… | |
… | |
25 | db_sync $db; |
25 | db_sync $db; |
26 | |
26 | |
27 | # when you also use Coro, management is easy: |
27 | # when you also use Coro, management is easy: |
28 | use Coro::BDB; |
28 | use Coro::BDB; |
29 | |
29 | |
30 | # automatic result processing with AnyEvent: |
30 | # automatic event loop intergration with AnyEvent: |
31 | our $FH; open $FH, "<&=" . BDB::poll_fileno; |
31 | use AnyEvent::BDB; |
32 | our $WATCHER = AnyEvent->io (fh => $FH, poll => 'r', cb => \&BDB::poll_cb); |
|
|
33 | |
32 | |
34 | # automatic result processing with EV: |
33 | # automatic result processing with EV: |
35 | my $WATCHER = EV::io BDB::poll_fileno, EV::READ, \&BDB::poll_cb; |
34 | my $WATCHER = EV::io BDB::poll_fileno, EV::READ, \&BDB::poll_cb; |
36 | |
35 | |
37 | # with Glib: |
36 | # with Glib: |
… | |
… | |
107 | BDB functions that cannot block (mostly functions that manipulate |
106 | BDB functions that cannot block (mostly functions that manipulate |
108 | settings) are method calls on the relevant objects, so the rule of thumb |
107 | settings) are method calls on the relevant objects, so the rule of thumb |
109 | is: if it's a method, it's not blocking, if it's a function, it takes a |
108 | is: if it's a method, it's not blocking, if it's a function, it takes a |
110 | callback as last argument. |
109 | callback as last argument. |
111 | |
110 | |
112 | In the following, $int signifies an integer return value, "octetstring" |
111 | In the following, $int signifies an integer return value, "bdb_filename" |
113 | is a "binary string" (i.e. a perl string with no character indices |
112 | is a "filename" (octets on unix, madness on windows), "U32" is an |
114 | >255), "U32" is an unsigned 32 bit integer, "int" is some integer, "NV" |
113 | unsigned 32 bit integer, "int" is some integer, "NV" is a floating point |
115 | is a floating point value. |
114 | value. |
116 | |
115 | |
117 | The "SV *" types are generic perl scalars (for input and output of data |
116 | Most "SV *" types are generic perl scalars (for input and output of data |
118 | values), and the "SV *callback" is the optional callback function to |
117 | values). |
119 | call when the request is completed. |
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|
120 | |
118 | |
121 | The various "DB_ENV" etc. arguments are handles return by |
119 | The various "DB_ENV" etc. arguments are handles return by |
122 | "db_env_create", "db_create", "txn_begin" and so on. If they have an |
120 | "db_env_create", "db_create", "txn_begin" and so on. If they have an |
123 | appended "_ornull" this means they are optional and you can pass "undef" |
121 | appended "_ornull" this means they are optional and you can pass "undef" |
124 | for them, resulting a NULL pointer on the C level. |
122 | for them, resulting a NULL pointer on the C level. |
125 | |
123 | |
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124 | The "SV *callback" is the optional callback function to call when the |
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125 | request is completed. This last callback argument is special: the |
|
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126 | callback is simply the last argument passed. If there are "optional" |
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127 | arguments before the callback they can be left out. The callback itself |
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128 | can be left out or specified as "undef", in which case the function will |
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129 | be executed synchronously. |
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130 | |
