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2905fb35 |
1 | package Package::Stash::PP; |
f10f6217 |
2 | use strict; |
3 | use warnings; |
2905fb35 |
4 | # ABSTRACT: pure perl implementation of the Package::Stash API |
f10f6217 |
5 | |
6 | use Carp qw(confess); |
eb53b1bd |
7 | use Scalar::Util qw(blessed reftype weaken); |
dc378b60 |
8 | use Symbol; |
9 | # before 5.12, assigning to the ISA glob would make it lose its magical ->isa |
10 | # powers |
11 | use constant BROKEN_ISA_ASSIGNMENT => ($] < 5.012); |
36cbfbad |
12 | # before 5.10, stashes don't ever seem to drop to a refcount of zero, so |
13 | # weakening them isn't helpful |
14 | use constant BROKEN_WEAK_STASH => ($] < 5.010); |
f4979588 |
15 | |
f4979588 |
16 | =head1 SYNOPSIS |
17 | |
2905fb35 |
18 | use Package::Stash; |
f4979588 |
19 | |
20 | =head1 DESCRIPTION |
21 | |
2905fb35 |
22 | This is a backend for L<Package::Stash> implemented in pure perl, for those without a compiler or who would like to use this inline in scripts. |
f4979588 |
23 | |
24 | =cut |
25 | |
f10f6217 |
26 | sub new { |
27 | my $class = shift; |
e55970bc |
28 | my ($package) = @_; |
774f4f10 |
29 | |
30 | if (!defined($package) || (ref($package) && ref($package) ne 'HASH')) { |
31 | confess "Package::Stash->new must be passed the name of the " |
32 | . "package to access"; |
33 | } |
34 | elsif (ref($package) eq 'HASH') { |
35 | confess "The pure perl implementation of Package::Stash doesn't " |
36 | . "currently support anonymous stashes. You should install " |
37 | . "Package::Stash::XS"; |
38 | } |
39 | |
e55970bc |
40 | return bless { |
eb53b1bd |
41 | 'package' => $package, |
e55970bc |
42 | }, $class; |
f10f6217 |
43 | } |
44 | |
45 | sub name { |
2905fb35 |
46 | confess "Can't call name as a class method" |
47 | unless blessed($_[0]); |
f10f6217 |
48 | return $_[0]->{package}; |
49 | } |
50 | |
51 | sub namespace { |
2905fb35 |
52 | confess "Can't call namespace as a class method" |
53 | unless blessed($_[0]); |
eb53b1bd |
54 | |
36cbfbad |
55 | if (BROKEN_WEAK_STASH) { |
eb53b1bd |
56 | no strict 'refs'; |
36cbfbad |
57 | return \%{$_[0]->name . '::'}; |
eb53b1bd |
58 | } |
36cbfbad |
59 | else { |
60 | return $_[0]->{namespace} if defined $_[0]->{namespace}; |
eb53b1bd |
61 | |
36cbfbad |
62 | { |
63 | no strict 'refs'; |
64 | $_[0]->{namespace} = \%{$_[0]->name . '::'}; |
65 | } |
66 | |
67 | weaken($_[0]->{namespace}); |
eb53b1bd |
68 | |
36cbfbad |
69 | return $_[0]->{namespace}; |
70 | } |
f10f6217 |
71 | } |
72 | |
73 | { |
74 | my %SIGIL_MAP = ( |
75 | '$' => 'SCALAR', |
76 | '@' => 'ARRAY', |
77 | '%' => 'HASH', |
78 | '&' => 'CODE', |
56a29840 |
79 | '' => 'IO', |
f10f6217 |
80 | ); |
81 | |
82 | sub _deconstruct_variable_name { |
83 | my ($self, $variable) = @_; |
84 | |
56a29840 |
85 | (defined $variable && length $variable) |
f10f6217 |
86 | || confess "You must pass a variable name"; |
87 | |
88 | my $sigil = substr($variable, 0, 1, ''); |
89 | |
56a29840 |
90 | if (exists $SIGIL_MAP{$sigil}) { |
91 | return ($variable, $sigil, $SIGIL_MAP{$sigil}); |
92 | } |
93 | else { |
94 | return ("${sigil}${variable}", '', $SIGIL_MAP{''}); |
