… | |
… | |
398 | |
398 | |
399 | =cut |
399 | =cut |
400 | |
400 | |
401 | sub rcv($@); |
401 | sub rcv($@); |
402 | |
402 | |
403 | sub _kilme { |
403 | my $KILME = sub { |
404 | die "received message on port without callback"; |
404 | (my $tag = substr $_[0], 0, 30) =~ s/([\x20-\x7e])/./g; |
405 | } |
405 | kil $SELF, unhandled_message => "no callback set for message (first element $tag)"; |
|
|
406 | }; |
406 | |
407 | |
407 | sub port(;&) { |
408 | sub port(;&) { |
408 | my $id = $UNIQ . ++$ID; |
409 | my $id = $UNIQ . ++$ID; |
409 | my $port = "$NODE#$id"; |
410 | my $port = "$NODE#$id"; |
410 | |
411 | |
411 | rcv $port, shift || \&_kilme; |
412 | rcv $port, shift || $KILME; |
412 | |
413 | |
413 | $port |
414 | $port |
414 | } |
415 | } |
415 | |
416 | |
416 | =item rcv $local_port, $callback->(@msg) |
417 | =item rcv $local_port, $callback->(@msg) |
… | |
… | |
421 | |
422 | |
422 | The global C<$SELF> (exported by this module) contains C<$port> while |
423 | The global C<$SELF> (exported by this module) contains C<$port> while |
423 | executing the callback. Runtime errors during callback execution will |
424 | executing the callback. Runtime errors during callback execution will |
424 | result in the port being C<kil>ed. |
425 | result in the port being C<kil>ed. |
425 | |
426 | |
426 | The default callback received all messages not matched by a more specific |
427 | The default callback receives all messages not matched by a more specific |
427 | C<tag> match. |
428 | C<tag> match. |
428 | |
429 | |
429 | =item rcv $local_port, tag => $callback->(@msg_without_tag), ... |
430 | =item rcv $local_port, tag => $callback->(@msg_without_tag), ... |
430 | |
431 | |
431 | Register (or replace) callbacks to be called on messages starting with the |
432 | Register (or replace) callbacks to be called on messages starting with the |
… | |
… | |
732 | will be reported as reason C<< die => $@ >>. |
733 | will be reported as reason C<< die => $@ >>. |
733 | |
734 | |
734 | Transport/communication errors are reported as C<< transport_error => |
735 | Transport/communication errors are reported as C<< transport_error => |
735 | $message >>. |
736 | $message >>. |
736 | |
737 | |
737 | =cut |
738 | Common idioms: |
|
|
739 | |
|
|
740 | # silently remove yourself, do not kill linked ports |
|
|
741 | kil $SELF; |
|
|
742 | |
|
|
743 | # report a failure in some detail |
|
|
744 | kil $SELF, failure_mode_1 => "it failed with too high temperature"; |
|
|
745 | |
|
|
746 | # do not waste much time with killing, just die when something goes wrong |
|
|
747 | open my $fh, "<file" |
|
|
748 | or die "file: $!"; |
738 | |
749 | |
739 | =item $port = spawn $node, $initfunc[, @initdata] |
750 | =item $port = spawn $node, $initfunc[, @initdata] |
740 | |
751 | |
741 | Creates a port on the node C<$node> (which can also be a port ID, in which |
752 | Creates a port on the node C<$node> (which can also be a port ID, in which |
742 | case it's the node where that port resides). |
753 | case it's the node where that port resides). |
… | |
… | |
894 | =back |
905 | =back |
895 | |
906 | |
896 | =head1 DISTRIBUTED DATABASE |
907 | =head1 DISTRIBUTED DATABASE |
897 | |
908 | |
898 | AnyEvent::MP comes with a simple distributed database. The database will |
909 | AnyEvent::MP comes with a simple distributed database. The database will |
899 | be mirrored asynchronously at all global nodes. Other nodes bind to one of |
910 | be mirrored asynchronously on all global nodes. Other nodes bind to one |
900 | the global nodes for their needs. |
911 | of the global nodes for their needs. Every node has a "local database" |
|
|
912 | which contains all the values that are set locally. All local databases |
|
|
913 | are merged together to form the global database, which can be queried. |
901 | |
914 | |
