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Comparing BDB/BDB.pm (file contents):
Revision 1.25 by root, Mon Dec 10 21:19:06 2007 UTC vs.
Revision 1.38 by root, Mon Jul 7 22:11:04 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:
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107use strict 'vars'; 109use strict 'vars';
108 110
109use base 'Exporter'; 111use base 'Exporter';
110 112
111BEGIN { 113BEGIN {
112 our $VERSION = '1.3'; 114 our $VERSION = '1.5';
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_upgrade 119 db_open db_close db_compact db_sync db_upgrade
118 db_put db_get db_pget db_del db_key_range 120 db_put db_get db_pget db_del db_key_range
119 db_txn_commit db_txn_abort db_txn_finish 121 db_txn_commit db_txn_abort db_txn_finish
120 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
121 db_sequence_open db_sequence_close 123 db_sequence_open db_sequence_close
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131 133
132 require XSLoader; 134 require XSLoader;
133 XSLoader::load ("BDB", $VERSION); 135 XSLoader::load ("BDB", $VERSION);
134} 136}
135 137
138=head2 WIN32 FILENAMES/DATABASE NAME MESS
139
140Perl on Win32 supports only ASCII filenames (the reason is that it abuses
141an internal flag to store wether a filename is Unicode or ANSI, but that
142flag is used for somethign else in the perl core, so there is no way to
143detect wether a filename is ANSI or Unicode-encoded). The BDB module
144tries to work around this issue by assuming that the filename is an ANSI
145filename and BDB was built for unicode support.
146
136=head2 BERKELEYDB FUNCTIONS 147=head2 BERKELEYDB FUNCTIONS
137 148
138All of these are functions. The create functions simply return a new 149All of these are functions. The create functions simply return a new
139object and never block. All the remaining functions all take an optional 150object and never block. All the remaining functions take an optional
140callback as last argument. If it is missing, then the function will be 151callback as last argument. If it is missing, then the function will be
141executed synchronously. In both cases, C<$!> will reflect the return value 152executed synchronously. In both cases, C<$!> will reflect the return value
142of the function. 153of the function.
143 154
144BDB functions that cannot block (mostly functions that manipulate 155BDB functions that cannot block (mostly functions that manipulate
145settings) are method calls on the relevant objects, so the rule of thumb 156settings) are method calls on the relevant objects, so the rule of thumb
146is: if its a method, its not blocking, if its a function, it takes a 157is: if it's a method, it's not blocking, if it's a function, it takes a
147callback as last argument. 158callback as last argument.
148 159
149In the following, C<$int> signifies an integer return value, 160In the following, C<$int> signifies an integer return value,
150C<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),
151indices >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
152integer, C<NV> is a floating point value. 163floating point value.
153 164
154The 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
155values), 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
156when the request is completed. 167when the request is completed.
157 168
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165Functions in the BDB namespace, exported by default: 176Functions in the BDB namespace, exported by default:
166 177
167 $env = db_env_create (U32 env_flags = 0) 178 $env = db_env_create (U32 env_flags = 0)
168 flags: RPCCLIENT 179 flags: RPCCLIENT
169 180
170 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)
171 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
172 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)
173 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)
174 flags: FORCE 185 flags: FORCE
175 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)
176 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
177 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)
178 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)
179 192
180 $db = db_create (DB_ENV *env = 0, U32 flags = 0) 193 $db = db_create (DB_ENV *env = 0, U32 flags = 0)
181 flags: XA_CREATE 194 flags: XA_CREATE
182 195
183 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)
184 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
185 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)
186 flags: DB_NOSYNC 199 flags: DB_NOSYNC
187 db_upgrade (DB *db, octetstring file, U32 flags = 0, SV *callback = &PL_sv_undef) 200 db_upgrade (DB *db, bdb_filename file, U32 flags = 0, SV *callback = &PL_sv_undef)
188 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)
189 flags: FREELIST_ONLY FREE_SPACE 202 flags: FREELIST_ONLY FREE_SPACE
190 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)
191 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)
192 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)
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388 DESTROY (DBC_ornull *dbc) 401 DESTROY (DBC_ornull *dbc)
389 CODE: 402 CODE:
390 if (dbc) 403 if (dbc)
391 dbc->c_close (dbc); 404 dbc->c_close (dbc);
392 405
406 $int = $cursor->set_priority ($priority = PRIORITY_*)
407
393=head4 Example: 408=head4 Example:
394 409
395 my $c = $db->cursor; 410 my $c = $db->cursor;
396 411
397 for (;;) { 412 for (;;) {
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435=item $msg = BDB::strerror [$errno] 450=item $msg = BDB::strerror [$errno]
436 451
437Returns the string corresponding to the given errno value. If no argument 452Returns the string corresponding to the given errno value. If no argument
438is given, use C<$!>. 453is given, use C<$!>.
