… | |
… | |
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: |
|
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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'; |
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108 | |
109 | |
109 | use base 'Exporter'; |
110 | use base 'Exporter'; |
110 | |
111 | |
|
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112 | our $VERSION; |
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113 | |
111 | BEGIN { |
114 | BEGIN { |
112 | our $VERSION = '1.2'; |
115 | $VERSION = '1.9'; |
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 |
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121 | db_open db_close db_compact db_sync db_verify db_upgrade |
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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", $VERSION); |
133 | } |
138 | } |
134 | |
139 | |
135 | =head2 BERKELEYDB FUNCTIONS |
140 | =head1 BERKELEYDB FUNCTIONS |
136 | |
141 | |
137 | All of these are functions. The create functions simply return a new |
142 | All of these are functions. The create functions simply return a new |
138 | object and never block. All the remaining functions all take an optional |
143 | object and never block. All the remaining functions take an optional |
139 | callback as last argument. If it is missing, then the fucntion will be |
144 | callback as last argument. If it is missing, then the function will be |
140 | executed synchronously. |
145 | executed synchronously. In both cases, C<$!> will reflect the return value |
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146 | of the function. |
141 | |
147 | |
142 | BDB functions that cannot block (mostly functions that manipulate |
148 | BDB functions that cannot block (mostly functions that manipulate |
143 | 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 |
144 | 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 |
145 | callback as last argument. |
151 | callback as last argument. |
146 | |
152 | |
147 | In the following, C<$int> signifies an integer return value, |
153 | In the following, C<$int> signifies an integer return value, |
148 | 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), |
149 | 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 |
150 | integer, C<NV> is a floating point value. |
156 | floating point value. |
151 | |
157 | |
152 | 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 |
153 | values), and the C<SV *callback> is the optional callback function to call |
159 | values). |
154 | when the request is completed. |
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155 | |
160 | |
156 | The various C<DB_ENV> etc. arguments are handles return by |
161 | The various C<DB_ENV> etc. arguments are handles return by |
157 | 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 |
158 | 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> |
159 | for them, resulting a NULL pointer on the C level. |
164 | for them, resulting a NULL pointer on the C level. |
160 | |
165 | |
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166 | The C<SV *callback> is the optional callback function to call when the |
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167 | request is completed. This last callback argument is special: the callback |
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168 | is simply the last argument passed. If there are "optional" arguments |
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169 | before the callback they can be left out. The callback itself can be left |
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170 | out or specified as C<undef>, in which case the function will be executed |
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171 | synchronously. |
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172 | |
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173 | For example, C<db_env_txn_checkpoint> usually is called with all integer |
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174 | arguments zero. These can be left out, so all of these specify a call |
