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Comparing BDB/BDB.pm (file contents):
Revision 1.12 by root, Mon Aug 13 12:07:46 2007 UTC vs.
Revision 1.16 by root, Sun Sep 16 18:17:58 2007 UTC

… …
72use strict 'vars'; 72use strict 'vars';
73 73
74use base 'Exporter'; 74use base 'Exporter';
75 75
76BEGIN { 76BEGIN {
77 our $VERSION = '1.0'; 77 our $VERSION = '1.1';
78 78
79 our @BDB_REQ = qw( 79 our @BDB_REQ = qw(
80 db_env_open db_env_close db_env_txn_checkpoint db_env_lock_detect 80 db_env_open db_env_close db_env_txn_checkpoint db_env_lock_detect
81 db_env_memp_sync db_env_memp_trickle 81 db_env_memp_sync db_env_memp_trickle
82 db_open db_close db_compact db_sync db_put db_get db_pget db_del db_key_range 82 db_open db_close db_compact db_sync db_put db_get db_pget db_del db_key_range
83 db_txn_commit db_txn_abort 83 db_txn_commit db_txn_abort db_txn_finish
84 db_c_close db_c_count db_c_put db_c_get db_c_pget db_c_del 84 db_c_close db_c_count db_c_put db_c_get db_c_pget db_c_del
85 db_sequence_open db_sequence_close 85 db_sequence_open db_sequence_close
86 db_sequence_get db_sequence_remove 86 db_sequence_get db_sequence_remove
87 ); 87 );
88 our @EXPORT = (@BDB_REQ, qw(dbreq_pri dbreq_nice db_env_create db_create)); 88 our @EXPORT = (@BDB_REQ, qw(dbreq_pri dbreq_nice db_env_create db_create));
… …
126=head3 BDB functions 126=head3 BDB functions
127 127
128Functions in the BDB namespace, exported by default: 128Functions in the BDB namespace, exported by default:
129 129
130 $env = db_env_create (U32 env_flags = 0) 130 $env = db_env_create (U32 env_flags = 0)
131 flags: RPCCLIENT
131 132
132 db_env_open (DB_ENV *env, octetstring db_home, U32 open_flags, int mode, SV *callback = &PL_sv_undef) 133 db_env_open (DB_ENV *env, octetstring db_home, U32 open_flags, int mode, SV *callback = &PL_sv_undef)
134 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
133 db_env_close (DB_ENV *env, U32 flags = 0, SV *callback = &PL_sv_undef) 135 db_env_close (DB_ENV *env, U32 flags = 0, SV *callback = &PL_sv_undef)
134 db_env_txn_checkpoint (DB_ENV *env, U32 kbyte = 0, U32 min = 0, U32 flags = 0, SV *callback = &PL_sv_undef) 136 db_env_txn_checkpoint (DB_ENV *env, U32 kbyte = 0, U32 min = 0, U32 flags = 0, SV *callback = &PL_sv_undef)
137 flags: FORCE
135 db_env_lock_detect (DB_ENV *env, U32 flags = 0, U32 atype = DB_LOCK_DEFAULT, SV *dummy = 0, SV *callback = &PL_sv_undef) 138 db_env_lock_detect (DB_ENV *env, U32 flags = 0, U32 atype = DB_LOCK_DEFAULT, SV *dummy = 0, SV *callback = &PL_sv_undef)
139 atype: LOCK_DEFAULT LOCK_EXPIRE LOCK_MAXLOCKS LOCK_MAXWRITE LOCK_MINLOCKS LOCK_MINWRITE LOCK_OLDEST LOCK_RANDOM LOCK_YOUNGEST
136 db_env_memp_sync (DB_ENV *env, SV *dummy = 0, SV *callback = &PL_sv_undef) 140 db_env_memp_sync (DB_ENV *env, SV *dummy = 0, SV *callback = &PL_sv_undef)
137 db_env_memp_trickle (DB_ENV *env, int percent, SV *dummy = 0, SV *callback = &PL_sv_undef) 141 db_env_memp_trickle (DB_ENV *env, int percent, SV *dummy = 0, SV *callback = &PL_sv_undef)
138 142
139 $db = db_create (DB_ENV *env = 0, U32 flags = 0) 143 $db = db_create (DB_ENV *env = 0, U32 flags = 0)
