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 | |
eca95e04 |
12 | our $VERSION = '0.78'; |
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 | |
44d6ea77 |
21 | unshift @args, 'metaclass' if @args % 2 == 1; |
22 | |
23 | my %options = ( |
24 | inline_accessors => 1, |
25 | inline_constructor => 1, |
26 | inline_destructor => 0, |
27 | constructor_name => 'new', |
28 | constructor_class => 'Class::MOP::Method::Constructor', |
29 | debug => 0, |
30 | @args, |
31 | ); |
1ae8e211 |
32 | |
0bfc85b8 |
33 | my $self = $class->_new( |
44d6ea77 |
34 | 'metaclass' => delete $options{metaclass}, |
35 | 'options' => \%options, |
8683db0e |
36 | 'immutable_metaclass' => undef, |
ec845081 |
37 | 'inlined_constructor' => undef, |
0bfc85b8 |
38 | ); |
0ac992ee |
39 | |
c23184fc |
40 | return $self; |
41 | } |
42 | |
0bfc85b8 |
43 | sub _new { |
44 | my $class = shift; |
45 | my $options = @_ == 1 ? $_[0] : {@_}; |
46 | |
47 | bless $options, $class; |
48 | } |
49 | |
76c20e30 |
50 | sub immutable_metaclass { |
51 | my $self = shift; |
52 | |
44d6ea77 |
53 | return $self->{'immutable_metaclass'} ||= $self->_create_immutable_metaclass; |
76c20e30 |
54 | } |
55 | |
8683db0e |
56 | sub metaclass { (shift)->{'metaclass'} } |
57 | sub options { (shift)->{'options'} } |
c1809cb1 |
58 | sub inlined_constructor { (shift)->{'inlined_constructor'} } |
c23184fc |
59 | |
44d6ea77 |
60 | sub _create_immutable_metaclass { |
c23184fc |
61 | my $self = shift; |
62 | |
44d6ea77 |
63 | # NOTE: The immutable version of the metaclass is just a |
64 | # anon-class which shadows the methods appropriately |
65 | return Class::MOP::Class->create_anon_class( |
c23184fc |
66 | superclasses => [ blessed($self->metaclass) ], |
44d6ea77 |
67 | methods => $self->_create_methods_for_immutable_metaclass, |
0ac992ee |
68 | ); |
c23184fc |
69 | } |
70 | |
c23184fc |
71 | sub make_metaclass_immutable { |
44d6ea77 |
72 | my $self = shift; |
1a84e3f3 |
73 | |
44d6ea77 |
74 | $self->_inline_accessors; |
75 | $self->_inline_constructor; |
76 | $self->_inline_destructor; |
77 | $self->_check_memoized_methods; |
0ac992ee |
78 | |
44d6ea77 |
79 | my $metaclass = $self->metaclass; |
75f173e5 |
80 | |
81 | $metaclass->{'___original_class'} = blessed($metaclass); |
82 | bless $metaclass => $self->immutable_metaclass->name; |
83 | } |
c23184fc |
84 | |
75f173e5 |
85 | sub _inline_accessors { |
44d6ea77 |
86 | my $self = shift; |
75f173e5 |
87 | |
44d6ea77 |
88 | return unless $self->options->{inline_accessors}; |
75f173e5 |
89 | |
44d6ea77 |
90 | foreach my $attr_name ( $self->metaclass->get_attribute_list ) { |
91 | $self->metaclass->get_attribute($attr_name)->install_accessors(1); |
0ac992ee |
92 | } |
75f173e5 |
93 | } |
0ac992ee |
94 | |
75f173e5 |
95 | sub _inline_constructor { |
44d6ea77 |
96 | my $self = shift; |
75f173e5 |
97 | |
44d6ea77 |
98 | return unless $self->options->{inline_constructor}; |
75f173e5 |
99 | |
2690a5c0 |
100 | return |
44d6ea77 |
101 | unless $self->options->{replace_constructor} |
102 | or !$self->metaclass->has_method( |
103 | $self->options->{constructor_name} |
104 | ); |
2690a5c0 |
105 | |
44d6ea77 |
106 | my $constructor_class = $self->options->{constructor_class}; |
2690a5c0 |
107 | |
f0de47d9 |
108 | my $constructor = $constructor_class->new( |
44d6ea77 |
109 | options => $self->options, |
110 | metaclass => $self->metaclass, |
f0de47d9 |
111 | is_inline => 1, |
44d6ea77 |
112 | package_name => $self->metaclass->name, |
113 | name => $self->options->{constructor_name}, |
2690a5c0 |
114 | ); |
115 | |
44d6ea77 |
116 | if ( $self->options->{replace_constructor} |
117 | or $constructor->can_be_inlined ) { |
118 | $self->metaclass->add_method( |
