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

Comparing BDB/BDB.pm (file contents):
Revision 1.25 by root, Mon Dec 10 21:19:06 2007 UTC vs.
Revision 1.67 by root, Tue Feb 2 04:07:06 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
		120	db_env_log_archive db_env_reset_lsn
117	db_open db_close db_compact db_sync db_upgrade	121	db_open db_close db_compact db_sync db_verify db_upgrade
118	db_put db_get db_pget db_del db_key_range	122	db_put db_exists db_get db_pget db_del db_key_range
119	db_txn_commit db_txn_abort db_txn_finish	123	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	124	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	125	db_sequence_open db_sequence_close
122	db_sequence_get db_sequence_remove	126	db_sequence_get db_sequence_remove
123	);	127	);
…		…
131		135
132	require XSLoader;	136	require XSLoader;
133	XSLoader::load ("BDB", $VERSION);	137	XSLoader::load ("BDB", $VERSION);
134	}	138	}
135		139
136	=head2 BERKELEYDB FUNCTIONS	140	=head1 BERKELEYDB FUNCTIONS
137		141
138	All of these are functions. The create functions simply return a new	142	All of these are functions. The create functions simply return a new
139	object and never block. All the remaining functions all take an optional	143	object and never block. All the remaining functions take an optional
140	callback as last argument. If it is missing, then the function will be	144	callback as last argument. If it is missing, then the function will be
141	executed synchronously. In both cases, C<$!> will reflect the return value	145	executed synchronously. In both cases, C<$!> will reflect the return value
142	of the function.	146	of the function.
143		147
144	BDB functions that cannot block (mostly functions that manipulate	148	BDB functions that cannot block (mostly functions that manipulate
145	settings) are method calls on the relevant objects, so the rule of thumb	149	settings) are method calls on the relevant objects, so the rule of thumb
146	is: if its a method, its not blocking, if its a function, it takes a	150	is: if it's a method, it's not blocking, if it's a function, it takes a
147	callback as last argument.	151	callback as last argument.
148		152
149	In the following, C<$int> signifies an integer return value,	153	In the following, C<$int> signifies an integer return value,
150	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),
151	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
152	integer, C<NV> is a floating point value.	156	floating point value.
153		157
154	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
155	values), and the C<SV *callback> is the optional callback function to call	159	values).
156	when the request is completed.
157		160
158	The various C<DB_ENV> etc. arguments are handles return by	161	The various C<DB_ENV> etc. arguments are handles return by
159	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
160	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>
161	for them, resulting a NULL pointer on the C level.	164	for them, resulting a NULL pointer on the C level.
162		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
163	=head3 BDB functions	189	=head2 BDB functions
164		190
165	Functions in the BDB namespace, exported by default:	191	Functions in the BDB namespace, exported by default:
166		192
167	$env = db_env_create (U32 env_flags = 0)	193	$env = db_env_create (U32 env_flags = 0)
168	flags: RPCCLIENT	194	flags: RPCCLIENT
169		195
170	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)
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	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
172	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)
173	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)
174	flags: FORCE	200	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)	201	db_env_lock_detect (DB_ENV env, U32 flags = 0, U32 atype = DB_LOCK_DEFAULT, SV dummy = 0, SV *callback = 0)
176	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
177	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)
178	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)
179		209
180	$db = db_create (DB_ENV *env = 0, U32 flags = 0)	210	$db = db_create (DB_ENV *env = 0, U32 flags = 0)
181	flags: XA_CREATE	211	flags: XA_CREATE
182		212
183	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)