95 | } |
f10f6217 |
96 | } |
97 | } |
98 | |
3634ce60 |
99 | sub _valid_for_type { |
100 | my $self = shift; |
101 | my ($value, $type) = @_; |
102 | if ($type eq 'HASH' || $type eq 'ARRAY' |
103 | || $type eq 'IO' || $type eq 'CODE') { |
104 | return reftype($value) eq $type; |
105 | } |
106 | else { |
107 | my $ref = reftype($value); |
bca98651 |
108 | return !defined($ref) || $ref eq 'SCALAR' || $ref eq 'REF' || $ref eq 'LVALUE' || $ref eq 'REGEXP'; |
3634ce60 |
109 | } |
110 | } |
111 | |
2905fb35 |
112 | sub add_symbol { |
640de369 |
113 | my ($self, $variable, $initial_value, %opts) = @_; |
f10f6217 |
114 | |
115 | my ($name, $sigil, $type) = ref $variable eq 'HASH' |
116 | ? @{$variable}{qw[name sigil type]} |
117 | : $self->_deconstruct_variable_name($variable); |
118 | |
4ada57e0 |
119 | my $pkg = $self->name; |
120 | |
3634ce60 |
121 | if (@_ > 2) { |
122 | $self->_valid_for_type($initial_value, $type) |
123 | || confess "$initial_value is not of type $type"; |
3634ce60 |
124 | |
4ada57e0 |
125 | # cheap fail-fast check for PERLDBf_SUBLINE and '&' |
126 | if ($^P and $^P & 0x10 && $sigil eq '&') { |
640de369 |
127 | my $filename = $opts{filename}; |
128 | my $first_line_num = $opts{first_line_num}; |
4ada57e0 |
129 | |
640de369 |
130 | (undef, $filename, $first_line_num) = caller |
4ada57e0 |
131 | if not defined $filename; |
640de369 |
132 | |
133 | my $last_line_num = $opts{last_line_num} || ($first_line_num ||= 0); |
4ada57e0 |
134 | |
135 | # http://perldoc.perl.org/perldebguts.html#Debugger-Internals |
640de369 |
136 | $DB::sub{$pkg . '::' . $name} = "$filename:$first_line_num-$last_line_num"; |
4ada57e0 |
137 | } |
138 | } |
f10f6217 |
139 | |
140 | no strict 'refs'; |
141 | no warnings 'redefine', 'misc', 'prototype'; |
142 | *{$pkg . '::' . $name} = ref $initial_value ? $initial_value : \$initial_value; |
143 | } |
144 | |
2905fb35 |
145 | sub remove_glob { |
f10f6217 |
146 | my ($self, $name) = @_; |
65b8253b |
147 | delete $self->namespace->{$name}; |
f10f6217 |
148 | } |
149 | |
2905fb35 |
150 | sub has_symbol { |
f10f6217 |
151 | my ($self, $variable) = @_; |
152 | |
153 | my ($name, $sigil, $type) = ref $variable eq 'HASH' |
154 | ? @{$variable}{qw[name sigil type]} |
155 | : $self->_deconstruct_variable_name($variable); |
156 | |
157 | my $namespace = $self->namespace; |
158 | |
159 | return unless exists $namespace->{$name}; |
160 | |
161 | my $entry_ref = \$namespace->{$name}; |
162 | if (reftype($entry_ref) eq 'GLOB') { |
f7543739 |
163 | # XXX: assigning to any typeglob slot also initializes the SCALAR slot, |
164 | # and saying that an undef scalar variable doesn't exist is probably |
165 | # vaguely less surprising than a scalar variable popping into existence |
166 | # without anyone defining it |
167 | if ($type eq 'SCALAR') { |
168 | return defined ${ *{$entry_ref}{$type} }; |
169 | } |
170 | else { |
171 | return defined *{$entry_ref}{$type}; |
172 | } |
f10f6217 |
173 | } |
174 | else { |
175 | # a symbol table entry can be -1 (stub), string (stub with prototype), |
176 | # or reference (constant) |
177 | return $type eq 'CODE'; |
178 | } |
179 | } |
180 | |