119 | $self->options->{constructor_name} => $constructor ); |
ec845081 |
120 | $self->{inlined_constructor} = $constructor; |
c1809cb1 |
121 | } |
75f173e5 |
122 | } |
123 | |
124 | sub _inline_destructor { |
44d6ea77 |
125 | my $self = shift; |
75f173e5 |
126 | |
44d6ea77 |
127 | return unless $self->options->{inline_destructor}; |
75f173e5 |
128 | |
44d6ea77 |
129 | ( exists $self->options->{destructor_class} ) |
75f173e5 |
130 | || confess "The 'inline_destructor' option is present, but " |
131 | . "no destructor class was specified"; |
132 | |
44d6ea77 |
133 | my $destructor_class = $self->options->{destructor_class}; |
75f173e5 |
134 | |
44d6ea77 |
135 | return unless $destructor_class->is_needed( $self->metaclass ); |
75f173e5 |
136 | |
2690a5c0 |
137 | my $destructor = $destructor_class->new( |
44d6ea77 |
138 | options => $self->options, |
139 | metaclass => $self->metaclass, |
140 | package_name => $self->metaclass->name, |
2690a5c0 |
141 | name => 'DESTROY' |
142 | ); |
143 | |
144 | return unless $destructor->is_needed; |
145 | |
44d6ea77 |
146 | $self->metaclass->add_method( 'DESTROY' => $destructor ); |
75f173e5 |
147 | } |
148 | |
bc79f8a3 |
149 | sub _check_memoized_methods { |
44d6ea77 |
150 | my $self = shift; |
0ac992ee |
151 | |
c23184fc |
152 | my $memoized_methods = $self->options->{memoize}; |
75f173e5 |
153 | foreach my $method_name ( keys %{$memoized_methods} ) { |
c23184fc |
154 | my $type = $memoized_methods->{$method_name}; |
0ac992ee |
155 | |
44d6ea77 |
156 | ( $self->metaclass->can($method_name) ) |
75f173e5 |
157 | || confess "Could not find the method '$method_name' in " |
44d6ea77 |
158 | . $self->metaclass->name; |
0ac992ee |
159 | } |
c23184fc |
160 | } |
44d6ea77 |
161 | my %DEFAULT_METHODS = ( |
162 | # I don't really understand this, but removing it breaks tests (groditi) |
163 | meta => sub { |
164 | my $self = shift; |
165 | # if it is not blessed, then someone is asking |
166 | # for the meta of Class::MOP::Immutable |
167 | return Class::MOP::Class->initialize($self) unless blessed($self); |
168 | # otherwise, they are asking for the metaclass |
169 | # which has been made immutable, which is itself |
170 | # except in the cases where it is a metaclass itself |
171 | # that has been made immutable and for that we need |
172 | # to dig a bit ... |
173 | if ($self->isa('Class::MOP::Class')) { |
174 | return $self->{'___original_class'}->meta; |
175 | } |
176 | else { |
177 | return $self; |
178 | } |
179 | }, |
180 | is_mutable => sub { 0 }, |
181 | is_immutable => sub { 1 }, |
182 | make_immutable => sub { () }, |
183 | ); |
c23184fc |
184 | |
44d6ea77 |
185 | sub _create_methods_for_immutable_metaclass { |
fd93a7b6 |
186 | my $self = shift; |
187 | |
fd93a7b6 |
188 | my $metaclass = $self->metaclass; |
189 | my $meta = $metaclass->meta; |
190 | |
fd93a7b6 |
191 | return { |
192 | %DEFAULT_METHODS, |
44d6ea77 |
193 | $self->_make_read_only_methods, |
194 | $self->_make_uncallable_methods, |
195 | $self->_make_memoized_methods, |
196 | $self->_make_wrapped_methods, |
fd93a7b6 |
197 | get_mutable_metaclass_name => sub { (shift)->{'___original_class'} }, |
198 | immutable_transformer => sub {$self}, |
199 | }; |
200 | } |
201 | |
202 | sub _make_read_only_methods { |
44d6ea77 |
203 | my $self = shift; |
204 | |
205 | my $metameta = $self->metaclass->meta; |
fd93a7b6 |
206 | |
207 | my %methods; |
208 | foreach my $read_only_method ( @{ $self->options->{read_only} } ) { |
44d6ea77 |
209 | my $method = $metameta->find_method_by_name($read_only_method); |
fd93a7b6 |
210 | |
211 | ( defined $method ) |
212 | || confess "Could not find the method '$read_only_method' in " |
44d6ea77 |
213 | . $self->metaclass->name; |
fd93a7b6 |
