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Comparing BDB/README (file contents):
Revision 1.4 by root, Fri Dec 7 13:39:04 2007 UTC vs.
Revision 1.6 by root, Tue Dec 25 14:23:21 2007 UTC

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22 db_put $db, undef, "key", "data", 0, sub { 22 db_put $db, undef, "key", "data", 0, sub {
23 db_del $db, undef, "key"; 23 db_del $db, undef, "key";
24 }; 24 };
25 db_sync $db; 25 db_sync $db;
26 26
27 # when you also use Coro, management is easy:
28 use Coro::BDB;
29
27 # automatic result processing with AnyEvent: 30 # automatic result processing with AnyEvent:
28 our $FH; open $FH, "<&=" . BDB::poll_fileno; 31 our $FH; open $FH, "<&=" . BDB::poll_fileno;
29 our $WATCHER = AnyEvent->io (fh => $FH, poll => 'r', cb => \&BDB::poll_cb); 32 our $WATCHER = AnyEvent->io (fh => $FH, poll => 'r', cb => \&BDB::poll_cb);
30 33
31 # automatic result processing with EV: 34 # automatic result processing with EV:
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87 either do nothing or result in a runtime error). 90 either do nothing or result in a runtime error).
88 91
89 BERKELEYDB FUNCTIONS 92 BERKELEYDB FUNCTIONS
90 All of these are functions. The create functions simply return a new 93 All of these are functions. The create functions simply return a new
91 object and never block. All the remaining functions all take an optional 94 object and never block. All the remaining functions all take an optional
92 callback as last argument. If it is missing, then the fucntion will be 95 callback as last argument. If it is missing, then the function will be
93 executed synchronously. 96 executed synchronously. In both cases, $! will reflect the return value
97 of the function.
94 98
95 BDB functions that cannot block (mostly functions that manipulate 99 BDB functions that cannot block (mostly functions that manipulate
96 settings) are method calls on the relevant objects, so the rule of thumb 100 settings) are method calls on the relevant objects, so the rule of thumb
97 is: if its a method, its not blocking, if its a function, it takes a 101 is: if its a method, its not blocking, if its a function, it takes a
98 callback as last argument. 102 callback as last argument.
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132 136
133 db_open (DB *db, DB_TXN_ornull *txnid, octetstring file, octetstring database, int type, U32 flags, int mode, SV *callback = &PL_sv_undef) 137 db_open (DB *db, DB_TXN_ornull *txnid, octetstring file, octetstring database, int type, U32 flags, int mode, SV *callback = &PL_sv_undef)
134 flags: AUTO_COMMIT CREATE EXCL MULTIVERSION NOMMAP RDONLY READ_UNCOMMITTED THREAD TRUNCATE 138 flags: AUTO_COMMIT CREATE EXCL MULTIVERSION NOMMAP RDONLY READ_UNCOMMITTED THREAD TRUNCATE
135 db_close (DB *db, U32 flags = 0, SV *callback = &PL_sv_undef) 139 db_close (DB *db, U32 flags = 0, SV *callback = &PL_sv_undef)
136 flags: DB_NOSYNC 140 flags: DB_NOSYNC
141 db_upgrade (DB *db, octetstring file, U32 flags = 0, SV *callback = &PL_sv_undef)
137 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) 142 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)
138 flags: FREELIST_ONLY FREE_SPACE 143 flags: FREELIST_ONLY FREE_SPACE
139 db_sync (DB *db, U32 flags = 0, SV *callback = &PL_sv_undef) 144 db_sync (DB *db, U32 flags = 0, SV *callback = &PL_sv_undef)
140 db_key_range (DB *db, DB_TXN_ornull *txn, SV *key, SV *key_range, 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)
141 db_put (DB *db, DB_TXN_ornull *txn, SV *key, SV *data, 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)
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327 DESTROY (DBC_ornull *dbc) 332 DESTROY (DBC_ornull *dbc)
328 CODE: 333 CODE:
329 if (dbc) 334 if (dbc)
330 dbc->c_close (dbc); 335 dbc->c_close (dbc);
331 336
337 $int = $cursor->set_priority ($priority = PRIORITY_*)
338
332 Example: 339 Example:
333 my $c = $db->cursor; 340 my $c = $db->cursor;
334 341
335 for (;;) { 342 for (;;) {
336 db_c_get $c, my $key, my $data, BDB::NEXT; 343 db_c_get $c, my $key, my $data, BDB::NEXT;
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360 db_sequence_open $seq, undef, "seq", BDB::CREATE; 367 db_sequence_open $seq, undef, "seq", BDB::CREATE;
361 db_sequence_get $seq, undef, 1, my $value; 368 db_sequence_get $seq, undef, 1, my $value;
362 369
363 SUPPORT FUNCTIONS 370 SUPPORT FUNCTIONS
364 EVENT PROCESSING AND EVENT LOOP INTEGRATION 371 EVENT PROCESSING AND EVENT LOOP INTEGRATION
372 $msg = BDB::strerror [$errno]
373 Returns the string corresponding to the given errno value. If no
374 argument is given, use $!.
375
365 $fileno = BDB::poll_fileno 376 $fileno = BDB::poll_fileno
366 Return the *request result pipe file descriptor*. This filehandle 377 Return the *request result pipe file descriptor*. This filehandle
367 must be polled for reading by some mechanism outside this module 378 must be polled for reading by some mechanism outside this module
368 (e.g. Event or select, see below or the SYNOPSIS). If the pipe 379 (e.g. Event or select, see below or the SYNOPSIS). If the pipe
369 becomes readable you have to call "poll_cb" to check the results. 380 becomes readable you have to call "poll_cb" to check the results.
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556 567
557 In short: the parent will, after a short pause, continue as if fork had 568 In short: the parent will, after a short pause, continue as if fork had
558 not been called, while the child will act as if BDB has not been used 569 not been called, while the child will act as if BDB has not been used
559 yet. 570 yet.
560 571
572 Win32 note: there is no fork on win32, and perls emulation of it is too
573 broken to be supported, so do not use BDB in a windows pseudo-fork,
574 better yet, switch to a more capable platform.
575
561 MEMORY USAGE 576 MEMORY USAGE
562 Per-request usage: 577 Per-request usage:
563 578
564 Each aio request uses - depending on your architecture - around 100-200 579 Each aio request uses - depending on your architecture - around 100-200
565 bytes of memory. In addition, stat requests need a stat buffer (possibly 580 bytes of memory. In addition, stat requests need a stat buffer (possibly

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