File Coverage

blib/lib/DBIx/Class/ResultSourceHandle.pm

Criterion	Covered	Total	%
statement	43	46	93.4
branch	10	16	62.5
condition	3	9	33.3
subroutine	12	12	100.0
pod	4	4	100.0
total	72	87	82.7

package DBIx::Class::ResultSourceHandle;

use strict;
use warnings;

use base qw/DBIx::Class/;

use DBIx::Class::_Util 'dbic_internal_try';
use namespace::clean;

use overload
    q/""/ => sub { __PACKAGE__ . ":" . shift->source_moniker; },
    fallback => 1;

__PACKAGE__->mk_group_accessors('simple' => qw/schema source_moniker _detached_source/);

# Schema to use when thawing.
our $thaw_schema;

=head1 NAME

DBIx::Class::ResultSourceHandle - Serializable pointers to ResultSource instances

=head1 DESCRIPTION

Currently instances of this class are used to allow proper serialization of
L (which may contain unserializable
elements like C references).

Originally this module was used to remove the fixed link between
L/L and the actual
L in order to obviate the need
of keeping a L constantly in scope, while
at the same time avoiding leaks due to circular dependencies. This is however
no longer needed after introduction of a proper mutual-assured-destruction
contract between a C instance and its C registrants.

=head1 METHODS

=head2 new

=cut

sub new {
  my ($class, $args) = @_;
  my $self = bless $args, ref $class || $class;

  unless( ($self->{schema} || $self->{_detached_source}) && $self->{source_moniker} ) {
    my $err = 'Expecting a schema instance and a source moniker';
    $self->{schema}
      ? $self->{schema}->throw_exception($err)
      : DBIx::Class::Exception->throw($err)
  }

  $self;
}

=head2 resolve

Resolve the moniker into the actual ResultSource object

=cut

sub resolve {
  return $_[0]->{schema}->source($_[0]->source_moniker) if $_[0]->{schema};

  $_[0]->_detached_source || DBIx::Class::Exception->throw( sprintf (
    # vague error message as this is never supposed to happen
    "Unable to resolve moniker '%s' - please contact the dev team at %s",
    $_[0]->source_moniker,
    DBIx::Class::_ENV_::HELP_URL,
  ), 'full_stacktrace');
}

=head2 STORABLE_freeze

Freezes a handle.

=cut

sub STORABLE_freeze {
  my ($self, $cloning) = @_;

  my $to_serialize = { %$self };

  delete $to_serialize->{schema};
  delete $to_serialize->{_detached_source};
  $to_serialize->{_frozen_from_class} = $self->{schema}
    ? $self->{schema}->class($self->source_moniker)
    : $self->{_detached_source}->result_class
  ;

  Storable::nfreeze($to_serialize);
}

=head2 STORABLE_thaw

Thaws frozen handle. Resets the internal schema reference to the package
variable C<$thaw_schema>. The recommended way of setting this is to use
C<< $schema->thaw($ice) >> which handles this for you.

=cut

sub STORABLE_thaw {
  my ($self, $cloning, $ice) = @_;
  %$self = %{ Storable::thaw($ice) };

  my $from_class = delete $self->{_frozen_from_class};

  if( $thaw_schema ) {
    $self->schema( $thaw_schema );
  }
  elsif( my $rs = $from_class->result_source_instance ) {
    # in the off-chance we are using CDBI-compat and have leaked $schema already
    if( my $s = dbic_internal_try { $rs->schema } ) {
      $self->schema( $s );
    }
    else {
      # FIXME do not use accessor here - will trigger the divergent meta logic
      # Ideally this should be investigated and fixed properly, but the
      # codepath is so obscure, and the trigger point (t/52leaks.t) so bizarre
      # that... meh.
      $rs->{source_name} = $self->source_moniker;

      $rs->{_detached_thaw} = 1;
      $self->_detached_source( $rs );
    }
  }
  else {
    DBIx::Class::Exception->throw(
      "Thaw failed - original result class '$from_class' does not exist on this system"
    );
  }
}

=head1 FURTHER QUESTIONS?

Check the list of L.

=head1 COPYRIGHT AND LICENSE

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

1;