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 | |
b4bd10ec |
12 | our $VERSION = '0.77'; |
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, |
ec845081 |
39 | 'inlined_constructor' => undef, |
0bfc85b8 |
40 | ); |
0ac992ee |
41 | |
c23184fc |
42 | return $self; |
43 | } |
44 | |
0bfc85b8 |
45 | sub _new { |
46 | my $class = shift; |
47 | my $options = @_ == 1 ? $_[0] : {@_}; |
48 | |
49 | bless $options, $class; |
50 | } |
51 | |
76c20e30 |
52 | sub immutable_metaclass { |
53 | my $self = shift; |
54 | |
55 | $self->create_immutable_metaclass unless $self->{'immutable_metaclass'}; |
56 | |
57 | return $self->{'immutable_metaclass'}; |
58 | } |
59 | |
8683db0e |
60 | sub metaclass { (shift)->{'metaclass'} } |
61 | sub options { (shift)->{'options'} } |
c1809cb1 |
62 | sub inlined_constructor { (shift)->{'inlined_constructor'} } |
c23184fc |
63 | |
64 | sub create_immutable_metaclass { |
65 | my $self = shift; |
66 | |
67 | # NOTE: |
0ac992ee |
68 | # The immutable version of the |
c23184fc |
69 | # metaclass is just a anon-class |
0ac992ee |
70 | # which shadows the methods |
c23184fc |
71 | # appropriately |
8683db0e |
72 | $self->{'immutable_metaclass'} = Class::MOP::Class->create_anon_class( |
c23184fc |
73 | superclasses => [ blessed($self->metaclass) ], |
74 | methods => $self->create_methods_for_immutable_metaclass, |
0ac992ee |
75 | ); |
c23184fc |
76 | } |
77 | |
d9586da2 |
78 | |
c23184fc |
79 | my %DEFAULT_METHODS = ( |
d9586da2 |
80 | # I don't really understand this, but removing it breaks tests (groditi) |
0ac992ee |
81 | meta => sub { |
c23184fc |
82 | my $self = shift; |
0ac992ee |
83 | # if it is not blessed, then someone is asking |
127d39a7 |
84 | # for the meta of Class::MOP::Immutable |
c23184fc |
85 | return Class::MOP::Class->initialize($self) unless blessed($self); |
0ac992ee |
86 | # otherwise, they are asking for the metaclass |
c23184fc |
87 | # which has been made immutable, which is itself |
84bc89b3 |
88 | # except in the cases where it is a metaclass itself |
89 | # that has been made immutable and for that we need |
90 | # to dig a bit ... |
91 | if ($self->isa('Class::MOP::Class')) { |
92 | return $self->{'___original_class'}->meta; |
93 | } |
94 | else { |
95 | return $self; |
96 | } |
c23184fc |
97 | }, |
d9586da2 |
98 | is_mutable => sub { 0 }, |
99 | is_immutable => sub { 1 }, |
100 | make_immutable => sub { () }, |
c23184fc |
101 | ); |
102 | |
103 | # NOTE: |
0ac992ee |
104 | # this will actually convert the |
105 | # existing metaclass to an immutable |
c23184fc |
106 | # version of itself |
107 | sub make_metaclass_immutable { |
229910b5 |
108 | my ($self, $metaclass, $options) = @_; |
109 | |
1a84e3f3 |
110 | my %options = ( |
111 | inline_accessors => 1, |
112 | inline_constructor => 1, |
113 | inline_destructor => 0, |
114 | constructor_name => 'new', |
115 | debug => 0, |
116 | %$options, |
117 | ); |
118 | |
119 | %$options = %options; # FIXME who the hell is relying on this?!? tests fail =( |
0ac992ee |
120 | |
75f173e5 |
121 | $self->_inline_accessors( $metaclass, \%options ); |
122 | $self->_inline_constructor( $metaclass, \%options ); |
123 | $self->_inline_destructor( $metaclass, \%options ); |
bc79f8a3 |
