Commit | Line | Data |
c23184fc |
1 | |
2 | package Class::MOP::Immutable; |
3 | |
4 | use strict; |
5 | use warnings; |
6 | |
7 | use Class::MOP::Method::Constructor; |
8 | |
9 | use Carp 'confess'; |
10 | use Scalar::Util 'blessed'; |
11 | |
7fe03d20 |
12 | our $VERSION = '0.64'; |
c23184fc |
13 | our $AUTHORITY = 'cpan:STEVAN'; |
14 | |
d7b2249e |
15 | use base 'Class::MOP::Object'; |
16 | |
0ac992ee |
17 | sub new { |
c23184fc |
18 | my ($class, $metaclass, $options) = @_; |
0ac992ee |
19 | |
c23184fc |
20 | my $self = bless { |
21 | '$!metaclass' => $metaclass, |
22 | '%!options' => $options, |
23 | '$!immutable_metaclass' => undef, |
24 | } => $class; |
0ac992ee |
25 | |
c23184fc |
26 | # NOTE: |
0ac992ee |
27 | # we initialize the immutable |
c23184fc |
28 | # version of the metaclass here |
29 | $self->create_immutable_metaclass; |
0ac992ee |
30 | |
c23184fc |
31 | return $self; |
32 | } |
33 | |
34 | sub immutable_metaclass { (shift)->{'$!immutable_metaclass'} } |
35 | sub metaclass { (shift)->{'$!metaclass'} } |
36 | sub options { (shift)->{'%!options'} } |
37 | |
38 | sub create_immutable_metaclass { |
39 | my $self = shift; |
40 | |
41 | # NOTE: |
0ac992ee |
42 | # The immutable version of the |
c23184fc |
43 | # metaclass is just a anon-class |
0ac992ee |
44 | # which shadows the methods |
c23184fc |
45 | # appropriately |
46 | $self->{'$!immutable_metaclass'} = Class::MOP::Class->create_anon_class( |
47 | superclasses => [ blessed($self->metaclass) ], |
48 | methods => $self->create_methods_for_immutable_metaclass, |
0ac992ee |
49 | ); |
c23184fc |
50 | } |
51 | |
d9586da2 |
52 | |
c23184fc |
53 | my %DEFAULT_METHODS = ( |
d9586da2 |
54 | # I don't really understand this, but removing it breaks tests (groditi) |
0ac992ee |
55 | meta => sub { |
c23184fc |
56 | my $self = shift; |
0ac992ee |
57 | # if it is not blessed, then someone is asking |
127d39a7 |
58 | # for the meta of Class::MOP::Immutable |
c23184fc |
59 | return Class::MOP::Class->initialize($self) unless blessed($self); |
0ac992ee |
60 | # otherwise, they are asking for the metaclass |
c23184fc |
61 | # which has been made immutable, which is itself |
84bc89b3 |
62 | # except in the cases where it is a metaclass itself |
63 | # that has been made immutable and for that we need |
64 | # to dig a bit ... |
65 | if ($self->isa('Class::MOP::Class')) { |
66 | return $self->{'___original_class'}->meta; |
67 | } |
68 | else { |
69 | return $self; |
70 | } |
c23184fc |
71 | }, |
d9586da2 |
72 | is_mutable => sub { 0 }, |
73 | is_immutable => sub { 1 }, |
74 | make_immutable => sub { () }, |
c23184fc |
75 | ); |
76 | |
77 | # NOTE: |
0ac992ee |
78 | # this will actually convert the |
79 | # existing metaclass to an immutable |
c23184fc |
80 | # version of itself |
81 | sub make_metaclass_immutable { |
229910b5 |
82 | my ($self, $metaclass, $options) = @_; |
83 | |
1a84e3f3 |
84 | my %options = ( |
85 | inline_accessors => 1, |
86 | inline_constructor => 1, |
87 | inline_destructor => 0, |
88 | constructor_name => 'new', |
89 | debug => 0, |
90 | %$options, |
91 | ); |
92 | |
93 | %$options = %options; # FIXME who the hell is relying on this?!? tests fail =( |
0ac992ee |
94 | |
c23184fc |
95 | if ($options{inline_accessors}) { |
96 | foreach my $attr_name ($metaclass->get_attribute_list) { |
97 | # inline the accessors |
98 | $metaclass->get_attribute($attr_name) |
0ac992ee |
99 | ->install_accessors(1); |
100 | } |
c23184fc |
101 | } |
102 | |
0ac992ee |
103 | if ($options{inline_constructor}) { |
c23184fc |
104 | my $constructor_class = $options{constructor_class} || 'Class::MOP::Method::Constructor'; |
