Commit | Line | Data |
24869f62 |
1 | |
2 | package Class::MOP::Instance; |
3 | |
4 | use strict; |
5 | use warnings; |
6 | |
fa16e528 |
7 | use Scalar::Util 'weaken', 'blessed'; |
24869f62 |
8 | |
eca95e04 |
9 | our $VERSION = '0.78'; |
d519662a |
10 | $VERSION = eval $VERSION; |
f0480c45 |
11 | our $AUTHORITY = 'cpan:STEVAN'; |
24869f62 |
12 | |
d7b2249e |
13 | use base 'Class::MOP::Object'; |
24869f62 |
14 | |
63d08a9e |
15 | sub BUILDARGS { |
d43737b3 |
16 | my ($class, @args) = @_; |
17 | |
18 | if ( @args == 1 ) { |
63d08a9e |
19 | unshift @args, "associated_metaclass"; |
d43737b3 |
20 | } elsif ( @args >= 2 && blessed($args[0]) && $args[0]->isa("Class::MOP::Class") ) { |
21 | # compat mode |
22 | my ( $meta, @attrs ) = @args; |
63d08a9e |
23 | @args = ( associated_metaclass => $meta, attributes => \@attrs ); |
d43737b3 |
24 | } |
25 | |
26 | my %options = @args; |
7c7fd869 |
27 | # FIXME lazy_build |
d43737b3 |
28 | $options{slots} ||= [ map { $_->slots } @{ $options{attributes} || [] } ]; |
63d08a9e |
29 | $options{slot_hash} = { map { $_ => undef } @{ $options{slots} } }; # FIXME lazy_build |
30 | |
31 | return \%options; |
32 | } |
33 | |
34 | sub new { |
35 | my $class = shift; |
36 | my $options = $class->BUILDARGS(@_); |
d43737b3 |
37 | |
38 | # FIXME replace with a proper constructor |
b4b5d65a |
39 | my $instance = $class->_new(%$options); |
40 | |
41 | # FIXME weak_ref => 1, |
42 | weaken($instance->{'associated_metaclass'}); |
43 | |
44 | return $instance; |
45 | } |
46 | |
47 | sub _new { |
48 | my ( $class, %options ) = @_; |
49 | bless { |
fc3ddd1d |
50 | # NOTE: |
51 | # I am not sure that it makes |
52 | # sense to pass in the meta |
8d2d4c67 |
53 | # The ideal would be to just |
54 | # pass in the class name, but |
55 | # that is placing too much of |
56 | # an assumption on bless(), |
fc3ddd1d |
57 | # which is *probably* a safe |
8d2d4c67 |
58 | # assumption,.. but you can |
fc3ddd1d |
59 | # never tell <:) |
b4b5d65a |
60 | 'associated_metaclass' => $options{associated_metaclass}, |
61 | 'attributes' => $options{attributes}, |
62 | 'slots' => $options{slots}, |
63 | 'slot_hash' => $options{slot_hash}, |
8d2d4c67 |
64 | } => $class; |
24869f62 |
65 | } |
66 | |
74890687 |
67 | sub _class_name { $_[0]->{_class_name} ||= $_[0]->associated_metaclass->name } |
68 | |
69 | sub associated_metaclass { $_[0]{'associated_metaclass'} } |
c23184fc |
70 | |
49c93440 |
71 | sub create_instance { |
72 | my $self = shift; |
becd03c6 |
73 | bless {}, $self->_class_name; |
2d711cc8 |
74 | } |
75 | |
becd03c6 |
76 | # for compatibility |
49c93440 |
77 | sub bless_instance_structure { |
78 | my ($self, $instance_structure) = @_; |
74890687 |
79 | bless $instance_structure, $self->_class_name; |
2d711cc8 |
80 | } |
81 | |
f7259199 |
82 | sub clone_instance { |
83 | my ($self, $instance) = @_; |
becd03c6 |
84 | bless { %$instance }, $self->_class_name; |
f7259199 |
85 | } |
86 | |
2d711cc8 |
87 | # operations on meta instance |
88 | |
eb49acde |
89 | sub get_all_slots { |
90 | my $self = shift; |
7c7fd869 |
91 | return @{$self->{'slots'}}; |
f7259199 |
92 | } |
93 | |
0b5d46da |
94 | sub get_all_attributes { |
95 | my $self = shift; |
96 | return @{$self->{attributes}}; |
97 | } |
98 | |
f7259199 |
99 | sub is_valid_slot { |
100 | my ($self, $slot_name) = @_; |
7c7fd869 |
101 | exists $self->{'slot_hash'}->{$slot_name}; |
839ea973 |
102 | } |
103 | |
2d711cc8 |
104 | # operations on created instances |
105 | |
839ea973 |
106 | sub get_slot_value { |
2bab2be6 |
107 | my ($self, $instance, $slot_name) = @_; |
230472a7 |
108 | $instance->{$slot_name}; |
839ea973 |