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175 | to C<< DB_ENV->txn_checkpoint >>, to be executed asynchronously with a |
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176 | callback to be called: |
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177 | |
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178 | db_env_txn_checkpoint $db_env, 0, 0, 0, sub { }; |
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179 | db_env_txn_checkpoint $db_env, 0, 0, sub { }; |
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180 | db_env_txn_checkpoint $db_env, sub { }; |
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181 | |
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182 | While these all specify a call to C<< DB_ENV->txn_checkpoint >> to be |
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183 | executed synchronously: |
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184 | |
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185 | db_env_txn_checkpoint $db_env, 0, 0, 0, undef; |
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186 | db_env_txn_checkpoint $db_env, 0, 0, 0; |
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187 | db_env_txn_checkpoint $db_env, 0; |
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188 | |
161 | =head3 BDB functions |
189 | =head2 BDB functions |
162 | |
190 | |
163 | Functions in the BDB namespace, exported by default: |
191 | Functions in the BDB namespace, exported by default: |
164 | |
192 | |
165 | $env = db_env_create (U32 env_flags = 0) |
193 | $env = db_env_create (U32 env_flags = 0) |
166 | flags: RPCCLIENT |
194 | flags: RPCCLIENT |
167 | |
195 | |
168 | 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) |
169 | 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 |
170 | 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) |
171 | 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) |
172 | flags: FORCE |
200 | flags: FORCE |
173 | 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) |
174 | 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 |
175 | 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) |
176 | 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) |
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205 | db_env_dbremove (DB_ENV *env, DB_TXN_ornull *txnid, bdb_filename file, bdb_filename database, U32 flags = 0, SV *callback = 0) |
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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) |
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207 | db_env_log_archive (DB_ENV *env, SV *listp, U32 flags = 0, SV *callback = 0) |
177 | |
208 | |
178 | $db = db_create (DB_ENV *env = 0, U32 flags = 0) |
209 | $db = db_create (DB_ENV *env = 0, U32 flags = 0) |
179 | flags: XA_CREATE |
210 | flags: XA_CREATE |
180 | |
211 | |
181 | db_open (DB *db, DB_TXN_ornull *txnid, octetstring file, octetstring database, int type, U32 flags, int mode, SV *callback = &PL_sv_undef) |
212 | db_open (DB *db, DB_TXN_ornull *txnid, bdb_filename file, bdb_filename database, int type, U32 flags, int mode, SV *callback = 0) |
182 | flags: AUTO_COMMIT CREATE EXCL MULTIVERSION NOMMAP RDONLY READ_UNCOMMITTED THREAD TRUNCATE |
213 | flags: AUTO_COMMIT CREATE EXCL MULTIVERSION NOMMAP RDONLY READ_UNCOMMITTED THREAD TRUNCATE |
183 | db_close (DB *db, U32 flags = 0, SV *callback = &PL_sv_undef) |
214 | db_close (DB *db, U32 flags = 0, SV *callback = 0) |
184 | flags: DB_NOSYNC |
215 | flags: DB_NOSYNC |
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216 | db_verify (DB *db, bdb_filename file, bdb_filename database = 0, SV *dummy = 0, U32 flags = 0, SV *callback = 0) |
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217 | db_upgrade (DB *db, bdb_filename file, U32 flags = 0, SV *callback = 0) |
185 | 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) |
218 | 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) |
186 | flags: FREELIST_ONLY FREE_SPACE |
219 | flags: FREELIST_ONLY FREE_SPACE |