c23184fc |
105 | $metaclass->add_method( |
106 | $options{constructor_name}, |
107 | $constructor_class->new( |
4c105333 |
108 | options => \%options, |
109 | metaclass => $metaclass, |
110 | is_inline => 1, |
111 | package_name => $metaclass->name, |
112 | name => $options{constructor_name} |
c23184fc |
113 | ) |
114 | ) unless $metaclass->has_method($options{constructor_name}); |
0ac992ee |
115 | } |
116 | |
117 | if ($options{inline_destructor}) { |
c23184fc |
118 | (exists $options{destructor_class}) |
119 | || confess "The 'inline_destructor' option is present, but " |
120 | . "no destructor class was specified"; |
0ac992ee |
121 | |
c23184fc |
122 | my $destructor_class = $options{destructor_class}; |
0ac992ee |
123 | |
cc05f61c |
124 | # NOTE: |
125 | # we allow the destructor to determine |
126 | # if it is needed or not before we actually |
127 | # create the destructor too |
128 | # - SL |
129 | if ($destructor_class->is_needed($metaclass)) { |
130 | my $destructor = $destructor_class->new( |
131 | options => \%options, |
132 | metaclass => $metaclass, |
133 | package_name => $metaclass->name, |
134 | name => 'DESTROY' |
135 | ); |
136 | |
137 | $metaclass->add_method('DESTROY' => $destructor) |
138 | # NOTE: |
139 | # we allow the destructor to determine |
140 | # if it is needed or not, it can perform |
141 | # all sorts of checks because it has the |
142 | # metaclass instance |
143 | if $destructor->is_needed; |
144 | } |
0ac992ee |
145 | } |
146 | |
c23184fc |
147 | my $memoized_methods = $self->options->{memoize}; |
148 | foreach my $method_name (keys %{$memoized_methods}) { |
149 | my $type = $memoized_methods->{$method_name}; |
0ac992ee |
150 | |
c23184fc |
151 | ($metaclass->can($method_name)) |
0ac992ee |
152 | || confess "Could not find the method '$method_name' in " . $metaclass->name; |
153 | |
c23184fc |
154 | if ($type eq 'ARRAY') { |
155 | $metaclass->{'___' . $method_name} = [ $metaclass->$method_name ]; |
156 | } |
157 | elsif ($type eq 'HASH') { |
0ac992ee |
158 | $metaclass->{'___' . $method_name} = { $metaclass->$method_name }; |
c23184fc |
159 | } |
160 | elsif ($type eq 'SCALAR') { |
161 | $metaclass->{'___' . $method_name} = $metaclass->$method_name; |
162 | } |
0ac992ee |
163 | } |
164 | |
0ac992ee |
165 | $metaclass->{'___original_class'} = blessed($metaclass); |
c23184fc |
166 | bless $metaclass => $self->immutable_metaclass->name; |
167 | } |
168 | |
0ac992ee |
169 | sub make_metaclass_mutable { |
229910b5 |
170 | my ($self, $immutable, $options) = @_; |
171 | |
172 | my %options = %$options; |
0ac992ee |
173 | |
174 | my $original_class = $immutable->get_mutable_metaclass_name; |
175 | delete $immutable->{'___original_class'} ; |
176 | bless $immutable => $original_class; |
177 | |
178 | my $memoized_methods = $self->options->{memoize}; |
179 | foreach my $method_name (keys %{$memoized_methods}) { |
180 | my $type = $memoized_methods->{$method_name}; |
181 | |
182 | ($immutable->can($method_name)) |
183 | || confess "Could not find the method '$method_name' in " . $immutable->name; |
184 | if ($type eq 'SCALAR' || $type eq 'ARRAY' || $type eq 'HASH' ) { |
185 | delete $immutable->{'___' . $method_name}; |
186 | } |
187 | } |
188 | |
189 | if ($options{inline_destructor} && $immutable->has_method('DESTROY')) { |
190 | $immutable->remove_method('DESTROY') |
11b56828 |
191 | if blessed($immutable->get_method('DESTROY')) eq $options{destructor_class}; |
0ac992ee |
192 | } |
193 | |
b817e248 |
194 | # NOTE: |
195 | # 14:01 <@stevan> nah,. you shouldnt |
196 | # 14:01 <@stevan> they are just inlined |
