) 306 $env->set_errfile (FILE *errfile = 0)
309 $env->set_msgfile (FILE *msgfile = 0) 307 $env->set_msgfile (FILE *msgfile = 0)
310 $int = $env->set_verbose (U32 which, int onoff = 1) 308 $int = $env->set_verbose (U32 which, int onoff = 1)
311 $int = $env->set_encrypt (const char *password, U32 flags = 0) 309 $int = $env->set_encrypt (const char *password, U32 flags = 0)
312 $int = $env->set_timeout (NV timeout_seconds, U32 flags = SET_TXN_TIMEOUT) 310 $int = $env->set_timeout (NV timeout_seconds, U32 flags = SET_TXN_TIMEOUT)
… …
324 $int = $env->mutex_set_max (U32 max) 322 $int = $env->mutex_set_max (U32 max)
325 $int = $env->mutex_set_align (U32 align) 323 $int = $env->mutex_set_align (U32 align)
326 324
327 $txn = $env->txn_begin (DB_TXN_ornull *parent = 0, U32 flags = 0) 325 $txn = $env->txn_begin (DB_TXN_ornull *parent = 0, U32 flags = 0)
328 flags: READ_COMMITTED READ_UNCOMMITTED TXN_NOSYNC TXN_NOWAIT TXN_SNAPSHOT TXN_SYNC TXN_WAIT TXN_WRITE_NOSYNC 326 flags: READ_COMMITTED READ_UNCOMMITTED TXN_NOSYNC TXN_NOWAIT TXN_SNAPSHOT TXN_SYNC TXN_WAIT TXN_WRITE_NOSYNC
327 $txn = $env->cdsgroup_begin; (v4.5)
329 328
330=head4 Example: 329=head3 Example:
331 330
332 use AnyEvent; 331 use AnyEvent;
333 use BDB; 332 use BDB;
334 333
335 our $FH; open $FH, "<&=" . BDB::poll_fileno; 334 our $FH; open $FH, "<&=" . BDB::poll_fileno;
… …
347 0600; 346 0600;
348 347
349 $env->set_flags (BDB::AUTO_COMMIT | BDB::TXN_NOSYNC, 1); 348 $env->set_flags (BDB::AUTO_COMMIT | BDB::TXN_NOSYNC, 1);
350 349
351 350
352=head3 DB/database methods 351=head2 DB/database methods
353 352
354Methods available on DB/$db handles: 353Methods available on DB/$db handles:
355 354
356 DESTROY (DB_ornull *db) 355 DESTROY (DB_ornull *db)
357 CODE: 356 CODE:
… …
383 382
384 $dbc = $db->cursor (DB_TXN_ornull *txn = 0, U32 flags = 0) 383 $dbc = $db->cursor (DB_TXN_ornull *txn = 0, U32 flags = 0)
385 flags: READ_COMMITTED READ_UNCOMMITTED WRITECURSOR TXN_SNAPSHOT 384 flags: READ_COMMITTED READ_UNCOMMITTED WRITECURSOR TXN_SNAPSHOT
386 $seq = $db->sequence (U32 flags = 0) 385 $seq = $db->sequence (U32 flags = 0)
387 386
388=head4 Example: 387=head3 Example:
389 388
390 my $db = db_create $env; 389 my $db = db_create $env;
391 db_open $db, undef, "table", undef, BDB::BTREE, BDB::AUTO_COMMIT | BDB::CREATE | BDB::READ_UNCOMMITTED, 0600; 390 db_open $db, undef, "table", undef, BDB::BTREE, BDB::AUTO_COMMIT | BDB::CREATE | BDB::READ_UNCOMMITTED, 0600;
392 391
393 for (1..1000) { 392 for (1..1000) {
… …
400 db_del $db, undef, "key $_" for 1..1000; 399 db_del $db, undef, "key $_" for 1..1000;
401 400
402 db_sync $db; 401 db_sync $db;
403 402
404 403
405=head3 DB_TXN/transaction methods 404=head2 DB_TXN/transaction methods
406 405
407Methods available on DB_TXN/$txn handles: 406Methods available on DB_TXN/$txn handles:
408 407