144 flags: XA_CREATE
140 145
141 db_open (DB *db, DB_TXN_ornull *txnid, octetstring file, octetstring database, int type, U32 flags, int mode, SV *callback = &PL_sv_undef) 146 db_open (DB *db, DB_TXN_ornull *txnid, octetstring file, octetstring database, int type, U32 flags, int mode, SV *callback = &PL_sv_undef)
147 flags: AUTO_COMMIT CREATE EXCL MULTIVERSION NOMMAP RDONLY READ_UNCOMMITTED THREAD TRUNCATE
142 db_close (DB *db, U32 flags = 0, SV *callback = &PL_sv_undef) 148 db_close (DB *db, U32 flags = 0, SV *callback = &PL_sv_undef)
149 flags: DB_NOSYNC
143 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) 150 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)
151 flags: FREELIST_ONLY FREE_SPACE
144 db_sync (DB *db, U32 flags = 0, SV *callback = &PL_sv_undef) 152 db_sync (DB *db, U32 flags = 0, SV *callback = &PL_sv_undef)
145 db_key_range (DB *db, DB_TXN_ornull *txn, SV *key, SV *key_range, U32 flags = 0, SV *callback = &PL_sv_undef) 153 db_key_range (DB *db, DB_TXN_ornull *txn, SV *key, SV *key_range, U32 flags = 0, SV *callback = &PL_sv_undef)
146 db_put (DB *db, DB_TXN_ornull *txn, SV *key, SV *data, U32 flags = 0, SV *callback = &PL_sv_undef) 154 db_put (DB *db, DB_TXN_ornull *txn, SV *key, SV *data, U32 flags = 0, SV *callback = &PL_sv_undef)
155 flags: APPEND NODUPDATA NOOVERWRITE
147 db_get (DB *db, DB_TXN_ornull *txn, SV *key, SV *data, U32 flags = 0, SV *callback = &PL_sv_undef) 156 db_get (DB *db, DB_TXN_ornull *txn, SV *key, SV *data, U32 flags = 0, SV *callback = &PL_sv_undef)
157 flags: CONSUME CONSUME_WAIT GET_BOTH SET_RECNO MULTIPLE READ_COMMITTED READ_UNCOMMITTED RMW
148 db_pget (DB *db, DB_TXN_ornull *txn, SV *key, SV *pkey, SV *data, U32 flags = 0, SV *callback = &PL_sv_undef) 158 db_pget (DB *db, DB_TXN_ornull *txn, SV *key, SV *pkey, SV *data, U32 flags = 0, SV *callback = &PL_sv_undef)
159 flags: CONSUME CONSUME_WAIT GET_BOTH SET_RECNO MULTIPLE READ_COMMITTED READ_UNCOMMITTED RMW
149 db_del (DB *db, DB_TXN_ornull *txn, SV *key, U32 flags = 0, SV *callback = &PL_sv_undef) 160 db_del (DB *db, DB_TXN_ornull *txn, SV *key, U32 flags = 0, SV *callback = &PL_sv_undef)
150 db_txn_commit (DB_TXN *txn, U32 flags = 0, SV *callback = &PL_sv_undef) 161 db_txn_commit (DB_TXN *txn, U32 flags = 0, SV *callback = &PL_sv_undef)
162 flags: TXN_NOSYNC TXN_SYNC
151 db_txn_abort (DB_TXN *txn, SV *callback = &PL_sv_undef) 163 db_txn_abort (DB_TXN *txn, SV *callback = &PL_sv_undef)
164
152 db_c_close (DBC *dbc, SV *callback = &PL_sv_undef) 165 db_c_close (DBC *dbc, SV *callback = &PL_sv_undef)
153 db_c_count (DBC *dbc, SV *count, U32 flags = 0, SV *callback = &PL_sv_undef) 166 db_c_count (DBC *dbc, SV *count, U32 flags = 0, SV *callback = &PL_sv_undef)
154 db_c_put (DBC *dbc, SV *key, SV *data, U32 flags = 0, SV *callback = &PL_sv_undef) 167 db_c_put (DBC *dbc, SV *key, SV *data, U32 flags = 0, SV *callback = &PL_sv_undef)
168 flags: AFTER BEFORE CURRENT KEYFIRST KEYLAST NODUPDATA
155 db_c_get (DBC *dbc, SV *key, SV *data, U32 flags = 0, SV *callback = &PL_sv_undef) 169 db_c_get (DBC *dbc, SV *key, SV *data, U32 flags = 0, SV *callback = &PL_sv_undef)
