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 | |
34147f49 |
12 | our $VERSION = '0.71_01'; |
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 | return $self; |
42 | } |
43 | |
0bfc85b8 |
44 | sub _new { |
45 | my $class = shift; |
46 | my $options = @_ == 1 ? $_[0] : {@_}; |
47 | |
48 | bless $options, $class; |
49 | } |
50 | |
76c20e30 |
51 | sub immutable_metaclass { |
52 | my $self = shift; |
53 | |
54 | $self->create_immutable_metaclass unless $self->{'immutable_metaclass'}; |
55 | |
56 | return $self->{'immutable_metaclass'}; |
57 | } |
58 | |
8683db0e |
59 | sub metaclass { (shift)->{'metaclass'} } |
60 | sub options { (shift)->{'options'} } |
c23184fc |
61 | |
62 | sub create_immutable_metaclass { |
63 | my $self = shift; |
64 | |
65 | # NOTE: |
0ac992ee |
66 | # The immutable version of the |
c23184fc |
67 | # metaclass is just a anon-class |
0ac992ee |
68 | # which shadows the methods |
c23184fc |
69 | # appropriately |
8683db0e |
70 | $self->{'immutable_metaclass'} = Class::MOP::Class->create_anon_class( |
c23184fc |
71 | superclasses => [ blessed($self->metaclass) ], |
72 | methods => $self->create_methods_for_immutable_metaclass, |
0ac992ee |
73 | ); |
c23184fc |
74 | } |
75 | |
d9586da2 |
76 | |
c23184fc |
77 | my %DEFAULT_METHODS = ( |
d9586da2 |
78 | # I don't really understand this, but removing it breaks tests (groditi) |
0ac992ee |
79 | meta => sub { |
c23184fc |
80 | my $self = shift; |
0ac992ee |
81 | # if it is not blessed, then someone is asking |
127d39a7 |
82 | # for the meta of Class::MOP::Immutable |
c23184fc |
83 | return Class::MOP::Class->initialize($self) unless blessed($self); |
0ac992ee |
84 | # otherwise, they are asking for the metaclass |
c23184fc |
85 | # which has been made immutable, which is itself |
84bc89b3 |
86 | # except in the cases where it is a metaclass itself |
87 | # that has been made immutable and for that we need |
88 | # to dig a bit ... |
89 | if ($self->isa('Class::MOP::Class')) { |
90 | return $self->{'___original_class'}->meta; |
91 | } |
92 | else { |
93 | return $self; |
94 | } |
c23184fc |
95 | }, |
d9586da2 |
96 | is_mutable => sub { 0 }, |
97 | is_immutable => sub { 1 }, |
98 | make_immutable => sub { () }, |
c23184fc |
99 | ); |
100 | |
101 | # NOTE: |
0ac992ee |
102 | # this will actually convert the |
103 | # existing metaclass to an immutable |
c23184fc |
104 | # version of itself |
105 | sub make_metaclass_immutable { |
229910b5 |
106 | my ($self, $metaclass, $options) = @_; |
107 | |
1a84e3f3 |
108 | my %options = ( |
109 | inline_accessors => 1, |
110 | inline_constructor => 1, |
111 | inline_destructor => 0, |
112 | constructor_name => 'new', |
113 | debug => 0, |
114 | %$options, |
115 | ); |
116 | |
117 | %$options = %options; # FIXME who the hell is relying on this?!? tests fail =( |
0ac992ee |
118 | |
75f173e5 |
119 | $self->_inline_accessors( $metaclass, \%options ); |
120 | $self->_inline_constructor( $metaclass, \%options ); |
121 | $self->_inline_destructor( $metaclass, \%options ); |
122 | $self->_memoize_methods( $metaclass, \%options ); |
123 | |
124 | $metaclass->{'___original_class'} = blessed($metaclass); |
125 | bless $metaclass => $self->immutable_metaclass->name; |
126 | } |
c23184fc |
127 | |
75f173e5 |
128 | sub _inline_accessors { |
129 | my ( $self, $metaclass, $options ) = @_; |
130 | |
131 | return unless $options->{inline_accessors}; |
132 | |
133 | foreach my $attr_name ( $metaclass->get_attribute_list ) { |
134 | $metaclass->get_attribute($attr_name)->install_accessors(1); |
0ac992ee |
135 | } |
75f173e5 |
136 | } |
0ac992ee |
137 | |
75f173e5 |
138 | sub _inline_constructor { |
139 | my ( $self, $metaclass, $options ) = @_; |
