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Comparing BDB/BDB.pm (file contents):
Revision 1.18 by root, Tue Dec 4 11:07:39 2007 UTC vs.
Revision 1.36 by root, Sat May 10 20:23:06 2008 UTC

… …
3BDB - Asynchronous Berkeley DB access 3BDB - Asynchronous Berkeley DB access
4 4
5=head1 SYNOPSIS 5=head1 SYNOPSIS
6 6
7 use BDB; 7 use BDB;
8
9 my $env = db_env_create;
10
11 mkdir "bdtest", 0700;
12 db_env_open
13 $env,
14 "bdtest",
15 BDB::INIT_LOCK | BDB::INIT_LOG | BDB::INIT_MPOOL
16 | BDB::INIT_TXN | BDB::RECOVER | BDB::USE_ENVIRON | BDB::CREATE,
17 0600;
18
19 $env->set_flags (BDB::AUTO_COMMIT | BDB::TXN_NOSYNC, 1);
20
21 my $db = db_create $env;
22 db_open $db, undef, "table", undef, BDB::BTREE, BDB::AUTO_COMMIT | BDB::CREATE
23 | BDB::READ_UNCOMMITTED, 0600;
24 db_put $db, undef, "key", "data", 0, sub {
25 db_del $db, undef, "key";
26 };
27 db_sync $db;
28
29 # when you also use Coro, management is easy:
30 use Coro::BDB;
31
32 # automatic event loop intergration with AnyEvent:
33 use AnyEvent::BDB;
34
35 # automatic result processing with EV:
36 my $WATCHER = EV::io BDB::poll_fileno, EV::READ, \&BDB::poll_cb;
37
38 # with Glib:
39 add_watch Glib::IO BDB::poll_fileno,
40 in => sub { BDB::poll_cb; 1 };
41
42 # or simply flush manually
43 BDB::flush;
44
8 45
9=head1 DESCRIPTION 46=head1 DESCRIPTION
10 47
11See the BerkeleyDB documentation (L<http://www.oracle.com/technology/documentation/berkeley-db/db/index.html>). 48See the BerkeleyDB documentation (L<http://www.oracle.com/technology/documentation/berkeley-db/db/index.html>).
12The BDB API is very similar to the C API (the translation has been very faithful). 49The BDB API is very similar to the C API (the translation has been very faithful).
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72use strict 'vars'; 109use strict 'vars';
73 110
74use base 'Exporter'; 111use base 'Exporter';
75 112
76BEGIN { 113BEGIN {
77 our $VERSION = '1.2'; 114 our $VERSION = '1.5';
78 115
79 our @BDB_REQ = qw( 116 our @BDB_REQ = qw(
80 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
81 db_env_memp_sync db_env_memp_trickle 118 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 119 db_open db_close db_compact db_sync db_upgrade
120 db_put db_get db_pget db_del db_key_range
83 db_txn_commit db_txn_abort db_txn_finish 121 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 122 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 123 db_sequence_open db_sequence_close
86 db_sequence_get db_sequence_remove 124 db_sequence_get db_sequence_remove
87 ); 125 );
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95 133
96 require XSLoader; 134 require XSLoader;
97 XSLoader::load ("BDB", $VERSION); 135 XSLoader::load ("BDB", $VERSION);
98} 136}
99 137
138=head2 WIN32 FILENAMES/DATABASE NAME MESS
139
140Perl on Win32 supports only ASCII filenames (the reason is that it abuses
141an internal flag to store wether a filename is Unicode or ANSI, but that
142flag is used for somethign else in the perl core, so there is no way to
143detect wether a filename is ANSI or Unicode-encoded). The BDB module
144tries to work around this issue by assuming that the filename is an ANSI
145filename and BDB was built for unicode support.
146
100=head2 BERKELEYDB FUNCTIONS 147=head2 BERKELEYDB FUNCTIONS
101 148
102All of these are functions. The create functions simply return a new 149All of these are functions. The create functions simply return a new
103object and never block. All the remaining functions all take an optional 150object and never block. All the remaining functions take an optional
104callback as last argument. If it is missing, then the fucntion will be 151callback as last argument. If it is missing, then the function will be
105executed synchronously. 152executed synchronously. In both cases, C<$!> will reflect the return value
153of the function.
106 154
107BDB functions that cannot block (mostly functions that manipulate 155BDB functions that cannot block (mostly functions that manipulate
108settings) 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
109is: 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
110callback as last argument. 158callback as last argument.
