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'; |
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8 | |
2e5c1a3f |
9 | our $VERSION = '0.65'; |
f0480c45 |
10 | our $AUTHORITY = 'cpan:STEVAN'; |
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11 | |
d7b2249e |
12 | use base 'Class::MOP::Object'; |
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13 | |
63d08a9e |
14 | sub BUILDARGS { |
d43737b3 |
15 | my ($class, @args) = @_; |
16 | |
17 | if ( @args == 1 ) { |
63d08a9e |
18 | unshift @args, "associated_metaclass"; |
d43737b3 |
19 | } elsif ( @args >= 2 && blessed($args[0]) && $args[0]->isa("Class::MOP::Class") ) { |
20 | # compat mode |
21 | my ( $meta, @attrs ) = @args; |
63d08a9e |
22 | @args = ( associated_metaclass => $meta, attributes => \@attrs ); |
d43737b3 |
23 | } |
24 | |
25 | my %options = @args; |
7c7fd869 |
26 | # FIXME lazy_build |
d43737b3 |
27 | $options{slots} ||= [ map { $_->slots } @{ $options{attributes} || [] } ]; |
63d08a9e |
28 | $options{slot_hash} = { map { $_ => undef } @{ $options{slots} } }; # FIXME lazy_build |
29 | |
30 | return \%options; |
31 | } |
32 | |
33 | sub new { |
34 | my $class = shift; |
35 | my $options = $class->BUILDARGS(@_); |
d43737b3 |
36 | |
37 | # FIXME replace with a proper constructor |
c23184fc |
38 | my $instance = bless { |
fc3ddd1d |
39 | # NOTE: |
40 | # I am not sure that it makes |
41 | # sense to pass in the meta |
8d2d4c67 |
42 | # The ideal would be to just |
43 | # pass in the class name, but |
44 | # that is placing too much of |
45 | # an assumption on bless(), |
fc3ddd1d |
46 | # which is *probably* a safe |
8d2d4c67 |
47 | # assumption,.. but you can |
fc3ddd1d |
48 | # never tell <:) |
63d08a9e |
49 | 'associated_metaclass' => $options->{associated_metaclass}, |
50 | 'slots' => $options->{slots}, |
51 | 'slot_hash' => $options->{slot_hash}, |
8d2d4c67 |
52 | } => $class; |
53 | |
d43737b3 |
54 | # FIXME weak_ref => 1, |
63d08a9e |
55 | weaken($instance->{'associated_metaclass'}); |
8d2d4c67 |
56 | |
c23184fc |
57 | return $instance; |
24869f62 |
58 | } |
59 | |
63d08a9e |
60 | sub associated_metaclass { (shift)->{'associated_metaclass'} } |
c23184fc |
61 | |
49c93440 |
62 | sub create_instance { |
63 | my $self = shift; |
64 | $self->bless_instance_structure({}); |
2d711cc8 |
65 | } |
66 | |
49c93440 |
67 | sub bless_instance_structure { |
68 | my ($self, $instance_structure) = @_; |
c23184fc |
69 | bless $instance_structure, $self->associated_metaclass->name; |
2d711cc8 |
70 | } |
71 | |
f7259199 |
72 | sub clone_instance { |
73 | my ($self, $instance) = @_; |
74 | $self->bless_instance_structure({ %$instance }); |
75 | } |
76 | |
2d711cc8 |
77 | # operations on meta instance |
78 | |
eb49acde |
79 | sub get_all_slots { |
80 | my $self = shift; |
7c7fd869 |
81 | return @{$self->{'slots'}}; |
f7259199 |
82 | } |
83 | |
84 | sub is_valid_slot { |
85 | my ($self, $slot_name) = @_; |
7c7fd869 |
86 | exists $self->{'slot_hash'}->{$slot_name}; |
839ea973 |
87 | } |
88 | |
2d711cc8 |
89 | # operations on created instances |
90 | |
839ea973 |
91 | sub get_slot_value { |
2bab2be6 |
92 | my ($self, $instance, $slot_name) = @_; |
230472a7 |
93 | $instance->{$slot_name}; |
839ea973 |
94 | } |
95 | |
2bab2be6 |
96 | sub set_slot_value { |
97 | my ($self, $instance, $slot_name, $value) = @_; |
98 | $instance->{$slot_name} = $value; |
99 | } |
100 | |
2d711cc8 |