170 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
156 db_c_pget (DBC *dbc, SV *key, SV *pkey, SV *data, U32 flags = 0, SV *callback = &PL_sv_undef) 171 db_c_pget (DBC *dbc, SV *key, SV *pkey, SV *data, U32 flags = 0, SV *callback = &PL_sv_undef)
157 db_c_del (DBC *dbc, U32 flags = 0, SV *callback = &PL_sv_undef) 172 db_c_del (DBC *dbc, U32 flags = 0, SV *callback = &PL_sv_undef)
158 173
159 db_sequence_open (DB_SEQUENCE *seq, DB_TXN_ornull *txnid, SV *key, U32 flags = 0, SV *callback = &PL_sv_undef) 174 db_sequence_open (DB_SEQUENCE *seq, DB_TXN_ornull *txnid, SV *key, U32 flags = 0, SV *callback = &PL_sv_undef)
175 flags: CREATE EXCL
160 db_sequence_close (DB_SEQUENCE *seq, U32 flags = 0, SV *callback = &PL_sv_undef) 176 db_sequence_close (DB_SEQUENCE *seq, U32 flags = 0, SV *callback = &PL_sv_undef)
161 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) 177 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)
178 flags: TXN_NOSYNC
162 db_sequence_remove (DB_SEQUENCE *seq, DB_TXN_ornull *txnid = 0, U32 flags = 0, SV *callback = &PL_sv_undef) 179 db_sequence_remove (DB_SEQUENCE *seq, DB_TXN_ornull *txnid = 0, U32 flags = 0, SV *callback = &PL_sv_undef)
180 flags: TXN_NOSYNC
163 181
182=head4 db_txn_finish (DB_TXN *txn, U32 flags = 0, SV *callback = &PL_sv_undef)
183
184This is not actually a Berkeley DB function but a BDB module
185extension. The background for this exytension is: It is very annoying to
186have to check every single BDB function for error returns and provide a
187codepath out of your transaction. While the BDB module still makes this
188possible, it contains the following extensions:
189
190When a transaction-protected function returns any operating system
191error (errno > 0), BDB will set the C<TXN_DEADLOCK> flag on the
192transaction. This flag is also set by Berkeley DB functions themselves
193when an operation fails with LOCK_DEADLOCK, and it causes all further
194operations on that transaction (including C<db_txn_commit>) to fail.
195
196The C<db_txn_finish> request will look at this flag, and, if it is set,
197will automatically call C<db_txn_abort> (setting errno to C<LOCK_DEADLOCK>
198if it isn't set to something else yet). If it isn't set, it will call
199C<db_txn_commit> and return the error normally.
200
201How to use this? Easy: just write your transaction normally:
202
203 my $txn = $db_env->txn_begin;
204 db_get $db, $txn, "key", my $data;
205 db_put $db, $txn, "key", $data + 1 unless $! == BDB::NOTFOUND;
206 db_txn_finish $txn;
207 die "transaction failed" if $!;
208
209That is, handle only the expected errors. If something unexpected happens
210(EIO, LOCK_NOTGRANTED or a deadlock in either db_get or db_put), then the remaining
211requests (db_put in this case) will simply be skipped (they will fail with
212LOCK_DEADLOCK) and the transaction will be aborted.
213
214You can use the C<< $txn->failed >> method to check wether a transaction
215has failed in this way and abort further processing (excluding
216C<db_txn_finish>).