140 | |
141 | return unless $options->{inline_constructor}; |
142 | |
2690a5c0 |
143 | return |
144 | unless $options->{replace_constructor} |
145 | or !$metaclass->has_method( $options->{constructor_name} ); |
146 | |
75f173e5 |
147 | my $constructor_class = $options->{constructor_class} |
148 | || 'Class::MOP::Method::Constructor'; |
2690a5c0 |
149 | |
75f173e5 |
150 | $metaclass->add_method( |
151 | $options->{constructor_name}, |
152 | $constructor_class->new( |
153 | options => $options, |
154 | metaclass => $metaclass, |
155 | is_inline => 1, |
156 | package_name => $metaclass->name, |
157 | name => $options->{constructor_name} |
158 | ) |
2690a5c0 |
159 | ); |
160 | |
75f173e5 |
161 | } |
162 | |
163 | sub _inline_destructor { |
164 | my ( $self, $metaclass, $options ) = @_; |
165 | |
166 | return unless $options->{inline_destructor}; |
167 | |
168 | ( exists $options->{destructor_class} ) |
169 | || confess "The 'inline_destructor' option is present, but " |
170 | . "no destructor class was specified"; |
171 | |
172 | my $destructor_class = $options->{destructor_class}; |
173 | |
2690a5c0 |
174 | return unless $destructor_class->is_needed($metaclass); |
75f173e5 |
175 | |
2690a5c0 |
176 | my $destructor = $destructor_class->new( |
177 | options => $options, |
178 | metaclass => $metaclass, |
179 | package_name => $metaclass->name, |
180 | name => 'DESTROY' |
181 | ); |
182 | |
183 | return unless $destructor->is_needed; |
184 | |
185 | $metaclass->add_method( 'DESTROY' => $destructor ) |
75f173e5 |
186 | } |
187 | |
188 | sub _memoize_methods { |
189 | my ( $self, $metaclass, $options ) = @_; |
0ac992ee |
190 | |
c23184fc |
191 | my $memoized_methods = $self->options->{memoize}; |
75f173e5 |
192 | foreach my $method_name ( keys %{$memoized_methods} ) { |
c23184fc |
193 | my $type = $memoized_methods->{$method_name}; |
0ac992ee |
194 | |
75f173e5 |
195 | ( $metaclass->can($method_name) ) |
196 | || confess "Could not find the method '$method_name' in " |
197 | . $metaclass->name; |
0ac992ee |
198 | } |
c23184fc |
199 | } |
200 | |
0ac992ee |
201 | sub make_metaclass_mutable { |
229910b5 |
202 | my ($self, $immutable, $options) = @_; |
203 | |
204 | my %options = %$options; |
0ac992ee |
205 | |
206 | my $original_class = $immutable->get_mutable_metaclass_name; |
207 | delete $immutable->{'___original_class'} ; |
208 | bless $immutable => $original_class; |
209 | |
210 | my $memoized_methods = $self->options->{memoize}; |
211 | foreach my $method_name (keys %{$memoized_methods}) { |
212 | my $type = $memoized_methods->{$method_name}; |
213 | |
214 | ($immutable->can($method_name)) |
215 | || confess "Could not find the method '$method_name' in " . $immutable->name; |
216 | if ($type eq 'SCALAR' || $type eq 'ARRAY' || $type eq 'HASH' ) { |
217 | delete $immutable->{'___' . $method_name}; |
218 | } |
219 | } |
220 | |
221 | if ($options{inline_destructor} && $immutable->has_method('DESTROY')) { |
222 | $immutable->remove_method('DESTROY') |
11b56828 |
223 | if blessed($immutable->get_method('DESTROY')) eq $options{destructor_class}; |
0ac992ee |
224 | } |
225 | |
b817e248 |
226 | # NOTE: |
227 | # 14:01 <@stevan> nah,. you shouldnt |
228 | # 14:01 <@stevan> they are just inlined |
229 | # 14:01 <@stevan> which is the default in Moose anyway |
230 | # 14:02 <@stevan> and adding new attributes will just DWIM |
231 | # 14:02 <@stevan> and you really cant change an attribute anyway |
232 | # if ($options{inline_accessors}) { |
233 | # foreach my $attr_name ($immutable->get_attribute_list) { |
234 | # my $attr = $immutable->get_attribute($attr_name); |
235 | # $attr->remove_accessors; |