109 | } |
110 | |
2bab2be6 |
111 | sub set_slot_value { |
112 | my ($self, $instance, $slot_name, $value) = @_; |
113 | $instance->{$slot_name} = $value; |
114 | } |
115 | |
2d711cc8 |
116 | sub initialize_slot { |
49c93440 |
117 | my ($self, $instance, $slot_name) = @_; |
a007159d |
118 | return; |
2d711cc8 |
119 | } |
120 | |
7d28758b |
121 | sub deinitialize_slot { |
122 | my ( $self, $instance, $slot_name ) = @_; |
123 | delete $instance->{$slot_name}; |
124 | } |
125 | |
c174112e |
126 | sub initialize_all_slots { |
127 | my ($self, $instance) = @_; |
128 | foreach my $slot_name ($self->get_all_slots) { |
129 | $self->initialize_slot($instance, $slot_name); |
130 | } |
131 | } |
132 | |
7d28758b |
133 | sub deinitialize_all_slots { |
134 | my ($self, $instance) = @_; |
135 | foreach my $slot_name ($self->get_all_slots) { |
136 | $self->deinitialize_slot($instance, $slot_name); |
137 | } |
138 | } |
139 | |
49c93440 |
140 | sub is_slot_initialized { |
141 | my ($self, $instance, $slot_name, $value) = @_; |
230472a7 |
142 | exists $instance->{$slot_name}; |
2bab2be6 |
143 | } |
839ea973 |
144 | |
5582521c |
145 | sub weaken_slot_value { |
69e3ab0a |
146 | my ($self, $instance, $slot_name) = @_; |
147 | weaken $instance->{$slot_name}; |
5582521c |
148 | } |
149 | |
150 | sub strengthen_slot_value { |
69e3ab0a |
151 | my ($self, $instance, $slot_name) = @_; |
152 | $self->set_slot_value($instance, $slot_name, $self->get_slot_value($instance, $slot_name)); |
5582521c |
153 | } |
154 | |
3d9e4646 |
155 | sub rebless_instance_structure { |
156 | my ($self, $instance, $metaclass) = @_; |
feb93c85 |
157 | |
158 | # we use $_[1] here because of t/306_rebless_overload.t regressions on 5.8.8 |
159 | bless $_[1], $metaclass->name; |
3d9e4646 |
160 | } |
161 | |
da5680be |
162 | sub is_dependent_on_superclasses { |
163 | return; # for meta instances that require updates on inherited slot changes |
164 | } |
165 | |
ee7c0467 |
166 | # inlinable operation snippets |
167 | |
c0cbf4d9 |
168 | sub is_inlinable { 1 } |
169 | |
170 | sub inline_create_instance { |
171 | my ($self, $class_variable) = @_; |
172 | 'bless {} => ' . $class_variable; |
173 | } |
174 | |
ee7c0467 |
175 | sub inline_slot_access { |
176 | my ($self, $instance, $slot_name) = @_; |
e9a19694 |
177 | sprintf q[%s->{"%s"}], $instance, quotemeta($slot_name); |
ee7c0467 |
178 | } |
179 | |
180 | sub inline_get_slot_value { |
181 | my ($self, $instance, $slot_name) = @_; |
230472a7 |
182 | $self->inline_slot_access($instance, $slot_name); |
ee7c0467 |
183 | } |
184 | |
185 | sub inline_set_slot_value { |
186 | my ($self, $instance, $slot_name, $value) = @_; |
8d2d4c67 |
187 | $self->inline_slot_access($instance, $slot_name) . " = $value", |
ee7c0467 |
188 | } |
189 | |
190 | sub inline_initialize_slot { |
191 | my ($self, $instance, $slot_name) = @_; |
a007159d |
192 | return ''; |
ee7c0467 |
193 | } |
194 | |
7d28758b |
195 | sub inline_deinitialize_slot { |
196 | my ($self, $instance, $slot_name) = @_; |
197 | "delete " . $self->inline_slot_access($instance, $slot_name); |
198 | } |
ee7c0467 |
199 | sub inline_is_slot_initialized { |
200 | my ($self, $instance, $slot_name) = @_; |
230472a7 |
201 | "exists " . $self->inline_slot_access($instance, $slot_name); |
ee7c0467 |
202 | } |
203 | |
204 | sub inline_weaken_slot_value { |
205 | my ($self, $instance, $slot_name) = @_; |
206 | sprintf "Scalar::Util::weaken( %s )", $self->inline_slot_access($instance, $slot_name); |
207 | } |
208 | |
209 | sub inline_strengthen_slot_value { |
210 | my ($self, $instance, $slot_name) = @_; |