409 DESTROY (DB_TXN_ornull *txn) 408 DESTROY (DB_TXN_ornull *txn)
410 CODE: 409 CODE:
… …
416 415
417 $bool = $txn->failed 416 $bool = $txn->failed
418 # see db_txn_finish documentation, above 417 # see db_txn_finish documentation, above
419 418
420 419
421=head3 DBC/cursor methods 420=head2 DBC/cursor methods
422 421
423Methods available on DBC/$dbc handles: 422Methods available on DBC/$dbc handles:
424 423
425 DESTROY (DBC_ornull *dbc) 424 DESTROY (DBC_ornull *dbc)
426 CODE: 425 CODE:
427 if (dbc) 426 if (dbc)
428 dbc->c_close (dbc); 427 dbc->c_close (dbc);
429 428
430 $int = $cursor->set_priority ($priority = PRIORITY_*) 429 $int = $cursor->set_priority ($priority = PRIORITY_*) (v4.6)
431 430
432=head4 Example: 431=head3 Example:
433 432
434 my $c = $db->cursor; 433 my $c = $db->cursor;
435 434
436 for (;;) { 435 for (;;) {
437 db_c_get $c, my $key, my $data, BDB::NEXT; 436 db_c_get $c, my $key, my $data, BDB::NEXT;
… …
440 } 439 }
441 440
442 db_c_close $c; 441 db_c_close $c;
443 442
444 443
445=head3 DB_SEQUENCE/sequence methods 444=head2 DB_SEQUENCE/sequence methods
446 445
447Methods available on DB_SEQUENCE/$seq handles: 446Methods available on DB_SEQUENCE/$seq handles:
448 447
449 DESTROY (DB_SEQUENCE_ornull *seq) 448 DESTROY (DB_SEQUENCE_ornull *seq)
450 CODE: 449 CODE:
… …
455 $int = $seq->set_cachesize (U32 size) 454 $int = $seq->set_cachesize (U32 size)
456 $int = $seq->set_flags (U32 flags) 455 $int = $seq->set_flags (U32 flags)
457 flags: SEQ_DEC SEQ_INC SEQ_WRAP 456 flags: SEQ_DEC SEQ_INC SEQ_WRAP
458 $int = $seq->set_range (db_seq_t min, db_seq_t max) 457 $int = $seq->set_range (db_seq_t min, db_seq_t max)
459 458
460=head4 Example: 459=head3 Example:
461 460
462 my $seq = $db->sequence; 461 my $seq = $db->sequence;
463 462
464 db_sequence_open $seq, undef, "seq", BDB::CREATE; 463 db_sequence_open $seq, undef, "seq", BDB::CREATE;
465 db_sequence_get $seq, undef, 1, my $value; 464 db_sequence_get $seq, undef, 1, my $value;
466 465
467 466
468=head2 SUPPORT FUNCTIONS 467=head1 SUPPORT FUNCTIONS
469 468
470=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 469=head2 EVENT PROCESSING AND EVENT LOOP INTEGRATION
471 470
472=over 4 471=over 4
473 472
474=item $msg = BDB::strerror [$errno] 473=item $msg = BDB::strerror [$errno]
475 474
… …
562 BDB::poll_wait, BDB::poll_cb 561 BDB::poll_wait, BDB::poll_cb
563 while BDB::nreqs; 562 while BDB::nreqs;
564 563
565=back 564=back
566 565
567=head3 VERSION CHECKING 566=head2 VERSION CHECKING
568 567
569BerkeleyDB comes in various versions, many of them have minor 568BerkeleyDB comes in various versions, many of them have minor
570incompatibilities. This means that traditional "at least version x.x" 569incompatibilities. This means that traditional "at least version x.x"
571checks are often not sufficient. 570checks are often not sufficient.
