[ViewVC] Diff of: cvs/BDB/BDB.pm

Comparing BDB/BDB.pm (file contents):
Revision 1.23 by root, Mon Dec 10 04:45:52 2007 UTC vs.
Revision 1.68 by root, Tue Feb 2 04:17:03 2016 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 integration 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:
…		…
101		103
102	=cut	104	=cut
103		105
104	package BDB;	106	package BDB;
105		107
106	no warnings;	108	use common::sense;
107	use strict 'vars';
108		109
109	use base 'Exporter';	110	use base 'Exporter';
110		111
		112	our $VERSION;
		113
111	BEGIN {	114	BEGIN {
112	our $VERSION = '1.3';	115	$VERSION = '1.91';
113		116
114	our @BDB_REQ = qw(	117	our @BDB_REQ = qw(
115	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
116	db_env_memp_sync db_env_memp_trickle	119	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	120	db_env_log_archive db_env_lsn_reset
		121	db_open db_close db_compact db_sync db_verify db_upgrade
		122	db_put db_exists db_get db_pget db_del db_key_range
118	db_txn_commit db_txn_abort db_txn_finish	123	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	124	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	125	db_sequence_open db_sequence_close
121	db_sequence_get db_sequence_remove	126	db_sequence_get db_sequence_remove
122	);	127	);
…		…
130		135
131	require XSLoader;	136	require XSLoader;
132	XSLoader::load ("BDB", $VERSION);	137	XSLoader::load ("BDB", $VERSION);
133	}	138	}
134		139
135	=head2 BERKELEYDB FUNCTIONS	140	=head1 BERKELEYDB FUNCTIONS
136		141
137	All of these are functions. The create functions simply return a new	142	All of these are functions. The create functions simply return a new
138	object and never block. All the remaining functions all take an optional	143	object and never block. All the remaining functions take an optional
139	callback as last argument that gets passed the return value. If it is	144	callback as last argument. If it is missing, then the function will be
140	missing, then the function will be executed synchronously, and the return	145	executed synchronously. In both cases, C<$!> will reflect the return value
141	value is returned as normally.	146	of the function.
142		147
143	BDB functions that cannot block (mostly functions that manipulate	148	BDB functions that cannot block (mostly functions that manipulate
144	settings) are method calls on the relevant objects, so the rule of thumb	149	settings) are method calls on the relevant objects, so the rule of thumb
145	is: if its a method, its not blocking, if its a function, it takes a	150	is: if it's a method, it's not blocking, if it's a function, it takes a
146	callback as last argument.	151	callback as last argument.
147		152
148	In the following, C<$int> signifies an integer return value,	153	In the following, C<$int> signifies an integer return value,
149	C<octetstring> is a "binary string" (i.e. a perl string with no character	154	C<bdb_filename> is a "filename" (octets on unix, madness on windows),
150	indices >255), C<U32> is an unsigned 32 bit integer, C<int> is some	155	C<U32> is an unsigned 32 bit integer, C<int> is some integer, C<NV> is a
151	integer, C<NV> is a floating point value.	156	floating point value.
152		157
153	The C<SV *> types are generic perl scalars (for input and output of data	158	Most C<SV *> types are generic perl scalars (for input and output of data
154	values), and the C<SV *callback> is the optional callback function to call	159	values).
155	when the request is completed.
156		160
157	The various C<DB_ENV> etc. arguments are handles return by	161	The various C<DB_ENV> etc. arguments are handles return by
158	C<db_env_create>, C<db_create>, C<txn_begin> and so on. If they have an	162	C<db_env_create>, C<db_create>, C<txn_begin> and so on. If they have an
159	appended C<_ornull> this means they are optional and you can pass C<undef>	163	appended C<_ornull> this means they are optional and you can pass C<undef>
160	for them, resulting a NULL pointer on the C level.	164	for them, resulting a NULL pointer on the C level.
161		165
		166	The C<SV *callback> is the optional callback function to call when the
		167	request is completed. This last callback argument is special: the callback
		168	is simply the last argument passed. If there are "optional" arguments
		169	before the callback they can be left out. The callback itself can be left
		170	out or specified as C<undef>, in which case the function will be executed
		171	synchronously.
