… | |
… | |
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: |
… | |
… | |
87 | Request has reached the end of its lifetime and holds no resources |
86 | Request has reached the end of its lifetime and holds no resources |
88 | anymore (except possibly for the Perl object, but its connection to |
87 | anymore (except possibly for the Perl object, but its connection to |
89 | the actual aio request is severed and calling its methods will |
88 | the actual aio request is severed and calling its methods will |
90 | either do nothing or result in a runtime error). |
89 | either do nothing or result in a runtime error). |
91 | |
90 | |
92 | FILENAMES/DATABASE NAMES |
91 | WIN32 FILENAMES/DATABASE NAME MESS |
93 | The BDB expects "binary" filenames (octet strings) for pathnames on |
92 | Perl on Win32 supports only ASCII filenames (the reason is that it |
94 | POSIX systems, and "unicode" filenames (strings with characters |
93 | abuses an internal flag to store wether a filename is Unicode or ANSI, |
95 | potentially >255) on Win32 (expecting a Unicode win32 build - win32 is a |
94 | but that flag is used for somethign else in the perl core, so there is |
96 | total mess). |
95 | no way to detect wether a filename is ANSI or Unicode-encoded). The BDB |
|
|
96 | module tries to work around this issue by assuming that the filename is |
|
|
97 | an ANSI filename and BDB was built for unicode support. |
97 | |
98 | |
98 | BERKELEYDB FUNCTIONS |
99 | BERKELEYDB FUNCTIONS |
99 | All of these are functions. The create functions simply return a new |
100 | All of these are functions. The create functions simply return a new |
100 | object and never block. All the remaining functions take an optional |
101 | object and never block. All the remaining functions take an optional |
101 | callback as last argument. If it is missing, then the function will be |
102 | callback as last argument. If it is missing, then the function will be |
… | |
… | |
105 | BDB functions that cannot block (mostly functions that manipulate |
106 | BDB functions that cannot block (mostly functions that manipulate |
106 | 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 |
107 | 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 |
108 | callback as last argument. |
109 | callback as last argument. |
109 | |
110 | |
110 | In the following, $int signifies an integer return value, "octetstring" |
111 | In the following, $int signifies an integer return value, "bdb_filename" |
111 | 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 |
112 | >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 |
113 | is a floating point value. |
114 | value. |
114 | |
115 | |
115 | The "SV *" types are generic perl scalars (for input and output of data |
116 | The "SV *" types are generic perl scalars (for input and output of data |
116 | values), and the "SV *callback" is the optional callback function to |
117 | values), and the "SV *callback" is the optional callback function to |
117 | call when the request is completed. |
118 | call when the request is completed. |
118 | |
119 | |
… | |
… | |
125 | Functions in the BDB namespace, exported by default: |
126 | Functions in the BDB namespace, exported by default: |
126 | |
127 | |
127 | $env = db_env_create (U32 env_flags = 0) |
128 | $env = db_env_create (U32 env_flags = 0) |
128 | flags: RPCCLIENT |
129 | flags: RPCCLIENT |
129 | |
130 | |
130 | db_env_open (DB_ENV *env, octetstring db_home, U32 open_flags, int mode, SV *callback = &PL_sv_undef) |