184	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
185	db_close (DB db, U32 flags = 0, SV callback = &PL_sv_undef)	215	db_close (DB db, U32 flags = 0, SV callback = 0)
186	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)
187	db_upgrade (DB db, octetstring file, U32 flags = 0, SV callback = &PL_sv_undef)	218	db_upgrade (DB db, bdb_filename file, U32 flags = 0, SV callback = 0)
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)	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)
189	flags: FREELIST_ONLY FREE_SPACE	220	flags: FREELIST_ONLY FREE_SPACE
190	db_sync (DB db, U32 flags = 0, SV callback = &PL_sv_undef)	221	db_sync (DB db, U32 flags = 0, SV callback = 0)
191	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)
192	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)
193	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)
194	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)
195	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
196	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)
197	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
198	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)
199	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)
200	flags: TXN_NOSYNC TXN_SYNC	232	flags: TXN_NOSYNC TXN_SYNC
201	db_txn_abort (DB_TXN txn, SV callback = &PL_sv_undef)	233	db_txn_abort (DB_TXN txn, SV callback = 0)
202		234
203	db_c_close (DBC dbc, SV callback = &PL_sv_undef)	235	db_c_close (DBC dbc, SV callback = 0)
204	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)
205	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)
206	flags: AFTER BEFORE CURRENT KEYFIRST KEYLAST NODUPDATA	238	flags: AFTER BEFORE CURRENT KEYFIRST KEYLAST NODUPDATA
207	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)
208	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
209	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)
210	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)
211		243
212	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)
213	flags: CREATE EXCL	245	flags: CREATE EXCL
214	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)
215	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)
216	flags: TXN_NOSYNC	248	flags: TXN_NOSYNC
217	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)
218	flags: TXN_NOSYNC	250	flags: TXN_NOSYNC
219		251
220	=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)
221		253
222	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
223	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
224	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
225	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
…		…
251		283
252	You can use the C<< $txn->failed >> method to check wether a transaction	284	You can use the C<< $txn->failed >> method to check wether a transaction
253	has failed in this way and abort further processing (excluding	285	has failed in this way and abort further processing (excluding
254	C<db_txn_finish>).	286	C<db_txn_finish>).
255		287
		288
256	=head3 DB_ENV/database environment methods	289	=head2 DB_ENV/database environment methods
257		290
258	Methods available on DB_ENV/$env handles:	291	Methods available on DB_ENV/$env handles:
259		292
260	DESTROY (DB_ENV_ornull *env)	293	DESTROY (DB_ENV_ornull *env)
261	CODE:	294	CODE:
…		…
265	$int = $env->set_data_dir (const char *dir)	298	$int = $env->set_data_dir (const char *dir)
266	$int = $env->set_tmp_dir (const char *dir)	299	$int = $env->set_tmp_dir (const char *dir)
267	$int = $env->set_lg_dir (const char *dir)	300	$int = $env->set_lg_dir (const char *dir)
268	$int = $env->set_shm_key (long shm_key)	301	$int = $env->set_shm_key (long shm_key)
269	$int = $env->set_cachesize (U32 gbytes, U32 bytes, int ncache = 0)	302	$int = $env->set_cachesize (U32 gbytes, U32 bytes, int ncache = 0)
270	$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)
271	$env->set_errfile (FILE *errfile = 0)	306	$env->set_errfile (FILE *errfile = 0)
272	$env->set_msgfile (FILE *msgfile = 0)	307	$env->set_msgfile (FILE *msgfile = 0)
273	$int = $env->set_verbose (U32 which, int onoff = 1)	308	$int = $env->set_verbose (U32 which, int onoff = 1)
274	$int = $env->set_encrypt (const char *password, U32 flags = 0)	309	$int = $env->set_encrypt (const char *password, U32 flags = 0)
275	$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)
…		…