124 | $self->_check_memoized_methods( $metaclass, \%options ); |
75f173e5 |
125 | |
126 | $metaclass->{'___original_class'} = blessed($metaclass); |
127 | bless $metaclass => $self->immutable_metaclass->name; |
128 | } |
c23184fc |
129 | |
75f173e5 |
130 | sub _inline_accessors { |
131 | my ( $self, $metaclass, $options ) = @_; |
132 | |
133 | return unless $options->{inline_accessors}; |
134 | |
135 | foreach my $attr_name ( $metaclass->get_attribute_list ) { |
136 | $metaclass->get_attribute($attr_name)->install_accessors(1); |
0ac992ee |
137 | } |
75f173e5 |
138 | } |
0ac992ee |
139 | |
75f173e5 |
140 | sub _inline_constructor { |
141 | my ( $self, $metaclass, $options ) = @_; |
142 | |
143 | return unless $options->{inline_constructor}; |
144 | |
2690a5c0 |
145 | return |
146 | unless $options->{replace_constructor} |
147 | or !$metaclass->has_method( $options->{constructor_name} ); |
148 | |
75f173e5 |
149 | my $constructor_class = $options->{constructor_class} |
150 | || 'Class::MOP::Method::Constructor'; |
2690a5c0 |
151 | |
f0de47d9 |
152 | my $constructor = $constructor_class->new( |
153 | options => $options, |
154 | metaclass => $metaclass, |
155 | is_inline => 1, |
156 | package_name => $metaclass->name, |
157 | name => $options->{constructor_name}, |
2690a5c0 |
158 | ); |
159 | |
c1809cb1 |
160 | if ( $options->{replace_constructor} or $constructor->can_be_inlined ) { |
161 | $metaclass->add_method( $options->{constructor_name} => $constructor ); |
ec845081 |
162 | $self->{inlined_constructor} = $constructor; |
c1809cb1 |
163 | } |
75f173e5 |
164 | } |
165 | |
166 | sub _inline_destructor { |
167 | my ( $self, $metaclass, $options ) = @_; |
168 | |
169 | return unless $options->{inline_destructor}; |
170 | |
171 | ( exists $options->{destructor_class} ) |
172 | || confess "The 'inline_destructor' option is present, but " |
173 | . "no destructor class was specified"; |
174 | |
175 | my $destructor_class = $options->{destructor_class}; |
176 | |
2690a5c0 |
177 | return unless $destructor_class->is_needed($metaclass); |
75f173e5 |
178 | |
2690a5c0 |
179 | my $destructor = $destructor_class->new( |
180 | options => $options, |
181 | metaclass => $metaclass, |
182 | package_name => $metaclass->name, |
183 | name => 'DESTROY' |
184 | ); |
185 | |
186 | return unless $destructor->is_needed; |
187 | |
188 | $metaclass->add_method( 'DESTROY' => $destructor ) |
75f173e5 |
189 | } |
190 | |
bc79f8a3 |
191 | sub _check_memoized_methods { |
75f173e5 |
192 | my ( $self, $metaclass, $options ) = @_; |
0ac992ee |
193 | |
c23184fc |
194 | my $memoized_methods = $self->options->{memoize}; |
75f173e5 |
195 | foreach my $method_name ( keys %{$memoized_methods} ) { |
c23184fc |
196 | my $type = $memoized_methods->{$method_name}; |
0ac992ee |
197 | |
75f173e5 |
198 | ( $metaclass->can($method_name) ) |
199 | || confess "Could not find the method '$method_name' in " |
200 | . $metaclass->name; |
0ac992ee |
201 | } |
c23184fc |
202 | } |
203 | |
fd93a7b6 |
204 | sub create_methods_for_immutable_metaclass { |
205 | my $self = shift; |
206 | |
207 | my %methods = %DEFAULT_METHODS; |
208 | my $metaclass = $self->metaclass; |
209 | my $meta = $metaclass->meta; |
210 | |
211 | $methods{get_mutable_metaclass_name} |