		172
		173	For example, C<db_env_txn_checkpoint> usually is called with all integer
		174	arguments zero. These can be left out, so all of these specify a call
		175	to C<< DB_ENV->txn_checkpoint >>, to be executed asynchronously with a
		176	callback to be called:
		177
		178	db_env_txn_checkpoint $db_env, 0, 0, 0, sub { };
		179	db_env_txn_checkpoint $db_env, 0, 0, sub { };
		180	db_env_txn_checkpoint $db_env, sub { };
		181
		182	While these all specify a call to C<< DB_ENV->txn_checkpoint >> to be
		183	executed synchronously:
		184
		185	db_env_txn_checkpoint $db_env, 0, 0, 0, undef;
		186	db_env_txn_checkpoint $db_env, 0, 0, 0;
		187	db_env_txn_checkpoint $db_env, 0;
		188
162	=head3 BDB functions	189	=head2 BDB functions
163		190
164	Functions in the BDB namespace, exported by default:	191	Functions in the BDB namespace, exported by default:
165		192
166	$env = db_env_create (U32 env_flags = 0)	193	$env = db_env_create (U32 env_flags = 0)
167	flags: RPCCLIENT	194	flags: RPCCLIENT
168		195
169	db_env_open (DB_ENV env, octetstring db_home, U32 open_flags, int mode, SV callback = &PL_sv_undef)	196	db_env_open (DB_ENV env, bdb_filename db_home, U32 open_flags, int mode, SV callback = 0)
170	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	197	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
171	db_env_close (DB_ENV env, U32 flags = 0, SV callback = &PL_sv_undef)	198	db_env_close (DB_ENV env, U32 flags = 0, SV callback = 0)
172	db_env_txn_checkpoint (DB_ENV env, U32 kbyte = 0, U32 min = 0, U32 flags = 0, SV callback = &PL_sv_undef)	199	db_env_txn_checkpoint (DB_ENV env, U32 kbyte = 0, U32 min = 0, U32 flags = 0, SV callback = 0)
173	flags: FORCE	200	flags: FORCE
174	db_env_lock_detect (DB_ENV env, U32 flags = 0, U32 atype = DB_LOCK_DEFAULT, SV dummy = 0, SV *callback = &PL_sv_undef)	201	db_env_lock_detect (DB_ENV env, U32 flags = 0, U32 atype = DB_LOCK_DEFAULT, SV dummy = 0, SV *callback = 0)
175	atype: LOCK_DEFAULT LOCK_EXPIRE LOCK_MAXLOCKS LOCK_MAXWRITE LOCK_MINLOCKS LOCK_MINWRITE LOCK_OLDEST LOCK_RANDOM LOCK_YOUNGEST	202	atype: LOCK_DEFAULT LOCK_EXPIRE LOCK_MAXLOCKS LOCK_MAXWRITE LOCK_MINLOCKS LOCK_MINWRITE LOCK_OLDEST LOCK_RANDOM LOCK_YOUNGEST
176	db_env_memp_sync (DB_ENV env, SV dummy = 0, SV *callback = &PL_sv_undef)	203	db_env_memp_sync (DB_ENV env, SV dummy = 0, SV *callback = 0)
177	db_env_memp_trickle (DB_ENV env, int percent, SV dummy = 0, SV *callback = &PL_sv_undef)	204	db_env_memp_trickle (DB_ENV env, int percent, SV dummy = 0, SV *callback = 0)
		205	db_env_dbremove (DB_ENV env, DB_TXN_ornull txnid, bdb_filename file, bdb_filename database, U32 flags = 0, SV *callback = 0)
		206	db_env_dbrename (DB_ENV env, DB_TXN_ornull txnid, bdb_filename file, bdb_filename database, bdb_filename newname, U32 flags = 0, SV *callback = 0)
		207	db_env_log_archive (DB_ENV env, SV listp, U32 flags = 0, SV *callback = 0)
		208	db_env_lsn_reset (DB_ENV env, bdb_filename db, U32 flags = 0, SV callback = 0)
178		209
179	$db = db_create (DB_ENV *env = 0, U32 flags = 0)	210	$db = db_create (DB_ENV *env = 0, U32 flags = 0)
180	flags: XA_CREATE	211	flags: XA_CREATE
181		212