439 454
455Note that the BDB module also patches the C<$!> variable directly, so you
456should be able to get a bdb error string by simply stringifying C<$!>.
457
440=item $fileno = BDB::poll_fileno 458=item $fileno = BDB::poll_fileno
441 459
442Return the I<request result pipe file descriptor>. This filehandle must be 460Return the I<request result pipe file descriptor>. This filehandle must be
443polled for reading by some mechanism outside this module (e.g. Event or 461polled for reading by some mechanism outside this module (e.g. Event or
444select, see below or the SYNOPSIS). If the pipe becomes readable you have 462select, see below or the SYNOPSIS). If the pipe becomes readable you have
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595 613
596=item BDB::set_sync_prepare $cb 614=item BDB::set_sync_prepare $cb
597 615
598Sets a callback that is called whenever a request is created without an 616Sets a callback that is called whenever a request is created without an
599explicit callback. It has to return two code references. The first is used 617explicit callback. It has to return two code references. The first is used
600as the request callback, and the second is called to wait until the first 618as the request callback (it should save the return status), and the second
619is called to wait until the first callback has been called (it must set
620C<$!> to the return status).
621
622This mechanism can be used to include BDB into other event mechanisms,
623such as L<AnyEvent::BDB> or L<Coro::BDB>.
624
601callback has been called. The default implementation works like this: 625The default implementation works like this:
602 626
603 sub { 627 sub {
604 my $status; 628 my $status;
605 ( 629 (
606 sub { $status = $! }, 630 sub { $status = $! },
607 sub { BDB::poll while !defined $status; $! = $status }, 631 sub { BDB::poll while !defined $status; $! = $status },
608 ) 632 )
609 } 633 }
634
635It simply blocks the process till the request has finished and then sets
636C<$!> to the return value. This means that if you don't use a callback,
637BDB will simply fall back to synchronous operations.
610 638
611=back 639=back
612 640
613=head3 STATISTICAL INFORMATION 641=head3 STATISTICAL INFORMATION
614 642
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671 699
672In short: the parent will, after a short pause, continue as if fork had 700In short: the parent will, after a short pause, continue as if fork had
673not been called, while the child will act as if BDB has not been used 701not been called, while the child will act as if BDB has not been used
674yet. 702yet.
675 703
704Win32 note: there is no fork on win32, and perls emulation of it is too
705broken to be supported, so do not use BDB in a windows pseudo-fork, better
706yet, switch to a more capable platform.
707
676=head2 MEMORY USAGE 708=head2 MEMORY USAGE
677 709
678Per-request usage: 710Per-request usage:
679 711
680Each aio request uses - depending on your architecture - around 100-200 712Each aio request uses - depending on your architecture - around 100-200
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701 TXN_DEADLOCK flag will be set on the transaction. See C<db_txn_finish>, 733 TXN_DEADLOCK flag will be set on the transaction. See C<db_txn_finish>,
702 above. 734 above.
703 735
704=head1 SEE ALSO 736=head1 SEE ALSO
705 737
706L<Coro::BDB>, L<IO::AIO>. 738L<AnyEvent::BDB> (event loop integration), L<Coro::BDB> (more natural
739syntax), L<IO::AIO> (nice to have).
707 740
708=head1 AUTHOR 741=head1 AUTHOR
709 742
710 Marc Lehmann <schmorp@schmorp.de> 743 Marc Lehmann <schmorp@schmorp.de>
711 http://home.schmorp.de/ 744 http://home.schmorp.de/

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