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Comparing cvsroot/AnyEvent-MP/MP.pm (file contents):
Revision 1.123 by root, Thu Mar 1 19:37:59 2012 UTC vs.
Revision 1.127 by root, Sat Mar 3 20:35:10 2012 UTC

185use common::sense; 185use common::sense;
186 186
187use Carp (); 187use Carp ();
188 188
189use AE (); 189use AE ();
190use Guard ();
190 191
191use base "Exporter"; 192use base "Exporter";
192 193
193our $VERSION = $AnyEvent::MP::Config::VERSION; 194our $VERSION = $AnyEvent::MP::Config::VERSION;
194 195
195our @EXPORT = qw( 196our @EXPORT = qw(
196 NODE $NODE *SELF node_of after 197 NODE $NODE *SELF node_of after
197 configure 198 configure
198 snd rcv mon mon_guard kil psub peval spawn cal 199 snd rcv mon mon_guard kil psub peval spawn cal
199 port 200 port
201 db_set db_del db_reg
200); 202);
201 203
202our $SELF; 204our $SELF;
203 205
204sub _self_die() { 206sub _self_die() {
228 230
229This function configures a node - it must be called exactly once (or 231This function configures a node - it must be called exactly once (or
230never) before calling other AnyEvent::MP functions. 232never) before calling other AnyEvent::MP functions.
231 233
232The key/value pairs are basically the same ones as documented for the 234The key/value pairs are basically the same ones as documented for the
233F<aemp> command line utility (sans the set/del prefix), with two additions: 235F<aemp> command line utility (sans the set/del prefix), with these additions:
234 236
235=over 4 237=over 4
236 238
237=item norc => $boolean (default false) 239=item norc => $boolean (default false)
238 240
243=item force => $boolean (default false) 245=item force => $boolean (default false)
244 246
245IF true, then the values specified in the C<configure> will take 247IF true, then the values specified in the C<configure> will take
246precedence over any values configured via the rc file. The default is for 248precedence over any values configured via the rc file. The default is for
247the rc file to override any options specified in the program. 249the rc file to override any options specified in the program.
250
251=item secure => $pass->($nodeid)
252
253In addition to specifying a boolean, you can specify a code reference that
254is called for every remote execution attempt - the execution request is
255granted iff the callback returns a true value.
256
257See F<semp setsecure> for more info.
248 258
249=back 259=back
250 260
251=over 4 261=over 4
252 262
269and the values specified directly via C<configure> have lowest priority, 279and the values specified directly via C<configure> have lowest priority,
270and can only be used to specify defaults. 280and can only be used to specify defaults.
271 281
272If the profile specifies a node ID, then this will become the node ID of 282If the profile specifies a node ID, then this will become the node ID of
273this process. If not, then the profile name will be used as node ID, with 283this process. If not, then the profile name will be used as node ID, with
274a slash (C</>) attached. 284a unique randoms tring (C</%u>) appended.
275 285
276If the node ID (or profile name) ends with a slash (C</>), then a random 286The node ID can contain some C<%> sequences that are expanded: C<%n>
277string is appended to make it unique. 287is expanded to the local nodename, C<%u> is replaced by a random
288strign to make the node unique. For example, the F<aemp> commandline
289utility uses C<aemp/%n/%u> as nodename, which might expand to
290C<aemp/cerebro/ZQDGSIkRhEZQDGSIkRhE>.
278 291
279=item step 2, bind listener sockets 292=item step 2, bind listener sockets
280 293
281The next step is to look up the binds in the profile, followed by binding 294The next step is to look up the binds in the profile, followed by binding
282aemp protocol listeners on all binds specified (it is possible and valid 295aemp protocol listeners on all binds specified (it is possible and valid
299Example: become a distributed node using the local node name as profile. 312Example: become a distributed node using the local node name as profile.
300This should be the most common form of invocation for "daemon"-type nodes. 313This should be the most common form of invocation for "daemon"-type nodes.
