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Comparing BDB/BDB.pm (file contents):
Revision 1.41 by root, Wed Jul 9 12:15:36 2008 UTC vs.
Revision 1.69 by root, Tue Feb 2 04:28:06 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 = '1.6'; 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_lsn_reset db_env_fileid_reset
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)
209 db_env_fileid_reset (DB_ENV *env, bdb_filename db, U32 flags = 0, SV *callback = 0)
214 210
215 $db = db_create (DB_ENV *env = 0, U32 flags = 0) 211 $db = db_create (DB_ENV *env = 0, U32 flags = 0)
216 flags: XA_CREATE 212 flags: XA_CREATE
217 213
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) 214 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 215 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) 216 db_close (DB *db, U32 flags = 0, SV *callback = 0)
221 flags: DB_NOSYNC 217 flags: DB_NOSYNC
218 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) 219 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) 220 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 221 flags: FREELIST_ONLY FREE_SPACE
225 db_sync (DB *db, U32 flags = 0, SV *callback = &PL_sv_undef) 222 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) 223 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) 224 db_put (DB *db, DB_TXN_ornull *txn, SV *key, SV *data, U32 flags = 0, SV *callback = 0)
228 flags: APPEND NODUPDATA NOOVERWRITE 225 flags: APPEND NODUPDATA NOOVERWRITE
226 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) 227 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 228 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) 229 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 230 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) 231 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) 232 db_txn_commit (DB_TXN *txn, U32 flags = 0, SV *callback = 0)
235 flags: TXN_NOSYNC TXN_SYNC 233 flags: TXN_NOSYNC TXN_SYNC
236 db_txn_abort (DB_TXN *txn, SV *callback = &PL_sv_undef) 234 db_txn_abort (DB_TXN *txn, SV *callback = 0)
237 235
238 db_c_close (DBC *dbc, SV *callback = &PL_sv_undef) 236 db_c_close (DBC *dbc, SV *callback = 0)
239 db_c_count (DBC *dbc, SV *count, U32 flags = 0, SV *callback = &PL_sv_undef) 237 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) 238 db_c_put (DBC *dbc, SV *key, SV *data, U32 flags = 0, SV *callback = 0)
241 flags: AFTER BEFORE CURRENT KEYFIRST KEYLAST NODUPDATA 239 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) 240 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 241 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) 242 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) 243 db_c_del (DBC *dbc, U32 flags = 0, SV *callback = 0)
246 244
247 db_sequence_open (DB_SEQUENCE *seq, DB_TXN_ornull *txnid, SV *key, U32 flags = 0, SV *callback = &PL_sv_undef) 245 db_sequence_open (DB_SEQUENCE *seq, DB_TXN_ornull *txnid, SV *key, U32 flags = 0, SV *callback = 0)
248 flags: CREATE EXCL 246 flags: CREATE EXCL
249 db_sequence_close (DB_SEQUENCE *seq, U32 flags = 0, SV *callback = &PL_sv_undef) 247 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) 248 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 249 flags: TXN_NOSYNC
252 db_sequence_remove (DB_SEQUENCE *seq, DB_TXN_ornull *txnid = 0, U32 flags = 0, SV *callback = &PL_sv_undef) 250 db_sequence_remove (DB_SEQUENCE *seq, DB_TXN_ornull *txnid = 0, U32 flags = 0, SV *callback = 0)
253 flags: TXN_NOSYNC 251 flags: TXN_NOSYNC
254 252
255=head4 db_txn_finish (DB_TXN *txn, U32 flags = 0, SV *callback = &PL_sv_undef) 253=head3 db_txn_finish (DB_TXN *txn, U32 flags = 0, SV *callback = 0)
256 254
257This is not actually a Berkeley DB function but a BDB module 255This is not actually a Berkeley DB function but a BDB module
258extension. The background for this exytension is: It is very annoying to 256extension. The background for this exytension is: It is very annoying to
259have to check every single BDB function for error returns and provide a 257have to check every single BDB function for error returns and provide a
260codepath out of your transaction. While the BDB module still makes this 258codepath out of your transaction. While the BDB module still makes this
… …
286 284
287You can use the C<< $txn->failed >> method to check wether a transaction 285You can use the C<< $txn->failed >> method to check wether a transaction
288has failed in this way and abort further processing (excluding 286has failed in this way and abort further processing (excluding
289C<db_txn_finish>). 287C<db_txn_finish>).