211 | $self->inline_set_slot_value($instance, $slot_name, $self->inline_slot_access($instance, $slot_name)); |
212 | } |
213 | |
24869f62 |
214 | 1; |
215 | |
216 | __END__ |
217 | |
218 | =pod |
219 | |
8d2d4c67 |
220 | =head1 NAME |
24869f62 |
221 | |
222 | Class::MOP::Instance - Instance Meta Object |
223 | |
24869f62 |
224 | =head1 DESCRIPTION |
225 | |
bc9e7815 |
226 | The meta instance is used by attributes for low level storage. |
227 | |
228 | Using this API generally violates attribute encapsulation and is not |
98bf345b |
229 | recommended, instead look at L<Class::MOP::Attribute/get_value>, |
230 | L<Class::MOP::Attribute/set_value> for the recommended way to fiddle with |
231 | attribute values in a generic way, independent of how/whether accessors have |
bc9e7815 |
232 | been defined. Accessors can be found using L<Class::MOP::Class/get_attribute>. |
9fa4d0b4 |
233 | |
8d2d4c67 |
234 | This may seem like over-abstraction, but by abstracting |
235 | this process into a sub-protocol we make it possible to |
236 | easily switch the details of how an object's instance is |
237 | stored with minimal impact. In most cases just subclassing |
238 | this class will be all you need to do (see the examples; |
239 | F<examples/ArrayBasedStorage.pod> and |
1becdfcc |
240 | F<examples/InsideOutClass.pod> for details). |
9fa4d0b4 |
241 | |
24869f62 |
242 | =head1 METHODS |
243 | |
244 | =over 4 |
245 | |
63d08a9e |
246 | =item B<new %args> |
9fa4d0b4 |
247 | |
8d2d4c67 |
248 | Creates a new instance meta-object and gathers all the slots from |
9fa4d0b4 |
249 | the list of C<@attrs> given. |
250 | |
63d08a9e |
251 | =item B<BUILDARGS> |
252 | |
253 | Processes arguments for compatibility. |
254 | |
9fa4d0b4 |
255 | =item B<meta> |
256 | |
63d08a9e |
257 | Returns the metaclass of L<Class::MOP::Instance>. |
9fa4d0b4 |
258 | |
259 | =back |
260 | |
261 | =head2 Creation of Instances |
262 | |
263 | =over 4 |
24869f62 |
264 | |
58287a97 |
265 | =item B<create_instance> |
266 | |
becd03c6 |
267 | This creates the appropriate structure needed for the instance and blesses it. |
0e76a376 |
268 | |
9fa4d0b4 |
269 | =item B<bless_instance_structure ($instance_structure)> |
839ea973 |
270 | |
9fa4d0b4 |
271 | This does just exactly what it says it does. |
0e76a376 |
272 | |
becd03c6 |
273 | This method has been deprecated but remains for compatibility reasons. None of |
274 | the subclasses of L<Class::MOP::Instance> ever bothered to actually make use of |
275 | it, so it was deemed unnecessary fluff. |
276 | |
f7259199 |
277 | =item B<clone_instance ($instance_structure)> |
278 | |
becd03c6 |
279 | Creates a shallow clone of $instance_structure. |
127d39a7 |
280 | |
9fa4d0b4 |
281 | =back |
839ea973 |
282 | |
98bf345b |
283 | =head2 Introspection |
58287a97 |
284 | |
8d2d4c67 |
285 | NOTE: There might be more methods added to this part of the API, |
9fa4d0b4 |
286 | we will add then when we need them basically. |
58287a97 |
287 | |
9fa4d0b4 |
288 | =over 4 |
289 | |
c23184fc |
290 | =item B<associated_metaclass> |
291 | |
127d39a7 |
292 | This returns the metaclass associated with this instance. |
293 | |
9fa4d0b4 |
294 | =item B<get_all_slots> |
295 | |
8d2d4c67 |
296 | This will return the current list of slots based on what was |
9fa4d0b4 |
297 | given to this object in C<new>. |
58287a97 |
298 | |
f7259199 |
299 | =item B<is_valid_slot ($slot_name)> |
300 | |
127d39a7 |
301 | This will return true if C<$slot_name> is a valid slot name. |
302 | |
da5680be |
303 | =item B<is_dependent_on_superclasses> |
304 | |
305 | This method returns true when the meta instance must be recreated on any |
306 | superclass changes. |
307 | |