902 | The database consists of a two-level hash - a hash contains a hash which |
915 | The database structure is that of a two-level hash - the database hash |
903 | contains values. |
916 | contains hashes which contain values, similarly to a perl hash of hashes, |
|
|
917 | i.e.: |
|
|
918 | |
|
|
919 | $DATABASE{$family}{$subkey} = $value |
904 | |
920 | |
905 | The top level hash key is called "family", and the second-level hash key |
921 | The top level hash key is called "family", and the second-level hash key |
906 | is called "subkey" or simply "key". |
922 | is called "subkey" or simply "key". |
907 | |
923 | |
908 | The family must be alphanumeric, i.e. start with a letter and consist |
924 | The family must be alphanumeric, i.e. start with a letter and consist |
… | |
… | |
913 | with the name of the application or module using it. |
929 | with the name of the application or module using it. |
914 | |
930 | |
915 | The subkeys must be non-empty strings, with no further restrictions. |
931 | The subkeys must be non-empty strings, with no further restrictions. |
916 | |
932 | |
917 | The values should preferably be strings, but other perl scalars should |
933 | The values should preferably be strings, but other perl scalars should |
918 | work as well (such as undef, arrays and hashes). |
934 | work as well (such as C<undef>, arrays and hashes). |
919 | |
935 | |
920 | Every database entry is owned by one node - adding the same family/subkey |
936 | Every database entry is owned by one node - adding the same family/subkey |
921 | combination on multiple nodes will not cause discomfort for AnyEvent::MP, |
937 | combination on multiple nodes will not cause discomfort for AnyEvent::MP, |
922 | but the result might be nondeterministic, i.e. the key might have |
938 | but the result might be nondeterministic, i.e. the key might have |
923 | different values on different nodes. |
939 | different values on different nodes. |
… | |
… | |
953 | =item db_set $family => $subkey [=> $value] |
969 | =item db_set $family => $subkey [=> $value] |
954 | |
970 | |
955 | Sets (or replaces) a key to the database - if C<$value> is omitted, |
971 | Sets (or replaces) a key to the database - if C<$value> is omitted, |
956 | C<undef> is used instead. |
972 | C<undef> is used instead. |
957 | |
973 | |
958 | =item db_del $family => $subkey |
974 | =item db_del $family => $subkey... |
959 | |
975 | |
960 | Deletes a key from the database. |
976 | Deletes one or more subkeys from the database family. |
961 | |
977 | |
962 | =item $guard = db_reg $family => $subkey [=> $value] |
978 | =item $guard = db_reg $family => $subkey [=> $value] |
963 | |
979 | |
964 | Sets the key on the database and returns a guard. When the guard is |
980 | Sets the key on the database and returns a guard. When the guard is |
965 | destroyed, the key is deleted from the database. If C<$value> is missing, |
981 | destroyed, the key is deleted from the database. If C<$value> is missing, |
… | |
… | |
978 | =item db_values $family => $cb->(\@values) |
994 | =item db_values $family => $cb->(\@values) |
979 | |
995 | |
980 | Same as C<db_family>, except it only queries the family I<values> and passes them |
996 | Same as C<db_family>, except it only queries the family I<values> and passes them |
981 | as array reference to the callback. |
997 | as array reference to the callback. |
982 | |
998 | |
983 | =item $guard = db_mon $family => $cb->($familyhash, \@subkeys...) |
999 | =item $guard = db_mon $family => $cb->($familyhash, \@added, \@changed, \@deleted) |
984 | |
1000 | |
985 | Creates a monitor on the given database family. Each time a key is set or |
1001 | Creates a monitor on the given database family. Each time a key is set |
986 | or is deleted the callback is called with a hash containing the database |
