foo

[gitmo/MooseX-Storage.git] / lib / MooseX / Storage / Engine.pm

diff --git a/lib/MooseX/Storage/Engine.pm b/lib/MooseX/Storage/Engine.pm
index 7f3bbb4..80f0f94 100644 (file)
--- a/lib/MooseX/Storage/Engine.pm
+++ b/lib/MooseX/Storage/Engine.pm
@@ -2,14 +2,20 @@
 package MooseX::Storage::Engine;
 use Moose;
 
-our $VERSION = '0.01';
+our $VERSION = '0.02';
 
 # the class marker when 
 # serializing an object. 
 our $CLASS_MARKER = '__CLASS__';
 
 has 'storage' => (
-    is      => 'rw',
+    is      => 'ro',
+    isa     => 'HashRef',
+    default => sub {{}}
+);
+
+has 'seen' => (
+    is      => 'ro',
     isa     => 'HashRef',
     default => sub {{}}
 );
@@ -21,13 +27,23 @@ has 'class'  => (is => 'rw', isa => 'Str');
 
 sub collapse_object {
        my $self = shift;
+
+       # NOTE:
+       # mark the root object as seen ...
+       $self->seen->{$self->object} = undef;
+       
     $self->map_attributes('collapse_attribute');
-    $self->storage->{$CLASS_MARKER} = $self->object->meta->name;    
+    $self->storage->{$CLASS_MARKER} = $self->object->meta->identifier;    
        return $self->storage;
 }
 
 sub expand_object {
     my ($self, $data) = @_;
+    
+       # NOTE:
+       # mark the root object as seen ...
+       $self->seen->{$data} = undef;    
+    
     $self->map_attributes('expand_attribute', $data);
        return $self->storage;    
 }
@@ -47,6 +63,14 @@ sub expand_attribute {
 sub collapse_attribute_value {
     my ($self, $attr)  = @_;
        my $value = $attr->get_value($self->object);
+       
+       # 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 = $self->find_type_handler($attr->type_constraint);
         (defined $type_converter)
@@ -58,6 +82,12 @@ sub collapse_attribute_value {
 
 sub expand_attribute_value {
     my ($self, $attr, $value)  = @_;
+
+       # NOTE:
+       # (see comment in method above ^^)
+    $self->check_for_cycle_in_expansion($attr, $value) 
+        if ref $value;    
+    
     if (defined $value && $attr->has_type_constraint) {
         my $type_converter = $self->find_type_handler($attr->type_constraint);
         $value = $type_converter->{expand}->($value);
@@ -65,12 +95,40 @@ sub expand_attribute_value {
        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 $self->seen->{$value})
+        || confess "Basic Engine does not support cycles in class(" 
+                 . ($attr->associated_class->name) . ").attr("
+                 . ($attr->name) . ") with $value";
+    $self->seen->{$value} = undef;
+}
+
+sub check_for_cycle_in_expansion {
+    my ($self, $attr, $value) = @_;
+    (!exists $self->seen->{$value})
+    || confess "Basic Engine does not support cycles in class(" 
+             . ($attr->associated_class->name) . ").attr("
+             . ($attr->name) . ") with $value";
+    $self->seen->{$value} = undef;
+}
+
 # util methods ...
 
 sub map_attributes {
     my ($self, $method_name, @args) = @_;
     map { 
         $self->$method_name($_, @args) 
+    } grep {
+        # Skip our special skip attribute :)
+        !$_->isa('MooseX::Storage::Meta::Attribute::DoNotSerialize')
     } ($self->object || $self->class)->meta->compute_all_applicable_attributes;
 }
 
@@ -89,7 +147,20 @@ my %OBJECT_HANDLERS = (
         my $data = shift;   
         (exists $data->{$CLASS_MARKER})
             || confess "Serialized item has no class marker";
-        $data->{$CLASS_MARKER}->unpack($data);
+        # check the class more thoroughly here ...
+        my ($class, $version, $authority) = (split '-' => $data->{$CLASS_MARKER});
+        my $meta = eval { $class->meta };
+        confess "Class ($class) is not loaded, cannot unpack" if $@;
+        ($meta->version == $version)
+            || confess "Class ($class) versions don't match." 
+                     . " got=($version) available=(" . ($meta->version || '') . ")"
+            if defined $version;
+        ($meta->authority eq $authority)
+            || confess "Class ($class) authorities don't match." 
+                     . " got=($authority) available=(" . ($meta->authority || '') . ")"
+            if defined $authority;            
+        # all is well ...
+        $class->unpack($data);
     },
     collapse => sub {
         my $obj = shift;
@@ -170,7 +241,7 @@ my %TYPES = (
     #'CodeRef' => {
     #    expand   => sub {}, # use eval ...
     #    collapse => sub {}, # use B::Deparse ...        
-    #}       
+    #} 
 );
 
 sub add_custom_type_handler {
@@ -233,12 +304,12 @@ __END__
 
 =head1 NAME
 
-MooseX::Storage::Engine
-
-=head1 SYNOPSIS
+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
@@ -251,6 +322,8 @@ MooseX::Storage::Engine
 
 =item B<storage>
 
+=item B<seen>
+
 =back
 
 =head2 API
@@ -275,6 +348,10 @@ MooseX::Storage::Engine
 
 =item B<expand_attribute_value>
 
+=item B<check_for_cycle_in_collapse>
+
+=item B<check_for_cycle_in_expansion>
+
 =item B<map_attributes>
 
 =back