2905fb35 |
181 | sub get_symbol { |
e55803fc |
182 | my ($self, $variable, %opts) = @_; |
f10f6217 |
183 | |
184 | my ($name, $sigil, $type) = ref $variable eq 'HASH' |
185 | ? @{$variable}{qw[name sigil type]} |
186 | : $self->_deconstruct_variable_name($variable); |
187 | |
188 | my $namespace = $self->namespace; |
189 | |
7486ccf3 |
190 | if (!exists $namespace->{$name}) { |
dc378b60 |
191 | if ($opts{vivify}) { |
192 | if ($type eq 'ARRAY') { |
193 | if (BROKEN_ISA_ASSIGNMENT) { |
2905fb35 |
194 | $self->add_symbol( |
dc378b60 |
195 | $variable, |
196 | $name eq 'ISA' ? () : ([]) |
197 | ); |
198 | } |
199 | else { |
2905fb35 |
200 | $self->add_symbol($variable, []); |
dc378b60 |
201 | } |
202 | } |
203 | elsif ($type eq 'HASH') { |
2905fb35 |
204 | $self->add_symbol($variable, {}); |
dc378b60 |
205 | } |
206 | elsif ($type eq 'SCALAR') { |
2905fb35 |
207 | $self->add_symbol($variable); |
dc378b60 |
208 | } |
209 | elsif ($type eq 'IO') { |
2905fb35 |
210 | $self->add_symbol($variable, Symbol::geniosym); |
dc378b60 |
211 | } |
212 | elsif ($type eq 'CODE') { |
213 | confess "Don't know how to vivify CODE variables"; |
214 | } |
215 | else { |
216 | confess "Unknown type $type in vivication"; |
217 | } |
5d3589c8 |
218 | } |
e55803fc |
219 | else { |
4723417a |
220 | return undef; |
e55803fc |
221 | } |
30d1a098 |
222 | } |
f10f6217 |
223 | |
224 | my $entry_ref = \$namespace->{$name}; |
225 | |
226 | if (ref($entry_ref) eq 'GLOB') { |
227 | return *{$entry_ref}{$type}; |
228 | } |
229 | else { |
230 | if ($type eq 'CODE') { |
231 | no strict 'refs'; |
232 | return \&{ $self->name . '::' . $name }; |
233 | } |
234 | else { |
235 | return undef; |
236 | } |
237 | } |
238 | } |
239 | |
2905fb35 |
240 | sub get_or_add_symbol { |
e55803fc |
241 | my $self = shift; |
2905fb35 |
242 | $self->get_symbol(@_, vivify => 1); |
e55803fc |
243 | } |
244 | |
2905fb35 |
245 | sub remove_symbol { |
f10f6217 |
246 | my ($self, $variable) = @_; |
247 | |
248 | my ($name, $sigil, $type) = ref $variable eq 'HASH' |
249 | ? @{$variable}{qw[name sigil type]} |
250 | : $self->_deconstruct_variable_name($variable); |
251 | |
252 | # FIXME: |
9a3d1390 |
253 | # no doubt this is grossly inefficient and |
f10f6217 |
254 | # could be done much easier and faster in XS |
255 | |
b1a00d0e |
256 | my ($scalar_desc, $array_desc, $hash_desc, $code_desc, $io_desc) = ( |
f10f6217 |
257 | { sigil => '$', type => 'SCALAR', name => $name }, |
258 | { sigil => '@', type => 'ARRAY', name => $name }, |
259 | { sigil => '%', type => 'HASH', name => $name }, |
260 | { sigil => '&', type => 'CODE', name => $name }, |
b1a00d0e |
261 | { sigil => '', type => 'IO', name => $name }, |
f10f6217 |
262 | ); |
263 | |
b1a00d0e |
264 | my ($scalar, $array, $hash, $code, $io); |
f10f6217 |
265 | if ($type eq 'SCALAR') { |
2905fb35 |
266 | $array = $self->get_symbol($array_desc) if $self->has_symbol($array_desc); |
267 | $hash = $self->get_symbol($hash_desc) if $self->has_symbol($hash_desc); |
268 | $code = $self->get_symbol($code_desc) if $self->has_symbol($code_desc); |
269 | $io = $self->get_symbol($io_desc) if $self->has_symbol($io_desc); |