212 | = sub { (shift)->{'___original_class'} }; |
213 | |
214 | $methods{immutable_transformer} = sub {$self}; |
215 | |
216 | return { |
217 | %DEFAULT_METHODS, |
218 | $self->_make_read_only_methods( $metaclass, $meta ), |
219 | $self->_make_uncallable_methods( $metaclass, $meta ), |
220 | $self->_make_memoized_methods( $metaclass, $meta ), |
221 | $self->_make_wrapped_methods( $metaclass, $meta ), |
222 | get_mutable_metaclass_name => sub { (shift)->{'___original_class'} }, |
223 | immutable_transformer => sub {$self}, |
224 | }; |
225 | } |
226 | |
227 | sub _make_read_only_methods { |
228 | my ( $self, $metaclass, $meta ) = @_; |
229 | |
230 | my %methods; |
231 | foreach my $read_only_method ( @{ $self->options->{read_only} } ) { |
232 | my $method = $meta->find_method_by_name($read_only_method); |
233 | |
234 | ( defined $method ) |
235 | || confess "Could not find the method '$read_only_method' in " |
236 | . $metaclass->name; |
237 | |
238 | $methods{$read_only_method} = sub { |
239 | confess "This method is read-only" if scalar @_ > 1; |
240 | goto &{ $method->body }; |
241 | }; |
242 | } |
243 | |
244 | return %methods; |
245 | } |
246 | |
247 | sub _make_uncallable_methods { |
248 | my ( $self, $metaclass, $meta ) = @_; |
249 | |
250 | my %methods; |
251 | foreach my $cannot_call_method ( @{ $self->options->{cannot_call} } ) { |
252 | $methods{$cannot_call_method} = sub { |
253 | confess |
254 | "This method ($cannot_call_method) cannot be called on an immutable instance"; |
255 | }; |
256 | } |
257 | |
258 | return %methods; |
259 | } |
260 | |
261 | sub _make_memoized_methods { |
262 | my ( $self, $metaclass, $meta ) = @_; |
263 | |
264 | my %methods; |
265 | |
266 | my $memoized_methods = $self->options->{memoize}; |
267 | foreach my $method_name ( keys %{$memoized_methods} ) { |
268 | my $type = $memoized_methods->{$method_name}; |
269 | my $key = '___' . $method_name; |
270 | my $method = $meta->find_method_by_name($method_name); |
271 | |
272 | if ( $type eq 'ARRAY' ) { |
273 | $methods{$method_name} = sub { |
274 | @{ $_[0]->{$key} } = $method->execute( $_[0] ) |
275 | if !exists $_[0]->{$key}; |
276 | return @{ $_[0]->{$key} }; |
277 | }; |
278 | } |
279 | elsif ( $type eq 'HASH' ) { |
280 | $methods{$method_name} = sub { |
281 | %{ $_[0]->{$key} } = $method->execute( $_[0] ) |
282 | if !exists $_[0]->{$key}; |
283 | return %{ $_[0]->{$key} }; |
284 | }; |
285 | } |
286 | elsif ( $type eq 'SCALAR' ) { |
287 | $methods{$method_name} = sub { |
288 | $_[0]->{$key} = $method->execute( $_[0] ) |
289 | if !exists $_[0]->{$key}; |
290 | return $_[0]->{$key}; |
291 | }; |
292 | } |
293 | } |
294 | |
295 | return %methods; |
296 | } |
297 | |
298 | sub _make_wrapped_methods { |
299 | my ( $self, $metaclass, $meta ) = @_; |
300 | |
301 | my %methods; |
302 | |
303 | my $wrapped_methods = $self->options->{wrapped}; |
304 | |
305 | foreach my $method_name ( keys %{$wrapped_methods} ) { |
306 | my $method = $meta->find_method_by_name($method_name); |
307 | |
308 | ( defined $method ) |
309 | || confess "Could not find the method '$method_name' in " |
310 | . $metaclass->name; |
311 | |
312 | my $wrapper = $wrapped_methods->{$method_name}; |
313 | |
