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 | |
d519662a |
9 | our $VERSION = '0.64_01'; |
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 | |
94 | sub is_valid_slot { |
95 | my ($self, $slot_name) = @_; |
7c7fd869 |
96 | exists $self->{'slot_hash'}->{$slot_name}; |
839ea973 |
97 | } |
98 | |
2d711cc8 |
99 | # operations on created instances |
100 | |
839ea973 |
101 | sub get_slot_value { |
2bab2be6 |
102 | my ($self, $instance, $slot_name) = @_; |
230472a7 |
103 | $instance->{$slot_name}; |
839ea973 |
104 | } |
105 | |
2bab2be6 |
106 | sub set_slot_value { |
107 | my ($self, $instance, $slot_name, $value) = @_; |
108 | $instance->{$slot_name} = $value; |
109 | } |
110 | |
2d711cc8 |
111 | sub initialize_slot { |
49c93440 |
112 | my ($self, $instance, $slot_name) = @_; |
a007159d |
113 | return; |
2d711cc8 |
114 | } |
115 | |
7d28758b |
116 | sub deinitialize_slot { |
117 | my ( $self, $instance, $slot_name ) = @_; |
118 | delete $instance->{$slot_name}; |
119 | } |
120 | |
c174112e |
121 | sub initialize_all_slots { |
122 | my ($self, $instance) = @_; |
123 | foreach my $slot_name ($self->get_all_slots) { |
124 | $self->initialize_slot($instance, $slot_name); |
125 | } |
126 | } |
127 | |
7d28758b |
128 | sub deinitialize_all_slots { |
129 | my ($self, $instance) = @_; |
130 | foreach my $slot_name ($self->get_all_slots) { |
131 | $self->deinitialize_slot($instance, $slot_name); |
132 | } |
133 | } |
134 | |
49c93440 |
135 | sub is_slot_initialized { |
136 | my ($self, $instance, $slot_name, $value) = @_; |
230472a7 |
137 | exists $instance->{$slot_name}; |
2bab2be6 |
138 | } |
839ea973 |
139 | |
5582521c |
140 | sub weaken_slot_value { |
69e3ab0a |
141 | my ($self, $instance, $slot_name) = @_; |
142 | weaken $instance->{$slot_name}; |
5582521c |
143 | } |
144 | |
145 | sub strengthen_slot_value { |
69e3ab0a |
146 | my ($self, $instance, $slot_name) = @_; |
147 | $self->set_slot_value($instance, $slot_name, $self->get_slot_value($instance, $slot_name)); |
5582521c |
148 | } |
149 | |
3d9e4646 |
150 | sub rebless_instance_structure { |
151 | my ($self, $instance, $metaclass) = @_; |
152 | bless $instance, $metaclass->name; |
153 | } |
154 | |
da5680be |
155 | sub is_dependent_on_superclasses { |
156 | return; # for meta instances that require updates on inherited slot changes |
157 | } |
158 | |
ee7c0467 |
159 | # inlinable operation snippets |
160 | |
c0cbf4d9 |
161 | sub is_inlinable { 1 } |
162 | |
163 | sub inline_create_instance { |
164 | my ($self, $class_variable) = @_; |
165 | 'bless {} => ' . $class_variable; |
166 | } |
167 | |
ee7c0467 |
168 | sub inline_slot_access { |
169 | my ($self, $instance, $slot_name) = @_; |
170 | sprintf "%s->{%s}", $instance, $slot_name; |
171 | } |
172 | |
173 | sub inline_get_slot_value { |
174 | my ($self, $instance, $slot_name) = @_; |
230472a7 |
175 | $self->inline_slot_access($instance, $slot_name); |
ee7c0467 |
176 | } |
177 | |
178 | sub inline_set_slot_value { |
179 | my ($self, $instance, $slot_name, $value) = @_; |
8d2d4c67 |
180 | $self->inline_slot_access($instance, $slot_name) . " = $value", |
ee7c0467 |
181 | } |
182 | |
183 | sub inline_initialize_slot { |
184 | my ($self, $instance, $slot_name) = @_; |
a007159d |
185 | return ''; |
ee7c0467 |
186 | } |
187 | |
7d28758b |
188 | sub inline_deinitialize_slot { |
189 | my ($self, $instance, $slot_name) = @_; |
190 | "delete " . $self->inline_slot_access($instance, $slot_name); |
191 | } |
ee7c0467 |
192 | sub inline_is_slot_initialized { |
193 | my ($self, $instance, $slot_name) = @_; |
230472a7 |
194 | "exists " . $self->inline_slot_access($instance, $slot_name); |
ee7c0467 |
195 | } |
196 | |