f10f6217 |
270 | } |
271 | elsif ($type eq 'ARRAY') { |
2905fb35 |
272 | $scalar = $self->get_symbol($scalar_desc); |
273 | $hash = $self->get_symbol($hash_desc) if $self->has_symbol($hash_desc); |
274 | $code = $self->get_symbol($code_desc) if $self->has_symbol($code_desc); |
275 | $io = $self->get_symbol($io_desc) if $self->has_symbol($io_desc); |
f10f6217 |
276 | } |
277 | elsif ($type eq 'HASH') { |
2905fb35 |
278 | $scalar = $self->get_symbol($scalar_desc); |
279 | $array = $self->get_symbol($array_desc) if $self->has_symbol($array_desc); |
280 | $code = $self->get_symbol($code_desc) if $self->has_symbol($code_desc); |
281 | $io = $self->get_symbol($io_desc) if $self->has_symbol($io_desc); |
f10f6217 |
282 | } |
283 | elsif ($type eq 'CODE') { |
2905fb35 |
284 | $scalar = $self->get_symbol($scalar_desc); |
285 | $array = $self->get_symbol($array_desc) if $self->has_symbol($array_desc); |
286 | $hash = $self->get_symbol($hash_desc) if $self->has_symbol($hash_desc); |
287 | $io = $self->get_symbol($io_desc) if $self->has_symbol($io_desc); |
b1a00d0e |
288 | } |
289 | elsif ($type eq 'IO') { |
2905fb35 |
290 | $scalar = $self->get_symbol($scalar_desc); |
291 | $array = $self->get_symbol($array_desc) if $self->has_symbol($array_desc); |
292 | $hash = $self->get_symbol($hash_desc) if $self->has_symbol($hash_desc); |
293 | $code = $self->get_symbol($code_desc) if $self->has_symbol($code_desc); |
f10f6217 |
294 | } |
295 | else { |
296 | confess "This should never ever ever happen"; |
297 | } |
298 | |
2905fb35 |
299 | $self->remove_glob($name); |
f10f6217 |
300 | |
2905fb35 |
301 | $self->add_symbol($scalar_desc => $scalar); |
302 | $self->add_symbol($array_desc => $array) if defined $array; |
303 | $self->add_symbol($hash_desc => $hash) if defined $hash; |
304 | $self->add_symbol($code_desc => $code) if defined $code; |
305 | $self->add_symbol($io_desc => $io) if defined $io; |
f10f6217 |
306 | } |
307 | |
2905fb35 |
308 | sub list_all_symbols { |
f10f6217 |
309 | my ($self, $type_filter) = @_; |
310 | |
311 | my $namespace = $self->namespace; |
312 | return keys %{$namespace} unless defined $type_filter; |
313 | |
314 | # NOTE: |
9a3d1390 |
315 | # or we can filter based on |
f10f6217 |
316 | # type (SCALAR|ARRAY|HASH|CODE) |
317 | if ($type_filter eq 'CODE') { |
318 | return grep { |
25c87f5c |
319 | # any non-typeglob in the symbol table is a constant or stub |
320 | ref(\$namespace->{$_}) ne 'GLOB' |
321 | # regular subs are stored in the CODE slot of the typeglob |
d1f721b3 |
322 | || defined(*{$namespace->{$_}}{CODE}) |
323 | } keys %{$namespace}; |
324 | } |
325 | elsif ($type_filter eq 'SCALAR') { |
326 | return grep { |
327 | ref(\$namespace->{$_}) eq 'GLOB' |
328 | && defined(${*{$namespace->{$_}}{'SCALAR'}}) |
329 | } keys %{$namespace}; |
330 | } |
331 | else { |
332 | return grep { |
333 | ref(\$namespace->{$_}) eq 'GLOB' |
334 | && defined(*{$namespace->{$_}}{$type_filter}) |
f10f6217 |
335 | } keys %{$namespace}; |
f10f6217 |
336 | } |
337 | } |
f4979588 |
338 | |
2905fb35 |
339 | sub get_all_symbols { |
340 | my ($self, $type_filter) = @_; |
341 | |
342 | my $namespace = $self->namespace; |