314 | $methods{$method_name} = sub { $wrapper->( $method, @_ ) }; |
315 | } |
316 | |
317 | return %methods; |
318 | } |
319 | |
0ac992ee |
320 | sub make_metaclass_mutable { |
229910b5 |
321 | my ($self, $immutable, $options) = @_; |
322 | |
323 | my %options = %$options; |
0ac992ee |
324 | |
325 | my $original_class = $immutable->get_mutable_metaclass_name; |
326 | delete $immutable->{'___original_class'} ; |
327 | bless $immutable => $original_class; |
328 | |
329 | my $memoized_methods = $self->options->{memoize}; |
330 | foreach my $method_name (keys %{$memoized_methods}) { |
331 | my $type = $memoized_methods->{$method_name}; |
332 | |
333 | ($immutable->can($method_name)) |
334 | || confess "Could not find the method '$method_name' in " . $immutable->name; |
335 | if ($type eq 'SCALAR' || $type eq 'ARRAY' || $type eq 'HASH' ) { |
336 | delete $immutable->{'___' . $method_name}; |
337 | } |
338 | } |
339 | |
340 | if ($options{inline_destructor} && $immutable->has_method('DESTROY')) { |
341 | $immutable->remove_method('DESTROY') |
11b56828 |
342 | if blessed($immutable->get_method('DESTROY')) eq $options{destructor_class}; |
0ac992ee |
343 | } |
344 | |
b817e248 |
345 | # NOTE: |
346 | # 14:01 <@stevan> nah,. you shouldnt |
347 | # 14:01 <@stevan> they are just inlined |
348 | # 14:01 <@stevan> which is the default in Moose anyway |
349 | # 14:02 <@stevan> and adding new attributes will just DWIM |
350 | # 14:02 <@stevan> and you really cant change an attribute anyway |
351 | # if ($options{inline_accessors}) { |
352 | # foreach my $attr_name ($immutable->get_attribute_list) { |
353 | # my $attr = $immutable->get_attribute($attr_name); |
354 | # $attr->remove_accessors; |
355 | # $attr->install_accessors(0); |
356 | # } |
357 | # } |
358 | |
359 | # 14:26 <@stevan> the only user of ::Method::Constructor is immutable |
360 | # 14:27 <@stevan> if someone uses it outside of immutable,.. they are either: mst or groditi |
361 | # 14:27 <@stevan> so I am not worried |
11b56828 |
362 | if ($options{inline_constructor} && $immutable->has_method($options{constructor_name})) { |
0ac992ee |
363 | my $constructor_class = $options{constructor_class} || 'Class::MOP::Method::Constructor'; |
c1809cb1 |
364 | |
365 | if ( blessed($immutable->get_method($options{constructor_name})) eq $constructor_class ) { |
366 | $immutable->remove_method( $options{constructor_name} ); |
ec845081 |
367 | $self->{inlined_constructor} = undef; |
c1809cb1 |
368 | } |
0ac992ee |
369 | } |
370 | } |
371 | |
c23184fc |
372 | 1; |
373 | |
374 | __END__ |
375 | |
376 | =pod |
377 | |
0ac992ee |
378 | =head1 NAME |
c23184fc |
379 | |
380 | Class::MOP::Immutable - A class to transform Class::MOP::Class metaclasses |
381 | |
382 | =head1 SYNOPSIS |
383 | |
96e38ba6 |
384 | use Class::MOP::Immutable; |
0ac992ee |
385 | |
96e38ba6 |
386 | my $immutable_metaclass = Class::MOP::Immutable->new($metaclass, { |
387 | read_only => [qw/superclasses/], |
388 | cannot_call => [qw/ |
389 | add_method |
390 | alias_method |
391 | remove_method |
392 | add_attribute |
393 | remove_attribute |
394 | add_package_symbol |
0ac992ee |
395 | remove_package_symbol |
96e38ba6 |
396 | /], |
397 | memoize => { |
398 | class_precedence_list => 'ARRAY', |
0ac992ee |