214 | |
215 | $methods{$read_only_method} = sub { |
216 | confess "This method is read-only" if scalar @_ > 1; |
217 | goto &{ $method->body }; |
218 | }; |
219 | } |
220 | |
221 | return %methods; |
222 | } |
223 | |
224 | sub _make_uncallable_methods { |
44d6ea77 |
225 | my $self = shift; |
fd93a7b6 |
226 | |
227 | my %methods; |
228 | foreach my $cannot_call_method ( @{ $self->options->{cannot_call} } ) { |
229 | $methods{$cannot_call_method} = sub { |
230 | confess |
231 | "This method ($cannot_call_method) cannot be called on an immutable instance"; |
232 | }; |
233 | } |
234 | |
235 | return %methods; |
236 | } |
237 | |
238 | sub _make_memoized_methods { |
44d6ea77 |
239 | my $self = shift; |
fd93a7b6 |
240 | |
241 | my %methods; |
242 | |
44d6ea77 |
243 | my $metameta = $self->metaclass->meta; |
244 | |
fd93a7b6 |
245 | my $memoized_methods = $self->options->{memoize}; |
246 | foreach my $method_name ( keys %{$memoized_methods} ) { |
247 | my $type = $memoized_methods->{$method_name}; |
248 | my $key = '___' . $method_name; |
44d6ea77 |
249 | my $method = $metameta->find_method_by_name($method_name); |
fd93a7b6 |
250 | |
251 | if ( $type eq 'ARRAY' ) { |
252 | $methods{$method_name} = sub { |
253 | @{ $_[0]->{$key} } = $method->execute( $_[0] ) |
254 | if !exists $_[0]->{$key}; |
255 | return @{ $_[0]->{$key} }; |
256 | }; |
257 | } |
258 | elsif ( $type eq 'HASH' ) { |
259 | $methods{$method_name} = sub { |
260 | %{ $_[0]->{$key} } = $method->execute( $_[0] ) |
261 | if !exists $_[0]->{$key}; |
262 | return %{ $_[0]->{$key} }; |
263 | }; |
264 | } |
265 | elsif ( $type eq 'SCALAR' ) { |
266 | $methods{$method_name} = sub { |
267 | $_[0]->{$key} = $method->execute( $_[0] ) |
268 | if !exists $_[0]->{$key}; |
269 | return $_[0]->{$key}; |
270 | }; |
271 | } |
272 | } |
273 | |
274 | return %methods; |
275 | } |
276 | |
277 | sub _make_wrapped_methods { |
44d6ea77 |
278 | my $self = shift; |
fd93a7b6 |
279 | |
280 | my %methods; |
281 | |
282 | my $wrapped_methods = $self->options->{wrapped}; |
283 | |
44d6ea77 |
284 | my $metameta = $self->metaclass->meta; |
285 | |
fd93a7b6 |
286 | foreach my $method_name ( keys %{$wrapped_methods} ) { |
44d6ea77 |
287 | my $method = $metameta->find_method_by_name($method_name); |
fd93a7b6 |
288 | |
289 | ( defined $method ) |
290 | || confess "Could not find the method '$method_name' in " |
44d6ea77 |
291 | . $self->metaclass->name; |
fd93a7b6 |
292 | |
293 | my $wrapper = $wrapped_methods->{$method_name}; |
294 | |
295 | $methods{$method_name} = sub { $wrapper->( $method, @_ ) }; |
296 | } |
297 | |
298 | return %methods; |
299 | } |
300 | |
0ac992ee |
301 | sub make_metaclass_mutable { |
44d6ea77 |
302 | my $self = shift; |
229910b5 |
303 | |
44d6ea77 |
304 | my $metaclass = $self->metaclass; |
0ac992ee |
305 | |
44d6ea77 |
306 | my $original_class = $metaclass->get_mutable_metaclass_name; |
307 | delete $metaclass->{'___original_class'}; |
308 | bless $metaclass => $original_class; |
0ac992ee |
309 | |
310 | my $memoized_methods = $self->options->{memoize}; |
44d6ea77 |
311 | foreach my $method_name ( keys %{$memoized_methods} ) { |
0ac992ee |
312 | my $type = $memoized_methods->{$method_name}; |
313 | |
44d6ea77 |
314 | ( $metaclass->can($method_name) ) |
315 | || confess "Could not find the method '$method_name' in " |
316 | . $metaclass->name; |
317 | if ( $type eq 'SCALAR' || $type eq 'ARRAY' || $type eq 'HASH' ) { |
318 | delete $metaclass->{ '___' . $method_name }; |
0ac992ee |
319 | } |
320 | } |
321 | |
44d6ea77 |
322 | if ( $self->options->{inline_destructor} |
323 | && $metaclass->has_method('DESTROY') ) { |
324 | $metaclass->remove_method('DESTROY') |
325 | if blessed( $metaclass->get_method('DESTROY') ) eq |
