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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 1.63 by root, Fri Jul 29 09:30:19 2011 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 = '1.89';
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
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)
214 208
215 $db = db_create (DB_ENV *env = 0, U32 flags = 0) 209 $db = db_create (DB_ENV *env = 0, U32 flags = 0)
216 flags: XA_CREATE 210 flags: XA_CREATE
217 211
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) 212 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 213 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) 214 db_close (DB *db, U32 flags = 0, SV *callback = 0)
221 flags: DB_NOSYNC 215 flags: DB_NOSYNC
216 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) 217 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) 218 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 219 flags: FREELIST_ONLY FREE_SPACE
225 db_sync (DB *db, U32 flags = 0, SV *callback = &PL_sv_undef) 220 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) 221 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) 222 db_put (DB *db, DB_TXN_ornull *txn, SV *key, SV *data, U32 flags = 0, SV *callback = 0)
228 flags: APPEND NODUPDATA NOOVERWRITE 223 flags: APPEND NODUPDATA NOOVERWRITE
224 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) 225 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 226 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) 227 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 228 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) 229 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) 230 db_txn_commit (DB_TXN *txn, U32 flags = 0, SV *callback = 0)
235 flags: TXN_NOSYNC TXN_SYNC 231 flags: TXN_NOSYNC TXN_SYNC
236 db_txn_abort (DB_TXN *txn, SV *callback = &PL_sv_undef) 232 db_txn_abort (DB_TXN *txn, SV *callback = 0)
237 233
238 db_c_close (DBC *dbc, SV *callback = &PL_sv_undef) 234 db_c_close (DBC *dbc, SV *callback = 0)
239 db_c_count (DBC *dbc, SV *count, U32 flags = 0, SV *callback = &PL_sv_undef) 235 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) 236 db_c_put (DBC *dbc, SV *key, SV *data, U32 flags = 0, SV *callback = 0)
241 flags: AFTER BEFORE CURRENT KEYFIRST KEYLAST NODUPDATA 237 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) 238 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 239 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) 240 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) 241 db_c_del (DBC *dbc, U32 flags = 0, SV *callback = 0)
246 242
247 db_sequence_open (DB_SEQUENCE *seq, DB_TXN_ornull *txnid, SV *key, U32 flags = 0, SV *callback = &PL_sv_undef) 243 db_sequence_open (DB_SEQUENCE *seq, DB_TXN_ornull *txnid, SV *key, U32 flags = 0, SV *callback = 0)
248 flags: CREATE EXCL 244 flags: CREATE EXCL
249 db_sequence_close (DB_SEQUENCE *seq, U32 flags = 0, SV *callback = &PL_sv_undef) 245 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) 246 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 247 flags: TXN_NOSYNC
252 db_sequence_remove (DB_SEQUENCE *seq, DB_TXN_ornull *txnid = 0, U32 flags = 0, SV *callback = &PL_sv_undef) 248 db_sequence_remove (DB_SEQUENCE *seq, DB_TXN_ornull *txnid = 0, U32 flags = 0, SV *callback = 0)
253 flags: TXN_NOSYNC 249 flags: TXN_NOSYNC
254 250
255=head4 db_txn_finish (DB_TXN *txn, U32 flags = 0, SV *callback = &PL_sv_undef) 251=head3 db_txn_finish (DB_TXN *txn, U32 flags = 0, SV *callback = 0)
256 252
257This is not actually a Berkeley DB function but a BDB module 253This is not actually a Berkeley DB function but a BDB module
258extension. The background for this exytension is: It is very annoying to 254extension. The background for this exytension is: It is very annoying to
259have to check every single BDB function for error returns and provide a 255have to check every single BDB function for error returns and provide a
260codepath out of your transaction. While the BDB module still makes this 256codepath out of your transaction. While the BDB module still makes this
… …
286 282
287You can use the C<< $txn->failed >> method to check wether a transaction 283You can use the C<< $txn->failed >> method to check wether a transaction
288has failed in this way and abort further processing (excluding 284has failed in this way and abort further processing (excluding
289C<db_txn_finish>). 285C<db_txn_finish>).
