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 | |
2e5c1a3f |
12 | our $VERSION = '0.65'; |
c23184fc |
13 | our $AUTHORITY = 'cpan:STEVAN'; |
14 | |
d7b2249e |
15 | use base 'Class::MOP::Object'; |
16 | |
0ac992ee |
17 | sub new { |
1ae8e211 |
18 | my ($class, @args) = @_; |
0ac992ee |
19 | |
1ae8e211 |
20 | my ( $metaclass, $options ); |
21 | |
22 | if ( @args == 2 ) { |
23 | # compatibility args |
24 | ( $metaclass, $options ) = @args; |
25 | } else { |
26 | unshift @args, "metaclass" if @args % 2 == 1; |
27 | |
28 | # default named args |
29 | my %options = @args; |
30 | $options = \%options; |
31 | $metaclass = $options{metaclass}; |
32 | } |
33 | |
34 | # FIXME make a proper constructor using ->meta->new_object |
c23184fc |
35 | my $self = bless { |
8683db0e |
36 | 'metaclass' => $metaclass, |
37 | 'options' => $options, |
38 | 'immutable_metaclass' => undef, |
c23184fc |
39 | } => $class; |
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 | |
8683db0e |
50 | sub immutable_metaclass { (shift)->{'immutable_metaclass'} } |
51 | sub metaclass { (shift)->{'metaclass'} } |
52 | sub options { (shift)->{'options'} } |
c23184fc |
53 | |
54 | sub create_immutable_metaclass { |
55 | my $self = shift; |
56 | |
57 | # NOTE: |
0ac992ee |
58 | # The immutable version of the |
c23184fc |
59 | # metaclass is just a anon-class |
0ac992ee |
60 | # which shadows the methods |
c23184fc |
61 | # appropriately |
8683db0e |
62 | $self->{'immutable_metaclass'} = Class::MOP::Class->create_anon_class( |
c23184fc |
63 | superclasses => [ blessed($self->metaclass) ], |
64 | methods => $self->create_methods_for_immutable_metaclass, |
0ac992ee |
65 | ); |
c23184fc |
66 | } |
67 | |
d9586da2 |
68 | |
c23184fc |
69 | my %DEFAULT_METHODS = ( |
d9586da2 |
70 | # I don't really understand this, but removing it breaks tests (groditi) |
0ac992ee |
71 | meta => sub { |
c23184fc |
72 | my $self = shift; |
0ac992ee |
73 | # if it is not blessed, then someone is asking |
127d39a7 |
74 | # for the meta of Class::MOP::Immutable |
c23184fc |
75 | return Class::MOP::Class->initialize($self) unless blessed($self); |
0ac992ee |
76 | # otherwise, they are asking for the metaclass |
c23184fc |
77 | # which has been made immutable, which is itself |
84bc89b3 |
78 | # except in the cases where it is a metaclass itself |
79 | # that has been made immutable and for that we need |
80 | # to dig a bit ... |
81 | if ($self->isa('Class::MOP::Class')) { |
82 | return $self->{'___original_class'}->meta; |
83 | } |
84 | else { |
85 | return $self; |
86 | } |
c23184fc |
87 | }, |
d9586da2 |
88 | is_mutable => sub { 0 }, |
89 | is_immutable => sub { 1 }, |
90 | make_immutable => sub { () }, |
c23184fc |
91 | ); |
92 | |
93 | # NOTE: |
0ac992ee |
94 | # this will actually convert the |
95 | # existing metaclass to an immutable |
c23184fc |
96 | # version of itself |
97 | sub make_metaclass_immutable { |
229910b5 |
98 | my ($self, $metaclass, $options) = @_; |
99 | |
1a84e3f3 |
100 | my %options = ( |
101 | inline_accessors => 1, |
102 | inline_constructor => 1, |
103 | inline_destructor => 0, |
104 | constructor_name => 'new', |
105 | debug => 0, |
106 | %$options, |
107 | ); |
108 | |
109 | %$options = %options; # FIXME who the hell is relying on this?!? tests fail =( |
0ac992ee |
110 | |
c23184fc |
111 | if ($options{inline_accessors}) { |
112 | foreach my $attr_name ($metaclass->get_attribute_list) { |
113 | # inline the accessors |
114 | $metaclass->get_attribute($attr_name) |
0ac992ee |
115 | ->install_accessors(1); |
116 | } |
c23184fc |
117 | } |
118 | |
0ac992ee |
119 | if ($options{inline_constructor}) { |
c23184fc |
