X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FStorage%2FDBI%2FReplicated.pm;h=48642ece68750d61a6493865866e5a14e3a64ba6;hb=d8cf3aa31fb3d6ff7813f021fcc002663725fc41;hp=5e02e7d6acc5f7847b7a7679f5e972f9425444fd;hpb=be64931c710bcde7abe7334349b4c8a123645332;p=dbsrgits%2FDBIx-Class.git diff --git a/lib/DBIx/Class/Storage/DBI/Replicated.pm b/lib/DBIx/Class/Storage/DBI/Replicated.pm index 5e02e7d..48642ec 100644 --- a/lib/DBIx/Class/Storage/DBI/Replicated.pm +++ b/lib/DBIx/Class/Storage/DBI/Replicated.pm @@ -1,9 +1,13 @@ package DBIx::Class::Storage::DBI::Replicated; +use warnings; +use strict; + BEGIN { - use DBIx::Class; - die('The following modules are required for Replication ' . DBIx::Class::Optional::Dependencies->req_missing_for ('replicated') . "\n" ) - unless DBIx::Class::Optional::Dependencies->req_ok_for ('replicated'); + require DBIx::Class::Optional::Dependencies; + if ( my $missing = DBIx::Class::Optional::Dependencies->req_missing_for('replicated') ) { + die "The following modules are required for Replicated storage support: $missing\n"; + } } use Moose; @@ -14,9 +18,8 @@ use DBIx::Class::Storage::DBI::Replicated::Types qw/BalancerClassNamePart DBICSc use MooseX::Types::Moose qw/ClassName HashRef Object/; use Scalar::Util 'reftype'; use Hash::Merge; -use List::Util qw/min max reduce/; -use Try::Tiny; -use namespace::clean; +use List::Util qw( min max ); +use Context::Preserve 'preserve_context'; use namespace::clean -except => 'meta'; @@ -35,7 +38,7 @@ also define your arguments, such as which balancer you want and any arguments that the Pool object should get. my $schema = Schema::Class->clone; - $schema->storage_type( ['::DBI::Replicated', {balancer=>'::Random'}] ); + $schema->storage_type(['::DBI::Replicated', { balancer_type => '::Random' }]); $schema->connection(...); Next, you need to add in the Replicants. Basically this is an array of @@ -263,7 +266,6 @@ my $method_dispatch = { build_datetime_parser last_insert_id insert - insert_bulk update delete dbh @@ -308,15 +310,16 @@ my $method_dispatch = { _parse_connect_do savepoints _sql_maker_opts + _use_multicolumn_in _conn_pid _dbh_autocommit _native_data_type _get_dbh sql_maker_class + insert_bulk + _insert_bulk _execute _do_query - _sth - _dbh_sth _dbh_execute /, Class::MOP::Class->initialize('DBIx::Class::Storage::DBIHacks')->get_method_list ], reader => [qw/ @@ -329,8 +332,7 @@ my $method_dispatch = { unimplemented => [qw/ _arm_global_destructor _verify_pid - - source_bind_attributes + __delicate_rollback get_use_dbms_capability set_use_dbms_capability @@ -338,31 +340,44 @@ my $method_dispatch = { set_dbms_capability _dbh_details _dbh_get_info + _get_rdbms_name + _get_server_version + _server_info + + _determine_connector_driver + _extract_driver_from_connect_info + _describe_connection + _warn_undetermined_driver sql_limit_dialect sql_quote_char sql_name_sep _prefetch_autovalues + _perform_autoinc_retrieval + _autoinc_supplied_for_op _resolve_bindattrs _max_column_bytesize _is_lob_type _is_binary_lob_type + _is_binary_type _is_text_lob_type - sth + _prepare_sth + _bind_sth_params /,( # the capability framework # not sure if CMOP->initialize does evil things to DBIC::S::DBI, fix if a problem grep - { $_ =~ /^ _ (?: use | supports | determine_supports ) _ /x } + { $_ =~ /^ _ (?: use | supports | determine_supports ) _ /x and $_ ne '_use_multicolumn_in' } ( Class::MOP::Class->initialize('DBIx::Class::Storage::DBI')->get_all_method_names ) )], }; -if (DBIx::Class::_ENV_::DBICTEST) { +# this only happens during DBIC-internal testing +if ( $INC{"t/lib/ANFANG.pm"} ) { my $seen; for my $type (keys %$method_dispatch) { @@ -391,13 +406,16 @@ if (DBIx::Class::_ENV_::DBICTEST) { for my $method (@{$method_dispatch->{unimplemented}}) { __PACKAGE__->meta->add_method($method, sub { my $self = shift; - $self->throw_exception("$method must not be called on ".(blessed $self).' objects'); + $self->throw_exception( + "$method() may not be called on '@{[ blessed $self ]}' objects, " + . 'call it on a specific pool instance instead' + ); }); } =head2 read_handler -Defines an object that implements the read side of L. +Defines an object that implements the read side of L. =cut @@ -410,7 +428,7 @@ has 'read_handler' => ( =head2 write_handler -Defines an object that implements the write side of L, +Defines an object that implements the write side of L, as well as methods that don't write or read that can be called on only one storage, methods that return a C<$dbh>, and any methods that don't make sense to run on a replicant. @@ -440,6 +458,11 @@ C, C, C and C. around connect_info => sub { my ($next, $self, $info, @extra) = @_; + $self->throw_exception( + 'connect_info can not be retrieved from a replicated storage - ' + . 