290 286
287
291=head3 DB_ENV/database environment methods 288=head2 DB_ENV/database environment methods
292 289
293Methods available on DB_ENV/$env handles: 290Methods available on DB_ENV/$env handles:
294 291
295 DESTROY (DB_ENV_ornull *env) 292 DESTROY (DB_ENV_ornull *env)
296 CODE: 293 CODE:
… …
301 $int = $env->set_tmp_dir (const char *dir) 298 $int = $env->set_tmp_dir (const char *dir)
302 $int = $env->set_lg_dir (const char *dir) 299 $int = $env->set_lg_dir (const char *dir)
303 $int = $env->set_shm_key (long shm_key) 300 $int = $env->set_shm_key (long shm_key)
304 $int = $env->set_cachesize (U32 gbytes, U32 bytes, int ncache = 0) 301 $int = $env->set_cachesize (U32 gbytes, U32 bytes, int ncache = 0)
305 $int = $env->set_flags (U32 flags, int onoff = 1) 302 $int = $env->set_flags (U32 flags, int onoff = 1)
306 $int = $env->log_set_config (U32 flags, int onoff = 1) [v4.7] 303 $int = $env->log_set_config (U32 flags, int onoff = 1) (v4.7)
307 $int = $env->set_intermediate_dir_mode (const char *modestring) [v4.7] 304 $int = $env->set_intermediate_dir_mode (const char *modestring) (v4.7)
308 $env->set_errfile (FILE *errfile = 0) 305 $env->set_errfile (FILE *errfile = 0)
309 $env->set_msgfile (FILE *msgfile = 0) 306 $env->set_msgfile (FILE *msgfile = 0)
310 $int = $env->set_verbose (U32 which, int onoff = 1) 307 $int = $env->set_verbose (U32 which, int onoff = 1)
311 $int = $env->set_encrypt (const char *password, U32 flags = 0) 308 $int = $env->set_encrypt (const char *password, U32 flags = 0)
312 $int = $env->set_timeout (NV timeout_seconds, U32 flags = SET_TXN_TIMEOUT) 309 $int = $env->set_timeout (NV timeout_seconds, U32 flags = SET_TXN_TIMEOUT)
… …
324 $int = $env->mutex_set_max (U32 max) 321 $int = $env->mutex_set_max (U32 max)
325 $int = $env->mutex_set_align (U32 align) 322 $int = $env->mutex_set_align (U32 align)
326 323
327 $txn = $env->txn_begin (DB_TXN_ornull *parent = 0, U32 flags = 0) 324 $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 325 flags: READ_COMMITTED READ_UNCOMMITTED TXN_NOSYNC TXN_NOWAIT TXN_SNAPSHOT TXN_SYNC TXN_WAIT TXN_WRITE_NOSYNC
326 $txn = $env->cdsgroup_begin; (v4.5)
329 327
330=head4 Example: 328=head3 Example:
331 329
332 use AnyEvent; 330 use AnyEvent;
333 use BDB; 331 use BDB;
334 332
335 our $FH; open $FH, "<&=" . BDB::poll_fileno; 333 our $FH; open $FH, "<&=" . BDB::poll_fileno;
… …
347 0600; 345 0600;
348 346
349 $env->set_flags (BDB::AUTO_COMMIT | BDB::TXN_NOSYNC, 1); 347 $env->set_flags (BDB::AUTO_COMMIT | BDB::TXN_NOSYNC, 1);
350 348
351 349
352=head3 DB/database methods 350=head2 DB/database methods
353 351
354Methods available on DB/$db handles: 352Methods available on DB/$db handles:
355 353
356 DESTROY (DB_ornull *db) 354 DESTROY (DB_ornull *db)
357 CODE: 355 CODE:
… …
383 381
384 $dbc = $db->cursor (DB_TXN_ornull *txn = 0, U32 flags = 0) 382 $dbc = $db->cursor (DB_TXN_ornull *txn = 0, U32 flags = 0)
385 flags: READ_COMMITTED READ_UNCOMMITTED WRITECURSOR TXN_SNAPSHOT 383 flags: READ_COMMITTED READ_UNCOMMITTED WRITECURSOR TXN_SNAPSHOT
386 $seq = $db->sequence (U32 flags = 0) 384 $seq = $db->sequence (U32 flags = 0)
387 385
388=head4 Example: 386=head3 Example:
389 387
390 my $db = db_create $env; 388 my $db = db_create $env;