326 | $self->options->{destructor_class}; |
0ac992ee |
327 | } |
328 | |
b817e248 |
329 | # NOTE: |
330 | # 14:01 <@stevan> nah,. you shouldnt |
331 | # 14:01 <@stevan> they are just inlined |
332 | # 14:01 <@stevan> which is the default in Moose anyway |
333 | # 14:02 <@stevan> and adding new attributes will just DWIM |
334 | # 14:02 <@stevan> and you really cant change an attribute anyway |
335 | # if ($options{inline_accessors}) { |
336 | # foreach my $attr_name ($immutable->get_attribute_list) { |
337 | # my $attr = $immutable->get_attribute($attr_name); |
338 | # $attr->remove_accessors; |
339 | # $attr->install_accessors(0); |
340 | # } |
341 | # } |
342 | |
343 | # 14:26 <@stevan> the only user of ::Method::Constructor is immutable |
344 | # 14:27 <@stevan> if someone uses it outside of immutable,.. they are either: mst or groditi |
345 | # 14:27 <@stevan> so I am not worried |
44d6ea77 |
346 | if ( $self->options->{inline_constructor} |
347 | && $metaclass->has_method( $self->options->{constructor_name} ) ) { |
348 | my $constructor_class = $self->options->{constructor_class} |
349 | || 'Class::MOP::Method::Constructor'; |
350 | |
351 | if ( |
352 | blessed( |
353 | $metaclass->get_method( $self->options->{constructor_name} ) |
354 | ) eq $constructor_class |
355 | ) { |
356 | $metaclass->remove_method( $self->options->{constructor_name} ); |
ec845081 |
357 | $self->{inlined_constructor} = undef; |
c1809cb1 |
358 | } |
0ac992ee |
359 | } |
360 | } |
361 | |
c23184fc |
362 | 1; |
363 | |
364 | __END__ |
365 | |
366 | =pod |
367 | |
0ac992ee |
368 | =head1 NAME |
c23184fc |
369 | |
370 | Class::MOP::Immutable - A class to transform Class::MOP::Class metaclasses |
371 | |
372 | =head1 SYNOPSIS |
373 | |
96e38ba6 |
374 | use Class::MOP::Immutable; |
0ac992ee |
375 | |
96e38ba6 |
376 | my $immutable_metaclass = Class::MOP::Immutable->new($metaclass, { |
377 | read_only => [qw/superclasses/], |
378 | cannot_call => [qw/ |
379 | add_method |
380 | alias_method |
381 | remove_method |
382 | add_attribute |
383 | remove_attribute |
384 | add_package_symbol |
0ac992ee |
385 | remove_package_symbol |
96e38ba6 |
386 | /], |
387 | memoize => { |
388 | class_precedence_list => 'ARRAY', |
0ac992ee |
389 | compute_all_applicable_attributes => 'ARRAY', |
390 | get_meta_instance => 'SCALAR', |
391 | get_method_map => 'SCALAR', |
96e38ba6 |
392 | } |
0ac992ee |
393 | }); |
96e38ba6 |
394 | |
44d6ea77 |
395 | $immutable_metaclass->make_metaclass_immutable; |
96e38ba6 |
396 | |
c23184fc |
397 | =head1 DESCRIPTION |
398 | |
1407d471 |
399 | This class encapsulates the logic behind immutabilization. |
96e38ba6 |
400 | |
1407d471 |
401 | This class provides generic immutabilization logic. Decisions about |
402 | I<what> gets transformed are up to the caller. |
403 | |
404 | Immutabilization allows for a number of transformations. It can ask |
405 | the calling metaclass to inline methods such as the constructor, |
406 | destructor, or accessors. It can memoize metaclass accessors |
407 | themselves. It can also turn read-write accessors in the metaclass |
408 | into read-only methods, and make attempting to set these values an |
409 | error. Finally, it can make some methods throw an exception when they |
410 | are called. This is used to disable methods that can alter the class. |
96e38ba6 |
411 | |
c23184fc |
412 | =head1 METHODS |
413 | |
414 | =over 4 |
415 | |
1407d471 |
416 | =item B<< Class::MOP::Immutable->new($metaclass, %options) >> |
96e38ba6 |
417 | |
1407d471 |
418 | This method takes a metaclass object (typically a L<Class::MOP::Class> |
419 | object) and a hash of options. |
96e38ba6 |
420 | |
1407d471 |