308 | Defaults to false. |
309 | |
0202ee96 |
310 | =item B<get_all_attributes> |
311 | |
312 | This will return the current list of attributes (as |
313 | Class::MOP::Attribute objects) based on what was given to this object |
314 | in C<new>. |
315 | |
24869f62 |
316 | =back |
317 | |
9fa4d0b4 |
318 | =head2 Operations on Instance Structures |
319 | |
8d2d4c67 |
320 | An important distinction of this sub-protocol is that the |
321 | instance meta-object is a different entity from the actual |
322 | instance it creates. For this reason, any actions on slots |
9fa4d0b4 |
323 | require that the C<$instance_structure> is passed into them. |
24869f62 |
324 | |
127d39a7 |
325 | The names of these methods pretty much explain exactly |
326 | what they do, if that is not enough then I suggest reading |
327 | the source, it is very straightfoward. |
328 | |
24869f62 |
329 | =over 4 |
330 | |
9fa4d0b4 |
331 | =item B<get_slot_value ($instance_structure, $slot_name)> |
24869f62 |
332 | |
9fa4d0b4 |
333 | =item B<set_slot_value ($instance_structure, $slot_name, $value)> |
334 | |
335 | =item B<initialize_slot ($instance_structure, $slot_name)> |
336 | |
7d28758b |
337 | =item B<deinitialize_slot ($instance_structure, $slot_name)> |
338 | |
9fa4d0b4 |
339 | =item B<initialize_all_slots ($instance_structure)> |
340 | |
7d28758b |
341 | =item B<deinitialize_all_slots ($instance_structure)> |
342 | |
9fa4d0b4 |
343 | =item B<is_slot_initialized ($instance_structure, $slot_name)> |
24869f62 |
344 | |
ee7c0467 |
345 | =item B<weaken_slot_value ($instance_structure, $slot_name)> |
346 | |
347 | =item B<strengthen_slot_value ($instance_structure, $slot_name)> |
348 | |
5fdf066d |
349 | =item B<rebless_instance_structure ($instance_structure, $new_metaclass)> |
350 | |
ee7c0467 |
351 | =back |
352 | |
353 | =head2 Inlineable Instance Operations |
354 | |
355 | =over 4 |
356 | |
c0cbf4d9 |
357 | =item B<is_inlinable> |
358 | |
8d2d4c67 |
359 | Each meta-instance should override this method to tell Class::MOP if it's |
127d39a7 |
360 | possible to inline the slot access. This is currently only used by |
361 | L<Class::MOP::Immutable> when performing optimizations. |
c0cbf4d9 |
362 | |
495af518 |
363 | =item B<inline_create_instance> |
364 | |
ee7c0467 |
365 | =item B<inline_slot_access ($instance_structure, $slot_name)> |
366 | |
367 | =item B<inline_get_slot_value ($instance_structure, $slot_name)> |
368 | |
369 | =item B<inline_set_slot_value ($instance_structure, $slot_name, $value)> |
370 | |
371 | =item B<inline_initialize_slot ($instance_structure, $slot_name)> |
372 | |
7d28758b |
373 | =item B<inline_deinitialize_slot ($instance_structure, $slot_name)> |
374 | |
ee7c0467 |
375 | =item B<inline_is_slot_initialized ($instance_structure, $slot_name)> |
5582521c |
376 | |
ee7c0467 |
377 | =item B<inline_weaken_slot_value ($instance_structure, $slot_name)> |
5582521c |
378 | |
ee7c0467 |
379 | =item B<inline_strengthen_slot_value ($instance_structure, $slot_name)> |
5582521c |
380 | |
24869f62 |
381 | =back |
382 | |
1a09d9cc |
383 | =head1 AUTHORS |
24869f62 |
384 | |
9fa4d0b4 |
385 | Yuval Kogman E<lt>nothingmuch@woobling.comE<gt> |
386 | |
24869f62 |
387 | Stevan Little E<lt>stevan@iinteractive.comE<gt> |
388 | |
389 | =head1 COPYRIGHT AND LICENSE |
390 | |
070bb6c9 |
391 | Copyright 2006-2009 by Infinity Interactive, Inc. |
24869f62 |
392 | |
393 | L<http://www.iinteractive.com> |
394 | |
395 | This library is free software; you can redistribute it and/or modify |
8d2d4c67 |
396 | it under the same terms as Perl itself. |
24869f62 |
397 | |
84ef30d1 |
398 | =cut |
5582521c |
399 | |