399 | compute_all_applicable_attributes => 'ARRAY', |
400 | get_meta_instance => 'SCALAR', |
401 | get_method_map => 'SCALAR', |
96e38ba6 |
402 | } |
0ac992ee |
403 | }); |
96e38ba6 |
404 | |
405 | $immutable_metaclass->make_metaclass_immutable(@_) |
406 | |
c23184fc |
407 | =head1 DESCRIPTION |
408 | |
0ac992ee |
409 | This is basically a module for applying a transformation on a given |
410 | metaclass. Current features include making methods read-only, |
96e38ba6 |
411 | making methods un-callable and memoizing methods (in a type specific |
0ac992ee |
412 | way too). |
96e38ba6 |
413 | |
127d39a7 |
414 | This module is not for the feint of heart, it does some whacky things |
415 | to the metaclass in order to make it immutable. If you are just curious, |
416 | I suggest you turn back now, there is nothing to see here. |
96e38ba6 |
417 | |
c23184fc |
418 | =head1 METHODS |
419 | |
420 | =over 4 |
421 | |
96e38ba6 |
422 | =item B<new ($metaclass, \%options)> |
423 | |
0ac992ee |
424 | Given a C<$metaclass> and a set of C<%options> this module will |
425 | prepare an immutable version of the C<$metaclass>, which can then |
426 | be applied to the C<$metaclass> using the C<make_metaclass_immutable> |
96e38ba6 |
427 | method. |
428 | |
c23184fc |
429 | =item B<options> |
430 | |
96e38ba6 |
431 | Returns the options HASH set in C<new>. |
432 | |
c23184fc |
433 | =item B<metaclass> |
434 | |
96e38ba6 |
435 | Returns the metaclass set in C<new>. |
436 | |
c23184fc |
437 | =item B<immutable_metaclass> |
438 | |
96e38ba6 |
439 | Returns the immutable metaclass created within C<new>. |
440 | |
c23184fc |
441 | =back |
442 | |
443 | =over 4 |
444 | |
445 | =item B<create_immutable_metaclass> |
446 | |
0ac992ee |
447 | This will create the immutable version of the C<$metaclass>, but will |
448 | not actually change the original metaclass. |
96e38ba6 |
449 | |
c23184fc |
450 | =item B<create_methods_for_immutable_metaclass> |
451 | |
0ac992ee |
452 | This will create all the methods for the immutable metaclass based |
96e38ba6 |
453 | on the C<%options> passed into C<new>. |
454 | |
0ac992ee |
455 | =item B<make_metaclass_immutable (%options)> |
c23184fc |
456 | |
96e38ba6 |
457 | This will actually change the C<$metaclass> into the immutable version. |
458 | |
0ac992ee |
459 | =item B<make_metaclass_mutable (%options)> |
460 | |
461 | This will change the C<$metaclass> into the mutable version by reversing |
462 | the immutable process. C<%options> should be the same options that were |
463 | given to make_metaclass_immutable. |
464 | |
c1809cb1 |
465 | =item B<inlined_constructor> |
466 | |
ec845081 |
467 | If the constructor was inlined, this returns the constructor method |
468 | object that was created to do this. |
469 | |
c23184fc |
470 | =back |
471 | |
472 | =head1 AUTHORS |
473 | |
474 | Stevan Little E<lt>stevan@iinteractive.comE<gt> |
475 | |
476 | =head1 COPYRIGHT AND LICENSE |
477 | |
69e3ab0a |
478 | Copyright 2006-2008 by Infinity Interactive, Inc. |
c23184fc |
479 | |
480 | L<http://www.iinteractive.com> |
481 | |
482 | This library is free software; you can redistribute it and/or modify |
0ac992ee |
483 | it under the same terms as Perl itself. |
c23184fc |
484 | |
485 | =cut |