572 571
573Example: set the log_autoremove option in a way compatible with <v.47 and 572Example: set the log_autoremove option in a way compatible with <v4.7 and
574v4.7. Note the use of & on the constants to avoid triggering a compiletime 573v4.7. Note the use of & on the constants to avoid triggering a compiletime
575bug when the symbol isn't available. 574bug when the symbol isn't available.
576 575
577 $DB_ENV->set_flags (&BDB::LOG_AUTOREMOVE ) if BDB::VERSION v0, v4.7; 576 $DB_ENV->set_flags (&BDB::LOG_AUTOREMOVE ) if BDB::VERSION v0, v4.7;
578 $DB_ENV->log_set_config (&BDB::LOG_AUTO_REMOVE) if BDB::VERSION v4.7; 577 $DB_ENV->log_set_config (&BDB::LOG_AUTO_REMOVE) if BDB::VERSION v4.7;
… …
611=back 610=back
612 611
613=cut 612=cut
614 613
615sub VERSION { 614sub VERSION {
615 # I was dumb enough to override the VERSION method here, so let's try
616 # to fix it up.
617
618 if ($_[0] eq __PACKAGE__) {
619 $VERSION
620 } else {
616 if (@_ > 0) { 621 if (@_ > 0) {
617 return undef if VERSION_v lt $_[0]; 622 return undef if VERSION_v lt $_[0];
618 if (@_ > 1) { 623 if (@_ > 1) {
619 return undef if VERSION_v ge $_[1]; 624 return undef if VERSION_v ge $_[1];
625 }
620 } 626 }
627
628 VERSION_v
621 } 629 }
622
623 VERSION_v
624} 630}
625 631
626=head3 CONTROLLING THE NUMBER OF THREADS 632=head2 CONTROLLING THE NUMBER OF THREADS
627 633
628=over 4 634=over 4
629 635
630=item BDB::min_parallel $nthreads 636=item BDB::min_parallel $nthreads
631 637
… …
692 698
693You can still queue as many requests as you want. Therefore, 699You can still queue as many requests as you want. Therefore,
694C<max_oustsanding> is mainly useful in simple scripts (with low values) or 700C<max_oustsanding> is mainly useful in simple scripts (with low values) or
695as a stop gap to shield against fatal memory overflow (with large values). 701as a stop gap to shield against fatal memory overflow (with large values).
696 702
697=item BDB::set_sync_prepare $cb 703=item $old_cb = BDB::set_sync_prepare $cb
698 704
699Sets a callback that is called whenever a request is created without an 705Sets a callback that is called whenever a request is created without an
700explicit callback. It has to return two code references. The first is used 706explicit callback. It has to return two code references. The first is used
701as the request callback (it should save the return status), and the second 707as the request callback (it should save the return status), and the second
702is called to wait until the first callback has been called (it must set 708is called to wait until the first callback has been called (it must set
703C<$!> to the return status). 709C<$!> to the return status).
704 710
705This mechanism can be used to include BDB into other event mechanisms, 711This mechanism can be used to include BDB into other event mechanisms,
706such as L<AnyEvent::BDB> or L<Coro::BDB>. 712such as L<Coro::BDB>.
707 713
708The default implementation works like this: 714To allow other, callback-based, events to be executed while callback-less
715ones are run, you could use this sync prepare function:
709 716
710 sub { 717 sub {
711 my $status; 718 my $status;
712 ( 719 (
713 sub { $status = $! }, 720 sub { $status = $! },
714 sub { BDB::poll while !defined $status; $! = $status }, 721 sub { BDB::poll while !defined $status; $! = $status },
715 ) 722 )
716 } 723 }
717 724
718It simply blocks the process till the request has finished and then sets 725It works by polling for results till the request has finished and then
719C<$!> to the return value. This means that if you don't use a callback, 726sets C<$!> to the return value. This means that if you don't use a
720BDB will simply fall back to synchronous operations. 727callback, BDB would simply fall back to synchronous operations.