164 217
165=head3 DB_ENV/database environment methods 218=head3 DB_ENV/database environment methods
166 219
167Methods available on DB_ENV/$env handles: 220Methods available on DB_ENV/$env handles:
168 221
… …
179 $int = $env->set_flags (U32 flags, int onoff) 232 $int = $env->set_flags (U32 flags, int onoff)
180 $env->set_errfile (FILE *errfile = 0) 233 $env->set_errfile (FILE *errfile = 0)
181 $env->set_msgfile (FILE *msgfile = 0) 234 $env->set_msgfile (FILE *msgfile = 0)
182 $int = $env->set_verbose (U32 which, int onoff = 1) 235 $int = $env->set_verbose (U32 which, int onoff = 1)
183 $int = $env->set_encrypt (const char *password, U32 flags = 0) 236 $int = $env->set_encrypt (const char *password, U32 flags = 0)
184 $int = $env->set_timeout (NV timeout, U32 flags) 237 $int = $env->set_timeout (NV timeout_seconds, U32 flags = SET_TXN_TIMEOUT)
185 $int = $env->set_mp_max_openfd (int maxopenfd); 238 $int = $env->set_mp_max_openfd (int maxopenfd);
186 $int = $env->set_mp_max_write (int maxwrite, int maxwrite_sleep); 239 $int = $env->set_mp_max_write (int maxwrite, int maxwrite_sleep);
187 $int = $env->set_mp_mmapsize (int mmapsize_mb) 240 $int = $env->set_mp_mmapsize (int mmapsize_mb)
188 $int = $env->set_lk_detect (U32 detect = DB_LOCK_DEFAULT) 241 $int = $env->set_lk_detect (U32 detect = DB_LOCK_DEFAULT)
189 $int = $env->set_lk_max_lockers (U32 max) 242 $int = $env->set_lk_max_lockers (U32 max)
… …
191 $int = $env->set_lk_max_objects (U32 max) 244 $int = $env->set_lk_max_objects (U32 max)
192 $int = $env->set_lg_bsize (U32 max) 245 $int = $env->set_lg_bsize (U32 max)
193 $int = $env->set_lg_max (U32 max) 246 $int = $env->set_lg_max (U32 max)
194 247
195 $txn = $env->txn_begin (DB_TXN_ornull *parent = 0, U32 flags = 0) 248 $txn = $env->txn_begin (DB_TXN_ornull *parent = 0, U32 flags = 0)
249 flags: READ_COMMITTED READ_UNCOMMITTED TXN_NOSYNC TXN_NOWAIT TXN_SNAPSHOT TXN_SYNC TXN_WAIT TXN_WRITE_NOSYNC
196 250
197=head4 Example: 251=head4 Example:
198 252
199 use AnyEvent; 253 use AnyEvent;
200 use BDB; 254 use BDB;
… …
229 SvREFCNT_dec (env); 283 SvREFCNT_dec (env);
230 } 284 }
231 285
232 $int = $db->set_cachesize (U32 gbytes, U32 bytes, int ncache = 0) 286 $int = $db->set_cachesize (U32 gbytes, U32 bytes, int ncache = 0)
233 $int = $db->set_flags (U32 flags) 287 $int = $db->set_flags (U32 flags)
288 flags: CHKSUM ENCRYPT TXN_NOT_DURABLE
289 Btree: DUP DUPSORT RECNUM REVSPLITOFF
290 Hash: DUP DUPSORT
291 Queue: INORDER
292 Recno: RENUMBER SNAPSHOT
293
234 $int = $db->set_encrypt (const char *password, U32 flags) 294 $int = $db->set_encrypt (const char *password, U32 flags)
235 $int = $db->set_lorder (int lorder) 295 $int = $db->set_lorder (int lorder)
236 $int = $db->set_bt_minkey (U32 minkey) 296 $int = $db->set_bt_minkey (U32 minkey)
237 $int = $db->set_re_delim (int delim) 297 $int = $db->set_re_delim (int delim)
238 $int = $db->set_re_pad (int re_pad) 298 $int = $db->set_re_pad (int re_pad)
… …
241 $int = $db->set_h_ffactor (U32 h_ffactor) 301 $int = $db->set_h_ffactor (U32 h_ffactor)
242 $int = $db->set_h_nelem (U32 h_nelem) 302 $int = $db->set_h_nelem (U32 h_nelem)
243 $int = $db->set_q_extentsize (U32 extentsize) 303 $int = $db->set_q_extentsize (U32 extentsize)
244 304