197 | sub inline_weaken_slot_value { |
198 | my ($self, $instance, $slot_name) = @_; |
199 | sprintf "Scalar::Util::weaken( %s )", $self->inline_slot_access($instance, $slot_name); |
200 | } |
201 | |
202 | sub inline_strengthen_slot_value { |
203 | my ($self, $instance, $slot_name) = @_; |
204 | $self->inline_set_slot_value($instance, $slot_name, $self->inline_slot_access($instance, $slot_name)); |
205 | } |
206 | |
24869f62 |
207 | 1; |
208 | |
209 | __END__ |
210 | |
211 | =pod |
212 | |
8d2d4c67 |
213 | =head1 NAME |
24869f62 |
214 | |
215 | Class::MOP::Instance - Instance Meta Object |
216 | |
24869f62 |
217 | =head1 DESCRIPTION |
218 | |
bc9e7815 |
219 | The meta instance is used by attributes for low level storage. |
220 | |
221 | Using this API generally violates attribute encapsulation and is not |
98bf345b |
222 | recommended, instead look at L<Class::MOP::Attribute/get_value>, |
223 | L<Class::MOP::Attribute/set_value> for the recommended way to fiddle with |
224 | attribute values in a generic way, independent of how/whether accessors have |
bc9e7815 |
225 | been defined. Accessors can be found using L<Class::MOP::Class/get_attribute>. |
9fa4d0b4 |
226 | |
8d2d4c67 |
227 | This may seem like over-abstraction, but by abstracting |
228 | this process into a sub-protocol we make it possible to |
229 | easily switch the details of how an object's instance is |
230 | stored with minimal impact. In most cases just subclassing |
231 | this class will be all you need to do (see the examples; |
232 | F<examples/ArrayBasedStorage.pod> and |
1becdfcc |
233 | F<examples/InsideOutClass.pod> for details). |
9fa4d0b4 |
234 | |
24869f62 |
235 | =head1 METHODS |
236 | |
237 | =over 4 |
238 | |
63d08a9e |
239 | =item B<new %args> |
9fa4d0b4 |
240 | |
8d2d4c67 |
241 | Creates a new instance meta-object and gathers all the slots from |
9fa4d0b4 |
242 | the list of C<@attrs> given. |
243 | |
63d08a9e |
244 | =item B<BUILDARGS> |
245 | |
246 | Processes arguments for compatibility. |
247 | |
9fa4d0b4 |
248 | =item B<meta> |
249 | |
63d08a9e |
250 | Returns the metaclass of L<Class::MOP::Instance>. |
9fa4d0b4 |
251 | |
252 | =back |
253 | |
254 | =head2 Creation of Instances |
255 | |
256 | =over 4 |
24869f62 |
257 | |
58287a97 |
258 | =item B<create_instance> |
259 | |
becd03c6 |
260 | This creates the appropriate structure needed for the instance and blesses it. |
0e76a376 |
261 | |
9fa4d0b4 |
262 | =item B<bless_instance_structure ($instance_structure)> |
839ea973 |
263 | |
9fa4d0b4 |
264 | This does just exactly what it says it does. |
0e76a376 |
265 | |
becd03c6 |
266 | This method has been deprecated but remains for compatibility reasons. None of |
267 | the subclasses of L<Class::MOP::Instance> ever bothered to actually make use of |
268 | it, so it was deemed unnecessary fluff. |
269 | |
f7259199 |
270 | =item B<clone_instance ($instance_structure)> |
271 | |
becd03c6 |
272 | Creates a shallow clone of $instance_structure. |
127d39a7 |
273 | |
9fa4d0b4 |
274 | =back |
839ea973 |
275 | |
98bf345b |
276 | =head2 Introspection |
58287a97 |
277 | |
8d2d4c67 |
278 | NOTE: There might be more methods added to this part of the API, |
9fa4d0b4 |
279 | we will add then when we need them basically. |
58287a97 |
280 | |
9fa4d0b4 |
281 | =over 4 |
282 | |
c23184fc |
283 | =item B<associated_metaclass> |
284 | |
127d39a7 |
285 | This returns the metaclass associated with this instance. |
286 | |
9fa4d0b4 |
287 | =item B<get_all_slots> |
288 | |
8d2d4c67 |
289 | This will return the current list of slots based on what was |
9fa4d0b4 |
290 | given to this object in C<new>. |
58287a97 |
291 | |
f7259199 |
292 | =item B<is_valid_slot ($slot_name)> |