187 | db_sync (DB *db, U32 flags = 0, SV *callback = &PL_sv_undef) |
220 | db_sync (DB *db, U32 flags = 0, SV *callback = 0) |
188 | db_key_range (DB *db, DB_TXN_ornull *txn, SV *key, SV *key_range, U32 flags = 0, SV *callback = &PL_sv_undef) |
221 | db_key_range (DB *db, DB_TXN_ornull *txn, SV *key, SV *key_range, U32 flags = 0, SV *callback = 0) |
189 | db_put (DB *db, DB_TXN_ornull *txn, SV *key, SV *data, U32 flags = 0, SV *callback = &PL_sv_undef) |
222 | db_put (DB *db, DB_TXN_ornull *txn, SV *key, SV *data, U32 flags = 0, SV *callback = 0) |
190 | flags: APPEND NODUPDATA NOOVERWRITE |
223 | flags: APPEND NODUPDATA NOOVERWRITE |
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224 | db_exists (DB *db, DB_TXN_ornull *txn, SV *key, U32 flags = 0, SV *callback = 0) (v4.6) |
191 | db_get (DB *db, DB_TXN_ornull *txn, SV *key, SV *data, U32 flags = 0, SV *callback = &PL_sv_undef) |
225 | db_get (DB *db, DB_TXN_ornull *txn, SV *key, SV *data, U32 flags = 0, SV *callback = 0) |
192 | flags: CONSUME CONSUME_WAIT GET_BOTH SET_RECNO MULTIPLE READ_COMMITTED READ_UNCOMMITTED RMW |
226 | flags: CONSUME CONSUME_WAIT GET_BOTH SET_RECNO MULTIPLE READ_COMMITTED READ_UNCOMMITTED RMW |
193 | db_pget (DB *db, DB_TXN_ornull *txn, SV *key, SV *pkey, SV *data, U32 flags = 0, SV *callback = &PL_sv_undef) |
227 | db_pget (DB *db, DB_TXN_ornull *txn, SV *key, SV *pkey, SV *data, U32 flags = 0, SV *callback = 0) |
194 | flags: CONSUME CONSUME_WAIT GET_BOTH SET_RECNO MULTIPLE READ_COMMITTED READ_UNCOMMITTED RMW |
228 | flags: CONSUME CONSUME_WAIT GET_BOTH SET_RECNO MULTIPLE READ_COMMITTED READ_UNCOMMITTED RMW |
195 | db_del (DB *db, DB_TXN_ornull *txn, SV *key, U32 flags = 0, SV *callback = &PL_sv_undef) |
229 | db_del (DB *db, DB_TXN_ornull *txn, SV *key, U32 flags = 0, SV *callback = 0) |
196 | db_txn_commit (DB_TXN *txn, U32 flags = 0, SV *callback = &PL_sv_undef) |
230 | db_txn_commit (DB_TXN *txn, U32 flags = 0, SV *callback = 0) |
197 | flags: TXN_NOSYNC TXN_SYNC |
231 | flags: TXN_NOSYNC TXN_SYNC |
198 | db_txn_abort (DB_TXN *txn, SV *callback = &PL_sv_undef) |
232 | db_txn_abort (DB_TXN *txn, SV *callback = 0) |
199 | |
233 | |
200 | db_c_close (DBC *dbc, SV *callback = &PL_sv_undef) |
234 | db_c_close (DBC *dbc, SV *callback = 0) |
201 | db_c_count (DBC *dbc, SV *count, U32 flags = 0, SV *callback = &PL_sv_undef) |
235 | db_c_count (DBC *dbc, SV *count, U32 flags = 0, SV *callback = 0) |
202 | db_c_put (DBC *dbc, SV *key, SV *data, U32 flags = 0, SV *callback = &PL_sv_undef) |
236 | db_c_put (DBC *dbc, SV *key, SV *data, U32 flags = 0, SV *callback = 0) |
203 | flags: AFTER BEFORE CURRENT KEYFIRST KEYLAST NODUPDATA |
237 | flags: AFTER BEFORE CURRENT KEYFIRST KEYLAST NODUPDATA |
204 | db_c_get (DBC *dbc, SV *key, SV *data, U32 flags = 0, SV *callback = &PL_sv_undef) |
238 | db_c_get (DBC *dbc, SV *key, SV *data, U32 flags = 0, SV *callback = 0) |
205 | 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 |
239 | 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 |
206 | db_c_pget (DBC *dbc, SV *key, SV *pkey, SV *data, U32 flags = 0, SV *callback = &PL_sv_undef) |
240 | db_c_pget (DBC *dbc, SV *key, SV *pkey, SV *data, U32 flags = 0, SV *callback = 0) |
207 | db_c_del (DBC *dbc, U32 flags = 0, SV *callback = &PL_sv_undef) |
241 | db_c_del (DBC *dbc, U32 flags = 0, SV *callback = 0) |
208 | |
242 | |
209 | db_sequence_open (DB_SEQUENCE *seq, DB_TXN_ornull *txnid, SV *key, U32 flags = 0, SV *callback = &PL_sv_undef) |
243 | db_sequence_open (DB_SEQUENCE *seq, DB_TXN_ornull *txnid, SV *key, U32 flags = 0, SV *callback = 0) |
210 | flags: CREATE EXCL |
244 | flags: CREATE EXCL |
211 | db_sequence_close (DB_SEQUENCE *seq, U32 flags = 0, SV *callback = &PL_sv_undef) |
245 | db_sequence_close (DB_SEQUENCE *seq, U32 flags = 0, SV *callback = 0) |
212 | 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) |
246 | db_sequence_get (DB_SEQUENCE *seq, DB_TXN_ornull *txnid, int delta, SV *seq_value, U32 flags = DB_TXN_NOSYNC, SV *callback = 0) |
213 | flags: TXN_NOSYNC |
247 | flags: TXN_NOSYNC |