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131 | For example, "db_env_txn_checkpoint" usually is called with all integer |
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132 | arguments zero. These can be left out, so all of these specify a call to |
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133 | "DB_ENV->txn_checkpoint", to be executed asynchronously with a callback |
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134 | to be called: |
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135 | |
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136 | db_env_txn_checkpoint $db_env, 0, 0, 0, sub { }; |
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137 | db_env_txn_checkpoint $db_env, 0, 0, sub { }; |
|
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138 | db_env_txn_checkpoint $db_env, sub { }; |
|
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139 | |
|
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140 | While these all specify a call to "DB_ENV->txn_checkpoint" to be |
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141 | executed synchronously: |
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142 | |
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143 | db_env_txn_checkpoint $db_env, 0, 0, 0, undef; |
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144 | db_env_txn_checkpoint $db_env, 0, 0, 0; |
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145 | db_env_txn_checkpoint $db_env, 0; |
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146 | |
126 | BDB functions |
147 | BDB functions |
127 | Functions in the BDB namespace, exported by default: |
148 | Functions in the BDB namespace, exported by default: |
128 | |
149 | |
129 | $env = db_env_create (U32 env_flags = 0) |
150 | $env = db_env_create (U32 env_flags = 0) |
130 | flags: RPCCLIENT |
151 | flags: RPCCLIENT |
131 | |
152 | |
132 | db_env_open (DB_ENV *env, octetstring db_home, U32 open_flags, int mode, SV *callback = &PL_sv_undef) |
153 | db_env_open (DB_ENV *env, bdb_filename db_home, U32 open_flags, int mode, SV *callback = &PL_sv_undef) |
133 | 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 |
154 | 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 |
134 | db_env_close (DB_ENV *env, U32 flags = 0, SV *callback = &PL_sv_undef) |
155 | db_env_close (DB_ENV *env, U32 flags = 0, SV *callback = &PL_sv_undef) |
135 | db_env_txn_checkpoint (DB_ENV *env, U32 kbyte = 0, U32 min = 0, U32 flags = 0, SV *callback = &PL_sv_undef) |
156 | db_env_txn_checkpoint (DB_ENV *env, U32 kbyte = 0, U32 min = 0, U32 flags = 0, SV *callback = &PL_sv_undef) |
136 | flags: FORCE |
157 | flags: FORCE |
137 | db_env_lock_detect (DB_ENV *env, U32 flags = 0, U32 atype = DB_LOCK_DEFAULT, SV *dummy = 0, SV *callback = &PL_sv_undef) |
158 | db_env_lock_detect (DB_ENV *env, U32 flags = 0, U32 atype = DB_LOCK_DEFAULT, SV *dummy = 0, SV *callback = &PL_sv_undef) |
138 | atype: LOCK_DEFAULT LOCK_EXPIRE LOCK_MAXLOCKS LOCK_MAXWRITE LOCK_MINLOCKS LOCK_MINWRITE LOCK_OLDEST LOCK_RANDOM LOCK_YOUNGEST |
159 | atype: LOCK_DEFAULT LOCK_EXPIRE LOCK_MAXLOCKS LOCK_MAXWRITE LOCK_MINLOCKS LOCK_MINWRITE LOCK_OLDEST LOCK_RANDOM LOCK_YOUNGEST |
139 | db_env_memp_sync (DB_ENV *env, SV *dummy = 0, SV *callback = &PL_sv_undef) |
160 | db_env_memp_sync (DB_ENV *env, SV *dummy = 0, SV *callback = &PL_sv_undef) |
140 | db_env_memp_trickle (DB_ENV *env, int percent, SV *dummy = 0, SV *callback = &PL_sv_undef) |
161 | db_env_memp_trickle (DB_ENV *env, int percent, SV *dummy = 0, SV *callback = &PL_sv_undef) |
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162 | db_env_dbremove (DB_ENV *env, DB_TXN_ornull *txnid, bdb_filename file, bdb_filename database, U32 flags = 0, SV *callback = &PL_sv_undef) |
