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 | |
2a755fe8 |
12 | our $VERSION = '0.64_05'; |
d519662a |
13 | $VERSION = eval $VERSION; |
c23184fc |
14 | our $AUTHORITY = 'cpan:STEVAN'; |
15 | |
d7b2249e |
16 | use base 'Class::MOP::Object'; |
17 | |
0ac992ee |
18 | sub new { |
1ae8e211 |
19 | my ($class, @args) = @_; |
0ac992ee |
20 | |
1ae8e211 |
21 | my ( $metaclass, $options ); |
22 | |
23 | if ( @args == 2 ) { |
24 | # compatibility args |
25 | ( $metaclass, $options ) = @args; |
26 | } else { |
27 | unshift @args, "metaclass" if @args % 2 == 1; |
28 | |
29 | # default named args |
30 | my %options = @args; |
31 | $options = \%options; |
32 | $metaclass = $options{metaclass}; |
33 | } |
34 | |
0bfc85b8 |
35 | my $self = $class->_new( |
8683db0e |
36 | 'metaclass' => $metaclass, |
37 | 'options' => $options, |
38 | 'immutable_metaclass' => undef, |
0bfc85b8 |
39 | ); |
0ac992ee |
40 | |
c23184fc |
41 | # NOTE: |
0ac992ee |
42 | # we initialize the immutable |
c23184fc |
43 | # version of the metaclass here |
1ae8e211 |
44 | # FIXME lazify |
c23184fc |
45 | $self->create_immutable_metaclass; |
0ac992ee |
46 | |
c23184fc |
47 | return $self; |
48 | } |
49 | |
0bfc85b8 |
50 | sub _new { |
51 | my $class = shift; |
52 | my $options = @_ == 1 ? $_[0] : {@_}; |
53 | |
54 | bless $options, $class; |
55 | } |
56 | |
8683db0e |
57 | sub immutable_metaclass { (shift)->{'immutable_metaclass'} } |
58 | sub metaclass { (shift)->{'metaclass'} } |
59 | sub options { (shift)->{'options'} } |
c23184fc |
60 | |
61 | sub create_immutable_metaclass { |
62 | my $self = shift; |
63 | |
64 | # NOTE: |
0ac992ee |
65 | # The immutable version of the |
c23184fc |
66 | # metaclass is just a anon-class |
0ac992ee |
67 | # which shadows the methods |
c23184fc |
68 | # appropriately |
8683db0e |
69 | $self->{'immutable_metaclass'} = Class::MOP::Class->create_anon_class( |
c23184fc |
70 | superclasses => [ blessed($self->metaclass) ], |
71 | methods => $self->create_methods_for_immutable_metaclass, |
0ac992ee |
72 | ); |
c23184fc |
73 | } |
74 | |
d9586da2 |
75 | |
c23184fc |
76 | my %DEFAULT_METHODS = ( |
d9586da2 |
77 | # I don't really understand this, but removing it breaks tests (groditi) |
0ac992ee |
78 | meta => sub { |
c23184fc |
79 | my $self = shift; |
0ac992ee |
80 | # if it is not blessed, then someone is asking |
127d39a7 |
81 | # for the meta of Class::MOP::Immutable |
c23184fc |
82 | return Class::MOP::Class->initialize($self) unless blessed($self); |
0ac992ee |
83 | # otherwise, they are asking for the metaclass |
c23184fc |
84 | # which has been made immutable, which is itself |
84bc89b3 |
85 | # except in the cases where it is a metaclass itself |
86 | # that has been made immutable and for that we need |
87 | # to dig a bit ... |
88 | if ($self->isa('Class::MOP::Class')) { |
89 | return $self->{'___original_class'}->meta; |
90 | } |
91 | else { |
92 | return $self; |
93 | } |
c23184fc |
94 | }, |
d9586da2 |
95 | is_mutable => sub { 0 }, |
96 | is_immutable => sub { 1 }, |
97 | make_immutable => sub { () }, |
c23184fc |
98 | ); |
99 | |
100 | # NOTE: |
0ac992ee |
101 | # this will actually convert the |
102 | # existing metaclass to an immutable |
c23184fc |
103 | # version of itself |
104 | sub make_metaclass_immutable { |
229910b5 |
105 | my ($self, $metaclass, $options) = @_; |
106 | |
1a84e3f3 |
107 | my %options = ( |
108 | inline_accessors => 1, |
109 | inline_constructor => 1, |
110 | inline_destructor => 0, |
111 | constructor_name => 'new', |
112 | debug => 0, |
113 | %$options, |
114 | ); |
115 | |
116 | %$options = %options; # FIXME who the hell is relying on this?!? tests fail =( |
0ac992ee |
117 | |
c23184fc |
118 | if ($options{inline_accessors}) { |