214 | db_sequence_remove (DB_SEQUENCE *seq, DB_TXN_ornull *txnid = 0, U32 flags = 0, SV *callback = &PL_sv_undef) |
248 | db_sequence_remove (DB_SEQUENCE *seq, DB_TXN_ornull *txnid = 0, U32 flags = 0, SV *callback = 0) |
215 | flags: TXN_NOSYNC |
249 | flags: TXN_NOSYNC |
216 | |
250 | |
217 | =head4 db_txn_finish (DB_TXN *txn, U32 flags = 0, SV *callback = &PL_sv_undef) |
251 | =head3 db_txn_finish (DB_TXN *txn, U32 flags = 0, SV *callback = 0) |
218 | |
252 | |
219 | This is not actually a Berkeley DB function but a BDB module |
253 | This is not actually a Berkeley DB function but a BDB module |
220 | extension. The background for this exytension is: It is very annoying to |
254 | extension. The background for this exytension is: It is very annoying to |
221 | have to check every single BDB function for error returns and provide a |
255 | have to check every single BDB function for error returns and provide a |
222 | codepath out of your transaction. While the BDB module still makes this |
256 | codepath out of your transaction. While the BDB module still makes this |
… | |
… | |
248 | |
282 | |
249 | You can use the C<< $txn->failed >> method to check wether a transaction |
283 | You can use the C<< $txn->failed >> method to check wether a transaction |
250 | has failed in this way and abort further processing (excluding |
284 | has failed in this way and abort further processing (excluding |
251 | C<db_txn_finish>). |
285 | C<db_txn_finish>). |
252 | |
286 | |
|
|
287 | |
253 | =head3 DB_ENV/database environment methods |
288 | =head2 DB_ENV/database environment methods |
254 | |
289 | |
255 | Methods available on DB_ENV/$env handles: |
290 | Methods available on DB_ENV/$env handles: |
256 | |
291 | |
257 | DESTROY (DB_ENV_ornull *env) |
292 | DESTROY (DB_ENV_ornull *env) |
258 | CODE: |
293 | CODE: |
… | |
… | |
262 | $int = $env->set_data_dir (const char *dir) |
297 | $int = $env->set_data_dir (const char *dir) |
263 | $int = $env->set_tmp_dir (const char *dir) |
298 | $int = $env->set_tmp_dir (const char *dir) |
264 | $int = $env->set_lg_dir (const char *dir) |
299 | $int = $env->set_lg_dir (const char *dir) |
265 | $int = $env->set_shm_key (long shm_key) |
300 | $int = $env->set_shm_key (long shm_key) |
266 | $int = $env->set_cachesize (U32 gbytes, U32 bytes, int ncache = 0) |
301 | $int = $env->set_cachesize (U32 gbytes, U32 bytes, int ncache = 0) |
267 | $int = $env->set_flags (U32 flags, int onoff) |
302 | $int = $env->set_flags (U32 flags, int onoff = 1) |
|
|
303 | $int = $env->log_set_config (U32 flags, int onoff = 1) (v4.7) |
|
|
304 | $int = $env->set_intermediate_dir_mode (const char *modestring) (v4.7) |
268 | $env->set_errfile (FILE *errfile = 0) |
305 | $env->set_errfile (FILE *errfile = 0) |
269 | $env->set_msgfile (FILE *msgfile = 0) |
306 | $env->set_msgfile (FILE *msgfile = 0) |
270 | $int = $env->set_verbose (U32 which, int onoff = 1) |
307 | $int = $env->set_verbose (U32 which, int onoff = 1) |
271 | $int = $env->set_encrypt (const char *password, U32 flags = 0) |
308 | $int = $env->set_encrypt (const char *password, U32 flags = 0) |
272 | $int = $env->set_timeout (NV timeout_seconds, U32 flags = SET_TXN_TIMEOUT) |
309 | $int = $env->set_timeout (NV timeout_seconds, U32 flags = SET_TXN_TIMEOUT) |
… | |
… | |
284 | $int = $env->mutex_set_max (U32 max) |
321 | $int = $env->mutex_set_max (U32 max) |
285 | $int = $env->mutex_set_align (U32 align) |
322 | $int = $env->mutex_set_align (U32 align) |
286 | |
323 | |
287 | $txn = $env->txn_begin (DB_TXN_ornull *parent = 0, U32 flags = 0) |
324 | $txn = $env->txn_begin (DB_TXN_ornull *parent = 0, U32 flags = 0) |
288 | flags: READ_COMMITTED READ_UNCOMMITTED TXN_NOSYNC TXN_NOWAIT TXN_SNAPSHOT TXN_SYNC TXN_WAIT TXN_WRITE_NOSYNC |
325 | flags: READ_COMMITTED READ_UNCOMMITTED TXN_NOSYNC TXN_NOWAIT TXN_SNAPSHOT TXN_SYNC TXN_WAIT TXN_WRITE_NOSYNC |
|
|
326 | $txn = $env->cdsgroup_begin; (v4.5) |
289 | |
327 | |
290 | =head4 Example: |
328 | =head3 Example: |
291 | |
329 | |
292 | use AnyEvent; |
330 | use AnyEvent; |
293 | use BDB; |
331 | use BDB; |