182	db_open (DB db, DB_TXN_ornull txnid, octetstring file, octetstring database, int type, U32 flags, int mode, SV *callback = &PL_sv_undef)	213	db_open (DB db, DB_TXN_ornull txnid, bdb_filename file, bdb_filename database, int type, U32 flags, int mode, SV *callback = 0)
183	flags: AUTO_COMMIT CREATE EXCL MULTIVERSION NOMMAP RDONLY READ_UNCOMMITTED THREAD TRUNCATE	214	flags: AUTO_COMMIT CREATE EXCL MULTIVERSION NOMMAP RDONLY READ_UNCOMMITTED THREAD TRUNCATE
184	db_close (DB db, U32 flags = 0, SV callback = &PL_sv_undef)	215	db_close (DB db, U32 flags = 0, SV callback = 0)
185	flags: DB_NOSYNC	216	flags: DB_NOSYNC
		217	db_verify (DB db, bdb_filename file, bdb_filename database = 0, SV dummy = 0, U32 flags = 0, SV *callback = 0)
		218	db_upgrade (DB db, bdb_filename file, U32 flags = 0, SV callback = 0)
186	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)	219	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 = 0)
187	flags: FREELIST_ONLY FREE_SPACE	220	flags: FREELIST_ONLY FREE_SPACE
188	db_sync (DB db, U32 flags = 0, SV callback = &PL_sv_undef)	221	db_sync (DB db, U32 flags = 0, SV callback = 0)
189	db_key_range (DB db, DB_TXN_ornull txn, SV key, SV key_range, U32 flags = 0, SV *callback = &PL_sv_undef)	222	db_key_range (DB db, DB_TXN_ornull txn, SV key, SV key_range, U32 flags = 0, SV *callback = 0)
190	db_put (DB db, DB_TXN_ornull txn, SV key, SV data, U32 flags = 0, SV *callback = &PL_sv_undef)	223	db_put (DB db, DB_TXN_ornull txn, SV key, SV data, U32 flags = 0, SV *callback = 0)
191	flags: APPEND NODUPDATA NOOVERWRITE	224	flags: APPEND NODUPDATA NOOVERWRITE
		225	db_exists (DB db, DB_TXN_ornull txn, SV key, U32 flags = 0, SV callback = 0) (v4.6)
192	db_get (DB db, DB_TXN_ornull txn, SV key, SV data, U32 flags = 0, SV *callback = &PL_sv_undef)	226	db_get (DB db, DB_TXN_ornull txn, SV key, SV data, U32 flags = 0, SV *callback = 0)
193	flags: CONSUME CONSUME_WAIT GET_BOTH SET_RECNO MULTIPLE READ_COMMITTED READ_UNCOMMITTED RMW	227	flags: CONSUME CONSUME_WAIT GET_BOTH SET_RECNO MULTIPLE READ_COMMITTED READ_UNCOMMITTED RMW
194	db_pget (DB db, DB_TXN_ornull txn, SV key, SV pkey, SV data, U32 flags = 0, SV callback = &PL_sv_undef)	228	db_pget (DB db, DB_TXN_ornull txn, SV key, SV pkey, SV data, U32 flags = 0, SV callback = 0)
195	flags: CONSUME CONSUME_WAIT GET_BOTH SET_RECNO MULTIPLE READ_COMMITTED READ_UNCOMMITTED RMW	229	flags: CONSUME CONSUME_WAIT GET_BOTH SET_RECNO MULTIPLE READ_COMMITTED READ_UNCOMMITTED RMW
196	db_del (DB db, DB_TXN_ornull txn, SV key, U32 flags = 0, SV callback = &PL_sv_undef)	230	db_del (DB db, DB_TXN_ornull txn, SV key, U32 flags = 0, SV callback = 0)
197	db_txn_commit (DB_TXN txn, U32 flags = 0, SV callback = &PL_sv_undef)	231	db_txn_commit (DB_TXN txn, U32 flags = 0, SV callback = 0)
198	flags: TXN_NOSYNC TXN_SYNC	232	flags: TXN_NOSYNC TXN_SYNC
199	db_txn_abort (DB_TXN txn, SV callback = &PL_sv_undef)	233	db_txn_abort (DB_TXN txn, SV callback = 0)
200		234
201	db_c_close (DBC dbc, SV callback = &PL_sv_undef)	235	db_c_close (DBC dbc, SV callback = 0)
202	db_c_count (DBC dbc, SV count, U32 flags = 0, SV *callback = &PL_sv_undef)	236	db_c_count (DBC dbc, SV count, U32 flags = 0, SV *callback = 0)
