X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FStorage%2FDBI%2FReplicated.pm;h=3275de26cc450e9c5fadc10e19b1b3764d1cbe0c;hb=243d702ea2d1350e9c08d52eb84cdde745913452;hp=bed8a1f698396695be5abc07fec035c8905f07cd;hpb=dcdf7b2cd485cc015ddbfd816f6735be075c3386;p=dbsrgits%2FDBIx-Class.git diff --git a/lib/DBIx/Class/Storage/DBI/Replicated.pm b/lib/DBIx/Class/Storage/DBI/Replicated.pm index bed8a1f..3275de2 100644 --- a/lib/DBIx/Class/Storage/DBI/Replicated.pm +++ b/lib/DBIx/Class/Storage/DBI/Replicated.pm @@ -2,37 +2,37 @@ package DBIx::Class::Storage::DBI::Replicated; BEGIN { use Carp::Clan qw/^DBIx::Class/; - + ## Modules required for Replication support not required for general DBIC ## use, so we explicitly test for these. - + my %replication_required = ( - Moose => '0.77', - MooseX::AttributeHelpers => '0.12', - MooseX::Types => '0.10', - namespace::clean => '0.11', + 'Moose' => '0.90', + 'MooseX::Types' => '0.21', + 'namespace::clean' => '0.11', + 'Hash::Merge' => '0.11' ); - + my @didnt_load; - + for my $module (keys %replication_required) { - eval "use $module $replication_required{$module}"; - push @didnt_load, "$module $replication_required{$module}" - if $@; + eval "use $module $replication_required{$module}"; + push @didnt_load, "$module $replication_required{$module}" + if $@; } - + croak("@{[ join ', ', @didnt_load ]} are missing and are required for Replication") - if @didnt_load; + if @didnt_load; } use Moose; use DBIx::Class::Storage::DBI; use DBIx::Class::Storage::DBI::Replicated::Pool; use DBIx::Class::Storage::DBI::Replicated::Balancer; -use DBIx::Class::Storage::DBI::Replicated::Types 'BalancerClassNamePart'; +use DBIx::Class::Storage::DBI::Replicated::Types qw/BalancerClassNamePart DBICSchema DBICStorageDBI/; use MooseX::Types::Moose qw/ClassName HashRef Object/; use Scalar::Util 'reftype'; -use Carp::Clan qw/^DBIx::Class/; +use Hash::Merge 'merge'; use namespace::clean -except => 'meta'; @@ -46,33 +46,47 @@ The Following example shows how to change an existing $schema to a replicated storage type, add some replicated (readonly) databases, and perform reporting tasks. - ## Change storage_type in your schema class +You should set the 'storage_type attribute to a replicated type. You should +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'}] ); - - ## Add some slaves. Basically this is an array of arrayrefs, where each - ## arrayref is database connect information - + $schema->connection(...); + +Next, you need to add in the Replicants. Basically this is an array of +arrayrefs, where each arrayref is database connect information. Think of these +arguments as what you'd pass to the 'normal' $schema->connect method. + $schema->storage->connect_replicants( [$dsn1, $user, $pass, \%opts], [$dsn2, $user, $pass, \%opts], [$dsn3, $user, $pass, \%opts], ); - - ## Now, just use the $schema as normal + +Now, just use the $schema as you normally would. Automatically all reads will +be delegated to the replicants, while writes to the master. + $schema->resultset('Source')->search({name=>'etc'}); - - ## You can force a given query to use a particular storage using the search - ### attribute 'force_pool'. For example: - + +You can force a given query to use a particular storage using the search +attribute 'force_pool'. For example: + my $RS = $schema->resultset('Source')->search(undef, {force_pool=>'master'}); - - ## Now $RS will force everything (both reads and writes) to use whatever was - ## setup as the master storage. 'master' is hardcoded to always point to the - ## Master, but you can also use any Replicant name. Please see: - ## L and the replicants attribute for - ## More. Also see transactions and L for alternative ways - ## to force read traffic to the master. - + +Now $RS will force everything (both reads and writes) to use whatever was setup +as the master storage. 'master' is hardcoded to always point to the Master, +but you can also use any Replicant name. Please see: +L and the replicants attribute for more. + +Also see transactions and L for alternative ways to +force read traffic to the master. In general, you should wrap your statements +in a transaction when you are reading and writing to the same tables at the +same time, since your replicants will often lag a bit behind the master. + +See L for more help and +walkthroughs. + =head1 DESCRIPTION Warning: This class is marked BETA. This has been running a production @@ -98,7 +112,7 @@ selected algorithm. The default algorithm is random weighted. =head1 NOTES The consistancy betweeen master