294 | |
332 | |
295 | our $FH; open $FH, "<&=" . BDB::poll_fileno; |
333 | our $FH; open $FH, "<&=" . BDB::poll_fileno; |
… | |
… | |
307 | 0600; |
345 | 0600; |
308 | |
346 | |
309 | $env->set_flags (BDB::AUTO_COMMIT | BDB::TXN_NOSYNC, 1); |
347 | $env->set_flags (BDB::AUTO_COMMIT | BDB::TXN_NOSYNC, 1); |
310 | |
348 | |
311 | |
349 | |
312 | =head3 DB/database methods |
350 | =head2 DB/database methods |
313 | |
351 | |
314 | Methods available on DB/$db handles: |
352 | Methods available on DB/$db handles: |
315 | |
353 | |
316 | DESTROY (DB_ornull *db) |
354 | DESTROY (DB_ornull *db) |
317 | CODE: |
355 | CODE: |
… | |
… | |
343 | |
381 | |
344 | $dbc = $db->cursor (DB_TXN_ornull *txn = 0, U32 flags = 0) |
382 | $dbc = $db->cursor (DB_TXN_ornull *txn = 0, U32 flags = 0) |
345 | flags: READ_COMMITTED READ_UNCOMMITTED WRITECURSOR TXN_SNAPSHOT |
383 | flags: READ_COMMITTED READ_UNCOMMITTED WRITECURSOR TXN_SNAPSHOT |
346 | $seq = $db->sequence (U32 flags = 0) |
384 | $seq = $db->sequence (U32 flags = 0) |
347 | |
385 | |
348 | =head4 Example: |
386 | =head3 Example: |
349 | |
387 | |
350 | my $db = db_create $env; |
388 | my $db = db_create $env; |
351 | db_open $db, undef, "table", undef, BDB::BTREE, BDB::AUTO_COMMIT | BDB::CREATE | BDB::READ_UNCOMMITTED, 0600; |
389 | db_open $db, undef, "table", undef, BDB::BTREE, BDB::AUTO_COMMIT | BDB::CREATE | BDB::READ_UNCOMMITTED, 0600; |
352 | |
390 | |
353 | for (1..1000) { |
391 | for (1..1000) { |
… | |
… | |
360 | db_del $db, undef, "key $_" for 1..1000; |
398 | db_del $db, undef, "key $_" for 1..1000; |
361 | |
399 | |
362 | db_sync $db; |
400 | db_sync $db; |
363 | |
401 | |
364 | |
402 | |
365 | =head3 DB_TXN/transaction methods |
403 | =head2 DB_TXN/transaction methods |
366 | |
404 | |
367 | Methods available on DB_TXN/$txn handles: |
405 | Methods available on DB_TXN/$txn handles: |
368 | |
406 | |
369 | DESTROY (DB_TXN_ornull *txn) |
407 | DESTROY (DB_TXN_ornull *txn) |
370 | CODE: |
408 | CODE: |
… | |
… | |
376 | |
414 | |
377 | $bool = $txn->failed |
415 | $bool = $txn->failed |
378 | # see db_txn_finish documentation, above |
416 | # see db_txn_finish documentation, above |
379 | |
417 | |
380 | |
418 | |
381 | =head3 DBC/cursor methods |
419 | =head2 DBC/cursor methods |
382 | |
420 | |
383 | Methods available on DBC/$dbc handles: |
421 | Methods available on DBC/$dbc handles: |
384 | |
422 | |
385 | DESTROY (DBC_ornull *dbc) |
423 | DESTROY (DBC_ornull *dbc) |
386 | CODE: |
424 | CODE: |
387 | if (dbc) |
425 | if (dbc) |
388 | dbc->c_close (dbc); |
426 | dbc->c_close (dbc); |
389 | |
427 | |
|
|
428 | $int = $cursor->set_priority ($priority = PRIORITY_*) (v4.6) |
|
|
429 | |
390 | =head4 Example: |
430 | =head3 Example: |
391 | |
431 | |
392 | my $c = $db->cursor; |
432 | my $c = $db->cursor; |
393 | |
433 | |
394 | for (;;) { |
434 | for (;;) { |
395 | db_c_get $c, my $key, my $data, BDB::NEXT; |
435 | db_c_get $c, my $key, my $data, BDB::NEXT; |
… | |
… | |
398 | } |
438 | } |
399 | |
439 | |
400 | db_c_close $c; |
440 | db_c_close $c; |
401 | |
441 | |
402 | |
442 | |
403 | =head3 DB_SEQUENCE/sequence methods |
443 | =head2 DB_SEQUENCE/sequence methods |
404 | |
444 | |
405 | Methods available on DB_SEQUENCE/$seq handles: |
445 | Methods available on DB_SEQUENCE/$seq handles: |
406 | |
446 | |
407 | DESTROY (DB_SEQUENCE_ornull *seq) |
447 | DESTROY (DB_SEQUENCE_ornull *seq) |
408 | CODE: |
448 | CODE: |
… | |
… | |
413 | $int = $seq->set_cachesize (U32 size) |
453 | $int = $seq->set_cachesize (U32 size) |
414 | $int = $seq->set_flags (U32 flags) |
454 | $int = $seq->set_flags (U32 flags) |
415 | flags: SEQ_DEC SEQ_INC SEQ_WRAP |
455 | flags: SEQ_DEC SEQ_INC SEQ_WRAP |
416 | $int = $seq->set_range (db_seq_t min, db_seq_t max) |
456 | $int = $seq->set_range (db_seq_t min, db_seq_t max) |
417 | |
457 | |
418 | =head4 Example: |
458 | =head3 Example: |
419 | |
459 | |
420 | my $seq = $db->sequence; |
460 | my $seq = $db->sequence; |
421 | |
461 | |
422 | db_sequence_open $seq, undef, "seq", BDB::CREATE; |