391 db_open $db, undef, "table", undef, BDB::BTREE, BDB::AUTO_COMMIT | BDB::CREATE | BDB::READ_UNCOMMITTED, 0600; 389 db_open $db, undef, "table", undef, BDB::BTREE, BDB::AUTO_COMMIT | BDB::CREATE | BDB::READ_UNCOMMITTED, 0600;
392 390
393 for (1..1000) { 391 for (1..1000) {
… …
400 db_del $db, undef, "key $_" for 1..1000; 398 db_del $db, undef, "key $_" for 1..1000;
401 399
402 db_sync $db; 400 db_sync $db;
403 401
404 402
405=head3 DB_TXN/transaction methods 403=head2 DB_TXN/transaction methods
406 404
407Methods available on DB_TXN/$txn handles: 405Methods available on DB_TXN/$txn handles:
408 406
409 DESTROY (DB_TXN_ornull *txn) 407 DESTROY (DB_TXN_ornull *txn)
410 CODE: 408 CODE:
… …
416 414
417 $bool = $txn->failed 415 $bool = $txn->failed
418 # see db_txn_finish documentation, above 416 # see db_txn_finish documentation, above
419 417
420 418
421=head3 DBC/cursor methods 419=head2 DBC/cursor methods
422 420
423Methods available on DBC/$dbc handles: 421Methods available on DBC/$dbc handles:
424 422
425 DESTROY (DBC_ornull *dbc) 423 DESTROY (DBC_ornull *dbc)
426 CODE: 424 CODE:
427 if (dbc) 425 if (dbc)
428 dbc->c_close (dbc); 426 dbc->c_close (dbc);
429 427
430 $int = $cursor->set_priority ($priority = PRIORITY_*) 428 $int = $cursor->set_priority ($priority = PRIORITY_*) (v4.6)
431 429
432=head4 Example: 430=head3 Example:
433 431
434 my $c = $db->cursor; 432 my $c = $db->cursor;
435 433
436 for (;;) { 434 for (;;) {
437 db_c_get $c, my $key, my $data, BDB::NEXT; 435 db_c_get $c, my $key, my $data, BDB::NEXT;
… …
440 } 438 }
441 439
442 db_c_close $c; 440 db_c_close $c;
443 441
444 442
445=head3 DB_SEQUENCE/sequence methods 443=head2 DB_SEQUENCE/sequence methods
446 444
447Methods available on DB_SEQUENCE/$seq handles: 445Methods available on DB_SEQUENCE/$seq handles:
448 446
449 DESTROY (DB_SEQUENCE_ornull *seq) 447 DESTROY (DB_SEQUENCE_ornull *seq)
450 CODE: 448 CODE:
… …
455 $int = $seq->set_cachesize (U32 size) 453 $int = $seq->set_cachesize (U32 size)
456 $int = $seq->set_flags (U32 flags) 454 $int = $seq->set_flags (U32 flags)
457 flags: SEQ_DEC SEQ_INC SEQ_WRAP 455 flags: SEQ_DEC SEQ_INC SEQ_WRAP
458 $int = $seq->set_range (db_seq_t min, db_seq_t max) 456 $int = $seq->set_range (db_seq_t min, db_seq_t max)
459 457
460=head4 Example: 458=head3 Example:
461 459
462 my $seq = $db->sequence; 460 my $seq = $db->sequence;
463 461
464 db_sequence_open $seq, undef, "seq", BDB::CREATE; 462 db_sequence_open $seq, undef, "seq", BDB::CREATE;
465 db_sequence_get $seq, undef, 1, my $value; 463 db_sequence_get $seq, undef, 1, my $value;
466 464
467 465
468=head2 SUPPORT FUNCTIONS 466=head1 SUPPORT FUNCTIONS
469 467
470=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 468=head2 EVENT PROCESSING AND EVENT LOOP INTEGRATION
471 469
472=over 4 470=over 4
473 471
474=item $msg = BDB::strerror [$errno] 472=item $msg = BDB::strerror [$errno]
475 473
… …
562 BDB::poll_wait, BDB::poll_cb 560 BDB::poll_wait, BDB::poll_cb
563 while BDB::nreqs; 561 while BDB::nreqs;
564 562
565=back 563=back
566 564
567=head3 VERSION CHECKING 565=head2 VERSION CHECKING
568 566
569BerkeleyDB comes in various versions, many of them have minor 567BerkeleyDB comes in various versions, many of them have minor
570incompatibilities. This means that traditional "at least version x.x" 568incompatibilities. This means that traditional "at least version x.x"
571checks are often not sufficient. 569checks are often not sufficient.
