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Comparing BDB/BDB.pm (file contents):
Revision 1.20 by root, Fri Dec 7 13:14:41 2007 UTC vs.
Revision 1.39 by root, Tue Jul 8 08:25:31 2008 UTC

24 db_put $db, undef, "key", "data", 0, sub { 24 db_put $db, undef, "key", "data", 0, sub {
25 db_del $db, undef, "key"; 25 db_del $db, undef, "key";
26 }; 26 };
27 db_sync $db; 27 db_sync $db;
28 28
29 # automatic result processing with AnyEvent: 29 # when you also use Coro, management is easy:
30 our $FH; open $FH, "<&=" . BDB::poll_fileno; 30 use Coro::BDB;
31 our $WATCHER = AnyEvent->io (fh => $FH, poll => 'r', cb => \&BDB::poll_cb); 31
32 # automatic event loop intergration with AnyEvent:
33 use AnyEvent::BDB;
32 34
33 # automatic result processing with EV: 35 # automatic result processing with EV:
34 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;
35 37
36 # with Glib: 38 # with Glib:
107use strict 'vars'; 109use strict 'vars';
108 110
109use base 'Exporter'; 111use base 'Exporter';
110 112
111BEGIN { 113BEGIN {
112 our $VERSION = '1.2'; 114 our $VERSION = '1.6';
113 115
114 our @BDB_REQ = qw( 116 our @BDB_REQ = qw(
115 db_env_open db_env_close db_env_txn_checkpoint db_env_lock_detect 117 db_env_open db_env_close db_env_txn_checkpoint db_env_lock_detect
116 db_env_memp_sync db_env_memp_trickle 118 db_env_memp_sync db_env_memp_trickle db_env_dbrename db_env_dbremove
117 db_open db_close db_compact db_sync db_put db_get db_pget db_del db_key_range 119 db_open db_close db_compact db_sync db_upgrade
120 db_put db_get db_pget db_del db_key_range
118 db_txn_commit db_txn_abort db_txn_finish 121 db_txn_commit db_txn_abort db_txn_finish
119 db_c_close db_c_count db_c_put db_c_get db_c_pget db_c_del 122 db_c_close db_c_count db_c_put db_c_get db_c_pget db_c_del
120 db_sequence_open db_sequence_close 123 db_sequence_open db_sequence_close
121 db_sequence_get db_sequence_remove 124 db_sequence_get db_sequence_remove
122 ); 125 );
130 133
131 require XSLoader; 134 require XSLoader;
132 XSLoader::load ("BDB", $VERSION); 135 XSLoader::load ("BDB", $VERSION);
133} 136}
134 137
138=head2 WIN32 FILENAMES/DATABASE NAME MESS
139
140Perl on Win32 supports only ASCII filenames (the reason is that it abuses
141an internal flag to store wether a filename is Unicode or ANSI, but that
142flag is used for somethign else in the perl core, so there is no way to
143detect wether a filename is ANSI or Unicode-encoded). The BDB module
144tries to work around this issue by assuming that the filename is an ANSI
145filename and BDB was built for unicode support.
146
135=head2 BERKELEYDB FUNCTIONS 147=head2 BERKELEYDB FUNCTIONS
136 148
137All of these are functions. The create functions simply return a new 149All of these are functions. The create functions simply return a new
138object and never block. All the remaining functions all take an optional 150object and never block. All the remaining functions take an optional
139callback as last argument. If it is missing, then the fucntion will be 151callback as last argument. If it is missing, then the function will be
140executed synchronously. 152executed synchronously. In both cases, C<$!> will reflect the return value
153of the function.
141 154
142BDB functions that cannot block (mostly functions that manipulate 155BDB functions that cannot block (mostly functions that manipulate
143settings) are method calls on the relevant objects, so the rule of thumb 156settings) are method calls on the relevant objects, so the rule of thumb
144is: if its a method, its not blocking, if its a function, it takes a 157is: if it's a method, it's not blocking, if it's a function, it takes a
145callback as last argument. 158callback as last argument.
146 159
147In the following, C<$int> signifies an integer return value, 160In the following, C<$int> signifies an integer return value,
148C<octetstring> is a "binary string" (i.e. a perl string with no character 161C<bdb_filename> is a "filename" (octets on unix, madness on windows),
149indices >255), C<U32> is an unsigned 32 bit integer, C<int> is some 162C<U32> is an unsigned 32 bit integer, C<int> is some integer, C<NV> is a
150integer, C<NV> is a floating point value. 163floating point value.