728
729By default, or if the sync prepare function is set to C<undef>, is to
730execute callback-less BDB requests in the foreground thread, setting C<$!>
731to the return value, without polling for other events.
721 732
722=back 733=back
723 734
724=head3 STATISTICAL INFORMATION 735=head2 STATISTICAL INFORMATION
725 736
726=over 4 737=over 4
727 738
728=item BDB::nreqs 739=item BDB::nreqs
729 740
… …
747 758
748=back 759=back
749 760
750=cut 761=cut
751 762
752set_sync_prepare { 763set_sync_prepare (undef);
753 my $status;
754 (
755 sub {
756 $status = $!;
757 },
758 sub {
759 BDB::poll while !defined $status;
760 $! = $status;
761 },
762 )
763};
764 764
765min_parallel 8; 765min_parallel 8;
766 766
767END { flush } 767END { flush }
768 768
7691; 7691;
770 770
771=head1 COMMON PITFALLS
772
773=head2 Unexpected Crashes
774
775Remember that, by default, BDB will execute requests in parallel, in
776somewhat random order. That means that it is easy to run a C<db_get>
777request on the same database as a concurrent C<db_close> request, leading
778to a crash, silent data corruption, eventually the next world war on
779terrorism.
780
781If you only ever use foreground requests (without a callback), this will
782not be an issue (unless you use threads).
783
784=head2 Unexpected Freezes or Deadlocks
785
786Remember that, by default, BDB will execute requests in parallel, which
787easily leads to deadlocks (even concurrent put's on the same database can
788deadlock).
789
790You either need to run deadlock detection (and handle the resulting
791errors), or make sure only one process ever updates the database, ine one
792thread, e.g. by using only foreground requests (without a callback).
793
771=head2 FORK BEHAVIOUR 794=head1 FORK BEHAVIOUR
772 795
773This module should do "the right thing" when the process using it forks: 796This module should do "the right thing" when the process using it forks:
774 797
775Before the fork, BDB enters a quiescent state where no requests 798Before the fork, BDB enters a quiescent state where no requests
776can be added in other threads and no results will be processed. After 799can be added in other threads and no results will be processed. After
… …
786 809
787Win32 note: there is no fork on win32, and perls emulation of it is too 810Win32 note: there is no fork on win32, and perls emulation of it is too
788broken to be supported, so do not use BDB in a windows pseudo-fork, better 811broken to be supported, so do not use BDB in a windows pseudo-fork, better
789yet, switch to a more capable platform. 812yet, switch to a more capable platform.
790 813
791=head2 MEMORY USAGE 814=head1 MEMORY USAGE
792 815
793Per-request usage: 816Per-request usage:
794 817
795Each aio request uses - depending on your architecture - around 100-200 818Each aio request uses - depending on your architecture - around 100-200
796bytes of memory. In addition, stat requests need a stat buffer (possibly 819bytes of memory. In addition, stat requests need a stat buffer (possibly
… …
805 828
806In the execution phase, some aio requests require more memory for 829In the execution phase, some aio requests require more memory for
807temporary buffers, and each thread requires a stack and other data 830temporary buffers, and each thread requires a stack and other data
808structures (usually around 16k-128k, depending on the OS). 831structures (usually around 16k-128k, depending on the OS).
809 832
833=head1 WIN32 FILENAMES/DATABASE NAME MESS
834
835Perl on Win32 supports only ASCII filenames (the reason is that it abuses
836an internal flag to store wether a filename is Unicode or ANSI, but that
837flag is used for somethign else in the perl core, so there is no way to
838detect wether a filename is ANSI or Unicode-encoded). The BDB module
839tries to work around this issue by assuming that the filename is an ANSI
840filename and BDB was built for unicode support.
841
810=head1 KNOWN BUGS 842=head1 KNOWN BUGS
811 843
812Known bugs will be fixed in the next release, except: 844Known bugs will be fixed in the next release, except:
813 845
814 If you use a transaction in any request, and the request returns 846 If you use a transaction in any request, and the request returns

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