572 570
573Example: set the log_autoremove option in a way compatible with <v.47 and 571Example: 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 572v4.7. Note the use of & on the constants to avoid triggering a compiletime
575bug when the symbol isn't available. 573bug when the symbol isn't available.
576 574
577 $DB_ENV->set_flags (&BDB::LOG_AUTOREMOVE ) if BDB::VERSION v0, v4.7; 575 $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; 576 $DB_ENV->log_set_config (&BDB::LOG_AUTO_REMOVE) if BDB::VERSION v4.7;
… …
611=back 609=back
612 610
613=cut 611=cut
614 612
615sub VERSION { 613sub VERSION {
614 # I was dumb enough to override the VERSION method here, so let's try
615 # to fix it up.
616
617 if ($_[0] eq __PACKAGE__) {
618 $VERSION
619 } else {
616 if (@_ > 0) { 620 if (@_ > 0) {
617 return undef if VERSION_v lt $_[0]; 621 return undef if VERSION_v lt $_[0];
618 if (@_ > 1) { 622 if (@_ > 1) {
619 return undef if VERSION_v ge $_[1]; 623 return undef if VERSION_v ge $_[1];
624 }
620 } 625 }
626
627 VERSION_v
621 } 628 }
622
623 VERSION_v
624} 629}
625 630
626=head3 CONTROLLING THE NUMBER OF THREADS 631=head2 CONTROLLING THE NUMBER OF THREADS
627 632
628=over 4 633=over 4
629 634
630=item BDB::min_parallel $nthreads 635=item BDB::min_parallel $nthreads
631 636
… …
692 697
693You can still queue as many requests as you want. Therefore, 698You can still queue as many requests as you want. Therefore,
694C<max_oustsanding> is mainly useful in simple scripts (with low values) or 699C<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). 700as a stop gap to shield against fatal memory overflow (with large values).
696 701
697=item BDB::set_sync_prepare $cb 702=item $old_cb = BDB::set_sync_prepare $cb
698 703
699Sets a callback that is called whenever a request is created without an 704Sets a callback that is called whenever a request is created without an
700explicit callback. It has to return two code references. The first is used 705explicit callback. It has to return two code references. The first is used
701as the request callback (it should save the return status), and the second 706as the request callback (it should save the return status), and the second
702is called to wait until the first callback has been called (it must set 707is called to wait until the first callback has been called (it must set
703C<$!> to the return status). 708C<$!> to the return status).
704 709
705This mechanism can be used to include BDB into other event mechanisms, 710This mechanism can be used to include BDB into other event mechanisms,
706such as L<AnyEvent::BDB> or L<Coro::BDB>. 711such as L<Coro::BDB>.
707 712
708The default implementation works like this: 713To allow other, callback-based, events to be executed while callback-less
714ones are run, you could use this sync prepare function:
709 715
710 sub { 716 sub {
711 my $status; 717 my $status;
712 ( 718 (
713 sub { $status = $! }, 719 sub { $status = $! },
714 sub { BDB::poll while !defined $status; $! = $status }, 720 sub { BDB::poll while !defined $status; $! = $status },
715 ) 721 )
716 } 722 }
717 723
718It simply blocks the process till the request has finished and then sets 724It works by polling for results till the request has finished and then
719C<$!> to the return value. This means that if you don't use a callback, 725sets C<$!> to the return value. This means that if you don't use a
720BDB will simply fall back to synchronous operations. 726callback, BDB would simply fall back to synchronous operations.