203	db_c_put (DBC dbc, SV key, SV data, U32 flags = 0, SV callback = &PL_sv_undef)	237	db_c_put (DBC dbc, SV key, SV data, U32 flags = 0, SV callback = 0)
204	flags: AFTER BEFORE CURRENT KEYFIRST KEYLAST NODUPDATA	238	flags: AFTER BEFORE CURRENT KEYFIRST KEYLAST NODUPDATA
205	db_c_get (DBC dbc, SV key, SV data, U32 flags = 0, SV callback = &PL_sv_undef)	239	db_c_get (DBC dbc, SV key, SV data, U32 flags = 0, SV callback = 0)
206	flags: CURRENT FIRST GET_BOTH GET_BOTH_RANGE GET_RECNO JOIN_ITEM LAST NEXT NEXT_DUP NEXT_NODUP PREV PREV_DUP PREV_NODUP SET SET_RANGE SET_RECNO READ_UNCOMMITTED MULTIPLE MULTIPLE_KEY RMW	240	flags: CURRENT FIRST GET_BOTH GET_BOTH_RANGE GET_RECNO JOIN_ITEM LAST NEXT NEXT_DUP NEXT_NODUP PREV PREV_DUP PREV_NODUP SET SET_RANGE SET_RECNO READ_UNCOMMITTED MULTIPLE MULTIPLE_KEY RMW
207	db_c_pget (DBC dbc, SV key, SV pkey, SV data, U32 flags = 0, SV *callback = &PL_sv_undef)	241	db_c_pget (DBC dbc, SV key, SV pkey, SV data, U32 flags = 0, SV *callback = 0)
208	db_c_del (DBC dbc, U32 flags = 0, SV callback = &PL_sv_undef)	242	db_c_del (DBC dbc, U32 flags = 0, SV callback = 0)
209		243
210	db_sequence_open (DB_SEQUENCE seq, DB_TXN_ornull txnid, SV key, U32 flags = 0, SV callback = &PL_sv_undef)	244	db_sequence_open (DB_SEQUENCE seq, DB_TXN_ornull txnid, SV key, U32 flags = 0, SV callback = 0)
211	flags: CREATE EXCL	245	flags: CREATE EXCL
212	db_sequence_close (DB_SEQUENCE seq, U32 flags = 0, SV callback = &PL_sv_undef)	246	db_sequence_close (DB_SEQUENCE seq, U32 flags = 0, SV callback = 0)
213	db_sequence_get (DB_SEQUENCE seq, DB_TXN_ornull txnid, int delta, SV seq_value, U32 flags = DB_TXN_NOSYNC, SV callback = &PL_sv_undef)	247	db_sequence_get (DB_SEQUENCE seq, DB_TXN_ornull txnid, int delta, SV seq_value, U32 flags = DB_TXN_NOSYNC, SV callback = 0)
214	flags: TXN_NOSYNC	248	flags: TXN_NOSYNC
215	db_sequence_remove (DB_SEQUENCE seq, DB_TXN_ornull txnid = 0, U32 flags = 0, SV *callback = &PL_sv_undef)	249	db_sequence_remove (DB_SEQUENCE seq, DB_TXN_ornull txnid = 0, U32 flags = 0, SV *callback = 0)
216	flags: TXN_NOSYNC	250	flags: TXN_NOSYNC
217		251
218	=head4 db_txn_finish (DB_TXN txn, U32 flags = 0, SV callback = &PL_sv_undef)	252	=head3 db_txn_finish (DB_TXN txn, U32 flags = 0, SV callback = 0)
219		253
220	This is not actually a Berkeley DB function but a BDB module	254	This is not actually a Berkeley DB function but a BDB module
221	extension. The background for this exytension is: It is very annoying to	255	extension. The background for this exytension is: It is very annoying to
222	have to check every single BDB function for error returns and provide a	256	have to check every single BDB function for error returns and provide a
223	codepath out of your transaction. While the BDB module still makes this	257	codepath out of your transaction. While the BDB module still makes this
…		…
249		283
250	You can use the C<< $txn->failed >> method to check wether a transaction	284	You can use the C<< $txn->failed >> method to check wether a transaction
251	has failed in this way and abort further processing (excluding	285	has failed in this way and abort further processing (excluding