287	$int = $env->mutex_set_max (U32 max)	322	$int = $env->mutex_set_max (U32 max)
288	$int = $env->mutex_set_align (U32 align)	323	$int = $env->mutex_set_align (U32 align)
289		324
290	$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)
291	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)
292		328
293	=head4 Example:	329	=head3 Example:
294		330
295	use AnyEvent;	331	use AnyEvent;
296	use BDB;	332	use BDB;
297		333
298	our $FH; open $FH, "<&=" . BDB::poll_fileno;	334	our $FH; open $FH, "<&=" . BDB::poll_fileno;
…		…
310	0600;	346	0600;
311		347
312	$env->set_flags (BDB::AUTO_COMMIT \| BDB::TXN_NOSYNC, 1);	348	$env->set_flags (BDB::AUTO_COMMIT \| BDB::TXN_NOSYNC, 1);
313		349
314		350
315	=head3 DB/database methods	351	=head2 DB/database methods
316		352
317	Methods available on DB/$db handles:	353	Methods available on DB/$db handles:
318		354
319	DESTROY (DB_ornull *db)	355	DESTROY (DB_ornull *db)
320	CODE:	356	CODE:
…		…
346		382
347	$dbc = $db->cursor (DB_TXN_ornull *txn = 0, U32 flags = 0)	383	$dbc = $db->cursor (DB_TXN_ornull *txn = 0, U32 flags = 0)
348	flags: READ_COMMITTED READ_UNCOMMITTED WRITECURSOR TXN_SNAPSHOT	384	flags: READ_COMMITTED READ_UNCOMMITTED WRITECURSOR TXN_SNAPSHOT
349	$seq = $db->sequence (U32 flags = 0)	385	$seq = $db->sequence (U32 flags = 0)
350		386
351	=head4 Example:	387	=head3 Example:
352		388
353	my $db = db_create $env;	389	my $db = db_create $env;
354	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;
355		391
356	for (1..1000) {	392	for (1..1000) {
…		…
363	db_del $db, undef, "key $_" for 1..1000;	399	db_del $db, undef, "key $_" for 1..1000;
364		400
365	db_sync $db;	401	db_sync $db;
366		402
367		403
368	=head3 DB_TXN/transaction methods	404	=head2 DB_TXN/transaction methods
369		405
370	Methods available on DB_TXN/$txn handles:	406	Methods available on DB_TXN/$txn handles:
371		407
372	DESTROY (DB_TXN_ornull *txn)	408	DESTROY (DB_TXN_ornull *txn)
373	CODE:	409	CODE:
…		…
379		415
380	$bool = $txn->failed	416	$bool = $txn->failed
381	# see db_txn_finish documentation, above	417	# see db_txn_finish documentation, above
382		418
383		419
384	=head3 DBC/cursor methods	420	=head2 DBC/cursor methods
385		421
386	Methods available on DBC/$dbc handles:	422	Methods available on DBC/$dbc handles:
387		423
388	DESTROY (DBC_ornull *dbc)	424	DESTROY (DBC_ornull *dbc)
389	CODE:	425	CODE:
390	if (dbc)	426	if (dbc)
391	dbc->c_close (dbc);	427	dbc->c_close (dbc);
392		428
		429	$int = $cursor->set_priority ($priority = PRIORITY_*) (v4.6)
		430
393	=head4 Example:	431	=head3 Example:
394		432
395	my $c = $db->cursor;	433	my $c = $db->cursor;
396		434
397	for (;;) {	435	for (;;) {
398	db_c_get $c, my $key, my $data, BDB::NEXT;	436	db_c_get $c, my $key, my $data, BDB::NEXT;
…		…
401	}	439	}
402		440
403	db_c_close $c;	441	db_c_close $c;
404		442
405		443
406	=head3 DB_SEQUENCE/sequence methods	444	=head2 DB_SEQUENCE/sequence methods
407		445
408	Methods available on DB_SEQUENCE/$seq handles:	446	Methods available on DB_SEQUENCE/$seq handles:
409		447
410	DESTROY (DB_SEQUENCE_ornull *seq)	448	DESTROY (DB_SEQUENCE_ornull *seq)
411	CODE:	449	CODE:
…		…
416	$int = $seq->set_cachesize (U32 size)	454	$int = $seq->set_cachesize (U32 size)
417	$int = $seq->set_flags (U32 flags)	455	$int = $seq->set_flags (U32 flags)
418	flags: SEQ_DEC SEQ_INC SEQ_WRAP	456	flags: SEQ_DEC SEQ_INC SEQ_WRAP
419	$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)
420		458
421	=head4 Example:	459	=head3 Example:
422		460
423	my $seq = $db->sequence;	461	my $seq = $db->sequence;
424		462
425	db_sequence_open $seq, undef, "seq", BDB::CREATE;	463	db_sequence_open $seq, undef, "seq", BDB::CREATE;
426	db_sequence_get $seq, undef, 1, my $value;	464	db_sequence_get $seq, undef, 1, my $value;
427		465
428		466
429	=head2 SUPPORT FUNCTIONS	467	=head1 SUPPORT FUNCTIONS
430		468
431	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION	469	=head2 EVENT PROCESSING AND EVENT LOOP INTEGRATION
432		470
433	=over 4	471	=over 4
434		472
435	=item $msg = BDB::strerror [$errno]	473	=item $msg = BDB::strerror [$errno]
436		474
437	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
438	is given, use C<$!>.	476	is given, use C<$!>.
		477
		478	Note that the BDB module also patches the C<$!> variable directly, so you
		479	should be able to get a bdb error string by simply stringifying C<$!>.