120 | my $constructor_class = $options{constructor_class} || 'Class::MOP::Method::Constructor'; |
c23184fc |
121 | $metaclass->add_method( |
122 | $options{constructor_name}, |
123 | $constructor_class->new( |
4c105333 |
124 | options => \%options, |
125 | metaclass => $metaclass, |
126 | is_inline => 1, |
127 | package_name => $metaclass->name, |
128 | name => $options{constructor_name} |
c23184fc |
129 | ) |
6c2f6b5c |
130 | ) if $options{replace_constructor} or !$metaclass->has_method($options{constructor_name}); |
0ac992ee |
131 | } |
132 | |
133 | if ($options{inline_destructor}) { |
c23184fc |
134 | (exists $options{destructor_class}) |
135 | || confess "The 'inline_destructor' option is present, but " |
136 | . "no destructor class was specified"; |
0ac992ee |
137 | |
c23184fc |
138 | my $destructor_class = $options{destructor_class}; |
0ac992ee |
139 | |
cc05f61c |
140 | # NOTE: |
141 | # we allow the destructor to determine |
142 | # if it is needed or not before we actually |
143 | # create the destructor too |
144 | # - SL |
145 | if ($destructor_class->is_needed($metaclass)) { |
146 | my $destructor = $destructor_class->new( |
147 | options => \%options, |
148 | metaclass => $metaclass, |
149 | package_name => $metaclass->name, |
150 | name => 'DESTROY' |
151 | ); |
152 | |
153 | $metaclass->add_method('DESTROY' => $destructor) |
154 | # NOTE: |
155 | # we allow the destructor to determine |
156 | # if it is needed or not, it can perform |
157 | # all sorts of checks because it has the |
158 | # metaclass instance |
159 | if $destructor->is_needed; |
160 | } |
0ac992ee |
161 | } |
162 | |
c23184fc |
163 | my $memoized_methods = $self->options->{memoize}; |
164 | foreach my $method_name (keys %{$memoized_methods}) { |
165 | my $type = $memoized_methods->{$method_name}; |
0ac992ee |
166 | |
c23184fc |
167 | ($metaclass->can($method_name)) |
0ac992ee |
168 | || confess "Could not find the method '$method_name' in " . $metaclass->name; |
169 | |
c23184fc |
170 | if ($type eq 'ARRAY') { |
171 | $metaclass->{'___' . $method_name} = [ $metaclass->$method_name ]; |
172 | } |
173 | elsif ($type eq 'HASH') { |
0ac992ee |
174 | $metaclass->{'___' . $method_name} = { $metaclass->$method_name }; |
c23184fc |
175 | } |
176 | elsif ($type eq 'SCALAR') { |
177 | $metaclass->{'___' . $method_name} = $metaclass->$method_name; |
178 | } |
0ac992ee |
179 | } |
180 | |
0ac992ee |
181 | $metaclass->{'___original_class'} = blessed($metaclass); |
c23184fc |
182 | bless $metaclass => $self->immutable_metaclass->name; |
183 | } |
184 | |
0ac992ee |
185 | sub make_metaclass_mutable { |
229910b5 |
186 | my ($self, $immutable, $options) = @_; |
187 | |
188 | my %options = %$options; |
0ac992ee |
189 | |
190 | my $original_class = $immutable->get_mutable_metaclass_name; |
191 | delete $immutable->{'___original_class'} ; |
192 | bless $immutable => $original_class; |
193 | |
194 | my $memoized_methods = $self->options->{memoize}; |
195 | foreach my $method_name (keys %{$memoized_methods}) { |
196 | my $type = $memoized_methods->{$method_name}; |
197 | |
198 | ($immutable->can($method_name)) |
199 | || confess "Could not find the method '$method_name' in " . $immutable->name; |
200 | if ($type eq 'SCALAR' || $type eq 'ARRAY' || $type eq 'HASH' ) { |
201 | delete $immutable->{'___' . $method_name}; |
202 | } |
203 | } |
204 | |
205 | if ($options{inline_destructor} && $immutable->has_method('DESTROY')) { |
206 | $immutable->remove_method('DESTROY') |
11b56828 |
207 | if blessed($immutable->get_method('DESTROY')) eq $options{destructor_class}; |
0ac992ee |
208 | } |
209 | |
b817e248 |
210 | # NOTE: |