252	C<db_txn_finish>).	286	C<db_txn_finish>).
253		287
		288
254	=head3 DB_ENV/database environment methods	289	=head2 DB_ENV/database environment methods
255		290
256	Methods available on DB_ENV/$env handles:	291	Methods available on DB_ENV/$env handles:
257		292
258	DESTROY (DB_ENV_ornull *env)	293	DESTROY (DB_ENV_ornull *env)
259	CODE:	294	CODE:
…		…
263	$int = $env->set_data_dir (const char *dir)	298	$int = $env->set_data_dir (const char *dir)
264	$int = $env->set_tmp_dir (const char *dir)	299	$int = $env->set_tmp_dir (const char *dir)
265	$int = $env->set_lg_dir (const char *dir)	300	$int = $env->set_lg_dir (const char *dir)
266	$int = $env->set_shm_key (long shm_key)	301	$int = $env->set_shm_key (long shm_key)
267	$int = $env->set_cachesize (U32 gbytes, U32 bytes, int ncache = 0)	302	$int = $env->set_cachesize (U32 gbytes, U32 bytes, int ncache = 0)
268	$int = $env->set_flags (U32 flags, int onoff)	303	$int = $env->set_flags (U32 flags, int onoff = 1)
		304	$int = $env->log_set_config (U32 flags, int onoff = 1) (v4.7)
		305	$int = $env->set_intermediate_dir_mode (const char *modestring) (v4.7)
269	$env->set_errfile (FILE *errfile = 0)	306	$env->set_errfile (FILE *errfile = 0)
270	$env->set_msgfile (FILE *msgfile = 0)	307	$env->set_msgfile (FILE *msgfile = 0)
271	$int = $env->set_verbose (U32 which, int onoff = 1)	308	$int = $env->set_verbose (U32 which, int onoff = 1)
272	$int = $env->set_encrypt (const char *password, U32 flags = 0)	309	$int = $env->set_encrypt (const char *password, U32 flags = 0)
273	$int = $env->set_timeout (NV timeout_seconds, U32 flags = SET_TXN_TIMEOUT)	310	$int = $env->set_timeout (NV timeout_seconds, U32 flags = SET_TXN_TIMEOUT)
…		…
285	$int = $env->mutex_set_max (U32 max)	322	$int = $env->mutex_set_max (U32 max)
286	$int = $env->mutex_set_align (U32 align)	323	$int = $env->mutex_set_align (U32 align)
287		324
288	$txn = $env->txn_begin (DB_TXN_ornull *parent = 0, U32 flags = 0)	325	$txn = $env->txn_begin (DB_TXN_ornull *parent = 0, U32 flags = 0)
289	flags: READ_COMMITTED READ_UNCOMMITTED TXN_NOSYNC TXN_NOWAIT TXN_SNAPSHOT TXN_SYNC TXN_WAIT TXN_WRITE_NOSYNC	326	flags: READ_COMMITTED READ_UNCOMMITTED TXN_NOSYNC TXN_NOWAIT TXN_SNAPSHOT TXN_SYNC TXN_WAIT TXN_WRITE_NOSYNC
		327	$txn = $env->cdsgroup_begin; (v4.5)
290		328
291	=head4 Example:	329	=head3 Example:
292		330
293	use AnyEvent;	331	use AnyEvent;
294	use BDB;	332	use BDB;
295		333
296	our $FH; open $FH, "<&=" . BDB::poll_fileno;	334	our $FH; open $FH, "<&=" . BDB::poll_fileno;
…		…
308	0600;	346	0600;
309		347
310	$env->set_flags (BDB::AUTO_COMMIT \| BDB::TXN_NOSYNC, 1);	348	$env->set_flags (BDB::AUTO_COMMIT \| BDB::TXN_NOSYNC, 1);
311		349
312		350
313	=head3 DB/database methods	351	=head2 DB/database methods
314		352
315	Methods available on DB/$db handles:	353	Methods available on DB/$db handles:
316		354
317	DESTROY (DB_ornull *db)	355	DESTROY (DB_ornull *db)
318	CODE:	356	CODE:
…		…
344		382
345	$dbc = $db->cursor (DB_TXN_ornull *txn = 0, U32 flags = 0)	383	$dbc = $db->cursor (DB_TXN_ornull *txn = 0, U32 flags = 0)
346	flags: READ_COMMITTED READ_UNCOMMITTED WRITECURSOR TXN_SNAPSHOT	384	flags: READ_COMMITTED READ_UNCOMMITTED WRITECURSOR TXN_SNAPSHOT
347	$seq = $db->sequence (U32 flags = 0)	385	$seq = $db->sequence (U32 flags = 0)
348		386
349	=head4 Example:	387	=head3 Example:
350		388
351	my $db = db_create $env;	389	my $db = db_create $env;
352	db_open $db, undef, "table", undef, BDB::BTREE, BDB::AUTO_COMMIT \| BDB::CREATE \| BDB::READ_UNCOMMITTED, 0600;	390	db_open $db, undef, "table", undef, BDB::BTREE, BDB::AUTO_COMMIT \| BDB::CREATE \| BDB::READ_UNCOMMITTED, 0600;
353		391
354	for (1..1000) {	392	for (1..1000) {
…		…
361	db_del $db, undef, "key $_" for 1..1000;	399	db_del $db, undef, "key $_" for 1..1000;
362		400
363	db_sync $db;	401	db_sync $db;
364		402
365		403
366	=head3 DB_TXN/transaction methods	404	=head2 DB_TXN/transaction methods
367		405
368	Methods available on DB_TXN/$txn handles:	406	Methods available on DB_TXN/$txn handles:
369		407