119 | foreach my $attr_name ($metaclass->get_attribute_list) { |
120 | # inline the accessors |
121 | $metaclass->get_attribute($attr_name) |
0ac992ee |
122 | ->install_accessors(1); |
123 | } |
c23184fc |
124 | } |
125 | |
0ac992ee |
126 | if ($options{inline_constructor}) { |
c23184fc |
127 | my $constructor_class = $options{constructor_class} || 'Class::MOP::Method::Constructor'; |
c23184fc |
128 | $metaclass->add_method( |
129 | $options{constructor_name}, |
130 | $constructor_class->new( |
4c105333 |
131 | options => \%options, |
132 | metaclass => $metaclass, |
133 | is_inline => 1, |
134 | package_name => $metaclass->name, |
135 | name => $options{constructor_name} |
c23184fc |
136 | ) |
6c2f6b5c |
137 | ) if $options{replace_constructor} or !$metaclass->has_method($options{constructor_name}); |
0ac992ee |
138 | } |
139 | |
140 | if ($options{inline_destructor}) { |
c23184fc |
141 | (exists $options{destructor_class}) |
142 | || confess "The 'inline_destructor' option is present, but " |
143 | . "no destructor class was specified"; |
0ac992ee |
144 | |
c23184fc |
145 | my $destructor_class = $options{destructor_class}; |
0ac992ee |
146 | |
cc05f61c |
147 | # NOTE: |
148 | # we allow the destructor to determine |
149 | # if it is needed or not before we actually |
150 | # create the destructor too |
151 | # - SL |
152 | if ($destructor_class->is_needed($metaclass)) { |
153 | my $destructor = $destructor_class->new( |
154 | options => \%options, |
155 | metaclass => $metaclass, |
156 | package_name => $metaclass->name, |
157 | name => 'DESTROY' |
158 | ); |
159 | |
160 | $metaclass->add_method('DESTROY' => $destructor) |
161 | # NOTE: |
162 | # we allow the destructor to determine |
163 | # if it is needed or not, it can perform |
164 | # all sorts of checks because it has the |
165 | # metaclass instance |
166 | if $destructor->is_needed; |
167 | } |
0ac992ee |
168 | } |
169 | |
c23184fc |
170 | my $memoized_methods = $self->options->{memoize}; |
171 | foreach my $method_name (keys %{$memoized_methods}) { |
172 | my $type = $memoized_methods->{$method_name}; |
0ac992ee |
173 | |
c23184fc |
174 | ($metaclass->can($method_name)) |
0ac992ee |
175 | || confess "Could not find the method '$method_name' in " . $metaclass->name; |
176 | |
c23184fc |
177 | if ($type eq 'ARRAY') { |
178 | $metaclass->{'___' . $method_name} = [ $metaclass->$method_name ]; |
179 | } |
180 | elsif ($type eq 'HASH') { |
0ac992ee |
181 | $metaclass->{'___' . $method_name} = { $metaclass->$method_name }; |
c23184fc |
182 | } |
183 | elsif ($type eq 'SCALAR') { |
184 | $metaclass->{'___' . $method_name} = $metaclass->$method_name; |
185 | } |
0ac992ee |
186 | } |
187 | |
0ac992ee |
188 | $metaclass->{'___original_class'} = blessed($metaclass); |
c23184fc |
189 | bless $metaclass => $self->immutable_metaclass->name; |
190 | } |
191 | |
0ac992ee |
192 | sub make_metaclass_mutable { |
229910b5 |
193 | my ($self, $immutable, $options) = @_; |
194 | |
195 | my %options = %$options; |
0ac992ee |
196 | |
197 | my $original_class = $immutable->get_mutable_metaclass_name; |
198 | delete $immutable->{'___original_class'} ; |
199 | bless $immutable => $original_class; |
200 | |
201 | my $memoized_methods = $self->options->{memoize}; |
202 | foreach my $method_name (keys %{$memoized_methods}) { |
203 | my $type = $memoized_methods->{$method_name}; |
204 | |
205 | ($immutable->can($method_name)) |
206 | || confess "Could not find the method '$method_name' in " . $immutable->name; |
207 | if ($type eq 'SCALAR' || $type eq 'ARRAY' || $type eq 'HASH' ) { |
208 | delete $immutable->{'___' . $method_name}; |
209 | } |
210 | } |
211 | |
212 | if ($options{inline_destructor} && $immutable->has_method('DESTROY')) { |
213 | $immutable->remove_method('DESTROY') |