211 | # 14:01 <@stevan> nah,. you shouldnt |
212 | # 14:01 <@stevan> they are just inlined |
213 | # 14:01 <@stevan> which is the default in Moose anyway |
214 | # 14:02 <@stevan> and adding new attributes will just DWIM |
215 | # 14:02 <@stevan> and you really cant change an attribute anyway |
216 | # if ($options{inline_accessors}) { |
217 | # foreach my $attr_name ($immutable->get_attribute_list) { |
218 | # my $attr = $immutable->get_attribute($attr_name); |
219 | # $attr->remove_accessors; |
220 | # $attr->install_accessors(0); |
221 | # } |
222 | # } |
223 | |
224 | # 14:26 <@stevan> the only user of ::Method::Constructor is immutable |
225 | # 14:27 <@stevan> if someone uses it outside of immutable,.. they are either: mst or groditi |
226 | # 14:27 <@stevan> so I am not worried |
11b56828 |
227 | if ($options{inline_constructor} && $immutable->has_method($options{constructor_name})) { |
0ac992ee |
228 | my $constructor_class = $options{constructor_class} || 'Class::MOP::Method::Constructor'; |
229 | $immutable->remove_method( $options{constructor_name} ) |
11b56828 |
230 | if blessed($immutable->get_method($options{constructor_name})) eq $constructor_class; |
0ac992ee |
231 | } |
232 | } |
233 | |
c23184fc |
234 | sub create_methods_for_immutable_metaclass { |
235 | my $self = shift; |
0ac992ee |
236 | |
c23184fc |
237 | my %methods = %DEFAULT_METHODS; |
0ac992ee |
238 | |
c23184fc |
239 | foreach my $read_only_method (@{$self->options->{read_only}}) { |
240 | my $method = $self->metaclass->meta->find_method_by_name($read_only_method); |
0ac992ee |
241 | |
c23184fc |
242 | (defined $method) |
243 | || confess "Could not find the method '$read_only_method' in " . $self->metaclass->name; |
0ac992ee |
244 | |
c23184fc |
245 | $methods{$read_only_method} = sub { |
246 | confess "This method is read-only" if scalar @_ > 1; |
247 | goto &{$method->body} |
248 | }; |
249 | } |
0ac992ee |
250 | |
c23184fc |
251 | foreach my $cannot_call_method (@{$self->options->{cannot_call}}) { |
252 | $methods{$cannot_call_method} = sub { |
253 | confess "This method ($cannot_call_method) cannot be called on an immutable instance"; |
254 | }; |
0ac992ee |
255 | } |
256 | |
c23184fc |
257 | my $memoized_methods = $self->options->{memoize}; |
c23184fc |
258 | foreach my $method_name (keys %{$memoized_methods}) { |
259 | my $type = $memoized_methods->{$method_name}; |
260 | if ($type eq 'ARRAY') { |
261 | $methods{$method_name} = sub { @{$_[0]->{'___' . $method_name}} }; |
262 | } |
263 | elsif ($type eq 'HASH') { |
264 | $methods{$method_name} = sub { %{$_[0]->{'___' . $method_name}} }; |
265 | } |
266 | elsif ($type eq 'SCALAR') { |
267 | $methods{$method_name} = sub { $_[0]->{'___' . $method_name} }; |
0ac992ee |
268 | } |
269 | } |
53299a7b |
270 | |
5f3efd66 |
271 | my $wrapped_methods = $self->options->{wrapped}; |
272 | |
273 | foreach my $method_name (keys %{ $wrapped_methods }) { |
53299a7b |
274 | my $method = $self->metaclass->meta->find_method_by_name($method_name); |
5f3efd66 |
275 | |
276 | (defined $method) |
277 | || confess "Could not find the method '$method_name' in " . $self->metaclass->name; |
278 | |
279 | my $wrapper = $wrapped_methods->{$method_name}; |
280 | |
281 | $methods{$method_name} = sub { $wrapper->($method, @_) }; |
53299a7b |
282 | } |
0ac992ee |
283 | |
284 | $methods{get_mutable_metaclass_name} = sub { (shift)->{'___original_class'} }; |
285 | |
9f3ff885 |
286 | $methods{immutable_transformer} = sub { $self }; |
287 | |
c23184fc |
288 | return \%methods; |
289 | } |
290 | |
291 | 1; |
292 | |
293 | __END__ |
294 | |
295 | =pod |
296 | |
0ac992ee |
297 | =head1 NAME |
c23184fc |
298 | |