197 | # 14:01 <@stevan> which is the default in Moose anyway |
198 | # 14:02 <@stevan> and adding new attributes will just DWIM |
199 | # 14:02 <@stevan> and you really cant change an attribute anyway |
200 | # if ($options{inline_accessors}) { |
201 | # foreach my $attr_name ($immutable->get_attribute_list) { |
202 | # my $attr = $immutable->get_attribute($attr_name); |
203 | # $attr->remove_accessors; |
204 | # $attr->install_accessors(0); |
205 | # } |
206 | # } |
207 | |
208 | # 14:26 <@stevan> the only user of ::Method::Constructor is immutable |
209 | # 14:27 <@stevan> if someone uses it outside of immutable,.. they are either: mst or groditi |
210 | # 14:27 <@stevan> so I am not worried |
11b56828 |
211 | if ($options{inline_constructor} && $immutable->has_method($options{constructor_name})) { |
0ac992ee |
212 | my $constructor_class = $options{constructor_class} || 'Class::MOP::Method::Constructor'; |
213 | $immutable->remove_method( $options{constructor_name} ) |
11b56828 |
214 | if blessed($immutable->get_method($options{constructor_name})) eq $constructor_class; |
0ac992ee |
215 | } |
216 | } |
217 | |
c23184fc |
218 | sub create_methods_for_immutable_metaclass { |
219 | my $self = shift; |
0ac992ee |
220 | |
c23184fc |
221 | my %methods = %DEFAULT_METHODS; |
0ac992ee |
222 | |
c23184fc |
223 | foreach my $read_only_method (@{$self->options->{read_only}}) { |
224 | my $method = $self->metaclass->meta->find_method_by_name($read_only_method); |
0ac992ee |
225 | |
c23184fc |
226 | (defined $method) |
227 | || confess "Could not find the method '$read_only_method' in " . $self->metaclass->name; |
0ac992ee |
228 | |
c23184fc |
229 | $methods{$read_only_method} = sub { |
230 | confess "This method is read-only" if scalar @_ > 1; |
231 | goto &{$method->body} |
232 | }; |
233 | } |
0ac992ee |
234 | |
c23184fc |
235 | foreach my $cannot_call_method (@{$self->options->{cannot_call}}) { |
236 | $methods{$cannot_call_method} = sub { |
237 | confess "This method ($cannot_call_method) cannot be called on an immutable instance"; |
238 | }; |
0ac992ee |
239 | } |
240 | |
c23184fc |
241 | my $memoized_methods = $self->options->{memoize}; |
c23184fc |
242 | foreach my $method_name (keys %{$memoized_methods}) { |
243 | my $type = $memoized_methods->{$method_name}; |
244 | if ($type eq 'ARRAY') { |
245 | $methods{$method_name} = sub { @{$_[0]->{'___' . $method_name}} }; |
246 | } |
247 | elsif ($type eq 'HASH') { |
248 | $methods{$method_name} = sub { %{$_[0]->{'___' . $method_name}} }; |
249 | } |
250 | elsif ($type eq 'SCALAR') { |
251 | $methods{$method_name} = sub { $_[0]->{'___' . $method_name} }; |
0ac992ee |
252 | } |
253 | } |
53299a7b |
254 | |
5f3efd66 |
255 | my $wrapped_methods = $self->options->{wrapped}; |
256 | |
257 | foreach my $method_name (keys %{ $wrapped_methods }) { |
53299a7b |
258 | my $method = $self->metaclass->meta->find_method_by_name($method_name); |
5f3efd66 |
259 | |
260 | (defined $method) |
261 | || confess "Could not find the method '$method_name' in " . $self->metaclass->name; |
262 | |
263 | my $wrapper = $wrapped_methods->{$method_name}; |
264 | |
265 | $methods{$method_name} = sub { $wrapper->($method, @_) }; |
53299a7b |
266 | } |
0ac992ee |
267 | |
268 | $methods{get_mutable_metaclass_name} = sub { (shift)->{'___original_class'} }; |
269 | |
9f3ff885 |
270 | $methods{immutable_transformer} = sub { $self }; |
271 | |
c23184fc |
272 | return \%methods; |
273 | } |
274 | |
275 | 1; |
276 | |
277 | __END__ |
278 | |
279 | =pod |
280 | |
0ac992ee |
281 | =head1 NAME |
c23184fc |
282 | |
283 | Class::MOP::Immutable - A class to transform Class::MOP::Class metaclasses |
