X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FMooseX%2FStorage%2FEngine.pm;h=10817631fc44318e4eebfdab81fb8030e2423279;hb=8919e01e95856d3dd17037352ef93275cdcf2fbd;hp=f31386c9e7df16e5435657f1370fa169df4b01bc;hpb=4d1850a68a911b072b7c9abba786099f9acb6a67;p=gitmo%2FMooseX-Storage.git diff --git a/lib/MooseX/Storage/Engine.pm b/lib/MooseX/Storage/Engine.pm index f31386c..1081763 100644 --- a/lib/MooseX/Storage/Engine.pm +++ b/lib/MooseX/Storage/Engine.pm @@ -1,141 +1,471 @@ package MooseX::Storage::Engine; use Moose; +use Scalar::Util qw(refaddr); + +our $VERSION = '0.26'; +our $AUTHORITY = 'cpan:STEVAN'; + +# the class marker when +# serializing an object. +our $CLASS_MARKER = '__CLASS__'; has 'storage' => ( - is => 'rw', + is => 'ro', isa => 'HashRef', default => sub {{}} ); -has 'object' => (is => 'rw', isa => 'Object'); +has 'seen' => ( + is => 'ro', + isa => 'HashRef[Int]', # int is the refaddr + default => sub {{}} +); + +has 'object' => (is => 'rw', isa => 'Object', predicate => '_has_object'); has 'class' => (is => 'rw', isa => 'Str'); ## this is the API used by other modules ... sub collapse_object { - my $self = shift; - $self->map_attributes('collapse_attribute'); - $self->storage->{'__class__'} = $self->object->meta->name; + my ( $self, %options ) = @_; + + # NOTE: + # mark the root object as seen ... + $self->seen->{refaddr $self->object} = undef; + + $self->map_attributes('collapse_attribute', \%options); + $self->storage->{$CLASS_MARKER} = $self->object->meta->identifier; return $self->storage; } sub expand_object { - my ($self, $data) = @_; - $self->map_attributes('expand_attribute', $data); - return $self->storage; + my ($self, $data, %options) = @_; + + $options{check_version} = 1 unless exists $options{check_version}; + $options{check_authority} = 1 unless exists $options{check_authority}; + + # NOTE: + # mark the root object as seen ... + $self->seen->{refaddr $data} = undef; + + $self->map_attributes('expand_attribute', $data, \%options); + return $self->storage; } ## this is the internal API ... sub collapse_attribute { - my ($self, $attr) = @_; - $self->storage->{$attr->name} = $self->collapse_attribute_value($attr) || return; + my ($self, $attr, $options) = @_; + my $value = $self->collapse_attribute_value($attr, $options); + return if !defined($value); + $self->storage->{$attr->name} = $value; } sub expand_attribute { - my ($self, $attr, $data) = @_; - $self->storage->{$attr->name} = $self->expand_attribute_value($attr, $data->{$attr->name}) || return; + my ($self, $attr, $data, $options) = @_; + my $value = $self->expand_attribute_value($attr, $data->{$attr->name}, $options); + $self->storage->{$attr->name} = defined $value ? $value : return; } sub collapse_attribute_value { - my ($self, $attr) = @_; + my ($self, $attr, $options) = @_; + # Faster, but breaks attributes without readers, do we care? + #my $value = $attr->get_read_method_ref->($self->object); my $value = $attr->get_value($self->object); - # TODO: - # we want to explicitly disallow - # cycles here, because the base - # storage engine does not support - # them + + # NOTE: + # this might not be enough, we might + # need to make it possible for the + # cycle checker to return the value + $self->check_for_cycle_in_collapse($attr, $value) + if ref $value; + if (defined $value && $attr->has_type_constraint) { - my $type_converter = $self->match_type($attr->type_constraint); + my $type_converter = $self->find_type_handler($attr->type_constraint, $value); (defined $type_converter) || confess "Cannot convert " . $attr->type_constraint->name; - $value = $type_converter->{collapse}->($value); + $value = $type_converter->{collapse}->($value, $options); } return $value; } sub expand_attribute_value { - my ($self, $attr, $value) = @_; - # TODO: - # we need to check $value here to - # make sure that we do not have - # a cycle here. + my ($self, $attr, $value, $options) = @_; + + # NOTE: + # (see comment in method above ^^) + if( ref $value and not( + $options->{disable_cycle_check} or + $self->class->does('MooseX::Storage::Traits::DisableCycleDetection') + )) { + $self->check_for_cycle_in_collapse($attr, $value) + } + if (defined $value && $attr->has_type_constraint) { - my $type_converter = $self->match_type($attr->type_constraint); - $value = $type_converter->{expand}->($value); + my $type_converter = $self->find_type_handler($attr->type_constraint, $value); + $value = $type_converter->{expand}->($value, $options); } return $value; } +# NOTE: +# possibly these two methods will +# be used by a cycle supporting +# engine. However, I am not sure +# if I can make a cycle one work +# anyway. + +sub check_for_cycle_in_collapse { + my ($self, $attr, $value) = @_; + (!exists $self->seen->{refaddr $value}) + || confess "Basic Engine does not support cycles in class(" + . ($attr->associated_class->name) . ").attr(" + . ($attr->name) . ") with $value"; + $self->seen->{refaddr $value} = undef; +} + +sub check_for_cycle_in_expansion { + my ($self, $attr, $value) = @_; + (!exists $self->seen->{refaddr $value}) + || confess "Basic Engine does not support cycles in class(" + . ($attr->associated_class->name) . ").attr(" + . ($attr->name) . ") with $value"; + $self->seen->{refaddr $value} = undef; +} + # util methods ... sub map_attributes { my ($self, $method_name, @args) = @_; - map { - $self->$method_name($_, @args) - } ($self->object || $self->class)->meta->compute_all_applicable_attributes; + map { + $self->$method_name($_, @args) + } grep { + # Skip our special skip attribute :) + !$_->does('MooseX::Storage::Meta::Attribute::Trait::DoNotSerialize') + } ($self->_has_object ? $self->object : $self->class)->meta->get_all_attributes; } +## ------------------------------------------------------------------ +## This is all the type handler stuff, it is in a state of flux +## right now, so this may change, or it may just continue to be +## improved upon. Comments and suggestions are welcomed. +## ------------------------------------------------------------------ + +# NOTE: +# these are needed by the +# ArrayRef and HashRef handlers +# below, so I need easy access +my %OBJECT_HANDLERS = ( + expand => sub { + my ($data, $options) = @_; + (exists $data->{$CLASS_MARKER}) + || confess "Serialized item has no class marker"; + # check the class more thoroughly here ... + my ($class, $version, $authority) = (split '-' => $data->{$CLASS_MARKER}); + my $meta = eval { $class->meta }; + confess "Class ($class) is not loaded, cannot unpack" if $@; + + if ($options->{check_version}) { + my $meta_version = $meta->version; + if (defined $meta_version && $version) { + if ($options->{check_version} eq 'allow_less_than') { + ($meta_version <= $version) + || confess "Class ($class) versions is not less than currently available." + . " got=($version) available=($meta_version)"; + } + elsif ($options->{check_version} eq 'allow_greater_than') { + ($meta->version >= $version) + || confess "Class ($class) versions is not greater than currently available." + . " got=($version) available=($meta_version)"; + } + else { + ($meta->version == $version) + || confess "Class ($class) versions don't match." + . " got=($version) available=($meta_version)"; + } + } + } + + if ($options->{check_authority}) { + my $meta_authority = $meta->authority; + ($meta->authority eq $authority) + || confess "Class ($class) authorities don't match." + . " got=($authority) available=($meta_authority)" + if defined $meta_authority && defined $authority; + } + + # all is well ... + $class->unpack($data, %$options); + }, + collapse => sub { + my ( $obj, $options ) = @_; +# ($obj->can('does') && $obj->does('MooseX::Storage::Basic')) +# || confess "Bad object ($obj) does not do MooseX::Storage::Basic role"; + ($obj->can('pack')) + || confess "Object ($obj) does not have a &pack method, cannot collapse"; + $obj->pack(%$options); + }, +); + + my %TYPES = ( - 'Int' => { expand => sub { shift }, collapse => sub { shift } }, - 'Num' => { expand => sub { shift }, collapse => sub { shift } }, + # NOTE: + # we need to make sure that we properly numify the numbers + # before and after them being futzed with, because some of + # the JSON engines are stupid/annoying/frustrating + 'Int' => { expand => sub { $_[0] + 0 }, collapse => sub { $_[0] + 0 } }, + 'Num' => { expand => sub { $_[0] + 0 }, collapse => sub { $_[0] + 0 } }, + # These are boring ones, so they use the identity function ... 'Str' => { expand => sub { shift }, collapse => sub { shift } }, - 'ArrayRef' => { expand => sub { shift }, collapse => sub { shift } }, - 'HashRef' => { expand => sub { shift }, collapse => sub { shift } }, - 'Object' => { + 'Bool' => { expand => sub { shift }, collapse => sub { shift } }, + # These are the trickier ones, (see notes) + # NOTE: + # Because we are nice guys, we will check + # your ArrayRef and/or HashRef one level + # down and inflate any objects we find. + # But this is where it ends, it is too + # expensive to try and do this any more + # recursively, when it is probably not + # nessecary in most of the use cases. + # However, if you need more then this, subtype + # and add a custom handler. + 'ArrayRef' => { expand => sub { - my $data = shift; - (exists $data->{'__class__'}) - || confess "Serialized item has no class marker"; - $data->{'__class__'}->unpack($data); + my ( $array, @args ) = @_; + foreach my $i (0 .. $#{$array}) { + next unless ref($array->[$i]) eq 'HASH' + && exists $array->[$i]->{$CLASS_MARKER}; + $array->[$i] = $OBJECT_HANDLERS{expand}->($array->[$i], @args); + } + $array; }, collapse => sub { - my $obj = shift; - ($obj->can('does') && $obj->does('MooseX::Storage::Basic')) - || confess "Bad object ($obj) does not do MooseX::Storage::Base role"; - $obj->pack(); + my ( $array, @args ) = @_; + # NOTE: + # we need to make a copy cause + # otherwise it will affect the + # other real version. + [ map { + blessed($_) + ? $OBJECT_HANDLERS{collapse}->($_, @args) + : $_ + } @$array ] + } + }, + 'HashRef' => { + expand => sub { + my ( $hash, @args ) = @_; + foreach my $k (keys %$hash) { + next unless ref($hash->{$k}) eq 'HASH' + && exists $hash->{$k}->{$CLASS_MARKER}; + $hash->{$k} = $OBJECT_HANDLERS{expand}->($hash->{$k}, @args); + } + $hash; }, - } + collapse => sub { + my ( $hash, @args ) = @_; + # NOTE: + # we need to make a copy cause + # otherwise it will affect the + # other real version. + +{ map { + blessed($hash->{$_}) + ? ($_ => $OBJECT_HANDLERS{collapse}->($hash->{$_}, @args)) + : ($_ => $hash->{$_}) + } keys %$hash } + } + }, + 'Object' => \%OBJECT_HANDLERS, + # NOTE: + # The sanity of enabling this feature by + # default is very questionable. + # - SL + #'CodeRef' => { + # expand => sub {}, # use eval ... + # collapse => sub {}, # use B::Deparse ... + #} ); -sub match_type { - my ($self, $type_constraint) = @_; - return $TYPES{$type_constraint->name} if exists $TYPES{$type_constraint->name}; +sub add_custom_type_handler { + my ($class, $type_name, %handlers) = @_; + (exists $handlers{expand} && exists $handlers{collapse}) + || confess "Custom type handlers need an expand *and* a collapse method"; + $TYPES{$type_name} = \%handlers; +} + +sub remove_custom_type_handler { + my ($class, $type_name) = @_; + delete $TYPES{$type_name} if exists $TYPES{$type_name}; +} + +sub find_type_handler { + my ($self, $type_constraint, $value) = @_; + + # check if the type is a Maybe and + # if its parent is not parameterized. + # If both is true recurse this method + # using ->type_parameter. + return $self->find_type_handler($type_constraint->type_parameter, $value) + if ($type_constraint->parent && $type_constraint->parent eq 'Maybe' + and not $type_constraint->parent->can('type_parameter')); + + # find_type_for is a method of a union type. If we can call that method + # then we are dealign with a union and we need to ascertain which of + # the union's types we need to use for the value we are serializing. + if($type_constraint->can('find_type_for')) { + my $tc = $type_constraint->find_type_for($value); + return $self->find_type_handler($tc, $value) if defined($tc); + } + + # this should handle most type usages + # since they they are usually just + # the standard set of built-ins + return $TYPES{$type_constraint->name} + if exists $TYPES{$type_constraint->name}; + + # the next possibility is they are + # a subtype of the built-in types, + # in which case this will DWIM in + # most cases. It is probably not + # 100% ideal though, but until I + # come up with a decent test case + # it will do for now. foreach my $type (keys %TYPES) { - return $TYPES{$type} + return $TYPES{$type} if $type_constraint->is_subtype_of($type); } - # TODO: - # from here we can expand this to support the following: - # - if it is subtype of Ref - # -- if it is a subtype of Object - # --- treat it like an object - # -- else - # --- treat it like any other Ref - # - else - # -- if it is a subtype of Num or Str - # --- treat it like Num or Str - # -- else - # --- pass it on - # this should cover 80% of all use cases - - # CHRIS: To cover the last 20% we need a way - # for people to extend this process. - + + # NOTE: + # the reason the above will work has to + # do with the fact that custom subtypes + # are mostly used for validation of + # the guts of a type, and not for some + # weird structural thing which would + # need to be accomidated by the serializer. + # Of course, mst or phaylon will probably + # do something to throw this assumption + # totally out the door ;) + # - SL + # NOTE: # if this method hasnt returned by now - # then we have no been able to find a - # type constraint handler to match - confess "Cannot handle type constraint (" . $type_constraint->name . ")"; + # then we have no been able to find a + # type constraint handler to match + confess "Cannot handle type constraint (" . $type_constraint->name . ")"; +} + +sub find_type_handler_for { + my ($self, $type_handler_name) = @_; + $TYPES{$type_handler_name} } +no Moose::Role; + 1; __END__ =pod +=head1 NAME + +MooseX::Storage::Engine - The meta-engine to handle collapsing and expanding objects + +=head1 DESCRIPTION + +No user serviceable parts inside. If you really want to know, read the source :) + +=head1 METHODS + +=head2 Accessors + +=over 4 + +=item B + +=item B + +=item B + +=item B + +=back + +=head2 API + +=over 4 + +=item B + +=item B + +=back + +=head2 ... + +=over 4 + +=item B + +=item B + +=item B + +=item B + +=item B + +=item B + +=item B + +=back + +=head2 Type Constraint Handlers + +=over 4 + +=item B + +=item B + +=item B + +=item B + +=back + +=head2 Introspection + +=over 4 + +=item B + +=back + +=head1 BUGS + +All complex software has bugs lurking in it, and this module is no +exception. If you find a bug please either email me, or add the bug +to cpan-RT. + +=head1 AUTHOR + +Chris Prather Echris.prather@iinteractive.comE + +Stevan Little Estevan.little@iinteractive.comE + +=head1 COPYRIGHT AND LICENSE + +Copyright 2007-2008 by Infinity Interactive, Inc. + +L + +This library is free software; you can redistribute it and/or modify +it under the same terms as Perl itself. + =cut +