370	DESTROY (DB_TXN_ornull *txn)	408	DESTROY (DB_TXN_ornull *txn)
371	CODE:	409	CODE:
…		…
377		415
378	$bool = $txn->failed	416	$bool = $txn->failed
379	# see db_txn_finish documentation, above	417	# see db_txn_finish documentation, above
380		418
381		419
382	=head3 DBC/cursor methods	420	=head2 DBC/cursor methods
383		421
384	Methods available on DBC/$dbc handles:	422	Methods available on DBC/$dbc handles:
385		423
386	DESTROY (DBC_ornull *dbc)	424	DESTROY (DBC_ornull *dbc)
387	CODE:	425	CODE:
388	if (dbc)	426	if (dbc)
389	dbc->c_close (dbc);	427	dbc->c_close (dbc);
390		428
		429	$int = $cursor->set_priority ($priority = PRIORITY_*) (v4.6)
		430
391	=head4 Example:	431	=head3 Example:
392		432
393	my $c = $db->cursor;	433	my $c = $db->cursor;
394		434
395	for (;;) {	435	for (;;) {
396	db_c_get $c, my $key, my $data, BDB::NEXT;	436	db_c_get $c, my $key, my $data, BDB::NEXT;
…		…
399	}	439	}
400		440
401	db_c_close $c;	441	db_c_close $c;
402		442
403		443
404	=head3 DB_SEQUENCE/sequence methods	444	=head2 DB_SEQUENCE/sequence methods
405		445
406	Methods available on DB_SEQUENCE/$seq handles:	446	Methods available on DB_SEQUENCE/$seq handles:
407		447
408	DESTROY (DB_SEQUENCE_ornull *seq)	448	DESTROY (DB_SEQUENCE_ornull *seq)
409	CODE:	449	CODE:
…		…
414	$int = $seq->set_cachesize (U32 size)	454	$int = $seq->set_cachesize (U32 size)
415	$int = $seq->set_flags (U32 flags)	455	$int = $seq->set_flags (U32 flags)
416	flags: SEQ_DEC SEQ_INC SEQ_WRAP	456	flags: SEQ_DEC SEQ_INC SEQ_WRAP
417	$int = $seq->set_range (db_seq_t min, db_seq_t max)	457	$int = $seq->set_range (db_seq_t min, db_seq_t max)
418		458
419	=head4 Example:	459	=head3 Example:
420		460
421	my $seq = $db->sequence;	461	my $seq = $db->sequence;
422		462
423	db_sequence_open $seq, undef, "seq", BDB::CREATE;	463	db_sequence_open $seq, undef, "seq", BDB::CREATE;
424	db_sequence_get $seq, undef, 1, my $value;	464	db_sequence_get $seq, undef, 1, my $value;
425		465
426		466
427	=head2 SUPPORT FUNCTIONS	467	=head1 SUPPORT FUNCTIONS
428		468
429	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION	469	=head2 EVENT PROCESSING AND EVENT LOOP INTEGRATION
430		470
431	=over 4	471	=over 4
432		472
433	=item $msg = BDB::strerror [$errno]	473	=item $msg = BDB::strerror [$errno]
434		474
435	Returns the string corresponding to the given errno value. If no argument	475	Returns the string corresponding to the given errno value. If no argument
436	is given, use C<$!>.	476	is given, use C<$!>.
		477
		478	Note that the BDB module also patches the C<$!> variable directly, so you
		479	should be able to get a bdb error string by simply stringifying C<$!>.
437		480
438	=item $fileno = BDB::poll_fileno	481	=item $fileno = BDB::poll_fileno
439		482
440	Return the I<request result pipe file descriptor>. This filehandle must be	483	Return the I<request result pipe file descriptor>. This filehandle must be
441	polled for reading by some mechanism outside this module (e.g. Event or	484	polled for reading by some mechanism outside this module (e.g. Event or
…		…
518	BDB::poll_wait, BDB::poll_cb	561	BDB::poll_wait, BDB::poll_cb
519	while BDB::nreqs;	562	while BDB::nreqs;
520		563
521	=back	564	=back
522		565
		566	=head2 VERSION CHECKING
		567
		568	BerkeleyDB comes in various versions, many of them have minor
		569	incompatibilities. This means that traditional "at least version x.x"
		570	checks are often not sufficient.
		571
		572	Example: set the log_autoremove option in a way compatible with <v4.7 and
		573	v4.7. Note the use of & on the constants to avoid triggering a compiletime
		574	bug when the symbol isn't available.
		575
		576	$DB_ENV->set_flags (&BDB::LOG_AUTOREMOVE ) if BDB::VERSION v0, v4.7;
		577	$DB_ENV->log_set_config (&BDB::LOG_AUTO_REMOVE) if BDB::VERSION v4.7;
		578
		579	=over 4
		580
		581	=item BDB::VERSION
		582
		583	The C<BDB::VERSION> function, when called without arguments, returns the
		584	Berkeley DB version as a v-string (usually with 3 components). You should
		585	use C<lt> and C<ge> operators exclusively to make comparisons.