284 | |
285 | =head1 SYNOPSIS |
286 | |
96e38ba6 |
287 | use Class::MOP::Immutable; |
0ac992ee |
288 | |
96e38ba6 |
289 | my $immutable_metaclass = Class::MOP::Immutable->new($metaclass, { |
290 | read_only => [qw/superclasses/], |
291 | cannot_call => [qw/ |
292 | add_method |
293 | alias_method |
294 | remove_method |
295 | add_attribute |
296 | remove_attribute |
297 | add_package_symbol |
0ac992ee |
298 | remove_package_symbol |
96e38ba6 |
299 | /], |
300 | memoize => { |
301 | class_precedence_list => 'ARRAY', |
0ac992ee |
302 | compute_all_applicable_attributes => 'ARRAY', |
303 | get_meta_instance => 'SCALAR', |
304 | get_method_map => 'SCALAR', |
96e38ba6 |
305 | } |
0ac992ee |
306 | }); |
96e38ba6 |
307 | |
308 | $immutable_metaclass->make_metaclass_immutable(@_) |
309 | |
c23184fc |
310 | =head1 DESCRIPTION |
311 | |
0ac992ee |
312 | This is basically a module for applying a transformation on a given |
313 | metaclass. Current features include making methods read-only, |
96e38ba6 |
314 | making methods un-callable and memoizing methods (in a type specific |
0ac992ee |
315 | way too). |
96e38ba6 |
316 | |
127d39a7 |
317 | This module is not for the feint of heart, it does some whacky things |
318 | to the metaclass in order to make it immutable. If you are just curious, |
319 | I suggest you turn back now, there is nothing to see here. |
96e38ba6 |
320 | |
c23184fc |
321 | =head1 METHODS |
322 | |
323 | =over 4 |
324 | |
96e38ba6 |
325 | =item B<new ($metaclass, \%options)> |
326 | |
0ac992ee |
327 | Given a C<$metaclass> and a set of C<%options> this module will |
328 | prepare an immutable version of the C<$metaclass>, which can then |
329 | be applied to the C<$metaclass> using the C<make_metaclass_immutable> |
96e38ba6 |
330 | method. |
331 | |
c23184fc |
332 | =item B<options> |
333 | |
96e38ba6 |
334 | Returns the options HASH set in C<new>. |
335 | |
c23184fc |
336 | =item B<metaclass> |
337 | |
96e38ba6 |
338 | Returns the metaclass set in C<new>. |
339 | |
c23184fc |
340 | =item B<immutable_metaclass> |
341 | |
96e38ba6 |
342 | Returns the immutable metaclass created within C<new>. |
343 | |
c23184fc |
344 | =back |
345 | |
346 | =over 4 |
347 | |
348 | =item B<create_immutable_metaclass> |
349 | |
0ac992ee |
350 | This will create the immutable version of the C<$metaclass>, but will |
351 | not actually change the original metaclass. |
96e38ba6 |
352 | |
c23184fc |
353 | =item B<create_methods_for_immutable_metaclass> |
354 | |
0ac992ee |
355 | This will create all the methods for the immutable metaclass based |
96e38ba6 |
356 | on the C<%options> passed into C<new>. |
357 | |
0ac992ee |
358 | =item B<make_metaclass_immutable (%options)> |
c23184fc |
359 | |
96e38ba6 |
360 | This will actually change the C<$metaclass> into the immutable version. |
361 | |
0ac992ee |
362 | =item B<make_metaclass_mutable (%options)> |
363 | |
364 | This will change the C<$metaclass> into the mutable version by reversing |
365 | the immutable process. C<%options> should be the same options that were |
366 | given to make_metaclass_immutable. |
367 | |
c23184fc |
368 | =back |
369 | |
370 | =head1 AUTHORS |
371 | |
372 | Stevan Little E<lt>stevan@iinteractive.comE<gt> |
373 | |
374 | =head1 COPYRIGHT AND LICENSE |
375 | |
69e3ab0a |
376 | Copyright 2006-2008 by Infinity Interactive, Inc. |
c23184fc |
377 | |
378 | L<http://www.iinteractive.com> |
379 | |
380 | This library is free software; you can redistribute it and/or modify |
0ac992ee |
381 | it under the same terms as Perl itself. |
c23184fc |
382 | |
383 | =cut |