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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 1.34 by root, Sun Mar 30 06:17:31 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 result processing with AnyEvent:
33 our $FH; open $FH, "<&=" . BDB::poll_fileno;
34 our $WATCHER = AnyEvent->io (fh => $FH, poll => 'r', cb => \&BDB::poll_cb);
35
36 # automatic result processing with EV:
37 my $WATCHER = EV::io BDB::poll_fileno, EV::READ, \&BDB::poll_cb;
38
39 # with Glib:
40 add_watch Glib::IO BDB::poll_fileno,
41 in => sub { BDB::poll_cb; 1 };
42
43 # or simply flush manually
44 BDB::flush;
45
8 46
9=head1 DESCRIPTION 47=head1 DESCRIPTION
10 48
11See the BerkeleyDB documentation (L<http://www.oracle.com/technology/documentation/berkeley-db/db/index.html>). 49See 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). 50The BDB API is very similar to the C API (the translation has been very faithful).
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72use strict 'vars'; 110use strict 'vars';
73 111
74use base 'Exporter'; 112use base 'Exporter';
75 113
76BEGIN { 114BEGIN {
77 our $VERSION = '1.2'; 115 our $VERSION = '1.44';
78 116
79 our @BDB_REQ = qw( 117 our @BDB_REQ = qw(
80 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
81 db_env_memp_sync db_env_memp_trickle 119 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 120 db_open db_close db_compact db_sync db_upgrade
121 db_put db_get db_pget db_del db_key_range
83 db_txn_commit db_txn_abort db_txn_finish 122 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 123 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 124 db_sequence_open db_sequence_close
86 db_sequence_get db_sequence_remove 125 db_sequence_get db_sequence_remove
87 ); 126 );
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95 134
96 require XSLoader; 135 require XSLoader;
97 XSLoader::load ("BDB", $VERSION); 136 XSLoader::load ("BDB", $VERSION);
98} 137}
99 138
139=head2 FILENAMES/DATABASE NAMES
140
141The BDB expects "binary" filenames (octet strings) for pathnames on POSIX
142systems, and "unicode" filenames (strings with characters potentially
143>255) on Win32 (expecting a Unicode win32 build - win32 is a total mess).
144
100=head2 BERKELEYDB FUNCTIONS 145=head2 BERKELEYDB FUNCTIONS
101 146
102All of these are functions. The create functions simply return a new 147All of these are functions. The create functions simply return a new
103object and never block. All the remaining functions all take an optional 148object and never block. All the remaining functions take an optional
104callback as last argument. If it is missing, then the fucntion will be 149callback as last argument. If it is missing, then the function will be
105executed synchronously. 150executed synchronously. In both cases, C<$!> will reflect the return value
151of the function.
106 152
107BDB functions that cannot block (mostly functions that manipulate 153BDB functions that cannot block (mostly functions that manipulate
108settings) are method calls on the relevant objects, so the rule of thumb 154settings) 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 155is: if it's a method, it's not blocking, if it's a function, it takes a
110callback as last argument. 156callback as last argument.
111 157
112In the following, C<$int> signifies an integer return value, 158In the following, C<$int> signifies an integer return value,
113C<octetstring> is a "binary string" (i.e. a perl string with no character 159C<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 160indices >255), C<U32> is an unsigned 32 bit integer, C<int> is some
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145 191
146 db_open (DB *db, DB_TXN_ornull *txnid, octetstring file, octetstring database, int type, U32 flags, int mode, SV *callback = &PL_sv_undef) 192 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 193 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) 194 db_close (DB *db, U32 flags = 0, SV *callback = &PL_sv_undef)
149 flags: DB_NOSYNC 195 flags: DB_NOSYNC
196 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) 197 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 198 flags: FREELIST_ONLY FREE_SPACE
152 db_sync (DB *db, U32 flags = 0, SV *callback = &PL_sv_undef) 199 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) 200 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) 201 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) 289 $int = $env->set_lk_max_lockers (U32 max)
243 $int = $env->set_lk_max_locks (U32 max) 290 $int = $env->set_lk_max_locks (U32 max)
244 $int = $env->set_lk_max_objects (U32 max) 291 $int = $env->set_lk_max_objects (U32 max)
245 $int = $env->set_lg_bsize (U32 max) 292 $int = $env->set_lg_bsize (U32 max)
246 $int = $env->set_lg_max (U32 max) 293 $int = $env->set_lg_max (U32 max)
294 $int = $env->mutex_set_increment (U32 increment)
295 $int = $env->mutex_set_tas_spins (U32 tas_spins)
296 $int = $env->mutex_set_max (U32 max)
297 $int = $env->mutex_set_align (U32 align)
247 298
248 $txn = $env->txn_begin (DB_TXN_ornull *parent = 0, U32 flags = 0) 299 $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 300 flags: READ_COMMITTED READ_UNCOMMITTED TXN_NOSYNC TXN_NOWAIT TXN_SNAPSHOT TXN_SYNC TXN_WAIT TXN_WRITE_NOSYNC
250 301
251=head4 Example: 302=head4 Example:
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346 DESTROY (DBC_ornull *dbc) 397 DESTROY (DBC_ornull *dbc)
347 CODE: 398 CODE:
348 if (dbc) 399 if (dbc)
349 dbc->c_close (dbc); 400 dbc->c_close (dbc);
350 401
402 $int = $cursor->set_priority ($priority = PRIORITY_*)
403
351=head4 Example: 404=head4 Example:
352 405
353 my $c = $db->cursor; 406 my $c = $db->cursor;
354 407
355 for (;;) { 408 for (;;) {
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387=head2 SUPPORT FUNCTIONS 440=head2 SUPPORT FUNCTIONS
388 441
389=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 442=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
390 443
391=over 4 444=over 4
445
446=item $msg = BDB::strerror [$errno]
447
448Returns the string corresponding to the given errno value. If no argument
449is given, use C<$!>.
450
451Note that the BDB module also patches the C<$!> variable directly, so you
452should be able to get a bdb error string by simply stringifying C<$!>.
392 453
393=item $fileno = BDB::poll_fileno 454=item $fileno = BDB::poll_fileno
394 455
395Return the I<request result pipe file descriptor>. This filehandle must be 456Return the I<request result pipe file descriptor>. This filehandle must be
396polled for reading by some mechanism outside this module (e.g. Event or 457polled for reading by some mechanism outside this module (e.g. Event or
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624 685
625In short: the parent will, after a short pause, continue as if fork had 686In 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 687not been called, while the child will act as if BDB has not been used
627yet. 688yet.
628 689
690Win32 note: there is no fork on win32, and perls emulation of it is too
691broken to be supported, so do not use BDB in a windows pseudo-fork, better
692yet, switch to a more capable platform.
693
629=head2 MEMORY USAGE 694=head2 MEMORY USAGE
630 695
631Per-request usage: 696Per-request usage:
632 697
633Each aio request uses - depending on your architecture - around 100-200 698Each aio request uses - depending on your architecture - around 100-200

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