11b56828 |
214 | if blessed($immutable->get_method('DESTROY')) eq $options{destructor_class}; |
0ac992ee |
215 | } |
216 | |
b817e248 |
217 | # NOTE: |
218 | # 14:01 <@stevan> nah,. you shouldnt |
219 | # 14:01 <@stevan> they are just inlined |
220 | # 14:01 <@stevan> which is the default in Moose anyway |
221 | # 14:02 <@stevan> and adding new attributes will just DWIM |
222 | # 14:02 <@stevan> and you really cant change an attribute anyway |
223 | # if ($options{inline_accessors}) { |
224 | # foreach my $attr_name ($immutable->get_attribute_list) { |
225 | # my $attr = $immutable->get_attribute($attr_name); |
226 | # $attr->remove_accessors; |
227 | # $attr->install_accessors(0); |
228 | # } |
229 | # } |
230 | |
231 | # 14:26 <@stevan> the only user of ::Method::Constructor is immutable |
232 | # 14:27 <@stevan> if someone uses it outside of immutable,.. they are either: mst or groditi |
233 | # 14:27 <@stevan> so I am not worried |
11b56828 |
234 | if ($options{inline_constructor} && $immutable->has_method($options{constructor_name})) { |
0ac992ee |
235 | my $constructor_class = $options{constructor_class} || 'Class::MOP::Method::Constructor'; |
236 | $immutable->remove_method( $options{constructor_name} ) |
11b56828 |
237 | if blessed($immutable->get_method($options{constructor_name})) eq $constructor_class; |
0ac992ee |
238 | } |
239 | } |
240 | |
c23184fc |
241 | sub create_methods_for_immutable_metaclass { |
242 | my $self = shift; |
0ac992ee |
243 | |
c23184fc |
244 | my %methods = %DEFAULT_METHODS; |
0ac992ee |
245 | |
c23184fc |
246 | foreach my $read_only_method (@{$self->options->{read_only}}) { |
247 | my $method = $self->metaclass->meta->find_method_by_name($read_only_method); |
0ac992ee |
248 | |
c23184fc |
249 | (defined $method) |
250 | || confess "Could not find the method '$read_only_method' in " . $self->metaclass->name; |
0ac992ee |
251 | |
c23184fc |
252 | $methods{$read_only_method} = sub { |
253 | confess "This method is read-only" if scalar @_ > 1; |
254 | goto &{$method->body} |
255 | }; |
256 | } |
0ac992ee |
257 | |
c23184fc |
258 | foreach my $cannot_call_method (@{$self->options->{cannot_call}}) { |
259 | $methods{$cannot_call_method} = sub { |
260 | confess "This method ($cannot_call_method) cannot be called on an immutable instance"; |
261 | }; |
0ac992ee |
262 | } |
263 | |
c23184fc |
264 | my $memoized_methods = $self->options->{memoize}; |
c23184fc |
265 | foreach my $method_name (keys %{$memoized_methods}) { |
266 | my $type = $memoized_methods->{$method_name}; |
267 | if ($type eq 'ARRAY') { |
268 | $methods{$method_name} = sub { @{$_[0]->{'___' . $method_name}} }; |
269 | } |
270 | elsif ($type eq 'HASH') { |
271 | $methods{$method_name} = sub { %{$_[0]->{'___' . $method_name}} }; |
272 | } |
273 | elsif ($type eq 'SCALAR') { |
274 | $methods{$method_name} = sub { $_[0]->{'___' . $method_name} }; |
0ac992ee |
275 | } |
276 | } |
53299a7b |
277 | |
5f3efd66 |
278 | my $wrapped_methods = $self->options->{wrapped}; |
279 | |
280 | foreach my $method_name (keys %{ $wrapped_methods }) { |
53299a7b |
281 | my $method = $self->metaclass->meta->find_method_by_name($method_name); |
5f3efd66 |
282 | |
283 | (defined $method) |
284 | || confess "Could not find the method '$method_name' in " . $self->metaclass->name; |
285 | |
286 | my $wrapper = $wrapped_methods->{$method_name}; |
287 | |
288 | $methods{$method_name} = sub { $wrapper->($method, @_) }; |
53299a7b |
289 | } |
0ac992ee |
290 | |
291 | $methods{get_mutable_metaclass_name} = sub { (shift)->{'___original_class'} }; |
292 | |
9f3ff885 |
293 | $methods{immutable_transformer} = sub { $self }; |
294 | |
c23184fc |
295 | return \%methods; |
296 | } |
297 | |
298 | 1; |
299 | |
300 | __END__ |