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163 | db_env_dbrename (DB_ENV *env, DB_TXN_ornull *txnid, bdb_filename file, bdb_filename database, bdb_filename newname, U32 flags = 0, SV *callback = &PL_sv_undef) |
141 | |
164 | |
142 | $db = db_create (DB_ENV *env = 0, U32 flags = 0) |
165 | $db = db_create (DB_ENV *env = 0, U32 flags = 0) |
143 | flags: XA_CREATE |
166 | flags: XA_CREATE |
144 | |
167 | |
145 | db_open (DB *db, DB_TXN_ornull *txnid, octetstring file, octetstring database, int type, U32 flags, int mode, SV *callback = &PL_sv_undef) |
168 | db_open (DB *db, DB_TXN_ornull *txnid, bdb_filename file, bdb_filename database, int type, U32 flags, int mode, SV *callback = &PL_sv_undef) |
146 | flags: AUTO_COMMIT CREATE EXCL MULTIVERSION NOMMAP RDONLY READ_UNCOMMITTED THREAD TRUNCATE |
169 | flags: AUTO_COMMIT CREATE EXCL MULTIVERSION NOMMAP RDONLY READ_UNCOMMITTED THREAD TRUNCATE |
147 | db_close (DB *db, U32 flags = 0, SV *callback = &PL_sv_undef) |
170 | db_close (DB *db, U32 flags = 0, SV *callback = &PL_sv_undef) |
148 | flags: DB_NOSYNC |
171 | flags: DB_NOSYNC |
149 | db_upgrade (DB *db, octetstring file, U32 flags = 0, SV *callback = &PL_sv_undef) |
172 | db_upgrade (DB *db, bdb_filename 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) |
173 | 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 |
174 | flags: FREELIST_ONLY FREE_SPACE |
152 | db_sync (DB *db, U32 flags = 0, SV *callback = &PL_sv_undef) |
175 | 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) |
176 | 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) |
177 | db_put (DB *db, DB_TXN_ornull *txn, SV *key, SV *data, U32 flags = 0, SV *callback = &PL_sv_undef) |
155 | flags: APPEND NODUPDATA NOOVERWRITE |
178 | flags: APPEND NODUPDATA NOOVERWRITE |
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179 | db_exists (DB *db, DB_TXN_ornull *txn, SV *key, U32 flags = 0, SV *callback = 0) (v4.6) |
156 | db_get (DB *db, DB_TXN_ornull *txn, SV *key, SV *data, U32 flags = 0, SV *callback = &PL_sv_undef) |
180 | db_get (DB *db, DB_TXN_ornull *txn, SV *key, SV *data, U32 flags = 0, SV *callback = &PL_sv_undef) |
157 | flags: CONSUME CONSUME_WAIT GET_BOTH SET_RECNO MULTIPLE READ_COMMITTED READ_UNCOMMITTED RMW |
181 | flags: CONSUME CONSUME_WAIT GET_BOTH SET_RECNO MULTIPLE READ_COMMITTED READ_UNCOMMITTED RMW |
158 | db_pget (DB *db, DB_TXN_ornull *txn, SV *key, SV *pkey, SV *data, U32 flags = 0, SV *callback = &PL_sv_undef) |
182 | db_pget (DB *db, DB_TXN_ornull *txn, SV *key, SV *pkey, SV *data, U32 flags = 0, SV *callback = &PL_sv_undef) |
159 | flags: CONSUME CONSUME_WAIT GET_BOTH SET_RECNO MULTIPLE READ_COMMITTED READ_UNCOMMITTED RMW |
183 | flags: CONSUME CONSUME_WAIT GET_BOTH SET_RECNO MULTIPLE READ_COMMITTED READ_UNCOMMITTED RMW |
160 | db_del (DB *db, DB_TXN_ornull *txn, SV *key, U32 flags = 0, SV *callback = &PL_sv_undef) |
184 | db_del (DB *db, DB_TXN_ornull *txn, SV *key, U32 flags = 0, SV *callback = &PL_sv_undef) |
… | |
… | |
225 | $int = $env->set_data_dir (const char *dir) |
249 | $int = $env->set_data_dir (const char *dir) |
226 | $int = $env->set_tmp_dir (const char *dir) |
250 | $int = $env->set_tmp_dir (const char *dir) |
227 | $int = $env->set_lg_dir (const char *dir) |
251 | $int = $env->set_lg_dir (const char *dir) |
228 | $int = $env->set_shm_key (long shm_key) |
252 | $int = $env->set_shm_key (long shm_key) |
229 | $int = $env->set_cachesize (U32 gbytes, U32 bytes, int ncache = 0) |
253 | $int = $env->set_cachesize (U32 gbytes, U32 bytes, int ncache = 0) |
230 | $int = $env->set_flags (U32 flags, int onoff) |
254 | $int = $env->set_flags (U32 flags, int onoff = 1) |
|
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255 | $int = $env->log_set_config (U32 flags, int onoff = 1) (v4.7) |