and replicants is database specific. The Pool -gives you a method to validate it's replicants, removing and replacing them +gives you a method to validate its replicants, removing and replacing them when they fail/pass predefined criteria. Please make careful use of the ways to force a query to run against Master when needed. @@ -106,11 +120,11 @@ to force a query to run against Master when needed. Replicated Storage has additional requirements not currently part of L - Moose => 0.77 - MooseX::AttributeHelpers => 0.12 - MooseX::Types => 0.10 - namespace::clean => 0.11 - + Moose => '0.90', + MooseX::Types => '0.21', + namespace::clean => '0.11', + Hash::Merge => '0.11' + You will need to install these modules manually via CPAN or make them part of the Makefile for your distribution. @@ -126,7 +140,7 @@ The underlying L object this storage is attaching has 'schema' => ( is=>'rw', - isa=>'DBIx::Class::Schema', + isa=>DBICSchema, weak_ref=>1, required=>1, ); @@ -150,7 +164,7 @@ has 'pool_type' => ( =head2 pool_args Contains a hashref of initialized information to pass to the Balancer object. -See L for available arguments. +See L for available arguments. =cut @@ -183,7 +197,7 @@ has 'balancer_type' => ( =head2 balancer_args Contains a hashref of initialized information to pass to the Balancer object. -See L for available arguments. +See L for available arguments. =cut @@ -207,7 +221,7 @@ has 'pool' => ( isa=>'DBIx::Class::Storage::DBI::Replicated::Pool', lazy_build=>1, handles=>[qw/ - connect_replicants + connect_replicants replicants has_replicants /], @@ -239,7 +253,7 @@ pool of databases that is allowed to handle write traffic. has 'master' => ( is=> 'ro', - isa=>'DBIx::Class::Storage::DBI', + isa=>DBICStorageDBI, lazy_build=>1, ); @@ -262,7 +276,7 @@ has 'read_handler' => ( select select_single columns_info_for - /], + /], ); =head2 write_handler @@ -275,10 +289,9 @@ has 'write_handler' => ( is=>'ro', isa=>Object, lazy_build=>1, - lazy_build=>1, - handles=>[qw/ + handles=>[qw/ on_connect_do - on_disconnect_do + on_disconnect_do connect_info throw_exception sql_maker @@ -286,7 +299,8 @@ has 'write_handler' => ( create_ddl_dir deployment_statements datetime_parser - datetime_parser_type + datetime_parser_type + build_datetime_parser last_insert_id insert insert_bulk @@ -301,10 +315,19 @@ has 'write_handler' => ( sth deploy with_deferred_fk_checks - + dbh_do reload_row + with_deferred_fk_checks _prep_for_execute - + + backup + is_datatype_numeric + _count_select + _subq_count_select + _subq_update_delete + svp_rollback + svp_begin + svp_release /], ); @@ -322,10 +345,12 @@ C, C, C and C. around connect_info => sub { my ($next, $self, $info, @extra) = @_; + my $wantarray = wantarray; + my %opts; for my $arg (@$info) { next unless (reftype($arg)||'') eq 'HASH'; - %opts = (%opts, %$arg); + %opts = %{ merge($arg, \%opts) }; } delete $opts{dsn}; @@ -333,29 +358,42 @@ around connect_info => sub { $self->pool_type(delete $opts{pool_type}) if $opts{pool_type}; - $self->pool_args({ - %{ $self->pool_args }, - %{ delete $opts{pool_args} || {} } - }); + $self->pool_args( + merge((delete $opts{pool_args} || {}), $self->pool_args) + ); - $self->pool($self->_build_pool); + $self->pool($self->_build_pool) + if $self->pool; } if (@opts{qw/balancer_type balancer_args/}) { $self->balancer_type(delete $opts{balancer_type}) if $opts{balancer_type}; - $self->balancer_args({ - %{ $self->balancer_args }, - %{ delete $opts{balancer_args} || {} } - }); + $self->balancer_args( + merge((delete $opts{balancer_args} || {}), $self->balancer_args) + ); - $self->balancer($self->_build_balancer); + $self->balancer($self->_build_balancer) + if $self->balancer; } $self->_master_connect_info_opts(\%opts); - $self->$next($info, @extra); + my (@res, $res); + if ($wantarray) { + @res = $self->$next($info, @extra); + } else { + $res = $self->$next($info, @extra); + } + + # 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); + + $wantarray ? @res : $res; }; =head1 METHODS @@ -364,19 +402,19 @@ This class defines the following methods. =head2 BUILDARGS -L when instantiating it's storage passed itself as the +L when instantiating its storage passed itself as the first argument. So we need to massage the arguments a bit so that all the bits get put into the correct places. =cut sub BUILDARGS { - my ($class, $schema, $storage_type_args, @args) = @_; - + my ($class, $schema, $storage_type_args, @args) = @_; + return { - schema=>$schema, - %$storage_type_args, - @args + schema=>$schema, + %$storage_type_args, + @args } } @@ -388,7 +426,8 @@ Lazy builder for the L attribute. sub _build_master { my $self = shift @_; - DBIx::Class::Storage::DBI->new($self->schema); + my $master = DBIx::Class::Storage::DBI->new($self->schema); + $master } =head2 _build_pool @@ -412,7 +451,7 @@ the balancer knows which pool it's balancing. sub _build_balancer { my $self = shift @_; $self->create_balancer( - pool=>$self->pool, + pool=>$self->pool, master=>$self->master, %{$self->balancer_args}, ); @@ -454,22 +493,39 @@ around connect_replicants => sub { for my $r (@args) { $r = [ $r ] unless reftype $r eq 'ARRAY'; - croak "coderef replicant connect_info not supported" + $self->throw_exception('coderef replicant connect_info not supported') if ref $r->[0] && reftype $r->[0] eq 'CODE'; # any connect_info options? my $i = 0; $i++ while $i < @$r && (reftype($r->[$i])||'') ne 'HASH'; -# make one if none +# make one if none $r->[$i] = {} unless $r->[$i]; # merge if two hashes - my %opts = map %$_, @$r[$i .. $#{$r}]; + my @hashes = @$r[$i .. $#{$r}]; + + $self->throw_exception('invalid connect_info options') + if (grep { reftype($_) eq 'HASH' } @hashes) != @hashes; + + $self->throw_exception('too many hashrefs in connect_info') + if @hashes > 2; + + my %opts = %{ merge(reverse @hashes) }; + +# delete them splice @$r, $i+1, ($#{$r} - $i), (); +# make sure master/replicants opts don't clash + my %master_opts = %{ $self->_master_connect_info_opts }; + if (exists $opts{dbh_maker}) { + delete @master_opts{qw/dsn user password/}; + } + delete $master_opts{dbh_maker}; + # merge with master - %opts = (%{ $self->_master_connect_info_opts }, %opts); + %opts = %{ merge(\%opts, \%master_opts) }; # update $r->[$i] = \%opts; @@ -518,24 +574,24 @@ inserted something and need to get a resultset including it, etc. 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); - + ## do whatever the caller needs my @result; my $want_array = wantarray; - + eval { if($want_array) { @result = $coderef->(@args); @@ -543,15 +599,15 @@ sub execute_reliably { ($result[0]) = ($coderef->(@args)); } else { $coderef->(@args); - } + } }; - + ##Reset to the original state - $self->read_handler($current); - + $self->read_handler($current); + ##Exception testing has to come last, otherwise you might leave the ##read_handler set to master. - + if($@) { $self->throw_exception("coderef returned an error: $@"); } else { @@ -563,14 +619,14 @@ sub execute_reliably { Sets the current $schema to be 'reliable', that is all queries, both read and write are sent to the master - + =cut sub set_reliable_storage { my $self = shift @_; my $schema = $self->schema; my $write_handler = $self->schema->storage->write_handler; - + $schema->storage->read_handler($write_handler); } @@ -578,29 +634,16 @@ sub set_reliable_storage { Sets the current $schema to be use the for all reads, while all writea are sent to the master only - + =cut sub set_balanced_storage { my $self = shift @_; my $schema = $self->schema; - my $write_handler = $self->schema->storage->balancer; - - $schema->storage->read_handler($write_handler); -} - -=head2 around: txn_do ($coderef) + my $balanced_handler = $self->schema->storage->balancer; -Overload to the txn_do method, which is delegated to whatever the -L is set to. We overload this in order to wrap in inside a -L method. - -=cut - -around 'txn_do' => sub { - my($txn_do, $self, $coderef, @args) = @_; - $self->execute_reliably(sub {$self->$txn_do($coderef, @args)}); -}; + $schema->storage->read_handler($balanced_handler); +} =head2 connected @@ -694,7 +737,7 @@ sub debug { if(@_) { foreach my $source ($self->all_storages) { $source->debug(@_); - } + } } return $self->master->debug; } @@ -710,7 +753,7 @@ sub debugobj { if(@_) { foreach my $source ($self->all_storages) { $source->debugobj(@_); - } + } } return $self->master->debugobj; } @@ -726,7 +769,7 @@ sub debugfh { if(@_) { foreach my $source ($self->all_storages) { $source->debugfh(@_); - } + } } return $self->master->debugfh; } @@ -742,7 +785,7 @@ sub debugcb { if(@_) { foreach my $source ($self->all_storages) { $source->debugcb(@_); - } + } } return $self->master->debugcb; } @@ -774,7 +817,7 @@ sub cursor_class { } $self->master->cursor_class; } - + =head1 GOTCHAS Due to the fact that replicants can lag behind a master, you must take care to @@ -808,7 +851,7 @@ using the Schema clone method. my $new_schema = $schema->clone; $new_schema->set_reliable_storage; - + ## $new_schema will use only the Master storage for all reads/writes while ## the $schema object will use replicated storage.