301 314
302 configure 315 configure
303 316
304Example: become an anonymous node. This form is often used for commandline 317Example: become a semi-anonymous node. This form is often used for
305clients. 318commandline clients.
306 319
307 configure nodeid => "anon/"; 320 configure nodeid => "myscript/%n/%u";
308 321
309Example: configure a node using a profile called seed, which is suitable 322Example: configure a node using a profile called seed, which is suitable
310for a seed node as it binds on all local addresses on a fixed port (4040, 323for a seed node as it binds on all local addresses on a fixed port (4040,
311customary for aemp). 324customary for aemp).
312 325
672 } 685 }
673 686
674 $node->monitor ($port, $cb); 687 $node->monitor ($port, $cb);
675 688
676 defined wantarray 689 defined wantarray
677 and ($cb += 0, AnyEvent::Util::guard { $node->unmonitor ($port, $cb) }) 690 and ($cb += 0, Guard::guard { $node->unmonitor ($port, $cb) })
678} 691}
679 692
680=item $guard = mon_guard $port, $ref, $ref... 693=item $guard = mon_guard $port, $ref, $ref...
681 694
682Monitors the given C<$port> and keeps the passed references. When the port 695Monitors the given C<$port> and keeps the passed references. When the port
875 $port 888 $port
876} 889}
877 890
878=back 891=back
879 892
893=head1 DISTRIBUTED DATABASE
894
895AnyEvent::MP comes with a simple distributed database. The database will
896be mirrored asynchronously at all global nodes. Other nodes bind to one of
897the global nodes for their needs.
898
899The database consists of a two-level hash - a hash contains a hash which
900contains values.
901
902The top level hash key is called "family", and the second-level hash key
903is called "subkey" or simply "key".
904
905The family must be alphanumeric, i.e. start with a letter and consist
906of letters, digits, underscores and colons (C<[A-Za-z][A-Za-z0-9_:]*>,
907pretty much like Perl module names.
908
909As the family namespace is global, it is recommended to prefix family names
910with the name of the application or module using it.
911
912The subkeys must be non-empty strings, with no further restrictions.
913
914The values should preferably be strings, but other perl scalars should
915work as well (such as undef, arrays and hashes).
916
917Every database entry is owned by one node - adding the same family/subkey
918combination on multiple nodes will not cause discomfort for AnyEvent::MP,
919but the result might be nondeterministic, i.e. the key might have
920different values on different nodes.
921
922Different subkeys in the same family can be owned by different nodes
923without problems, and in fact, this is the common method to create worker
924pools. For example, a worker port for image scaling might do this:
925
926 db_set my_image_scalers => $port;
927
928And clients looking for an image scaler will want to get the
929C<my_image_scalers> keys:
930
931 db_keys "my_image_scalers" => 60 => sub {
932 #d##TODO#
933
934=over
935
936=item db_set $family => $subkey [=> $value]
937
938Sets (or replaces) a key to the database - if C<$value> is omitted,
939C<undef> is used instead.
940
941=item db_del $family => $subkey
942
943Deletes a key from the database.
944
945=item $guard = db_reg $family => $subkey [=> $value]
946
947Sets the key on the database and returns a guard. When the guard is
948destroyed, the key is deleted from the database. If C<$value> is missing,
949then C<undef> is used.
950
951=cut
952
953=back
954
880=head1 AnyEvent::MP vs. Distributed Erlang 955=head1 AnyEvent::MP vs. Distributed Erlang
881 956
882AnyEvent::MP got lots of its ideas from distributed Erlang (Erlang node 957AnyEvent::MP got lots of its ideas from distributed Erlang (Erlang node
883== aemp node, Erlang process == aemp port), so many of the documents and 958== aemp node, Erlang process == aemp port), so many of the documents and
884programming techniques employed by Erlang apply to AnyEvent::MP. Here is a 959programming techniques employed by Erlang apply to AnyEvent::MP. Here is a

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