|
|
256 | $int = $env->set_intermediate_dir_mode (const char *modestring) (v4.7) |
231 | $env->set_errfile (FILE *errfile = 0) |
257 | $env->set_errfile (FILE *errfile = 0) |
232 | $env->set_msgfile (FILE *msgfile = 0) |
258 | $env->set_msgfile (FILE *msgfile = 0) |
233 | $int = $env->set_verbose (U32 which, int onoff = 1) |
259 | $int = $env->set_verbose (U32 which, int onoff = 1) |
234 | $int = $env->set_encrypt (const char *password, U32 flags = 0) |
260 | $int = $env->set_encrypt (const char *password, U32 flags = 0) |
235 | $int = $env->set_timeout (NV timeout_seconds, U32 flags = SET_TXN_TIMEOUT) |
261 | $int = $env->set_timeout (NV timeout_seconds, U32 flags = SET_TXN_TIMEOUT) |
… | |
… | |
247 | $int = $env->mutex_set_max (U32 max) |
273 | $int = $env->mutex_set_max (U32 max) |
248 | $int = $env->mutex_set_align (U32 align) |
274 | $int = $env->mutex_set_align (U32 align) |
249 | |
275 | |
250 | $txn = $env->txn_begin (DB_TXN_ornull *parent = 0, U32 flags = 0) |
276 | $txn = $env->txn_begin (DB_TXN_ornull *parent = 0, U32 flags = 0) |
251 | flags: READ_COMMITTED READ_UNCOMMITTED TXN_NOSYNC TXN_NOWAIT TXN_SNAPSHOT TXN_SYNC TXN_WAIT TXN_WRITE_NOSYNC |
277 | flags: READ_COMMITTED READ_UNCOMMITTED TXN_NOSYNC TXN_NOWAIT TXN_SNAPSHOT TXN_SYNC TXN_WAIT TXN_WRITE_NOSYNC |
|
|
278 | $txn = $env->cdsgroup_begin; (v4.5) |
252 | |
279 | |
253 | Example: |
280 | Example: |
254 | use AnyEvent; |
281 | use AnyEvent; |
255 | use BDB; |
282 | use BDB; |
256 | |
283 | |
… | |
… | |
340 | DESTROY (DBC_ornull *dbc) |
367 | DESTROY (DBC_ornull *dbc) |
341 | CODE: |
368 | CODE: |
342 | if (dbc) |
369 | if (dbc) |
343 | dbc->c_close (dbc); |
370 | dbc->c_close (dbc); |
344 | |
371 | |
345 | $int = $cursor->set_priority ($priority = PRIORITY_*) |
372 | $int = $cursor->set_priority ($priority = PRIORITY_*) (v4.6) |
346 | |
373 | |
347 | Example: |
374 | Example: |
348 | my $c = $db->cursor; |
375 | my $c = $db->cursor; |
349 | |
376 | |
350 | for (;;) { |
377 | for (;;) { |
… | |
… | |
461 | Strictly equivalent to: |
488 | Strictly equivalent to: |
462 | |
489 | |
463 | BDB::poll_wait, BDB::poll_cb |
490 | BDB::poll_wait, BDB::poll_cb |
464 | while BDB::nreqs; |
491 | while BDB::nreqs; |
465 | |
492 | |
|
|
493 | VERSION CHECKING |
|
|
494 | BerkeleyDB comes in various versions, many of them have minor |
|
|
495 | incompatibilities. This means that traditional "at least version x.x" |
|
|
496 | checks are often not sufficient. |
|
|
497 | |
|
|
498 | Example: set the log_autoremove option in a way compatible with <v4.7 |
|
|
499 | and v4.7. Note the use of & on the constants to avoid triggering a |
|
|
500 | compiletime bug when the symbol isn't available. |
|
|
501 | |
|
|
502 | $DB_ENV->set_flags (&BDB::LOG_AUTOREMOVE ) if BDB::VERSION v0, v4.7; |
|
|
503 | $DB_ENV->log_set_config (&BDB::LOG_AUTO_REMOVE) if BDB::VERSION v4.7; |
|
|
504 | |
|
|
505 | BDB::VERSION |
|
|
506 | The "BDB::VERSION" function, when called without arguments, returns |
|
|
507 | the Berkeley DB version as a v-string (usually with 3 components). |
|
|
508 | You should use "lt" and "ge" operators exclusively to make |
|
|
509 | comparisons. |
|
|
510 | |
|
|
511 | Example: check for at least version 4.7. |
|
|
512 | |
|
|
513 | BDB::VERSION ge v4.7 or die; |
|
|
514 | |
|
|
515 | BDB::VERSION min-version |
|
|
516 | Returns true if the BDB version is at least the given version |
|
|
517 | (specified as a v-string), false otherwise. |
|
|
518 | |
|
|
519 | Example: check for at least version 4.5. |
|
|
520 | |
|
|
521 | BDB::VERSION v4.7 or die; |
|
|
522 | |
|
|
523 | BDB::VERSION min-version, max-version |
|
|
524 | Returns true of the BDB version is at least version "min-version" |