101 | sub initialize_slot { |
49c93440 |
102 | my ($self, $instance, $slot_name) = @_; |
a007159d |
103 | return; |
2d711cc8 |
104 | } |
105 | |
7d28758b |
106 | sub deinitialize_slot { |
107 | my ( $self, $instance, $slot_name ) = @_; |
108 | delete $instance->{$slot_name}; |
109 | } |
110 | |
c174112e |
111 | sub initialize_all_slots { |
112 | my ($self, $instance) = @_; |
113 | foreach my $slot_name ($self->get_all_slots) { |
114 | $self->initialize_slot($instance, $slot_name); |
115 | } |
116 | } |
117 | |
7d28758b |
118 | sub deinitialize_all_slots { |
119 | my ($self, $instance) = @_; |
120 | foreach my $slot_name ($self->get_all_slots) { |
121 | $self->deinitialize_slot($instance, $slot_name); |
122 | } |
123 | } |
124 | |
49c93440 |
125 | sub is_slot_initialized { |
126 | my ($self, $instance, $slot_name, $value) = @_; |
230472a7 |
127 | exists $instance->{$slot_name}; |
2bab2be6 |
128 | } |
839ea973 |
129 | |
5582521c |
130 | sub weaken_slot_value { |
69e3ab0a |
131 | my ($self, $instance, $slot_name) = @_; |
132 | weaken $instance->{$slot_name}; |
5582521c |
133 | } |
134 | |
135 | sub strengthen_slot_value { |
69e3ab0a |
136 | my ($self, $instance, $slot_name) = @_; |
137 | $self->set_slot_value($instance, $slot_name, $self->get_slot_value($instance, $slot_name)); |
5582521c |
138 | } |
139 | |
3d9e4646 |
140 | sub rebless_instance_structure { |
141 | my ($self, $instance, $metaclass) = @_; |
142 | bless $instance, $metaclass->name; |
143 | } |
144 | |
ee7c0467 |
145 | # inlinable operation snippets |
146 | |
c0cbf4d9 |
147 | sub is_inlinable { 1 } |
148 | |
149 | sub inline_create_instance { |
150 | my ($self, $class_variable) = @_; |
151 | 'bless {} => ' . $class_variable; |
152 | } |
153 | |
ee7c0467 |
154 | sub inline_slot_access { |
155 | my ($self, $instance, $slot_name) = @_; |
156 | sprintf "%s->{%s}", $instance, $slot_name; |
157 | } |
158 | |
159 | sub inline_get_slot_value { |
160 | my ($self, $instance, $slot_name) = @_; |
230472a7 |
161 | $self->inline_slot_access($instance, $slot_name); |
ee7c0467 |
162 | } |
163 | |
164 | sub inline_set_slot_value { |
165 | my ($self, $instance, $slot_name, $value) = @_; |
8d2d4c67 |
166 | $self->inline_slot_access($instance, $slot_name) . " = $value", |
ee7c0467 |
167 | } |
168 | |
169 | sub inline_initialize_slot { |
170 | my ($self, $instance, $slot_name) = @_; |
a007159d |
171 | return ''; |
ee7c0467 |
172 | } |
173 | |
7d28758b |
174 | sub inline_deinitialize_slot { |
175 | my ($self, $instance, $slot_name) = @_; |
176 | "delete " . $self->inline_slot_access($instance, $slot_name); |
177 | } |
ee7c0467 |
178 | sub inline_is_slot_initialized { |
179 | my ($self, $instance, $slot_name) = @_; |
230472a7 |
180 | "exists " . $self->inline_slot_access($instance, $slot_name); |
ee7c0467 |
181 | } |
182 | |
183 | sub inline_weaken_slot_value { |
184 | my ($self, $instance, $slot_name) = @_; |
185 | sprintf "Scalar::Util::weaken( %s )", $self->inline_slot_access($instance, $slot_name); |
186 | } |
187 | |
188 | sub inline_strengthen_slot_value { |
189 | my ($self, $instance, $slot_name) = @_; |
190 | $self->inline_set_slot_value($instance, $slot_name, $self->inline_slot_access($instance, $slot_name)); |
191 | } |
192 | |
24869f62 |
193 | 1; |
194 | |
195 | __END__ |
196 | |
197 | =pod |
198 | |
8d2d4c67 |
199 | =head1 NAME |
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200 | |