131 | db_env_open (DB_ENV *env, bdb_filename db_home, U32 open_flags, int mode, SV *callback = &PL_sv_undef) |
131 | 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 |
132 | 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 |
132 | db_env_close (DB_ENV *env, U32 flags = 0, SV *callback = &PL_sv_undef) |
133 | db_env_close (DB_ENV *env, U32 flags = 0, SV *callback = &PL_sv_undef) |
133 | db_env_txn_checkpoint (DB_ENV *env, U32 kbyte = 0, U32 min = 0, U32 flags = 0, SV *callback = &PL_sv_undef) |
134 | db_env_txn_checkpoint (DB_ENV *env, U32 kbyte = 0, U32 min = 0, U32 flags = 0, SV *callback = &PL_sv_undef) |
134 | flags: FORCE |
135 | flags: FORCE |
135 | db_env_lock_detect (DB_ENV *env, U32 flags = 0, U32 atype = DB_LOCK_DEFAULT, SV *dummy = 0, SV *callback = &PL_sv_undef) |
136 | db_env_lock_detect (DB_ENV *env, U32 flags = 0, U32 atype = DB_LOCK_DEFAULT, SV *dummy = 0, SV *callback = &PL_sv_undef) |
136 | atype: LOCK_DEFAULT LOCK_EXPIRE LOCK_MAXLOCKS LOCK_MAXWRITE LOCK_MINLOCKS LOCK_MINWRITE LOCK_OLDEST LOCK_RANDOM LOCK_YOUNGEST |
137 | atype: LOCK_DEFAULT LOCK_EXPIRE LOCK_MAXLOCKS LOCK_MAXWRITE LOCK_MINLOCKS LOCK_MINWRITE LOCK_OLDEST LOCK_RANDOM LOCK_YOUNGEST |
137 | db_env_memp_sync (DB_ENV *env, SV *dummy = 0, SV *callback = &PL_sv_undef) |
138 | db_env_memp_sync (DB_ENV *env, SV *dummy = 0, SV *callback = &PL_sv_undef) |
138 | db_env_memp_trickle (DB_ENV *env, int percent, SV *dummy = 0, SV *callback = &PL_sv_undef) |
139 | db_env_memp_trickle (DB_ENV *env, int percent, SV *dummy = 0, SV *callback = &PL_sv_undef) |
|
|
140 | db_env_dbremove (DB_ENV *env, DB_TXN_ornull *txnid, bdb_filename file, bdb_filename database, U32 flags = 0, SV *callback = &PL_sv_undef) |
|
|
141 | 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) |
139 | |
142 | |
140 | $db = db_create (DB_ENV *env = 0, U32 flags = 0) |
143 | $db = db_create (DB_ENV *env = 0, U32 flags = 0) |
141 | flags: XA_CREATE |
144 | flags: XA_CREATE |
142 | |
145 | |
143 | db_open (DB *db, DB_TXN_ornull *txnid, octetstring file, octetstring database, int type, U32 flags, int mode, SV *callback = &PL_sv_undef) |
146 | 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) |
144 | flags: AUTO_COMMIT CREATE EXCL MULTIVERSION NOMMAP RDONLY READ_UNCOMMITTED THREAD TRUNCATE |
147 | flags: AUTO_COMMIT CREATE EXCL MULTIVERSION NOMMAP RDONLY READ_UNCOMMITTED THREAD TRUNCATE |
145 | db_close (DB *db, U32 flags = 0, SV *callback = &PL_sv_undef) |
148 | db_close (DB *db, U32 flags = 0, SV *callback = &PL_sv_undef) |
146 | flags: DB_NOSYNC |
149 | flags: DB_NOSYNC |
147 | db_upgrade (DB *db, octetstring file, U32 flags = 0, SV *callback = &PL_sv_undef) |
150 | db_upgrade (DB *db, bdb_filename file, U32 flags = 0, SV *callback = &PL_sv_undef) |
148 | 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 | 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) |
149 | flags: FREELIST_ONLY FREE_SPACE |
152 | flags: FREELIST_ONLY FREE_SPACE |
150 | db_sync (DB *db, U32 flags = 0, SV *callback = &PL_sv_undef) |
153 | db_sync (DB *db, U32 flags = 0, SV *callback = &PL_sv_undef) |
151 | db_key_range (DB *db, DB_TXN_ornull *txn, SV *key, SV *key_range, U32 flags = 0, SV *callback = &PL_sv_undef) |
154 | db_key_range (DB *db, DB_TXN_ornull *txn, SV *key, SV *key_range, U32 flags = 0, SV *callback = &PL_sv_undef) |
152 | db_put (DB *db, DB_TXN_ornull *txn, SV *key, SV *data, U32 flags = 0, SV *callback = &PL_sv_undef) |