236 | # $attr->install_accessors(0); |
237 | # } |
238 | # } |
239 | |
240 | # 14:26 <@stevan> the only user of ::Method::Constructor is immutable |
241 | # 14:27 <@stevan> if someone uses it outside of immutable,.. they are either: mst or groditi |
242 | # 14:27 <@stevan> so I am not worried |
11b56828 |
243 | if ($options{inline_constructor} && $immutable->has_method($options{constructor_name})) { |
0ac992ee |
244 | my $constructor_class = $options{constructor_class} || 'Class::MOP::Method::Constructor'; |
245 | $immutable->remove_method( $options{constructor_name} ) |
11b56828 |
246 | if blessed($immutable->get_method($options{constructor_name})) eq $constructor_class; |
0ac992ee |
247 | } |
248 | } |
249 | |
c23184fc |
250 | sub create_methods_for_immutable_metaclass { |
251 | my $self = shift; |
0ac992ee |
252 | |
c23184fc |
253 | my %methods = %DEFAULT_METHODS; |
41885bab |
254 | my $metaclass = $self->metaclass; |
255 | my $meta = $metaclass->meta; |
0ac992ee |
256 | |
c23184fc |
257 | foreach my $read_only_method (@{$self->options->{read_only}}) { |
41885bab |
258 | my $method = $meta->find_method_by_name($read_only_method); |
0ac992ee |
259 | |
c23184fc |
260 | (defined $method) |
41885bab |
261 | || confess "Could not find the method '$read_only_method' in " . $metaclass->name; |
0ac992ee |
262 | |
c23184fc |
263 | $methods{$read_only_method} = sub { |
264 | confess "This method is read-only" if scalar @_ > 1; |
265 | goto &{$method->body} |
266 | }; |
267 | } |
0ac992ee |
268 | |
c23184fc |
269 | foreach my $cannot_call_method (@{$self->options->{cannot_call}}) { |
270 | $methods{$cannot_call_method} = sub { |
271 | confess "This method ($cannot_call_method) cannot be called on an immutable instance"; |
272 | }; |
0ac992ee |
273 | } |
274 | |
c23184fc |
275 | my $memoized_methods = $self->options->{memoize}; |
c23184fc |
276 | foreach my $method_name (keys %{$memoized_methods}) { |
277 | my $type = $memoized_methods->{$method_name}; |
9ec62360 |
278 | my $key = '___' . $method_name; |
279 | my $method = $meta->find_method_by_name($method_name); |
280 | |
c23184fc |
281 | if ($type eq 'ARRAY') { |
9ec62360 |
282 | $methods{$method_name} = sub { |
283 | @{$_[0]->{$key}} = $method->execute($_[0]) |
284 | if !exists $_[0]->{$key}; |
285 | return @{$_[0]->{$key}}; |
286 | }; |
c23184fc |
287 | } |
288 | elsif ($type eq 'HASH') { |
9ec62360 |
289 | $methods{$method_name} = sub { |
290 | %{$_[0]->{$key}} = $method->execute($_[0]) |
291 | if !exists $_[0]->{$key}; |
292 | return %{$_[0]->{$key}}; |
293 | }; |
c23184fc |
294 | } |
295 | elsif ($type eq 'SCALAR') { |
9ec62360 |
296 | $methods{$method_name} = sub { |
297 | $_[0]->{$key} = $method->execute($_[0]) |
298 | if !exists $_[0]->{$key}; |
299 | return $_[0]->{$key}; |
300 | }; |
0ac992ee |
301 | } |
302 | } |
53299a7b |
303 | |
5f3efd66 |
304 | my $wrapped_methods = $self->options->{wrapped}; |
305 | |
306 | foreach my $method_name (keys %{ $wrapped_methods }) { |
41885bab |
307 | my $method = $meta->find_method_by_name($method_name); |
5f3efd66 |
308 | |
309 | (defined $method) |
41885bab |
310 | || confess "Could not find the method '$method_name' in " . $metaclass->name; |
5f3efd66 |
311 | |
312 | my $wrapper = $wrapped_methods->{$method_name}; |
313 | |
314 | $methods{$method_name} = sub { $wrapper->($method, @_) }; |
53299a7b |
315 | } |
0ac992ee |
316 | |
317 | $methods{get_mutable_metaclass_name} = sub { (shift)->{'___original_class'} }; |
318 | |
9f3ff885 |
319 | $methods{immutable_transformer} = sub { $self }; |
320 | |
c23184fc |
321 | return \%methods; |
322 | } |
323 | |
324 | 1; |
325 | |
326 | __END__ |
327 | |
328 | =pod |
329 | |
0ac992ee |
330 | =head1 NAME |