		586
		587	Example: check for at least version 4.7.
		588
		589	BDB::VERSION ge v4.7 or die;
		590
		591	=item BDB::VERSION min-version
		592
		593	Returns true if the BDB version is at least the given version (specified
		594	as a v-string), false otherwise.
		595
		596	Example: check for at least version 4.5.
		597
		598	BDB::VERSION v4.7 or die;
		599
		600	=item BDB::VERSION min-version, max-version
		601
		602	Returns true of the BDB version is at least version C<min-version> (specify C<undef> or C<v0> for any minimum version)
		603	and less then C<max-version>.
		604
		605	Example: check wether version is strictly less then v4.7.
		606
		607	BDB::VERSION v0, v4.7
		608	or die "version 4.7 is not yet supported";
		609
		610	=back
		611
		612	=cut
		613
		614	sub VERSION {
		615	# I was dumb enough to override the VERSION method here, so let's try
		616	# to fix it up.
		617
		618	if ($_[0] eq __PACKAGE__) {
		619	$VERSION
		620	} else {
		621	if (@_ > 0) {
		622	return undef if VERSION_v lt $_[0];
		623	if (@_ > 1) {
		624	return undef if VERSION_v ge $_[1];
		625	}
		626	}
		627
		628	VERSION_v
		629	}
		630	}
		631
523	=head3 CONTROLLING THE NUMBER OF THREADS	632	=head2 CONTROLLING THE NUMBER OF THREADS
524		633
525	=over 4	634	=over 4
526		635
527	=item BDB::min_parallel $nthreads	636	=item BDB::min_parallel $nthreads
528		637
…		…
589		698
590	You can still queue as many requests as you want. Therefore,	699	You can still queue as many requests as you want. Therefore,
591	C<max_oustsanding> is mainly useful in simple scripts (with low values) or	700	C<max_oustsanding> is mainly useful in simple scripts (with low values) or
592	as a stop gap to shield against fatal memory overflow (with large values).	701	as a stop gap to shield against fatal memory overflow (with large values).
593		702
594	=item BDB::set_sync_prepare $cb	703	=item $old_cb = BDB::set_sync_prepare $cb
595		704
596	Sets a callback that is called whenever a request is created without an	705	Sets a callback that is called whenever a request is created without an
597	explicit callback. It has to return two code references. The first is used	706	explicit callback. It has to return two code references. The first is used
598	as the request callback, and the second is called to wait until the first	707	as the request callback (it should save the return status), and the second
599	callback has been called. The default implementation works like this:	708	is called to wait until the first callback has been called (it must set
		709	C<$!> to the return status).
		710
		711	This mechanism can be used to include BDB into other event mechanisms,
		712	such as L<Coro::BDB>.
		713
		714	To allow other, callback-based, events to be executed while callback-less
		715	ones are run, you could use this sync prepare function:
600		716
601	sub {	717	sub {
602	my $status;	718	my $status;
603	(	719	(
604	sub { $status = $! },	720	sub { $status = $! },
605	sub { BDB::poll while !defined $status; $! = $status },	721	sub { BDB::poll while !defined $status; $! = $status },
606	)	722	)
607	}	723	}
608		724
		725	It works by polling for results till the request has finished and then
		726	sets C<$!> to the return value. This means that if you don't use a
		727	callback, BDB would simply fall back to synchronous operations.
		728
		729	By default, or if the sync prepare function is set to C<undef>, is to
		730	execute callback-less BDB requests in the foreground thread, setting C<$!>
		731	to the return value, without polling for other events.
		732
609	=back	733	=back
610		734
611	=head3 STATISTICAL INFORMATION	735	=head2 STATISTICAL INFORMATION
612		736
613	=over 4	737	=over 4
614		738
615	=item BDB::nreqs	739	=item BDB::nreqs
616		740
…		…
634		758
635	=back	759	=back
636		760
637	=cut	761	=cut
638		762
639	set_sync_prepare {	763	set_sync_prepare (undef);
640	my $status;
641	(
642	sub {
643	$status = $!;
644	},
645	sub {
646	BDB::poll while !defined $status;
647	$! = $status;
648	},
649	)
650	};
651		764
652	min_parallel 8;	765	min_parallel 8;
653		766
654	END { flush }	767	END { flush }
655		768
656	1;	769	1;
657		770
		771	=head1 COMMON PITFALLS
		772
		773	=head2 Unexpected Crashes
		774
		775	Remember that, by default, BDB will execute requests in parallel, in
		776	somewhat random order. That means that it is easy to run a C<db_get>
		777	request on the same database as a concurrent C<db_close> request, leading
		778	to a crash, silent data corruption, eventually the next world war on
		779	terrorism.