151 164
152The C<SV *> types are generic perl scalars (for input and output of data 165The C<SV *> types are generic perl scalars (for input and output of data
153values), and the C<SV *callback> is the optional callback function to call 166values), and the C<SV *callback> is the optional callback function to call
154when the request is completed. 167when the request is completed.
155 168
163Functions in the BDB namespace, exported by default: 176Functions in the BDB namespace, exported by default:
164 177
165 $env = db_env_create (U32 env_flags = 0) 178 $env = db_env_create (U32 env_flags = 0)
166 flags: RPCCLIENT 179 flags: RPCCLIENT
167 180
168 db_env_open (DB_ENV *env, octetstring db_home, U32 open_flags, int mode, SV *callback = &PL_sv_undef) 181 db_env_open (DB_ENV *env, bdb_filename db_home, U32 open_flags, int mode, SV *callback = &PL_sv_undef)
169 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 182 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
170 db_env_close (DB_ENV *env, U32 flags = 0, SV *callback = &PL_sv_undef) 183 db_env_close (DB_ENV *env, U32 flags = 0, SV *callback = &PL_sv_undef)
171 db_env_txn_checkpoint (DB_ENV *env, U32 kbyte = 0, U32 min = 0, U32 flags = 0, SV *callback = &PL_sv_undef) 184 db_env_txn_checkpoint (DB_ENV *env, U32 kbyte = 0, U32 min = 0, U32 flags = 0, SV *callback = &PL_sv_undef)
172 flags: FORCE 185 flags: FORCE
173 db_env_lock_detect (DB_ENV *env, U32 flags = 0, U32 atype = DB_LOCK_DEFAULT, SV *dummy = 0, SV *callback = &PL_sv_undef) 186 db_env_lock_detect (DB_ENV *env, U32 flags = 0, U32 atype = DB_LOCK_DEFAULT, SV *dummy = 0, SV *callback = &PL_sv_undef)
174 atype: LOCK_DEFAULT LOCK_EXPIRE LOCK_MAXLOCKS LOCK_MAXWRITE LOCK_MINLOCKS LOCK_MINWRITE LOCK_OLDEST LOCK_RANDOM LOCK_YOUNGEST 187 atype: LOCK_DEFAULT LOCK_EXPIRE LOCK_MAXLOCKS LOCK_MAXWRITE LOCK_MINLOCKS LOCK_MINWRITE LOCK_OLDEST LOCK_RANDOM LOCK_YOUNGEST
175 db_env_memp_sync (DB_ENV *env, SV *dummy = 0, SV *callback = &PL_sv_undef) 188 db_env_memp_sync (DB_ENV *env, SV *dummy = 0, SV *callback = &PL_sv_undef)
176 db_env_memp_trickle (DB_ENV *env, int percent, SV *dummy = 0, SV *callback = &PL_sv_undef) 189 db_env_memp_trickle (DB_ENV *env, int percent, SV *dummy = 0, SV *callback = &PL_sv_undef)
190 db_env_dbremove (DB_ENV *env, DB_TXN_ornull *txnid, bdb_filename file, bdb_filename database, U32 flags = 0, SV *callback = &PL_sv_undef)
191 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)
177 192
178 $db = db_create (DB_ENV *env = 0, U32 flags = 0) 193 $db = db_create (DB_ENV *env = 0, U32 flags = 0)
179 flags: XA_CREATE 194 flags: XA_CREATE
180 195
181 db_open (DB *db, DB_TXN_ornull *txnid, octetstring file, octetstring database, int type, U32 flags, int mode, SV *callback = &PL_sv_undef) 196 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)
182 flags: AUTO_COMMIT CREATE EXCL MULTIVERSION NOMMAP RDONLY READ_UNCOMMITTED THREAD TRUNCATE 197 flags: AUTO_COMMIT CREATE EXCL MULTIVERSION NOMMAP RDONLY READ_UNCOMMITTED THREAD TRUNCATE
183 db_close (DB *db, U32 flags = 0, SV *callback = &PL_sv_undef) 198 db_close (DB *db, U32 flags = 0, SV *callback = &PL_sv_undef)
184 flags: DB_NOSYNC 199 flags: DB_NOSYNC
200 db_upgrade (DB *db, bdb_filename file, U32 flags = 0, SV *callback = &PL_sv_undef)
185 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) 201 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)
186 flags: FREELIST_ONLY FREE_SPACE 202 flags: FREELIST_ONLY FREE_SPACE
187 db_sync (DB *db, U32 flags = 0, SV *callback = &PL_sv_undef) 203 db_sync (DB *db, U32 flags = 0, SV *callback = &PL_sv_undef)