c23184fc |
331 | |
332 | Class::MOP::Immutable - A class to transform Class::MOP::Class metaclasses |
333 | |
334 | =head1 SYNOPSIS |
335 | |
96e38ba6 |
336 | use Class::MOP::Immutable; |
0ac992ee |
337 | |
96e38ba6 |
338 | my $immutable_metaclass = Class::MOP::Immutable->new($metaclass, { |
339 | read_only => [qw/superclasses/], |
340 | cannot_call => [qw/ |
341 | add_method |
342 | alias_method |
343 | remove_method |
344 | add_attribute |
345 | remove_attribute |
346 | add_package_symbol |
0ac992ee |
347 | remove_package_symbol |
96e38ba6 |
348 | /], |
349 | memoize => { |
350 | class_precedence_list => 'ARRAY', |
0ac992ee |
351 | compute_all_applicable_attributes => 'ARRAY', |
352 | get_meta_instance => 'SCALAR', |
353 | get_method_map => 'SCALAR', |
96e38ba6 |
354 | } |
0ac992ee |
355 | }); |
96e38ba6 |
356 | |
357 | $immutable_metaclass->make_metaclass_immutable(@_) |
358 | |
c23184fc |
359 | =head1 DESCRIPTION |
360 | |
0ac992ee |
361 | This is basically a module for applying a transformation on a given |
362 | metaclass. Current features include making methods read-only, |
96e38ba6 |
363 | making methods un-callable and memoizing methods (in a type specific |
0ac992ee |
364 | way too). |
96e38ba6 |
365 | |
127d39a7 |
366 | This module is not for the feint of heart, it does some whacky things |
367 | to the metaclass in order to make it immutable. If you are just curious, |
368 | I suggest you turn back now, there is nothing to see here. |
96e38ba6 |
369 | |
c23184fc |
370 | =head1 METHODS |
371 | |
372 | =over 4 |
373 | |
96e38ba6 |
374 | =item B<new ($metaclass, \%options)> |
375 | |
0ac992ee |
376 | Given a C<$metaclass> and a set of C<%options> this module will |
377 | prepare an immutable version of the C<$metaclass>, which can then |
378 | be applied to the C<$metaclass> using the C<make_metaclass_immutable> |
96e38ba6 |
379 | method. |
380 | |
c23184fc |
381 | =item B<options> |
382 | |
96e38ba6 |
383 | Returns the options HASH set in C<new>. |
384 | |
c23184fc |
385 | =item B<metaclass> |
386 | |
96e38ba6 |
387 | Returns the metaclass set in C<new>. |
388 | |
c23184fc |
389 | =item B<immutable_metaclass> |
390 | |
96e38ba6 |
391 | Returns the immutable metaclass created within C<new>. |
392 | |
c23184fc |
393 | =back |
394 | |
395 | =over 4 |
396 | |
397 | =item B<create_immutable_metaclass> |
398 | |
0ac992ee |
399 | This will create the immutable version of the C<$metaclass>, but will |
400 | not actually change the original metaclass. |
96e38ba6 |
401 | |
c23184fc |
402 | =item B<create_methods_for_immutable_metaclass> |
403 | |
0ac992ee |
404 | This will create all the methods for the immutable metaclass based |
96e38ba6 |
405 | on the C<%options> passed into C<new>. |
406 | |
0ac992ee |
407 | =item B<make_metaclass_immutable (%options)> |
c23184fc |
408 | |
96e38ba6 |
409 | This will actually change the C<$metaclass> into the immutable version. |
410 | |
0ac992ee |
411 | =item B<make_metaclass_mutable (%options)> |
412 | |
413 | This will change the C<$metaclass> into the mutable version by reversing |
414 | the immutable process. C<%options> should be the same options that were |
415 | given to make_metaclass_immutable. |
416 | |
c23184fc |
417 | =back |
418 | |
419 | =head1 AUTHORS |
420 | |
421 | Stevan Little E<lt>stevan@iinteractive.comE<gt> |
422 | |
423 | =head1 COPYRIGHT AND LICENSE |
424 | |
69e3ab0a |
425 | Copyright 2006-2008 by Infinity Interactive, Inc. |
c23184fc |
426 | |
427 | L<http://www.iinteractive.com> |
428 | |
429 | This library is free software; you can redistribute it and/or modify |
0ac992ee |
430 | it under the same terms as Perl itself. |
c23184fc |
431 | |
432 | =cut |