462 | db_sequence_open $seq, undef, "seq", BDB::CREATE; |
423 | db_sequence_get $seq, undef, 1, my $value; |
463 | db_sequence_get $seq, undef, 1, my $value; |
424 | |
464 | |
425 | |
465 | |
426 | =head2 SUPPORT FUNCTIONS |
466 | =head1 SUPPORT FUNCTIONS |
427 | |
467 | |
428 | =head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION |
468 | =head2 EVENT PROCESSING AND EVENT LOOP INTEGRATION |
429 | |
469 | |
430 | =over 4 |
470 | =over 4 |
|
|
471 | |
|
|
472 | =item $msg = BDB::strerror [$errno] |
|
|
473 | |
|
|
474 | Returns the string corresponding to the given errno value. If no argument |
|
|
475 | is given, use C<$!>. |
|
|
476 | |
|
|
477 | Note that the BDB module also patches the C<$!> variable directly, so you |
|
|
478 | should be able to get a bdb error string by simply stringifying C<$!>. |
431 | |
479 | |
432 | =item $fileno = BDB::poll_fileno |
480 | =item $fileno = BDB::poll_fileno |
433 | |
481 | |
434 | Return the I<request result pipe file descriptor>. This filehandle must be |
482 | Return the I<request result pipe file descriptor>. This filehandle must be |
435 | polled for reading by some mechanism outside this module (e.g. Event or |
483 | polled for reading by some mechanism outside this module (e.g. Event or |
… | |
… | |
512 | BDB::poll_wait, BDB::poll_cb |
560 | BDB::poll_wait, BDB::poll_cb |
513 | while BDB::nreqs; |
561 | while BDB::nreqs; |
514 | |
562 | |
515 | =back |
563 | =back |
516 | |
564 | |
|
|
565 | =head2 VERSION CHECKING |
|
|
566 | |
|
|
567 | BerkeleyDB comes in various versions, many of them have minor |
|
|
568 | incompatibilities. This means that traditional "at least version x.x" |
|
|
569 | checks are often not sufficient. |
|
|
570 | |
|
|
571 | Example: set the log_autoremove option in a way compatible with <v4.7 and |
|
|
572 | v4.7. Note the use of & on the constants to avoid triggering a compiletime |
|
|
573 | bug when the symbol isn't available. |
|
|
574 | |
|
|
575 | $DB_ENV->set_flags (&BDB::LOG_AUTOREMOVE ) if BDB::VERSION v0, v4.7; |
|
|
576 | $DB_ENV->log_set_config (&BDB::LOG_AUTO_REMOVE) if BDB::VERSION v4.7; |
|
|
577 | |
|
|
578 | =over 4 |
|
|
579 | |
|
|
580 | =item BDB::VERSION |
|
|
581 | |
|
|
582 | The C<BDB::VERSION> function, when called without arguments, returns the |
|
|
583 | Berkeley DB version as a v-string (usually with 3 components). You should |
|
|
584 | use C<lt> and C<ge> operators exclusively to make comparisons. |
|
|
585 | |
|
|
586 | Example: check for at least version 4.7. |
|
|
587 | |
|
|
588 | BDB::VERSION ge v4.7 or die; |
|
|
589 | |
|
|
590 | =item BDB::VERSION min-version |
|
|
591 | |
|
|
592 | Returns true if the BDB version is at least the given version (specified |
|
|
593 | as a v-string), false otherwise. |
|
|
594 | |
|
|
595 | Example: check for at least version 4.5. |
|
|
596 | |
|
|
597 | BDB::VERSION v4.7 or die; |
|
|
598 | |
|
|
599 | =item BDB::VERSION min-version, max-version |
|
|
600 | |
|
|
601 | Returns true of the BDB version is at least version C<min-version> (specify C<undef> or C<v0> for any minimum version) |
|
|
602 | and less then C<max-version>. |
|
|
603 | |
|
|
604 | Example: check wether version is strictly less then v4.7. |
|
|
605 | |
|
|
606 | BDB::VERSION v0, v4.7 |
|
|
607 | or die "version 4.7 is not yet supported"; |
|
|
608 | |
|
|
609 | =back |
|
|
610 | |
|
|
611 | =cut |
|
|
612 | |
|
|
613 | sub VERSION { |
|
|
614 | # I was dumb enough to override the VERSION method here, so let's try |
|
|
615 | # to fix it up. |
|
|
616 | |
|
|
617 | if ($_[0] eq __PACKAGE__) { |
|
|
618 | $VERSION |
|
|
619 | } else { |
|
|
620 | if (@_ > 0) { |
|
|
621 | return undef if VERSION_v lt $_[0]; |
|
|
622 | if (@_ > 1) { |
|
|
623 | return undef if VERSION_v ge $_[1]; |
|
|
624 | } |
|
|
625 | } |
|
|
626 | |
|
|
627 | VERSION_v |
|
|
628 | } |
|
|
629 | } |
|
|
630 | |
517 | =head3 CONTROLLING THE NUMBER OF THREADS |
631 | =head2 CONTROLLING THE NUMBER OF THREADS |
518 | |
632 | |
519 | =over 4 |
633 | =over 4 |
520 | |
634 | |
521 | =item BDB::min_parallel $nthreads |