201 | Class::MOP::Instance - Instance Meta Object |
202 | |
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203 | =head1 DESCRIPTION |
204 | |
bc9e7815 |
205 | The meta instance is used by attributes for low level storage. |
206 | |
207 | Using this API generally violates attribute encapsulation and is not |
98bf345b |
208 | recommended, instead look at L<Class::MOP::Attribute/get_value>, |
209 | L<Class::MOP::Attribute/set_value> for the recommended way to fiddle with |
210 | attribute values in a generic way, independent of how/whether accessors have |
bc9e7815 |
211 | been defined. Accessors can be found using L<Class::MOP::Class/get_attribute>. |
9fa4d0b4 |
212 | |
8d2d4c67 |
213 | This may seem like over-abstraction, but by abstracting |
214 | this process into a sub-protocol we make it possible to |
215 | easily switch the details of how an object's instance is |
216 | stored with minimal impact. In most cases just subclassing |
217 | this class will be all you need to do (see the examples; |
218 | F<examples/ArrayBasedStorage.pod> and |
1becdfcc |
219 | F<examples/InsideOutClass.pod> for details). |
9fa4d0b4 |
220 | |
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221 | =head1 METHODS |
222 | |
223 | =over 4 |
224 | |
63d08a9e |
225 | =item B<new %args> |
9fa4d0b4 |
226 | |
8d2d4c67 |
227 | Creates a new instance meta-object and gathers all the slots from |
9fa4d0b4 |
228 | the list of C<@attrs> given. |
229 | |
63d08a9e |
230 | =item B<BUILDARGS> |
231 | |
232 | Processes arguments for compatibility. |
233 | |
9fa4d0b4 |
234 | =item B<meta> |
235 | |
63d08a9e |
236 | Returns the metaclass of L<Class::MOP::Instance>. |
9fa4d0b4 |
237 | |
238 | =back |
239 | |
240 | =head2 Creation of Instances |
241 | |
242 | =over 4 |
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243 | |
58287a97 |
244 | =item B<create_instance> |
245 | |
8d2d4c67 |
246 | This creates the appropriate structure needed for the instance and |
9fa4d0b4 |
247 | then calls C<bless_instance_structure> to bless it into the class. |
0e76a376 |
248 | |
9fa4d0b4 |
249 | =item B<bless_instance_structure ($instance_structure)> |
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250 | |
9fa4d0b4 |
251 | This does just exactly what it says it does. |
0e76a376 |
252 | |
f7259199 |
253 | =item B<clone_instance ($instance_structure)> |
254 | |
127d39a7 |
255 | This too does just exactly what it says it does. |
256 | |
9fa4d0b4 |
257 | =back |
839ea973 |
258 | |
98bf345b |
259 | =head2 Introspection |
58287a97 |
260 | |
8d2d4c67 |
261 | NOTE: There might be more methods added to this part of the API, |
9fa4d0b4 |
262 | we will add then when we need them basically. |
58287a97 |
263 | |
9fa4d0b4 |
264 | =over 4 |
265 | |
c23184fc |
266 | =item B<associated_metaclass> |
267 | |
127d39a7 |
268 | This returns the metaclass associated with this instance. |
269 | |
9fa4d0b4 |
270 | =item B<get_all_slots> |
271 | |
8d2d4c67 |
272 | This will return the current list of slots based on what was |
9fa4d0b4 |
273 | given to this object in C<new>. |
58287a97 |
274 | |
f7259199 |
275 | =item B<is_valid_slot ($slot_name)> |
276 | |
127d39a7 |
277 | This will return true if C<$slot_name> is a valid slot name. |
278 | |
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279 | =back |
280 | |
9fa4d0b4 |
281 | =head2 Operations on Instance Structures |
282 | |
8d2d4c67 |