421 | It returns a new transformer, but does not actually do any |
422 | transforming yet. |
c23184fc |
423 | |
1407d471 |
424 | This method accepts the following options: |
96e38ba6 |
425 | |
1407d471 |
426 | =over 8 |
c23184fc |
427 | |
1407d471 |
428 | =item * inline_accessors |
96e38ba6 |
429 | |
1407d471 |
430 | =item * inline_constructor |
c23184fc |
431 | |
1407d471 |
432 | =item * inline_destructor |
96e38ba6 |
433 | |
1407d471 |
434 | These are all booleans indicating whether the specified method(s) |
435 | should be inlined. |
c23184fc |
436 | |
1407d471 |
437 | By default, accessors and the constructor are inlined, but not the |
438 | destructor. |
439 | |
440 | =item * replace_constructor |
441 | |
442 | This is a boolean indicating whether an existing constructor should be |
443 | replaced when inlining a constructor. This defaults to false. |
444 | |
445 | =item * constructor_name |
446 | |
447 | This is the constructor method name. This defaults to "new". |
448 | |
449 | =item * constructor_class |
450 | |
451 | The name of the method metaclass for constructors. It will be used to |
452 | generate the inlined constructor. This defaults to |
453 | "Class::MOP::Method::Constructor". |
454 | |
455 | =item * destructor_class |
c23184fc |
456 | |
1407d471 |
457 | The name of the method metaclass for destructors. It will be used to |
458 | generate the inlined destructor. This defaults to |
459 | "Class::MOP::Method::Denstructor". |
c23184fc |
460 | |
1407d471 |
461 | =item * memoize |
462 | |
463 | This option takes a hash reference. They keys are method names to be |
464 | memoized, and the values are the type of data the method returns. This |
465 | can be one of "SCALAR", "ARRAY", or "HASH". |
466 | |
467 | =item * read_only |
468 | |
469 | This option takes an array reference of read-write methods which will |
470 | be made read-only. After they are transformed, attempting to set them |
471 | will throw an error. |
472 | |
473 | =item * cannot_call |
474 | |
475 | This option takes an array reference of methods which cannot be called |
476 | after immutabilization. Attempting to call these methods will throw an |
477 | error. |
478 | |
479 | =item * wrapped |
480 | |
481 | This option takes a hash reference. The keys are method names and the |
482 | body is a subroutine reference which will wrap the named method. This |
483 | allows you to do some sort of custom transformation to a method. |
484 | |
485 | =back |
96e38ba6 |
486 | |
1407d471 |
487 | =item B<< $transformer->options >> |
c23184fc |
488 | |
1407d471 |
489 | Returns a hash reference of the options passed to C<new>. |
96e38ba6 |
490 | |
1407d471 |
491 | =item B<< $transformer->metaclass >> |
c23184fc |
492 | |
1407d471 |
493 | Returns the metaclass object passed to C<new>. |
96e38ba6 |
494 | |
1407d471 |
495 | =item B<< $transformer->immutable_metaclass >> |
0ac992ee |
496 | |
1407d471 |
497 | Returns the immutable metaclass object that is created by the |
498 | transformation process. |
0ac992ee |
499 | |
1407d471 |
500 | =item B<< $transformer->inlined_constructor >> |
c1809cb1 |
501 | |
ec845081 |
502 | If the constructor was inlined, this returns the constructor method |
503 | object that was created to do this. |
504 | |
c23184fc |
505 | =back |
506 | |
507 | =head1 AUTHORS |
508 | |
509 | Stevan Little E<lt>stevan@iinteractive.comE<gt> |
510 | |
511 | =head1 COPYRIGHT AND LICENSE |
512 | |
070bb6c9 |
513 | Copyright 2006-2009 by Infinity Interactive, Inc. |
c23184fc |
514 | |
515 | L<http://www.iinteractive.com> |
516 | |
517 | This library is free software; you can redistribute it and/or modify |
0ac992ee |
518 | it under the same terms as Perl itself. |
c23184fc |
519 | |
520 | =cut |