635 | =item BDB::min_parallel $nthreads |
522 | |
636 | |
… | |
… | |
583 | |
697 | |
584 | You can still queue as many requests as you want. Therefore, |
698 | You can still queue as many requests as you want. Therefore, |
585 | C<max_oustsanding> is mainly useful in simple scripts (with low values) or |
699 | C<max_oustsanding> is mainly useful in simple scripts (with low values) or |
586 | as a stop gap to shield against fatal memory overflow (with large values). |
700 | as a stop gap to shield against fatal memory overflow (with large values). |
587 | |
701 | |
588 | =item BDB::set_sync_prepare $cb |
702 | =item $old_cb = BDB::set_sync_prepare $cb |
589 | |
703 | |
590 | Sets a callback that is called whenever a request is created without an |
704 | Sets a callback that is called whenever a request is created without an |
591 | explicit callback. It has to return two code references. The first is used |
705 | explicit callback. It has to return two code references. The first is used |
592 | as the request callback, and the second is called to wait until the first |
706 | as the request callback (it should save the return status), and the second |
593 | callback has been called. The default implementation works like this: |
707 | is called to wait until the first callback has been called (it must set |
|
|
708 | C<$!> to the return status). |
|
|
709 | |
|
|
710 | This mechanism can be used to include BDB into other event mechanisms, |
|
|
711 | such as L<Coro::BDB>. |
|
|
712 | |
|
|
713 | To allow other, callback-based, events to be executed while callback-less |
|
|
714 | ones are run, you could use this sync prepare function: |
594 | |
715 | |
595 | sub { |
716 | sub { |
596 | my $status; |
717 | my $status; |
597 | ( |
718 | ( |
598 | sub { $status = $! }, |
719 | sub { $status = $! }, |
599 | sub { BDB::poll while !defined $status; $! = $status }, |
720 | sub { BDB::poll while !defined $status; $! = $status }, |
600 | ) |
721 | ) |
601 | } |
722 | } |
602 | |
723 | |
|
|
724 | It works by polling for results till the request has finished and then |
|
|
725 | sets C<$!> to the return value. This means that if you don't use a |
|
|
726 | callback, BDB would simply fall back to synchronous operations. |
|
|
727 | |
|
|
728 | By default, or if the sync prepare function is set to C<undef>, is to |
|
|
729 | execute callback-less BDB requests in the foreground thread, setting C<$!> |
|
|
730 | to the return value, without polling for other events. |
|
|
731 | |
603 | =back |
732 | =back |
604 | |
733 | |
605 | =head3 STATISTICAL INFORMATION |
734 | =head2 STATISTICAL INFORMATION |
606 | |
735 | |
607 | =over 4 |
736 | =over 4 |
608 | |
737 | |
609 | =item BDB::nreqs |
738 | =item BDB::nreqs |
610 | |
739 | |
… | |
… | |
628 | |
757 | |
629 | =back |
758 | =back |
630 | |
759 | |
631 | =cut |
760 | =cut |
632 | |
761 | |
633 | set_sync_prepare { |
762 | set_sync_prepare (undef); |
634 | my $status; |
|
|
635 | ( |
|
|
636 | sub { |
|
|
637 | $status = $!; |
|
|
638 | }, |
|
|
639 | sub { |
|
|
640 | BDB::poll while !defined $status; |
|
|
641 | $! = $status; |
|
|
642 | }, |
|
|
643 | ) |
|
|
644 | }; |
|
|
645 | |
763 | |
646 | min_parallel 8; |
764 | min_parallel 8; |
647 | |
765 | |
648 | END { flush } |
766 | END { flush } |
649 | |
767 | |
650 | 1; |
768 | 1; |
651 | |
769 | |
|
|
770 | =head1 COMMON PITFALLS |
|
|
771 | |
|
|
772 | =head2 Unexpected Crashes |
|
|
773 | |
|
|
774 | Remember that, by default, BDB will execute requests in parallel, in |
|
|
775 | somewhat random order. That means that it is easy to run a C<db_get> |
|
|
776 | request on thesa me database as a concurrent C<db_close> request, leading |
|
|
777 | to a crash, silent data corruption, eventually the next world war on |
|
|
778 | terrorism. |
|
|
779 | |
|
|
780 | If you only ever use foreground requests (without a callback), this will |
|
|
781 | not be an issue. |
|
|
782 | |
|
|
783 | =head2 Unexpected Freezes or Deadlocks |
|
|
784 | |
|
|
785 | Remember that, by default, BDB will execute requests in parallel, which |
|
|