		780
		781	If you only ever use foreground requests (without a callback), this will
		782	not be an issue (unless you use threads).
		783
		784	=head2 Unexpected Freezes or Deadlocks
		785
		786	Remember that, by default, BDB will execute requests in parallel, which
		787	easily leads to deadlocks (even concurrent put's on the same database can
		788	deadlock).
		789
		790	You either need to run deadlock detection (and handle the resulting
		791	errors), or make sure only one process ever updates the database, ine one
		792	thread, e.g. by using only foreground requests (without a callback).
		793
658	=head2 FORK BEHAVIOUR	794	=head1 FORK BEHAVIOUR
659		795
660	This module should do "the right thing" when the process using it forks:	796	This module should do "the right thing" when the process using it forks:
661		797
662	Before the fork, BDB enters a quiescent state where no requests	798	Before the fork, BDB enters a quiescent state where no requests
663	can be added in other threads and no results will be processed. After	799	can be added in other threads and no results will be processed. After
…		…
669		805
670	In short: the parent will, after a short pause, continue as if fork had	806	In short: the parent will, after a short pause, continue as if fork had
671	not been called, while the child will act as if BDB has not been used	807	not been called, while the child will act as if BDB has not been used
672	yet.	808	yet.
673		809
		810	Win32 note: there is no fork on win32, and perls emulation of it is too
		811	broken to be supported, so do not use BDB in a windows pseudo-fork, better
		812	yet, switch to a more capable platform.
		813
674	=head2 MEMORY USAGE	814	=head1 MEMORY USAGE
675		815
676	Per-request usage:	816	Per-request usage:
677		817
678	Each aio request uses - depending on your architecture - around 100-200	818	Each aio request uses - depending on your architecture - around 100-200
679	bytes of memory. In addition, stat requests need a stat buffer (possibly	819	bytes of memory. In addition, stat requests need a stat buffer (possibly
…		…
688		828
689	In the execution phase, some aio requests require more memory for	829	In the execution phase, some aio requests require more memory for
690	temporary buffers, and each thread requires a stack and other data	830	temporary buffers, and each thread requires a stack and other data
691	structures (usually around 16k-128k, depending on the OS).	831	structures (usually around 16k-128k, depending on the OS).
692		832
		833	=head1 WIN32 FILENAMES/DATABASE NAME MESS
		834
		835	Perl on Win32 supports only ASCII filenames (the reason is that it abuses
		836	an internal flag to store wether a filename is Unicode or ANSI, but that
		837	flag is used for somethign else in the perl core, so there is no way to
		838	detect wether a filename is ANSI or Unicode-encoded). The BDB module
		839	tries to work around this issue by assuming that the filename is an ANSI
		840	filename and BDB was built for unicode support.
		841
693	=head1 KNOWN BUGS	842	=head1 KNOWN BUGS
694		843
695	Known bugs will be fixed in the next release, except:	844	Known bugs will be fixed in the next release, except:
696		845
697	If you use a transaction in any request, and the request returns	846	If you use a transaction in any request, and the request returns
…		…
699	TXN_DEADLOCK flag will be set on the transaction. See C<db_txn_finish>,	848	TXN_DEADLOCK flag will be set on the transaction. See C<db_txn_finish>,
700	above.	849	above.
701		850
702	=head1 SEE ALSO	851	=head1 SEE ALSO
703		852
704	L<Coro::BDB>, L<IO::AIO>.	853	L<AnyEvent::BDB> (event loop integration), L<Coro::BDB> (more natural
		854	syntax), L<IO::AIO> (nice to have).
705		855
706	=head1 AUTHOR	856	=head1 AUTHOR
707		857
708	Marc Lehmann <schmorp@schmorp.de>	858	Marc Lehmann <schmorp@schmorp.de>
709	http://home.schmorp.de/	859	http://home.schmorp.de/

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Comparing BDB/BDB.pm (file contents): Revision 1.23 by root, Mon Dec 10 04:45:52 2007 UTC vs. Revision 1.68 by root, Tue Feb 2 04:17:03 2016 UTC

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Comparing BDB/BDB.pm (file contents):
Revision 1.23 by root, Mon Dec 10 04:45:52 2007 UTC vs.
Revision 1.68 by root, Tue Feb 2 04:17:03 2016 UTC