'accessor must be called on a specific pool instance' + ) unless defined $info; + my $merge = Hash::Merge->new('LEFT_PRECEDENT'); my %opts; @@ -476,24 +499,19 @@ around connect_info => sub { $self->_master_connect_info_opts(\%opts); - my @res; - if (wantarray) { - @res = $self->$next($info, @extra); - } else { - $res[0] = $self->$next($info, @extra); - } + return preserve_context { + $self->$next($info, @extra); + } after => sub { + # Make sure master is blessed into the correct class and apply role to it. + my $master = $self->master; + $master->_determine_driver; + Moose::Meta::Class->initialize(ref $master); - # Make sure master is blessed into the correct class and apply role to it. - my $master = $self->master; - $master->_determine_driver; - Moose::Meta::Class->initialize(ref $master); + DBIx::Class::Storage::DBI::Replicated::WithDSN->meta->apply($master); - DBIx::Class::Storage::DBI::Replicated::WithDSN->meta->apply($master); - - # link pool back to master - $self->pool->master($master); - - wantarray ? @res : $res[0]; + # link pool back to master + $self->pool->master($master); + }; }; =head1 METHODS @@ -582,7 +600,8 @@ sub _build_read_handler { =head2 around: connect_replicants All calls to connect_replicants needs to have an existing $schema tacked onto -top of the args, since L needs it, and any C +top of the args, since L needs it, and any +L options merged with the master, with replicant opts having higher priority. =cut @@ -637,8 +656,8 @@ around connect_replicants => sub { =head2 all_storages -Returns an array of of all the connected storage backends. The first element -in the returned array is the master, and the remainings are each of the +Returns an array of all the connected storage backends. The first element +in the returned array is the master, and the rest are each of the replicants. =cut @@ -674,41 +693,16 @@ inserted something and need to get a resultset including it, etc. =cut sub execute_reliably { - my ($self, $coderef, @args) = @_; - - unless( ref $coderef eq 'CODE') { - $self->throw_exception('Second argument must be a coderef'); - } - - ##Get copy of master storage - my $master = $self->master; - - ##Get whatever the current read hander is - my $current = $self->read_handler; - - ##Set the read handler to master - $self->read_handler($master); + my $self = shift; + my $coderef = shift; - ## do whatever the caller needs - my @result; - my $want_array = wantarray; + $self->throw_exception('Second argument must be a coderef') + unless( ref $coderef eq 'CODE'); - try { - if($want_array) { - @result = $coderef->(@args); - } elsif(defined $want_array) { - ($result[0]) = ($coderef->(@args)); - } else { - $coderef->(@args); - } - } catch { - $self->throw_exception("coderef returned an error: $_"); - } finally { - ##Reset to the original state - $self->read_handler($current); - }; + ## replace the current read handler for the remainder of the scope + local $self->{read_handler} = $self->master; - return wantarray ? @result : $result[0]; + &$coderef; } =head2 set_reliable_storage @@ -1058,41 +1052,13 @@ sub _ping { return min map $_->_ping, $self->all_storages; } -# not using the normalized_version, because we want to preserve -# version numbers much longer than the conventional xxx.yyyzzz -my $numify_ver = sub { - my $ver = shift; - my @numparts = split /\D+/, $ver; - my $format = '%d.' . (join '', ('%06d') x (@numparts - 1)); - - return sprintf $format, @numparts; -}; -sub _server_info { - my $self = shift; - - if (not $self->_dbh_details->{info}) { - $self->_dbh_details->{info} = ( - reduce { $a->[0] < $b->[0] ? $a : $b } - map [ $numify_ver->($_->{dbms_version}), $_ ], - map $_->_server_info, $self->all_storages - )->[1]; - } - - return $self->next::method; -} - -sub _get_server_version { - my $self = shift; - - return $self->_server_info->{dbms_version}; -} - =head1 GOTCHAS Due to the fact that replicants can lag behind a master, you must take care to make sure you use one of the methods to force read queries to a master should you need realtime data integrity. For example, if you insert a row, and then -immediately re-read it from the database (say, by doing $row->discard_changes) +immediately re-read it from the database (say, by doing +L<< $result->discard_changes|DBIx::Class::Row/discard_changes >>) or you insert a row and then immediately build a query that expects that row to be an item, you should force the master to handle reads. Otherwise, due to the lag, there is no certainty your data will be in the expected state. @@ -1104,9 +1070,9 @@ method to force the master to handle all read queries. Otherwise, you can force a single query to use the master with the 'force_pool' attribute: - my $row = $resultset->search(undef, {force_pool=>'master'})->find($pk); + my $result = $resultset->search(undef, {force_pool=>'master'})->find($pk); -This attribute will safely be ignore by non replicated storages, so you can use +This attribute will safely be ignored by non replicated storages, so you can use the same code for both types of systems. Lastly, you can use the L method, which works very much like @@ -1124,18 +1090,16 @@ using the Schema clone method. ## $new_schema will use only the Master storage for all reads/writes while ## the $schema object will use replicated storage. -=head1 AUTHOR - - John Napiorkowski - -Based on code originated by: +=head1 FURTHER QUESTIONS? - Norbert Csongrádi - Peter Siklósi +Check the list of L. -=head1 LICENSE +=head1 COPYRIGHT AND LICENSE -You may distribute this code under the same terms as Perl itself. +This module is free software L +by the L. You can +redistribute it and/or modify it under the same terms as the +L. =cut