299 | Class::MOP::Immutable - A class to transform Class::MOP::Class metaclasses |
300 | |
301 | =head1 SYNOPSIS |
302 | |
96e38ba6 |
303 | use Class::MOP::Immutable; |
0ac992ee |
304 | |
96e38ba6 |
305 | my $immutable_metaclass = Class::MOP::Immutable->new($metaclass, { |
306 | read_only => [qw/superclasses/], |
307 | cannot_call => [qw/ |
308 | add_method |
309 | alias_method |
310 | remove_method |
311 | add_attribute |
312 | remove_attribute |
313 | add_package_symbol |
0ac992ee |
314 | remove_package_symbol |
96e38ba6 |
315 | /], |
316 | memoize => { |
317 | class_precedence_list => 'ARRAY', |
0ac992ee |
318 | compute_all_applicable_attributes => 'ARRAY', |
319 | get_meta_instance => 'SCALAR', |
320 | get_method_map => 'SCALAR', |
96e38ba6 |
321 | } |
0ac992ee |
322 | }); |
96e38ba6 |
323 | |
324 | $immutable_metaclass->make_metaclass_immutable(@_) |
325 | |
c23184fc |
326 | =head1 DESCRIPTION |
327 | |
0ac992ee |
328 | This is basically a module for applying a transformation on a given |
329 | metaclass. Current features include making methods read-only, |
96e38ba6 |
330 | making methods un-callable and memoizing methods (in a type specific |
0ac992ee |
331 | way too). |
96e38ba6 |
332 | |
127d39a7 |
333 | This module is not for the feint of heart, it does some whacky things |
334 | to the metaclass in order to make it immutable. If you are just curious, |
335 | I suggest you turn back now, there is nothing to see here. |
96e38ba6 |
336 | |
c23184fc |
337 | =head1 METHODS |
338 | |
339 | =over 4 |
340 | |
96e38ba6 |
341 | =item B<new ($metaclass, \%options)> |
342 | |
0ac992ee |
343 | Given a C<$metaclass> and a set of C<%options> this module will |
344 | prepare an immutable version of the C<$metaclass>, which can then |
345 | be applied to the C<$metaclass> using the C<make_metaclass_immutable> |
96e38ba6 |
346 | method. |
347 | |
c23184fc |
348 | =item B<options> |
349 | |
96e38ba6 |
350 | Returns the options HASH set in C<new>. |
351 | |
c23184fc |
352 | =item B<metaclass> |
353 | |
96e38ba6 |
354 | Returns the metaclass set in C<new>. |
355 | |
c23184fc |
356 | =item B<immutable_metaclass> |
357 | |
96e38ba6 |
358 | Returns the immutable metaclass created within C<new>. |
359 | |
c23184fc |
360 | =back |
361 | |
362 | =over 4 |
363 | |
364 | =item B<create_immutable_metaclass> |
365 | |
0ac992ee |
366 | This will create the immutable version of the C<$metaclass>, but will |
367 | not actually change the original metaclass. |
96e38ba6 |
368 | |
c23184fc |
369 | =item B<create_methods_for_immutable_metaclass> |
370 | |
0ac992ee |
371 | This will create all the methods for the immutable metaclass based |
96e38ba6 |
372 | on the C<%options> passed into C<new>. |
373 | |
0ac992ee |
374 | =item B<make_metaclass_immutable (%options)> |
c23184fc |
375 | |
96e38ba6 |
376 | This will actually change the C<$metaclass> into the immutable version. |
377 | |
0ac992ee |
378 | =item B<make_metaclass_mutable (%options)> |
379 | |
380 | This will change the C<$metaclass> into the mutable version by reversing |
381 | the immutable process. C<%options> should be the same options that were |
382 | given to make_metaclass_immutable. |
383 | |
c23184fc |
384 | =back |
385 | |
386 | =head1 AUTHORS |
387 | |
388 | Stevan Little E<lt>stevan@iinteractive.comE<gt> |
389 | |
390 | =head1 COPYRIGHT AND LICENSE |
391 | |
69e3ab0a |
392 | Copyright 2006-2008 by Infinity Interactive, Inc. |
c23184fc |
393 | |
394 | L<http://www.iinteractive.com> |
395 | |
396 | This library is free software; you can redistribute it and/or modify |
0ac992ee |
397 | it under the same terms as Perl itself. |
c23184fc |
398 | |
399 | =cut |