188 db_key_range (DB *db, DB_TXN_ornull *txn, SV *key, SV *key_range, U32 flags = 0, SV *callback = &PL_sv_undef) 204 db_key_range (DB *db, DB_TXN_ornull *txn, SV *key, SV *key_range, U32 flags = 0, SV *callback = &PL_sv_undef)
189 db_put (DB *db, DB_TXN_ornull *txn, SV *key, SV *data, U32 flags = 0, SV *callback = &PL_sv_undef) 205 db_put (DB *db, DB_TXN_ornull *txn, SV *key, SV *data, U32 flags = 0, SV *callback = &PL_sv_undef)
262 $int = $env->set_data_dir (const char *dir) 278 $int = $env->set_data_dir (const char *dir)
263 $int = $env->set_tmp_dir (const char *dir) 279 $int = $env->set_tmp_dir (const char *dir)
264 $int = $env->set_lg_dir (const char *dir) 280 $int = $env->set_lg_dir (const char *dir)
265 $int = $env->set_shm_key (long shm_key) 281 $int = $env->set_shm_key (long shm_key)
266 $int = $env->set_cachesize (U32 gbytes, U32 bytes, int ncache = 0) 282 $int = $env->set_cachesize (U32 gbytes, U32 bytes, int ncache = 0)
267 $int = $env->set_flags (U32 flags, int onoff) 283 $int = $env->set_flags (U32 flags, int onoff = 1)
284 $int = $env->log_set_config (U32 flags, int onoff = 1) [v4.7]
285 $int = $env->set_intermediate_dir_mode (const char *modestring) [v4.7]
268 $env->set_errfile (FILE *errfile = 0) 286 $env->set_errfile (FILE *errfile = 0)
269 $env->set_msgfile (FILE *msgfile = 0) 287 $env->set_msgfile (FILE *msgfile = 0)
270 $int = $env->set_verbose (U32 which, int onoff = 1) 288 $int = $env->set_verbose (U32 which, int onoff = 1)
271 $int = $env->set_encrypt (const char *password, U32 flags = 0) 289 $int = $env->set_encrypt (const char *password, U32 flags = 0)
272 $int = $env->set_timeout (NV timeout_seconds, U32 flags = SET_TXN_TIMEOUT) 290 $int = $env->set_timeout (NV timeout_seconds, U32 flags = SET_TXN_TIMEOUT)
385 DESTROY (DBC_ornull *dbc) 403 DESTROY (DBC_ornull *dbc)
386 CODE: 404 CODE:
387 if (dbc) 405 if (dbc)
388 dbc->c_close (dbc); 406 dbc->c_close (dbc);
389 407
408 $int = $cursor->set_priority ($priority = PRIORITY_*)
409
390=head4 Example: 410=head4 Example:
391 411
392 my $c = $db->cursor; 412 my $c = $db->cursor;
393 413
394 for (;;) { 414 for (;;) {
427 447
428=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 448=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
429 449
430=over 4 450=over 4
431 451
452=item $msg = BDB::strerror [$errno]
453
454Returns the string corresponding to the given errno value. If no argument
455is given, use C<$!>.
456
457Note that the BDB module also patches the C<$!> variable directly, so you
458should be able to get a bdb error string by simply stringifying C<$!>.
459
432=item $fileno = BDB::poll_fileno 460=item $fileno = BDB::poll_fileno
433 461
434Return the I<request result pipe file descriptor>. This filehandle must be 462Return the I<request result pipe file descriptor>. This filehandle must be
435polled for reading by some mechanism outside this module (e.g. Event or 463polled for reading by some mechanism outside this module (e.g. Event or
436select, see below or the SYNOPSIS). If the pipe becomes readable you have 464select, see below or the SYNOPSIS). If the pipe becomes readable you have
512 BDB::poll_wait, BDB::poll_cb 540 BDB::poll_wait, BDB::poll_cb
513 while BDB::nreqs; 541 while BDB::nreqs;
514 542
515=back 543=back
516 544
545=head3 VERSION CHECKING
546
547BerkeleyDB comes in various versions, many of them have minor
548incompatibilities. This means that traditional "at least version x.x"
549checks are often not sufficient.