293 | |
127d39a7 |
294 | This will return true if C<$slot_name> is a valid slot name. |
295 | |
da5680be |
296 | =item B<is_dependent_on_superclasses> |
297 | |
298 | This method returns true when the meta instance must be recreated on any |
299 | superclass changes. |
300 | |
301 | Defaults to false. |
302 | |
24869f62 |
303 | =back |
304 | |
9fa4d0b4 |
305 | =head2 Operations on Instance Structures |
306 | |
8d2d4c67 |
307 | An important distinction of this sub-protocol is that the |
308 | instance meta-object is a different entity from the actual |
309 | instance it creates. For this reason, any actions on slots |
9fa4d0b4 |
310 | require that the C<$instance_structure> is passed into them. |
24869f62 |
311 | |
127d39a7 |
312 | The names of these methods pretty much explain exactly |
313 | what they do, if that is not enough then I suggest reading |
314 | the source, it is very straightfoward. |
315 | |
24869f62 |
316 | =over 4 |
317 | |
9fa4d0b4 |
318 | =item B<get_slot_value ($instance_structure, $slot_name)> |
24869f62 |
319 | |
9fa4d0b4 |
320 | =item B<set_slot_value ($instance_structure, $slot_name, $value)> |
321 | |
322 | =item B<initialize_slot ($instance_structure, $slot_name)> |
323 | |
7d28758b |
324 | =item B<deinitialize_slot ($instance_structure, $slot_name)> |
325 | |
9fa4d0b4 |
326 | =item B<initialize_all_slots ($instance_structure)> |
327 | |
7d28758b |
328 | =item B<deinitialize_all_slots ($instance_structure)> |
329 | |
9fa4d0b4 |
330 | =item B<is_slot_initialized ($instance_structure, $slot_name)> |
24869f62 |
331 | |
ee7c0467 |
332 | =item B<weaken_slot_value ($instance_structure, $slot_name)> |
333 | |
334 | =item B<strengthen_slot_value ($instance_structure, $slot_name)> |
335 | |
5fdf066d |
336 | =item B<rebless_instance_structure ($instance_structure, $new_metaclass)> |
337 | |
ee7c0467 |
338 | =back |
339 | |
340 | =head2 Inlineable Instance Operations |
341 | |
342 | =over 4 |
343 | |
c0cbf4d9 |
344 | =item B<is_inlinable> |
345 | |
8d2d4c67 |
346 | Each meta-instance should override this method to tell Class::MOP if it's |
127d39a7 |
347 | possible to inline the slot access. This is currently only used by |
348 | L<Class::MOP::Immutable> when performing optimizations. |
c0cbf4d9 |
349 | |
495af518 |
350 | =item B<inline_create_instance> |
351 | |
ee7c0467 |
352 | =item B<inline_slot_access ($instance_structure, $slot_name)> |
353 | |
354 | =item B<inline_get_slot_value ($instance_structure, $slot_name)> |
355 | |
356 | =item B<inline_set_slot_value ($instance_structure, $slot_name, $value)> |
357 | |
358 | =item B<inline_initialize_slot ($instance_structure, $slot_name)> |
359 | |
7d28758b |
360 | =item B<inline_deinitialize_slot ($instance_structure, $slot_name)> |
361 | |
ee7c0467 |
362 | =item B<inline_is_slot_initialized ($instance_structure, $slot_name)> |
5582521c |
363 | |
ee7c0467 |
364 | =item B<inline_weaken_slot_value ($instance_structure, $slot_name)> |
5582521c |
365 | |
ee7c0467 |
366 | =item B<inline_strengthen_slot_value ($instance_structure, $slot_name)> |
5582521c |
367 | |
24869f62 |
368 | =back |
369 | |
1a09d9cc |
370 | =head1 AUTHORS |
24869f62 |
371 | |
9fa4d0b4 |
372 | Yuval Kogman E<lt>nothingmuch@woobling.comE<gt> |
373 | |
24869f62 |
374 | Stevan Little E<lt>stevan@iinteractive.comE<gt> |
375 | |
376 | =head1 COPYRIGHT AND LICENSE |
377 | |
69e3ab0a |
378 | Copyright 2006-2008 by Infinity Interactive, Inc. |
24869f62 |
379 | |
380 | L<http://www.iinteractive.com> |
381 | |
382 | This library is free software; you can redistribute it and/or modify |
8d2d4c67 |
383 | it under the same terms as Perl itself. |
24869f62 |
384 | |
84ef30d1 |
385 | =cut |
5582521c |
386 | |