1002 | or or is deleted the callback is called with a hash containing the |
987 | family and an arrayref with subkeys that have changed. |
1003 | database family and three lists of added, changed and deleted subkeys, |
|
|
1004 | respectively. If no keys have changed then the array reference might be |
|
|
1005 | C<undef> or even missing. |
988 | |
1006 | |
989 | Specifically, if one of the passed subkeys exists in the $familyhash, then |
1007 | If not called in void context, a guard object is returned that, when |
990 | it is currently set to the value in the $familyhash. Otherwise, it has |
1008 | destroyed, stops the monitor. |
991 | been deleted. |
|
|
992 | |
1009 | |
993 | The family hash reference belongs to AnyEvent::MP and B<must not be |
1010 | The family hash reference and the key arrays belong to AnyEvent::MP and |
994 | modified or stored> by the callback. When in doubt, make a copy. |
1011 | B<must not be modified or stored> by the callback. When in doubt, make a |
|
|
1012 | copy. |
995 | |
1013 | |
996 | The first call will be with the current contents of the family and all |
1014 | As soon as possible after the monitoring starts, the callback will be |
997 | keys, as if they were just added. |
1015 | called with the intiial contents of the family, even if it is empty, |
|
|
1016 | i.e. there will always be a timely call to the callback with the current |
|
|
1017 | contents. |
998 | |
1018 | |
999 | It is possible that the callback is called with a change event even though |
1019 | It is possible that the callback is called with a change event even though |
1000 | the subkey is already present and the value has not changed. |
1020 | the subkey is already present and the value has not changed. |
1001 | |
1021 | |
1002 | The monitoring stops when the guard object is destroyed. |
1022 | The monitoring stops when the guard object is destroyed. |
1003 | |
1023 | |
1004 | Example: on every change to the family "mygroup", print out all keys. |
1024 | Example: on every change to the family "mygroup", print out all keys. |
1005 | |
1025 | |
1006 | my $guard = db_mon mygroup => sub { |
1026 | my $guard = db_mon mygroup => sub { |
1007 | my ($family, $keys) = @_; |
1027 | my ($family, $a, $c, $d) = @_; |
1008 | print "mygroup members: ", (join " ", keys %$family), "\n"; |
1028 | print "mygroup members: ", (join " ", keys %$family), "\n"; |
1009 | }; |
1029 | }; |
1010 | |
1030 | |
1011 | Exmaple: wait until the family "My::Module::workers" is non-empty. |
1031 | Exmaple: wait until the family "My::Module::workers" is non-empty. |
1012 | |
1032 | |
1013 | my $guard; $guard = db_mon My::Module::workers => sub { |
1033 | my $guard; $guard = db_mon My::Module::workers => sub { |
1014 | my ($family, $keys) = @_; |
1034 | my ($family, $a, $c, $d) = @_; |
1015 | return unless %$family; |
1035 | return unless %$family; |
1016 | undef $guard; |
1036 | undef $guard; |
1017 | print "My::Module::workers now nonempty\n"; |
1037 | print "My::Module::workers now nonempty\n"; |
1018 | }; |
1038 | }; |
1019 | |
1039 | |
1020 | Example: print all changes to the family "AnyRvent::Fantasy::Module". |
1040 | Example: print all changes to the family "AnyRvent::Fantasy::Module". |
1021 | |
1041 | |
1022 | my $guard = db_mon AnyRvent::Fantasy::Module => sub { |
1042 | my $guard = db_mon AnyRvent::Fantasy::Module => sub { |
1023 | my ($family, $keys) = @_; |
1043 | my ($family, $a, $c, $d) = @_; |
1024 | |
1044 | |
1025 | for (@$keys) { |
1045 | print "+$_=$family->{$_}\n" for @$a; |
1026 | print "$_: ", |
1046 | print "*$_=$family->{$_}\n" for @$c; |
1027 | (exists $family->{$_} |
1047 | print "-$_=$family->{$_}\n" for @$d; |
1028 | ? $family->{$_} |
|
|
1029 | : "(deleted)"), |
|
|
1030 | "\n"; |
|
|
1031 | } |
|
|
1032 | }; |
1048 | }; |
1033 | |
1049 | |
1034 | =cut |
1050 | =cut |
1035 | |
1051 | |
1036 | =back |
1052 | =back |