290 288
289
291=head3 DB_ENV/database environment methods 290=head2 DB_ENV/database environment methods
292 291
293Methods available on DB_ENV/$env handles: 292Methods available on DB_ENV/$env handles:
294 293
295 DESTROY (DB_ENV_ornull *env) 294 DESTROY (DB_ENV_ornull *env)
296 CODE: 295 CODE:
… …
301 $int = $env->set_tmp_dir (const char *dir) 300 $int = $env->set_tmp_dir (const char *dir)
302 $int = $env->set_lg_dir (const char *dir) 301 $int = $env->set_lg_dir (const char *dir)
303 $int = $env->set_shm_key (long shm_key) 302 $int = $env->set_shm_key (long shm_key)
304 $int = $env->set_cachesize (U32 gbytes, U32 bytes, int ncache = 0) 303 $int = $env->set_cachesize (U32 gbytes, U32 bytes, int ncache = 0)
305 $int = $env->set_flags (U32 flags, int onoff = 1) 304 $int = $env->set_flags (U32 flags, int onoff = 1)
306 $int = $env->log_set_config (U32 flags, int onoff = 1) [v4.7] 305 $int = $env->log_set_config (U32 flags, int onoff = 1) (v4.7)
307 $int = $env->set_intermediate_dir_mode (const char *modestring) [v4.7] 306 $int = $env->set_intermediate_dir_mode (const char *modestring) (v4.7)
308 $env->set_errfile (FILE *errfile = 0) 307 $env->set_errfile (FILE *errfile = 0)
309 $env->set_msgfile (FILE *msgfile = 0) 308 $env->set_msgfile (FILE *msgfile = 0)
310 $int = $env->set_verbose (U32 which, int onoff = 1) 309 $int = $env->set_verbose (U32 which, int onoff = 1)
311 $int = $env->set_encrypt (const char *password, U32 flags = 0) 310 $int = $env->set_encrypt (const char *password, U32 flags = 0)
312 $int = $env->set_timeout (NV timeout_seconds, U32 flags = SET_TXN_TIMEOUT) 311 $int = $env->set_timeout (NV timeout_seconds, U32 flags = SET_TXN_TIMEOUT)
… …
324 $int = $env->mutex_set_max (U32 max) 323 $int = $env->mutex_set_max (U32 max)
325 $int = $env->mutex_set_align (U32 align) 324 $int = $env->mutex_set_align (U32 align)
326 325
327 $txn = $env->txn_begin (DB_TXN_ornull *parent = 0, U32 flags = 0) 326 $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 327 flags: READ_COMMITTED READ_UNCOMMITTED TXN_NOSYNC TXN_NOWAIT TXN_SNAPSHOT TXN_SYNC TXN_WAIT TXN_WRITE_NOSYNC
328 $txn = $env->cdsgroup_begin; (v4.5)
329 329
330=head4 Example: 330=head3 Example:
331 331
332 use AnyEvent; 332 use AnyEvent;
333 use BDB; 333 use BDB;
334 334
335 our $FH; open $FH, "<&=" . BDB::poll_fileno; 335 our $FH; open $FH, "<&=" . BDB::poll_fileno;
… …
347 0600; 347 0600;
348 348
349 $env->set_flags (BDB::AUTO_COMMIT | BDB::TXN_NOSYNC, 1); 349 $env->set_flags (BDB::AUTO_COMMIT | BDB::TXN_NOSYNC, 1);
350 350
351 351
352=head3 DB/database methods 352=head2 DB/database methods
353 353
354Methods available on DB/$db handles: 354Methods available on DB/$db handles:
355 355
356 DESTROY (DB_ornull *db) 356 DESTROY (DB_ornull *db)
357 CODE: 357 CODE:
… …
383 383
384 $dbc = $db->cursor (DB_TXN_ornull *txn = 0, U32 flags = 0) 384 $dbc = $db->cursor (DB_TXN_ornull *txn = 0, U32 flags = 0)
385 flags: READ_COMMITTED READ_UNCOMMITTED WRITECURSOR TXN_SNAPSHOT 385 flags: READ_COMMITTED READ_UNCOMMITTED WRITECURSOR TXN_SNAPSHOT
386 $seq = $db->sequence (U32 flags = 0) 386 $seq = $db->sequence (U32 flags = 0)
387 387
388=head4 Example: 388=head3 Example:
389 389
390 my $db = db_create $env; 390 my $db = db_create $env;