245 $dbc = $db->cursor (DB_TXN_ornull *txn = 0, U32 flags = 0) 305 $dbc = $db->cursor (DB_TXN_ornull *txn = 0, U32 flags = 0)
306 flags: READ_COMMITTED READ_UNCOMMITTED WRITECURSOR TXN_SNAPSHOT
246 $seq = $db->sequence (U32 flags = 0) 307 $seq = $db->sequence (U32 flags = 0)
247 308
248=head4 Example: 309=head4 Example:
249 310
250 my $db = db_create $env; 311 my $db = db_create $env;
… …
269 DESTROY (DB_TXN_ornull *txn) 330 DESTROY (DB_TXN_ornull *txn)
270 CODE: 331 CODE:
271 if (txn) 332 if (txn)
272 txn->abort (txn); 333 txn->abort (txn);
273 334
274 $int = $txn->set_timeout (NV timeout, U32 flags) 335 $int = $txn->set_timeout (NV timeout_seconds, U32 flags = SET_TXN_TIMEOUT)
336 flags: SET_LOCK_TIMEOUT SET_TXN_TIMEOUT
337
338 $bool = $txn->failed
339 # see db_txn_finish documentation, above
275 340
276 341
277=head3 DBC/cursor methods 342=head3 DBC/cursor methods
278 343
279Methods available on DBC/$dbc handles: 344Methods available on DBC/$dbc handles:
… …
306 seq->close (seq, 0); 371 seq->close (seq, 0);
307 372
308 $int = $seq->initial_value (db_seq_t value) 373 $int = $seq->initial_value (db_seq_t value)
309 $int = $seq->set_cachesize (U32 size) 374 $int = $seq->set_cachesize (U32 size)
310 $int = $seq->set_flags (U32 flags) 375 $int = $seq->set_flags (U32 flags)
376 flags: SEQ_DEC SEQ_INC SEQ_WRAP
311 $int = $seq->set_range (db_seq_t min, db_seq_t max) 377 $int = $seq->set_range (db_seq_t min, db_seq_t max)
312 378
313=head4 Example: 379=head4 Example:
314 380
315 my $seq = $db->sequence; 381 my $seq = $db->sequence;
… …
571bytes of memory. In addition, stat requests need a stat buffer (possibly 637bytes of memory. In addition, stat requests need a stat buffer (possibly
572a few hundred bytes), readdir requires a result buffer and so on. Perl 638a few hundred bytes), readdir requires a result buffer and so on. Perl
573scalars and other data passed into aio requests will also be locked and 639scalars and other data passed into aio requests will also be locked and
574will consume memory till the request has entered the done state. 640will consume memory till the request has entered the done state.
575 641
576This is now awfully much, so queuing lots of requests is not usually a 642This is not awfully much, so queuing lots of requests is not usually a
577problem. 643problem.
578 644
579Per-thread usage: 645Per-thread usage:
580 646
581In the execution phase, some aio requests require more memory for 647In the execution phase, some aio requests require more memory for
582temporary buffers, and each thread requires a stack and other data 648temporary buffers, and each thread requires a stack and other data
583structures (usually around 16k-128k, depending on the OS). 649structures (usually around 16k-128k, depending on the OS).
584 650
585=head1 KNOWN BUGS 651=head1 KNOWN BUGS
586 652
587Known bugs will be fixed in the next release. 653Known bugs will be fixed in the next release, except:
654
655 If you use a transaction in any request, and the request returns
656 with an operating system error or DB_LOCK_NOTGRANTED, the internal
657 TXN_DEADLOCK flag will be set on the transaction. See C<db_txn_finish>,
658 above.
588 659
589=head1 SEE ALSO 660=head1 SEE ALSO
590 661
591L<Coro::AIO>. 662L<Coro::AIO>.
592 663

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