155 | db_put (DB *db, DB_TXN_ornull *txn, SV *key, SV *data, U32 flags = 0, SV *callback = &PL_sv_undef) |
… | |
… | |
223 | $int = $env->set_data_dir (const char *dir) |
226 | $int = $env->set_data_dir (const char *dir) |
224 | $int = $env->set_tmp_dir (const char *dir) |
227 | $int = $env->set_tmp_dir (const char *dir) |
225 | $int = $env->set_lg_dir (const char *dir) |
228 | $int = $env->set_lg_dir (const char *dir) |
226 | $int = $env->set_shm_key (long shm_key) |
229 | $int = $env->set_shm_key (long shm_key) |
227 | $int = $env->set_cachesize (U32 gbytes, U32 bytes, int ncache = 0) |
230 | $int = $env->set_cachesize (U32 gbytes, U32 bytes, int ncache = 0) |
228 | $int = $env->set_flags (U32 flags, int onoff) |
231 | $int = $env->set_flags (U32 flags, int onoff = 1) |
|
|
232 | $int = $env->log_set_config (U32 flags, int onoff = 1) [v4.7] |
|
|
233 | $int = $env->set_intermediate_dir_mode (const char *modestring) [v4.7] |
229 | $env->set_errfile (FILE *errfile = 0) |
234 | $env->set_errfile (FILE *errfile = 0) |
230 | $env->set_msgfile (FILE *msgfile = 0) |
235 | $env->set_msgfile (FILE *msgfile = 0) |
231 | $int = $env->set_verbose (U32 which, int onoff = 1) |
236 | $int = $env->set_verbose (U32 which, int onoff = 1) |
232 | $int = $env->set_encrypt (const char *password, U32 flags = 0) |
237 | $int = $env->set_encrypt (const char *password, U32 flags = 0) |
233 | $int = $env->set_timeout (NV timeout_seconds, U32 flags = SET_TXN_TIMEOUT) |
238 | $int = $env->set_timeout (NV timeout_seconds, U32 flags = SET_TXN_TIMEOUT) |
… | |
… | |
459 | Strictly equivalent to: |
464 | Strictly equivalent to: |
460 | |
465 | |
461 | BDB::poll_wait, BDB::poll_cb |
466 | BDB::poll_wait, BDB::poll_cb |
462 | while BDB::nreqs; |
467 | while BDB::nreqs; |
463 | |
468 | |
|
|
469 | VERSION CHECKING |
|
|
470 | BerkeleyDB comes in various versions, many of them have minor |
|
|
471 | incompatibilities. This means that traditional "at least version x.x" |
|
|
472 | checks are often not sufficient. |
|
|
473 | |
|
|
474 | Example: set the log_autoremove option in a way compatible with <v.47 |
|
|
475 | and v4.7. Note the use of & on the constants to avoid triggering a |
|
|
476 | compiletime bug when the symbol isn't available. |
|
|
477 | |
|
|
478 | $DB_ENV->set_flags (&BDB::LOG_AUTOREMOVE ) if BDB::VERSION v0, v4.7; |
|
|
479 | $DB_ENV->log_set_config (&BDB::LOG_AUTO_REMOVE) if BDB::VERSION v4.7; |
|
|
480 | |
|
|
481 | BDB::VERSION |
|
|
482 | The "BDB::VERSION" function, when called without arguments, returns |
|
|
483 | the Berkeley DB version as a v-string (usually with 3 components). |
|
|
484 | You should use "lt" and "ge" operators exclusively to make |
|
|
485 | comparisons. |
|
|
486 | |
|
|
487 | Example: check for at least version 4.7. |
|
|
488 | |
|
|
489 | BDB::VERSION ge v4.7 or die; |
|
|
490 | |
|
|
491 | BDB::VERSION min-version |
|
|
492 | Returns true if the BDB version is at least the given version |
|
|
493 | (specified as a v-string), false otherwise. |
|
|
494 | |
|
|
495 | Example: check for at least version 4.5. |
|
|
496 | |
|
|
497 | BDB::VERSION v4.7 or die; |
|
|
498 | |
|
|
499 | BDB::VERSION min-version, max-version |
|
|
500 | Returns true of the BDB version is at least version "min-version" |
|
|
501 | (specify "undef" or "v0" for any minimum version) and less then |
|
|
502 | "max-version". |
|
|
503 | |
|
|
504 | Example: check wether version is strictly less then v4.7. |
|
|
505 | |
|
|
506 | BDB::VERSION v0, v4.7 |
|
|