343 | return { %{$namespace} } unless defined $type_filter; |
344 | |
345 | return { |
346 | map { $_ => $self->get_symbol({name => $_, type => $type_filter}) } |
347 | $self->list_all_symbols($type_filter) |
348 | } |
349 | } |
350 | |
0992f4ec |
351 | =head1 BUGS |
352 | |
2905fb35 |
353 | =over 4 |
354 | |
355 | =item * Scalar slots are only considered to exist if they are defined |
356 | |
357 | This is due to a shortcoming within perl itself. See |
358 | L<perlref/Making References> point 7 for more information. |
359 | |
360 | =item * remove_symbol also replaces the associated typeglob |
361 | |
362 | This can cause unexpected behavior when doing manipulation at compile time - |
363 | removing subroutines will still allow them to be called from within the package |
364 | as subroutines (although they will not be available as methods). This can be |
365 | considered a feature in some cases (this is how L<namespace::clean> works, for |
366 | instance), but should not be relied upon - use C<remove_glob> directly if you |
367 | want this behavior. |
368 | |
cdb543b5 |
369 | =item * Some minor memory leaks |
370 | |
371 | The pure perl implementation has a couple minor memory leaks (see the TODO |
372 | tests in t/20-leaks.t) that I'm having a hard time tracking down - these may be |
373 | core perl bugs, it's hard to tell. |
374 | |
2905fb35 |
375 | =back |
0992f4ec |
376 | |
377 | Please report any bugs through RT: email |
378 | C<bug-package-stash at rt.cpan.org>, or browse to |
379 | L<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Package-Stash>. |
380 | |
f4979588 |
381 | =head1 SEE ALSO |
382 | |
f4979588 |
383 | =over 4 |
384 | |
988beb41 |
385 | =item * L<Class::MOP::Package> |
f4979588 |
386 | |
988beb41 |
387 | This module is a factoring out of code that used to live here |
f4979588 |
388 | |
389 | =back |
390 | |
0992f4ec |
391 | =head1 SUPPORT |
392 | |
393 | You can find this documentation for this module with the perldoc command. |
394 | |
395 | perldoc Package::Stash |
396 | |
397 | You can also look for information at: |
398 | |
399 | =over 4 |
400 | |
401 | =item * AnnoCPAN: Annotated CPAN documentation |
402 | |
403 | L<http://annocpan.org/dist/Package-Stash> |
404 | |
405 | =item * CPAN Ratings |
406 | |
407 | L<http://cpanratings.perl.org/d/Package-Stash> |
408 | |
409 | =item * RT: CPAN's request tracker |
410 | |
411 | L<http://rt.cpan.org/NoAuth/Bugs.html?Dist=Package-Stash> |
412 | |
413 | =item * Search CPAN |
414 | |
415 | L<http://search.cpan.org/dist/Package-Stash> |
416 | |
417 | =back |
418 | |
419 | =head1 AUTHOR |
420 | |
421 | Jesse Luehrs <doy at tozt dot net> |
422 | |
423 | Mostly copied from code from L<Class::MOP::Package>, by Stevan Little and the |
424 | Moose Cabal. |
425 | |
a912fc4b |
426 | =begin Pod::Coverage |
427 | |
428 | BROKEN_ISA_ASSIGNMENT |
429 | add_symbol |
430 | get_all_symbols |
431 | get_or_add_symbol |
432 | get_symbol |
433 | has_symbol |
434 | list_all_symbols |
435 | name |
436 | namespace |
437 | new |
438 | remove_glob |
439 | |
440 | =end Pod::Coverage |
441 | |
f4979588 |
442 | =cut |
443 | |
444 | 1; |