439		480
440	=item $fileno = BDB::poll_fileno	481	=item $fileno = BDB::poll_fileno
441		482
442	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
443	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
…		…
520	BDB::poll_wait, BDB::poll_cb	561	BDB::poll_wait, BDB::poll_cb
521	while BDB::nreqs;	562	while BDB::nreqs;
522		563
523	=back	564	=back
524		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
525	=head3 CONTROLLING THE NUMBER OF THREADS	632	=head2 CONTROLLING THE NUMBER OF THREADS
526		633
527	=over 4	634	=over 4
528		635
529	=item BDB::min_parallel $nthreads	636	=item BDB::min_parallel $nthreads
530		637
…		…
591		698
592	You can still queue as many requests as you want. Therefore,	699	You can still queue as many requests as you want. Therefore,
593	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
594	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).
595		702
596	=item BDB::set_sync_prepare $cb	703	=item $old_cb = BDB::set_sync_prepare $cb
597		704
598	Sets a callback that is called whenever a request is created without an	705	Sets a callback that is called whenever a request is created without an
599	explicit callback. It has to return two code references. The first is used	706	explicit callback. It has to return two code references. The first is used
600	as the request callback, and the second is called to wait until the first	707	as the request callback (it should save the return status), and the second
601	callback has been called. The default implementation works like this:	708	is called to wait until the first callback has been called (it must set
		709	C<$!> 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:
602		716
603	sub {	717	sub {
604	my $status;	718	my $status;
605	(	719	(
606	sub { $status = $! },	720	sub { $status = $! },
607	sub { BDB::poll while !defined $status; $! = $status },	721	sub { BDB::poll while !defined $status; $! = $status },
608	)	722	)
609	}	723	}
610		724
		725	It works by polling for results till the request has finished and then
		726	sets C<$!> 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
611	=back	733	=back
612		734
613	=head3 STATISTICAL INFORMATION	735	=head2 STATISTICAL INFORMATION
614		736
615	=over 4	737	=over 4
616		738
617	=item BDB::nreqs	739	=item BDB::nreqs
618		740
…		…
636		758
637	=back	759	=back
638		760
639	=cut	761	=cut
640		762
641	set_sync_prepare {	763	set_sync_prepare (undef);
642	my $status;
643	(
644	sub {
645	$status = $!;
646	},
647	sub {
648	BDB::poll while !defined $status;
649	$! = $status;
650	},
651	)
652	};
653		764
654	min_parallel 8;	765	min_parallel 8;
655		766
656	END { flush }	767	END { flush }
657		768
658	1;	769	1;
659		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
660	=head2 FORK BEHAVIOUR	794	=head1 FORK BEHAVIOUR
661		795
662	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:
663		797
664	Before the fork, BDB enters a quiescent state where no requests	798	Before the fork, BDB enters a quiescent state where no requests
665	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
…		…
671		805
672	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
673	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
674	yet.	808	yet.
675		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
676	=head2 MEMORY USAGE	814	=head1 MEMORY USAGE
677		815
678	Per-request usage:	816	Per-request usage:
679		817
680	Each aio request uses - depending on your architecture - around 100-200	818	Each aio request uses - depending on your architecture - around 100-200
681	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
…		…
690		828
691	In the execution phase, some aio requests require more memory for	829	In the execution phase, some aio requests require more memory for
692	temporary buffers, and each thread requires a stack and other data	830	temporary buffers, and each thread requires a stack and other data
693	structures (usually around 16k-128k, depending on the OS).	831	structures (usually around 16k-128k, depending on the OS).
694		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
695	=head1 KNOWN BUGS	842	=head1 KNOWN BUGS
696		843
697	Known bugs will be fixed in the next release, except:	844	Known bugs will be fixed in the next release, except:
698		845
699	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
…		…
701	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>,
702	above.	849	above.
703		850
704	=head1 SEE ALSO	851	=head1 SEE ALSO
705		852
706	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).
707		855
708	=head1 AUTHOR	856	=head1 AUTHOR
709		857
710	Marc Lehmann <schmorp@schmorp.de>	858	Marc Lehmann <schmorp@schmorp.de>
711	http://home.schmorp.de/	859	http://home.schmorp.de/

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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 1.67 by root, Tue Feb 2 04:07:06 2016 UTC

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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 1.67 by root, Tue Feb 2 04:07:06 2016 UTC