727
728By default, or if the sync prepare function is set to C<undef>, is to
729execute callback-less BDB requests in the foreground thread, setting C<$!>
730to the return value, without polling for other events.
721 731
722=back 732=back
723 733
724=head3 STATISTICAL INFORMATION 734=head2 STATISTICAL INFORMATION
725 735
726=over 4 736=over 4
727 737
728=item BDB::nreqs 738=item BDB::nreqs
729 739
… …
747 757
748=back 758=back
749 759
750=cut 760=cut
751 761
752set_sync_prepare { 762set_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};
764 763
765min_parallel 8; 764min_parallel 8;
766 765
767END { flush } 766END { flush }
768 767
7691; 7681;
770 769
770=head1 COMMON PITFALLS
771
772=head2 Unexpected Crashes
773
774Remember that, by default, BDB will execute requests in parallel, in
775somewhat random order. That means that it is easy to run a C<db_get>
776request on thesa me database as a concurrent C<db_close> request, leading
777to a crash, silent data corruption, eventually the next world war on
778terrorism.
779
780If you only ever use foreground requests (without a callback), this will
781not be an issue.
782
783=head2 Unexpected Freezes or Deadlocks
784
785Remember that, by default, BDB will execute requests in parallel, which
786easily leads to deadlocks (even concurrent put's on the same database can
787deadlock).
788
789You either need to run deadlock detection (and handle the resulting
790errors), or make sure only one process ever updates the database, ine one
791thread, e.g. by using only foreground requests (without a callback).
792
771=head2 FORK BEHAVIOUR 793=head1 FORK BEHAVIOUR
772 794
773This module should do "the right thing" when the process using it forks: 795This module should do "the right thing" when the process using it forks:
774 796
775Before the fork, BDB enters a quiescent state where no requests 797Before the fork, BDB enters a quiescent state where no requests
776can be added in other threads and no results will be processed. After 798can be added in other threads and no results will be processed. After
… …
786 808
787Win32 note: there is no fork on win32, and perls emulation of it is too 809Win32 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 810broken to be supported, so do not use BDB in a windows pseudo-fork, better
789yet, switch to a more capable platform. 811yet, switch to a more capable platform.
790 812
791=head2 MEMORY USAGE 813=head1 MEMORY USAGE
792 814
793Per-request usage: 815Per-request usage:
794 816
795Each aio request uses - depending on your architecture - around 100-200 817Each aio request uses - depending on your architecture - around 100-200
796bytes of memory. In addition, stat requests need a stat buffer (possibly 818bytes of memory. In addition, stat requests need a stat buffer (possibly
… …
805 827
806In the execution phase, some aio requests require more memory for 828In the execution phase, some aio requests require more memory for
807temporary buffers, and each thread requires a stack and other data 829temporary buffers, and each thread requires a stack and other data
808structures (usually around 16k-128k, depending on the OS). 830structures (usually around 16k-128k, depending on the OS).
809 831
832=head1 WIN32 FILENAMES/DATABASE NAME MESS
833
834Perl on Win32 supports only ASCII filenames (the reason is that it abuses
835an internal flag to store wether a filename is Unicode or ANSI, but that
836flag is used for somethign else in the perl core, so there is no way to
837detect wether a filename is ANSI or Unicode-encoded). The BDB module
838tries to work around this issue by assuming that the filename is an ANSI
839filename and BDB was built for unicode support.
840
810=head1 KNOWN BUGS 841=head1 KNOWN BUGS
811 842
812Known bugs will be fixed in the next release, except: 843Known bugs will be fixed in the next release, except:
813 844
814 If you use a transaction in any request, and the request returns 845 If you use a transaction in any request, and the request returns

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