301 | |
302 | =pod |
303 | |
0ac992ee |
304 | =head1 NAME |
c23184fc |
305 | |
306 | Class::MOP::Immutable - A class to transform Class::MOP::Class metaclasses |
307 | |
308 | =head1 SYNOPSIS |
309 | |
96e38ba6 |
310 | use Class::MOP::Immutable; |
0ac992ee |
311 | |
96e38ba6 |
312 | my $immutable_metaclass = Class::MOP::Immutable->new($metaclass, { |
313 | read_only => [qw/superclasses/], |
314 | cannot_call => [qw/ |
315 | add_method |
316 | alias_method |
317 | remove_method |
318 | add_attribute |
319 | remove_attribute |
320 | add_package_symbol |
0ac992ee |
321 | remove_package_symbol |
96e38ba6 |
322 | /], |
323 | memoize => { |
324 | class_precedence_list => 'ARRAY', |
0ac992ee |
325 | compute_all_applicable_attributes => 'ARRAY', |
326 | get_meta_instance => 'SCALAR', |
327 | get_method_map => 'SCALAR', |
96e38ba6 |
328 | } |
0ac992ee |
329 | }); |
96e38ba6 |
330 | |
331 | $immutable_metaclass->make_metaclass_immutable(@_) |
332 | |
c23184fc |
333 | =head1 DESCRIPTION |
334 | |
0ac992ee |
335 | This is basically a module for applying a transformation on a given |
336 | metaclass. Current features include making methods read-only, |
96e38ba6 |
337 | making methods un-callable and memoizing methods (in a type specific |
0ac992ee |
338 | way too). |
96e38ba6 |
339 | |
127d39a7 |
340 | This module is not for the feint of heart, it does some whacky things |
341 | to the metaclass in order to make it immutable. If you are just curious, |
342 | I suggest you turn back now, there is nothing to see here. |
96e38ba6 |
343 | |
c23184fc |
344 | =head1 METHODS |
345 | |
346 | =over 4 |
347 | |
96e38ba6 |
348 | =item B<new ($metaclass, \%options)> |
349 | |
0ac992ee |
350 | Given a C<$metaclass> and a set of C<%options> this module will |
351 | prepare an immutable version of the C<$metaclass>, which can then |
352 | be applied to the C<$metaclass> using the C<make_metaclass_immutable> |
96e38ba6 |
353 | method. |
354 | |
c23184fc |
355 | =item B<options> |
356 | |
96e38ba6 |
357 | Returns the options HASH set in C<new>. |
358 | |
c23184fc |
359 | =item B<metaclass> |
360 | |
96e38ba6 |
361 | Returns the metaclass set in C<new>. |
362 | |
c23184fc |
363 | =item B<immutable_metaclass> |
364 | |
96e38ba6 |
365 | Returns the immutable metaclass created within C<new>. |
366 | |
c23184fc |
367 | =back |
368 | |
369 | =over 4 |
370 | |
371 | =item B<create_immutable_metaclass> |
372 | |
0ac992ee |
373 | This will create the immutable version of the C<$metaclass>, but will |
374 | not actually change the original metaclass. |
96e38ba6 |
375 | |
c23184fc |
376 | =item B<create_methods_for_immutable_metaclass> |
377 | |
0ac992ee |
378 | This will create all the methods for the immutable metaclass based |
96e38ba6 |
379 | on the C<%options> passed into C<new>. |
380 | |
0ac992ee |
381 | =item B<make_metaclass_immutable (%options)> |
c23184fc |
382 | |
96e38ba6 |
383 | This will actually change the C<$metaclass> into the immutable version. |
384 | |
0ac992ee |
385 | =item B<make_metaclass_mutable (%options)> |
386 | |
387 | This will change the C<$metaclass> into the mutable version by reversing |
388 | the immutable process. C<%options> should be the same options that were |
389 | given to make_metaclass_immutable. |
390 | |
c23184fc |
391 | =back |
392 | |
393 | =head1 AUTHORS |
394 | |
395 | Stevan Little E<lt>stevan@iinteractive.comE<gt> |
396 | |
397 | =head1 COPYRIGHT AND LICENSE |
398 | |
69e3ab0a |
399 | Copyright 2006-2008 by Infinity Interactive, Inc. |
c23184fc |
400 | |
401 | L<http://www.iinteractive.com> |
402 | |
403 | This library is free software; you can redistribute it and/or modify |
0ac992ee |
404 | it under the same terms as Perl itself. |
c23184fc |
405 | |
406 | =cut |