786 | easily leads to deadlocks (even concurrent put's on the same database can |
|
|
787 | deadlock). |
|
|
788 | |
|
|
789 | You either need to run deadlock detection (and handle the resulting |
|
|
790 | errors), or make sure only one process ever updates the database, ine one |
|
|
791 | thread, e.g. by using only foreground requests (without a callback). |
|
|
792 | |
652 | =head2 FORK BEHAVIOUR |
793 | =head1 FORK BEHAVIOUR |
653 | |
794 | |
654 | This module should do "the right thing" when the process using it forks: |
795 | This module should do "the right thing" when the process using it forks: |
655 | |
796 | |
656 | Before the fork, BDB enters a quiescent state where no requests |
797 | Before the fork, BDB enters a quiescent state where no requests |
657 | can be added in other threads and no results will be processed. After |
798 | can be added in other threads and no results will be processed. After |
… | |
… | |
663 | |
804 | |
664 | In short: the parent will, after a short pause, continue as if fork had |
805 | In short: the parent will, after a short pause, continue as if fork had |
665 | not been called, while the child will act as if BDB has not been used |
806 | not been called, while the child will act as if BDB has not been used |
666 | yet. |
807 | yet. |
667 | |
808 | |
|
|
809 | Win32 note: there is no fork on win32, and perls emulation of it is too |
|
|
810 | broken to be supported, so do not use BDB in a windows pseudo-fork, better |
|
|
811 | yet, switch to a more capable platform. |
|
|
812 | |
668 | =head2 MEMORY USAGE |
813 | =head1 MEMORY USAGE |
669 | |
814 | |
670 | Per-request usage: |
815 | Per-request usage: |
671 | |
816 | |
672 | Each aio request uses - depending on your architecture - around 100-200 |
817 | Each aio request uses - depending on your architecture - around 100-200 |
673 | bytes of memory. In addition, stat requests need a stat buffer (possibly |
818 | bytes of memory. In addition, stat requests need a stat buffer (possibly |
… | |
… | |
682 | |
827 | |
683 | In the execution phase, some aio requests require more memory for |
828 | In the execution phase, some aio requests require more memory for |
684 | temporary buffers, and each thread requires a stack and other data |
829 | temporary buffers, and each thread requires a stack and other data |
685 | structures (usually around 16k-128k, depending on the OS). |
830 | structures (usually around 16k-128k, depending on the OS). |
686 | |
831 | |
|
|
832 | =head1 WIN32 FILENAMES/DATABASE NAME MESS |
|
|
833 | |
|
|
834 | Perl on Win32 supports only ASCII filenames (the reason is that it abuses |
|
|
835 | an internal flag to store wether a filename is Unicode or ANSI, but that |
|
|
836 | flag is used for somethign else in the perl core, so there is no way to |
|
|
837 | detect wether a filename is ANSI or Unicode-encoded). The BDB module |
|
|
838 | tries to work around this issue by assuming that the filename is an ANSI |
|
|
839 | filename and BDB was built for unicode support. |
|
|
840 | |
687 | =head1 KNOWN BUGS |
841 | =head1 KNOWN BUGS |
688 | |
842 | |
689 | Known bugs will be fixed in the next release, except: |
843 | Known bugs will be fixed in the next release, except: |
690 | |
844 | |
691 | If you use a transaction in any request, and the request returns |
845 | If you use a transaction in any request, and the request returns |
… | |
… | |
693 | TXN_DEADLOCK flag will be set on the transaction. See C<db_txn_finish>, |
847 | TXN_DEADLOCK flag will be set on the transaction. See C<db_txn_finish>, |
694 | above. |
848 | above. |
695 | |
849 | |
696 | =head1 SEE ALSO |
850 | =head1 SEE ALSO |
697 | |
851 | |
698 | L<Coro::BDB>, L<IO::AIO>. |
852 | L<AnyEvent::BDB> (event loop integration), L<Coro::BDB> (more natural |
|
|
853 | syntax), L<IO::AIO> (nice to have). |
699 | |
854 | |
700 | =head1 AUTHOR |
855 | =head1 AUTHOR |
701 | |
856 | |
702 | Marc Lehmann <schmorp@schmorp.de> |
857 | Marc Lehmann <schmorp@schmorp.de> |
703 | http://home.schmorp.de/ |
858 | http://home.schmorp.de/ |