391 db_open $db, undef, "table", undef, BDB::BTREE, BDB::AUTO_COMMIT | BDB::CREATE | BDB::READ_UNCOMMITTED, 0600; 391 db_open $db, undef, "table", undef, BDB::BTREE, BDB::AUTO_COMMIT | BDB::CREATE | BDB::READ_UNCOMMITTED, 0600;
392 392
393 for (1..1000) { 393 for (1..1000) {
… …
400 db_del $db, undef, "key $_" for 1..1000; 400 db_del $db, undef, "key $_" for 1..1000;
401 401
402 db_sync $db; 402 db_sync $db;
403 403
404 404
405=head3 DB_TXN/transaction methods 405=head2 DB_TXN/transaction methods
406 406
407Methods available on DB_TXN/$txn handles: 407Methods available on DB_TXN/$txn handles:
408 408
409 DESTROY (DB_TXN_ornull *txn) 409 DESTROY (DB_TXN_ornull *txn)
410 CODE: 410 CODE:
… …
416 416
417 $bool = $txn->failed 417 $bool = $txn->failed
418 # see db_txn_finish documentation, above 418 # see db_txn_finish documentation, above
419 419
420 420
421=head3 DBC/cursor methods 421=head2 DBC/cursor methods
422 422
423Methods available on DBC/$dbc handles: 423Methods available on DBC/$dbc handles:
424 424
425 DESTROY (DBC_ornull *dbc) 425 DESTROY (DBC_ornull *dbc)
426 CODE: 426 CODE:
427 if (dbc) 427 if (dbc)
428 dbc->c_close (dbc); 428 dbc->c_close (dbc);
429 429
430 $int = $cursor->set_priority ($priority = PRIORITY_*) 430 $int = $cursor->set_priority ($priority = PRIORITY_*) (v4.6)
431 431
432=head4 Example: 432=head3 Example:
433 433
434 my $c = $db->cursor; 434 my $c = $db->cursor;
435 435
436 for (;;) { 436 for (;;) {
437 db_c_get $c, my $key, my $data, BDB::NEXT; 437 db_c_get $c, my $key, my $data, BDB::NEXT;
… …
440 } 440 }
441 441
442 db_c_close $c; 442 db_c_close $c;
443 443
444 444
445=head3 DB_SEQUENCE/sequence methods 445=head2 DB_SEQUENCE/sequence methods
446 446
447Methods available on DB_SEQUENCE/$seq handles: 447Methods available on DB_SEQUENCE/$seq handles:
448 448
449 DESTROY (DB_SEQUENCE_ornull *seq) 449 DESTROY (DB_SEQUENCE_ornull *seq)
450 CODE: 450 CODE:
… …
455 $int = $seq->set_cachesize (U32 size) 455 $int = $seq->set_cachesize (U32 size)
456 $int = $seq->set_flags (U32 flags) 456 $int = $seq->set_flags (U32 flags)
457 flags: SEQ_DEC SEQ_INC SEQ_WRAP 457 flags: SEQ_DEC SEQ_INC SEQ_WRAP
458 $int = $seq->set_range (db_seq_t min, db_seq_t max) 458 $int = $seq->set_range (db_seq_t min, db_seq_t max)
459 459
460=head4 Example: 460=head3 Example:
461 461
462 my $seq = $db->sequence; 462 my $seq = $db->sequence;
463 463
464 db_sequence_open $seq, undef, "seq", BDB::CREATE; 464 db_sequence_open $seq, undef, "seq", BDB::CREATE;
465 db_sequence_get $seq, undef, 1, my $value; 465 db_sequence_get $seq, undef, 1, my $value;
466 466
467 467
468=head2 SUPPORT FUNCTIONS 468=head1 SUPPORT FUNCTIONS
469 469
470=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 470=head2 EVENT PROCESSING AND EVENT LOOP INTEGRATION
471 471
472=over 4 472=over 4
473 473
474=item $msg = BDB::strerror [$errno] 474=item $msg = BDB::strerror [$errno]
475 475
… …
562 BDB::poll_wait, BDB::poll_cb 562 BDB::poll_wait, BDB::poll_cb
563 while BDB::nreqs; 563 while BDB::nreqs;
564 564
565=back 565=back
566 566
567=head3 VERSION CHECKING 567=head2 VERSION CHECKING
568 568
569BerkeleyDB comes in various versions, many of them have minor 569BerkeleyDB comes in various versions, many of them have minor
570incompatibilities. This means that traditional "at least version x.x" 570incompatibilities. This means that traditional "at least version x.x"
571checks are often not sufficient. 571checks are often not sufficient.