|
|
525 | (specify "undef" or "v0" for any minimum version) and less then |
|
|
526 | "max-version". |
|
|
527 | |
|
|
528 | Example: check wether version is strictly less then v4.7. |
|
|
529 | |
|
|
530 | BDB::VERSION v0, v4.7 |
|
|
531 | or die "version 4.7 is not yet supported"; |
|
|
532 | |
466 | CONTROLLING THE NUMBER OF THREADS |
533 | CONTROLLING THE NUMBER OF THREADS |
467 | BDB::min_parallel $nthreads |
534 | BDB::min_parallel $nthreads |
468 | Set the minimum number of BDB threads to $nthreads. The current |
535 | Set the minimum number of BDB threads to $nthreads. The current |
469 | default is 8, which means eight asynchronous operations can execute |
536 | default is 8, which means eight asynchronous operations can execute |
470 | concurrently at any one time (the number of outstanding requests, |
537 | concurrently at any one time (the number of outstanding requests, |
… | |
… | |
533 | (with large values). |
600 | (with large values). |
534 | |
601 | |
535 | BDB::set_sync_prepare $cb |
602 | BDB::set_sync_prepare $cb |
536 | Sets a callback that is called whenever a request is created without |
603 | Sets a callback that is called whenever a request is created without |
537 | an explicit callback. It has to return two code references. The |
604 | an explicit callback. It has to return two code references. The |
538 | first is used as the request callback, and the second is called to |
605 | first is used as the request callback (it should save the return |
539 | wait until the first callback has been called. The default |
606 | status), and the second is called to wait until the first callback |
|
|
607 | has been called (it must set $! to the return status). |
|
|
608 | |
|
|
609 | This mechanism can be used to include BDB into other event |
|
|
610 | mechanisms, such as AnyEvent::BDB or Coro::BDB. |
|
|
611 | |
540 | implementation works like this: |
612 | The default implementation works like this: |
541 | |
613 | |
542 | sub { |
614 | sub { |
543 | my $status; |
615 | my $status; |
544 | ( |
616 | ( |
545 | sub { $status = $! }, |
617 | sub { $status = $! }, |
546 | sub { BDB::poll while !defined $status; $! = $status }, |
618 | sub { BDB::poll while !defined $status; $! = $status }, |
547 | ) |
619 | ) |
548 | } |
620 | } |
549 | |
621 | |
|
|
622 | It simply blocks the process till the request has finished and then |
|
|
623 | sets $! to the return value. This means that if you don't use a |
|
|
624 | callback, BDB will simply fall back to synchronous operations. |
|
|
625 | |
550 | STATISTICAL INFORMATION |
626 | STATISTICAL INFORMATION |
551 | BDB::nreqs |
627 | BDB::nreqs |
552 | Returns the number of requests currently in the ready, execute or |
628 | Returns the number of requests currently in the ready, execute or |
553 | pending states (i.e. for which their callback has not been invoked |
629 | pending states (i.e. for which their callback has not been invoked |
554 | yet). |
630 | yet). |
… | |
… | |
610 | with an operating system error or DB_LOCK_NOTGRANTED, the internal |
686 | with an operating system error or DB_LOCK_NOTGRANTED, the internal |
611 | TXN_DEADLOCK flag will be set on the transaction. See C<db_txn_finish>, |
687 | TXN_DEADLOCK flag will be set on the transaction. See C<db_txn_finish>, |
612 | above. |
688 | above. |
613 | |
689 | |
614 | SEE ALSO |
690 | SEE ALSO |
615 | Coro::BDB, IO::AIO. |
691 | AnyEvent::BDB (event loop integration), Coro::BDB (more natural syntax), |
|
|
692 | IO::AIO (nice to have). |
616 | |
693 | |
617 | AUTHOR |
694 | AUTHOR |
618 | Marc Lehmann <schmorp@schmorp.de> |
695 | Marc Lehmann <schmorp@schmorp.de> |
619 | http://home.schmorp.de/ |
696 | http://home.schmorp.de/ |
620 | |
697 | |