550
551=over 4
552
553=item BDB::VERSION
554
555The C<BDB::VERSION> function, when called without arguments, returns the
556Berkeley DB version as a v-string (usually with 3 components). You should
557use C<lt> and C<ge> operators exclusively to make comparisons.
558
559Example: check for at least version 4.7.
560
561 BDB::VERSION ge v4.7 or die;
562
563=item BDB::VERSION min-version
564
565Returns true if the BDB version is at least the given version (specified
566as a v-string), false otherwise.
567
568Example: check for at least version 4.5.
569
570 BDB::VERSION v4.7 or die;
571
572=item BDB::VERSION min-version, max-version
573
574Returns true of the BDB version is at least version C<min-version> (specify C<undef> or C<v0> for any minimum version)
575and less then C<max-version>.
576
577Example: check wether version is strictly less then v4.7.
578
579 BDB::VERSION v0, v4.7
580 or die "version 4.7 is not yet supported";
581
582=back
583
584=cut
585
586sub VERSION {
587 if (@_ > 0) {
588 return undef if VERSION_v lt $_[0];
589 if (@_ > 1) {
590 return undef if VERSION_v ge $_[1];
591 }
592 }
593
594 VERSION_v
595}
596
517=head3 CONTROLLING THE NUMBER OF THREADS 597=head3 CONTROLLING THE NUMBER OF THREADS
518 598
519=over 4 599=over 4
520 600
521=item BDB::min_parallel $nthreads 601=item BDB::min_parallel $nthreads
587 667
588=item BDB::set_sync_prepare $cb 668=item BDB::set_sync_prepare $cb
589 669
590Sets a callback that is called whenever a request is created without an 670Sets a callback that is called whenever a request is created without an
591explicit callback. It has to return two code references. The first is used 671explicit callback. It has to return two code references. The first is used
592as the request callback, and the second is called to wait until the first 672as the request callback (it should save the return status), and the second
673is called to wait until the first callback has been called (it must set
674C<$!> to the return status).
675
676This mechanism can be used to include BDB into other event mechanisms,
677such as L<AnyEvent::BDB> or L<Coro::BDB>.
678
593callback has been called. The default implementation works like this: 679The default implementation works like this:
594 680
595 sub { 681 sub {
596 my $status; 682 my $status;
597 ( 683 (
598 sub { $status = $! }, 684 sub { $status = $! },
599 sub { BDB::poll while !defined $status; $! = $status }, 685 sub { BDB::poll while !defined $status; $! = $status },
600 ) 686 )
601 } 687 }
688
689It simply blocks the process till the request has finished and then sets
690C<$!> to the return value. This means that if you don't use a callback,
691BDB will simply fall back to synchronous operations.
602 692
603=back 693=back
604 694
605=head3 STATISTICAL INFORMATION 695=head3 STATISTICAL INFORMATION
606 696
663 753
664In short: the parent will, after a short pause, continue as if fork had 754In short: the parent will, after a short pause, continue as if fork had
665not been called, while the child will act as if BDB has not been used 755not been called, while the child will act as if BDB has not been used
666yet. 756yet.
667 757
758Win32 note: there is no fork on win32, and perls emulation of it is too
759broken to be supported, so do not use BDB in a windows pseudo-fork, better
760yet, switch to a more capable platform.
761
668=head2 MEMORY USAGE 762=head2 MEMORY USAGE
669 763
670Per-request usage: 764Per-request usage:
671 765
672Each aio request uses - depending on your architecture - around 100-200 766Each aio request uses - depending on your architecture - around 100-200
693 TXN_DEADLOCK flag will be set on the transaction. See C<db_txn_finish>, 787 TXN_DEADLOCK flag will be set on the transaction. See C<db_txn_finish>,
694 above. 788 above.
695 789
696=head1 SEE ALSO 790=head1 SEE ALSO
697 791
698L<Coro::BDB>, L<IO::AIO>. 792L<AnyEvent::BDB> (event loop integration), L<Coro::BDB> (more natural
793syntax), L<IO::AIO> (nice to have).
699 794
700=head1 AUTHOR 795=head1 AUTHOR
701 796
702 Marc Lehmann <schmorp@schmorp.de> 797 Marc Lehmann <schmorp@schmorp.de>
703 http://home.schmorp.de/ 798 http://home.schmorp.de/

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