572 572
573Example: set the log_autoremove option in a way compatible with <v.47 and 573Example: 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 574v4.7. Note the use of & on the constants to avoid triggering a compiletime
575bug when the symbol isn't available. 575bug when the symbol isn't available.
576 576
577 $DB_ENV->set_flags (&BDB::LOG_AUTOREMOVE ) if BDB::VERSION v0, v4.7; 577 $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; 578 $DB_ENV->log_set_config (&BDB::LOG_AUTO_REMOVE) if BDB::VERSION v4.7;
… …
611=back 611=back
612 612
613=cut 613=cut
614 614
615sub VERSION { 615sub VERSION {
616 # I was dumb enough to override the VERSION method here, so let's try
617 # to fix it up.
618
619 if ($_[0] eq __PACKAGE__) {
620 $VERSION
621 } else {
616 if (@_ > 0) { 622 if (@_ > 0) {
617 return undef if VERSION_v lt $_[0]; 623 return undef if VERSION_v lt $_[0];
618 if (@_ > 1) { 624 if (@_ > 1) {
619 return undef if VERSION_v ge $_[1]; 625 return undef if VERSION_v ge $_[1];
626 }
620 } 627 }
628
629 VERSION_v
621 } 630 }
622
623 VERSION_v
624} 631}
625 632
626=head3 CONTROLLING THE NUMBER OF THREADS 633=head2 CONTROLLING THE NUMBER OF THREADS
627 634
628=over 4 635=over 4
629 636
630=item BDB::min_parallel $nthreads 637=item BDB::min_parallel $nthreads
631 638
… …
692 699
693You can still queue as many requests as you want. Therefore, 700You can still queue as many requests as you want. Therefore,
694C<max_oustsanding> is mainly useful in simple scripts (with low values) or 701C<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). 702as a stop gap to shield against fatal memory overflow (with large values).
696 703
697=item BDB::set_sync_prepare $cb 704=item $old_cb = BDB::set_sync_prepare $cb
698 705
699Sets a callback that is called whenever a request is created without an 706Sets a callback that is called whenever a request is created without an
700explicit callback. It has to return two code references. The first is used 707explicit callback. It has to return two code references. The first is used
701as the request callback (it should save the return status), and the second 708as the request callback (it should save the return status), and the second
702is called to wait until the first callback has been called (it must set 709is called to wait until the first callback has been called (it must set
703C<$!> to the return status). 710C<$!> to the return status).
704 711
705This mechanism can be used to include BDB into other event mechanisms, 712This mechanism can be used to include BDB into other event mechanisms,
706such as L<AnyEvent::BDB> or L<Coro::BDB>. 713such as L<Coro::BDB>.