507 | or die "version 4.7 is not yet supported"; |
|
|
508 | |
464 | CONTROLLING THE NUMBER OF THREADS |
509 | CONTROLLING THE NUMBER OF THREADS |
465 | BDB::min_parallel $nthreads |
510 | BDB::min_parallel $nthreads |
466 | Set the minimum number of BDB threads to $nthreads. The current |
511 | Set the minimum number of BDB threads to $nthreads. The current |
467 | default is 8, which means eight asynchronous operations can execute |
512 | default is 8, which means eight asynchronous operations can execute |
468 | concurrently at any one time (the number of outstanding requests, |
513 | concurrently at any one time (the number of outstanding requests, |
… | |
… | |
531 | (with large values). |
576 | (with large values). |
532 | |
577 | |
533 | BDB::set_sync_prepare $cb |
578 | BDB::set_sync_prepare $cb |
534 | Sets a callback that is called whenever a request is created without |
579 | Sets a callback that is called whenever a request is created without |
535 | an explicit callback. It has to return two code references. The |
580 | an explicit callback. It has to return two code references. The |
536 | first is used as the request callback, and the second is called to |
581 | first is used as the request callback (it should save the return |
537 | wait until the first callback has been called. The default |
582 | status), and the second is called to wait until the first callback |
|
|
583 | has been called (it must set $! to the return status). |
|
|
584 | |
|
|
585 | This mechanism can be used to include BDB into other event |
|
|
586 | mechanisms, such as AnyEvent::BDB or Coro::BDB. |
|
|
587 | |
538 | implementation works like this: |
588 | The default implementation works like this: |
539 | |
589 | |
540 | sub { |
590 | sub { |
541 | my $status; |
591 | my $status; |
542 | ( |
592 | ( |
543 | sub { $status = $! }, |
593 | sub { $status = $! }, |
544 | sub { BDB::poll while !defined $status; $! = $status }, |
594 | sub { BDB::poll while !defined $status; $! = $status }, |
545 | ) |
595 | ) |
546 | } |
596 | } |
547 | |
597 | |
|
|
598 | It simply blocks the process till the request has finished and then |
|
|
599 | sets $! to the return value. This means that if you don't use a |
|
|
600 | callback, BDB will simply fall back to synchronous operations. |
|
|
601 | |
548 | STATISTICAL INFORMATION |
602 | STATISTICAL INFORMATION |
549 | BDB::nreqs |
603 | BDB::nreqs |
550 | Returns the number of requests currently in the ready, execute or |
604 | Returns the number of requests currently in the ready, execute or |
551 | pending states (i.e. for which their callback has not been invoked |
605 | pending states (i.e. for which their callback has not been invoked |
552 | yet). |
606 | yet). |
… | |
… | |
608 | with an operating system error or DB_LOCK_NOTGRANTED, the internal |
662 | with an operating system error or DB_LOCK_NOTGRANTED, the internal |
609 | TXN_DEADLOCK flag will be set on the transaction. See C<db_txn_finish>, |
663 | TXN_DEADLOCK flag will be set on the transaction. See C<db_txn_finish>, |
610 | above. |
664 | above. |
611 | |
665 | |
612 | SEE ALSO |
666 | SEE ALSO |
613 | Coro::BDB, IO::AIO. |
667 | AnyEvent::BDB (event loop integration), Coro::BDB (more natural syntax), |
|
|
668 | IO::AIO (nice to have). |
614 | |
669 | |
615 | AUTHOR |
670 | AUTHOR |
616 | Marc Lehmann <schmorp@schmorp.de> |
671 | Marc Lehmann <schmorp@schmorp.de> |
617 | http://home.schmorp.de/ |
672 | http://home.schmorp.de/ |
618 | |
673 | |