283 | An important distinction of this sub-protocol is that the |
284 | instance meta-object is a different entity from the actual |
285 | instance it creates. For this reason, any actions on slots |
9fa4d0b4 |
286 | require that the C<$instance_structure> is passed into them. |
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287 | |
127d39a7 |
288 | The names of these methods pretty much explain exactly |
289 | what they do, if that is not enough then I suggest reading |
290 | the source, it is very straightfoward. |
291 | |
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292 | =over 4 |
293 | |
9fa4d0b4 |
294 | =item B<get_slot_value ($instance_structure, $slot_name)> |
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295 | |
9fa4d0b4 |
296 | =item B<set_slot_value ($instance_structure, $slot_name, $value)> |
297 | |
298 | =item B<initialize_slot ($instance_structure, $slot_name)> |
299 | |
7d28758b |
300 | =item B<deinitialize_slot ($instance_structure, $slot_name)> |
301 | |
9fa4d0b4 |
302 | =item B<initialize_all_slots ($instance_structure)> |
303 | |
7d28758b |
304 | =item B<deinitialize_all_slots ($instance_structure)> |
305 | |
9fa4d0b4 |
306 | =item B<is_slot_initialized ($instance_structure, $slot_name)> |
24869f62 |
307 | |
ee7c0467 |
308 | =item B<weaken_slot_value ($instance_structure, $slot_name)> |
309 | |
310 | =item B<strengthen_slot_value ($instance_structure, $slot_name)> |
311 | |
5fdf066d |
312 | =item B<rebless_instance_structure ($instance_structure, $new_metaclass)> |
313 | |
ee7c0467 |
314 | =back |
315 | |
316 | =head2 Inlineable Instance Operations |
317 | |
318 | =over 4 |
319 | |
c0cbf4d9 |
320 | =item B<is_inlinable> |
321 | |
8d2d4c67 |
322 | Each meta-instance should override this method to tell Class::MOP if it's |
127d39a7 |
323 | possible to inline the slot access. This is currently only used by |
324 | L<Class::MOP::Immutable> when performing optimizations. |
c0cbf4d9 |
325 | |
495af518 |
326 | =item B<inline_create_instance> |
327 | |
ee7c0467 |
328 | =item B<inline_slot_access ($instance_structure, $slot_name)> |
329 | |
330 | =item B<inline_get_slot_value ($instance_structure, $slot_name)> |
331 | |
332 | =item B<inline_set_slot_value ($instance_structure, $slot_name, $value)> |
333 | |
334 | =item B<inline_initialize_slot ($instance_structure, $slot_name)> |
335 | |
7d28758b |
336 | =item B<inline_deinitialize_slot ($instance_structure, $slot_name)> |
337 | |
ee7c0467 |
338 | =item B<inline_is_slot_initialized ($instance_structure, $slot_name)> |
5582521c |
339 | |
ee7c0467 |
340 | =item B<inline_weaken_slot_value ($instance_structure, $slot_name)> |
5582521c |
341 | |
ee7c0467 |
342 | =item B<inline_strengthen_slot_value ($instance_structure, $slot_name)> |
5582521c |
343 | |
24869f62 |
344 | =back |
345 | |
1a09d9cc |
346 | =head1 AUTHORS |
24869f62 |
347 | |
9fa4d0b4 |
348 | Yuval Kogman E<lt>nothingmuch@woobling.comE<gt> |
349 | |
24869f62 |
350 | Stevan Little E<lt>stevan@iinteractive.comE<gt> |
351 | |
352 | =head1 COPYRIGHT AND LICENSE |
353 | |
69e3ab0a |
354 | Copyright 2006-2008 by Infinity Interactive, Inc. |
24869f62 |
355 | |
356 | L<http://www.iinteractive.com> |
357 | |
358 | This library is free software; you can redistribute it and/or modify |
8d2d4c67 |
359 | it under the same terms as Perl itself. |
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360 | |
84ef30d1 |
361 | =cut |
5582521c |
362 | |