707 714
708The default implementation works like this: 715To allow other, callback-based, events to be executed while callback-less
716ones are run, you could use this sync prepare function:
709 717
710 sub { 718 sub {
711 my $status; 719 my $status;
712 ( 720 (
713 sub { $status = $! }, 721 sub { $status = $! },
714 sub { BDB::poll while !defined $status; $! = $status }, 722 sub { BDB::poll while !defined $status; $! = $status },
715 ) 723 )
716 } 724 }
717 725
718It simply blocks the process till the request has finished and then sets 726It works by polling for results till the request has finished and then
719C<$!> to the return value. This means that if you don't use a callback, 727sets C<$!> to the return value. This means that if you don't use a
720BDB will simply fall back to synchronous operations. 728callback, BDB would simply fall back to synchronous operations.
729
730By default, or if the sync prepare function is set to C<undef>, is to
731execute callback-less BDB requests in the foreground thread, setting C<$!>
732to the return value, without polling for other events.
721 733
722=back 734=back
723 735
724=head3 STATISTICAL INFORMATION 736=head2 STATISTICAL INFORMATION
725 737
726=over 4 738=over 4
727 739
728=item BDB::nreqs 740=item BDB::nreqs
729 741
… …
747 759
748=back 760=back
749 761
750=cut 762=cut
751 763
752set_sync_prepare { 764set_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};
764 765
765min_parallel 8; 766min_parallel 8;
766 767
767END { flush } 768END { flush }
768 769
7691; 7701;
770 771
772=head1 COMMON PITFALLS
773
774=head2 Unexpected Crashes
775
776Remember that, by default, BDB will execute requests in parallel, in
777somewhat random order. That means that it is easy to run a C<db_get>
778request on the same database as a concurrent C<db_close> request, leading
779to a crash, silent data corruption, eventually the next world war on
780terrorism.
781
782If you only ever use foreground requests (without a callback), this will
783not be an issue (unless you use threads).
784
785=head2 Unexpected Freezes or Deadlocks
786
787Remember that, by default, BDB will execute requests in parallel, which
788easily leads to deadlocks (even concurrent put's on the same database can
789deadlock).
790
791You either need to run deadlock detection (and handle the resulting
792errors), or make sure only one process ever updates the database, ine one
793thread, e.g. by using only foreground requests (without a callback).
794
771=head2 FORK BEHAVIOUR 795=head1 FORK BEHAVIOUR
772 796
773This module should do "the right thing" when the process using it forks: 797This module should do "the right thing" when the process using it forks:
774 798
775Before the fork, BDB enters a quiescent state where no requests 799Before the fork, BDB enters a quiescent state where no requests
776can be added in other threads and no results will be processed. After 800can be added in other threads and no results will be processed. After
… …
786 810
787Win32 note: there is no fork on win32, and perls emulation of it is too 811Win32 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 812broken to be supported, so do not use BDB in a windows pseudo-fork, better
789yet, switch to a more capable platform. 813yet, switch to a more capable platform.
790 814
791=head2 MEMORY USAGE 815=head1 MEMORY USAGE
792 816
793Per-request usage: 817Per-request usage:
794 818
795Each aio request uses - depending on your architecture - around 100-200 819Each aio request uses - depending on your architecture - around 100-200
796bytes of memory. In addition, stat requests need a stat buffer (possibly 820bytes of memory. In addition, stat requests need a stat buffer (possibly
… …
805 829
806In the execution phase, some aio requests require more memory for 830In the execution phase, some aio requests require more memory for
807temporary buffers, and each thread requires a stack and other data 831temporary buffers, and each thread requires a stack and other data
808structures (usually around 16k-128k, depending on the OS). 832structures (usually around 16k-128k, depending on the OS).
809 833
834=head1 WIN32 FILENAMES/DATABASE NAME MESS
835
836Perl on Win32 supports only ASCII filenames (the reason is that it abuses
837an internal flag to store wether a filename is Unicode or ANSI, but that
838flag is used for somethign else in the perl core, so there is no way to
839detect wether a filename is ANSI or Unicode-encoded). The BDB module
840tries to work around this issue by assuming that the filename is an ANSI
841filename and BDB was built for unicode support.
842
810=head1 KNOWN BUGS 843=head1 KNOWN BUGS
811 844
812Known bugs will be fixed in the next release, except: 845Known bugs will be fixed in the next release, except:
813 846
814 If you use a transaction in any request, and the request returns 847 If you use a transaction in any request, and the request returns

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