111 159
112In the following, C<$int> signifies an integer return value, 160In the following, C<$int> signifies an integer return value,
113C<octetstring> is a "binary string" (i.e. a perl string with no character 161C<octetstring> is a "binary string" (i.e. a perl string with no character
114indices >255), C<U32> is an unsigned 32 bit integer, C<int> is some 162indices >255), C<U32> is an unsigned 32 bit integer, C<int> is some
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145 193
146 db_open (DB *db, DB_TXN_ornull *txnid, octetstring file, octetstring database, int type, U32 flags, int mode, SV *callback = &PL_sv_undef) 194 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 195 flags: AUTO_COMMIT CREATE EXCL MULTIVERSION NOMMAP RDONLY READ_UNCOMMITTED THREAD TRUNCATE
148 db_close (DB *db, U32 flags = 0, SV *callback = &PL_sv_undef) 196 db_close (DB *db, U32 flags = 0, SV *callback = &PL_sv_undef)
149 flags: DB_NOSYNC 197 flags: DB_NOSYNC
198 db_upgrade (DB *db, octetstring file, U32 flags = 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) 199 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 200 flags: FREELIST_ONLY FREE_SPACE
152 db_sync (DB *db, U32 flags = 0, SV *callback = &PL_sv_undef) 201 db_sync (DB *db, 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) 202 db_key_range (DB *db, DB_TXN_ornull *txn, SV *key, SV *key_range, 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) 203 db_put (DB *db, DB_TXN_ornull *txn, SV *key, SV *data, U32 flags = 0, SV *callback = &PL_sv_undef)
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242 $int = $env->set_lk_max_lockers (U32 max) 291 $int = $env->set_lk_max_lockers (U32 max)
243 $int = $env->set_lk_max_locks (U32 max) 292 $int = $env->set_lk_max_locks (U32 max)
244 $int = $env->set_lk_max_objects (U32 max) 293 $int = $env->set_lk_max_objects (U32 max)
245 $int = $env->set_lg_bsize (U32 max) 294 $int = $env->set_lg_bsize (U32 max)
246 $int = $env->set_lg_max (U32 max) 295 $int = $env->set_lg_max (U32 max)
296 $int = $env->mutex_set_increment (U32 increment)
297 $int = $env->mutex_set_tas_spins (U32 tas_spins)
298 $int = $env->mutex_set_max (U32 max)
299 $int = $env->mutex_set_align (U32 align)
247 300
248 $txn = $env->txn_begin (DB_TXN_ornull *parent = 0, U32 flags = 0) 301 $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 302 flags: READ_COMMITTED READ_UNCOMMITTED TXN_NOSYNC TXN_NOWAIT TXN_SNAPSHOT TXN_SYNC TXN_WAIT TXN_WRITE_NOSYNC
250 303
251=head4 Example: 304=head4 Example:
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346 DESTROY (DBC_ornull *dbc) 399 DESTROY (DBC_ornull *dbc)
347 CODE: 400 CODE:
348 if (dbc) 401 if (dbc)
349 dbc->c_close (dbc); 402 dbc->c_close (dbc);
350 403
404 $int = $cursor->set_priority ($priority = PRIORITY_*)
405
351=head4 Example: 406=head4 Example:
352 407
353 my $c = $db->cursor; 408 my $c = $db->cursor;
354 409
355 for (;;) { 410 for (;;) {
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387=head2 SUPPORT FUNCTIONS 442=head2 SUPPORT FUNCTIONS
388 443
389=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 444=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
390 445
391=over 4 446=over 4
447
448=item $msg = BDB::strerror [$errno]
449
450Returns the string corresponding to the given errno value. If no argument
451is given, use C<$!>.
452
453Note that the BDB module also patches the C<$!> variable directly, so you
454should be able to get a bdb error string by simply stringifying C<$!>.
392 455
393=item $fileno = BDB::poll_fileno 456=item $fileno = BDB::poll_fileno
394 457
395Return the I<request result pipe file descriptor>. This filehandle must be 458Return the I<request result pipe file descriptor>. This filehandle must be
396polled for reading by some mechanism outside this module (e.g. Event or 459polled for reading by some mechanism outside this module (e.g. Event or
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624 687
625In short: the parent will, after a short pause, continue as if fork had 688In short: the parent will, after a short pause, continue as if fork had
626not been called, while the child will act as if BDB has not been used 689not been called, while the child will act as if BDB has not been used
627yet. 690yet.
628 691
692Win32 note: there is no fork on win32, and perls emulation of it is too
693broken to be supported, so do not use BDB in a windows pseudo-fork, better
694yet, switch to a more capable platform.
695
629=head2 MEMORY USAGE 696=head2 MEMORY USAGE
630 697
631Per-request usage: 698Per-request usage:
632 699
633Each aio request uses - depending on your architecture - around 100-200 700Each aio request uses - depending on your architecture - around 100-200
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654 TXN_DEADLOCK flag will be set on the transaction. See C<db_txn_finish>, 721 TXN_DEADLOCK flag will be set on the transaction. See C<db_txn_finish>,
655 above. 722 above.
656 723
657=head1 SEE ALSO 724=head1 SEE ALSO
658 725
659L<Coro::BDB>, L<IO::AIO>. 726L<AnyEvent::BDB> (event loop integration), L<Coro::BDB> (more natural
727syntax), L<IO::AIO> (nice to have).
660 728
661=head1 AUTHOR 729=head1 AUTHOR
662 730
663 Marc Lehmann <schmorp@schmorp.de> 731 Marc Lehmann <schmorp@schmorp.de>
664 http://home.schmorp.de/ 732 http://home.schmorp.de/

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