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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 | |
7ef54f40 |
6 | use B; |
f10f6217 |
7 | use Carp qw(confess); |
eb53b1bd |
8 | use Scalar::Util qw(blessed reftype weaken); |
dc378b60 |
9 | use Symbol; |
10 | # before 5.12, assigning to the ISA glob would make it lose its magical ->isa |
11 | # powers |
12 | use constant BROKEN_ISA_ASSIGNMENT => ($] < 5.012); |
36cbfbad |
13 | # before 5.10, stashes don't ever seem to drop to a refcount of zero, so |
14 | # weakening them isn't helpful |
15 | use constant BROKEN_WEAK_STASH => ($] < 5.010); |
7ef54f40 |
16 | # before 5.10, the scalar slot was always treated as existing if the |
17 | # glob existed |
18 | use constant BROKEN_SCALAR_INITIALIZATION => ($] < 5.010); |
f4979588 |
19 | |
f4979588 |
20 | =head1 SYNOPSIS |
21 | |
2905fb35 |
22 | use Package::Stash; |
f4979588 |
23 | |
24 | =head1 DESCRIPTION |
25 | |
2905fb35 |
26 | 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 |
27 | |
28 | =cut |
29 | |
f10f6217 |
30 | sub new { |
31 | my $class = shift; |
e55970bc |
32 | my ($package) = @_; |
774f4f10 |
33 | |
91a61819 |
34 | if (!defined($package) || (ref($package) && reftype($package) ne 'HASH')) { |
774f4f10 |
35 | confess "Package::Stash->new must be passed the name of the " |
36 | . "package to access"; |
37 | } |
91a61819 |
38 | elsif (ref($package) && reftype($package) eq 'HASH') { |
39 | return bless { |
40 | 'namespace' => $package, |
41 | }, $class; |
774f4f10 |
42 | } |
91a61819 |
43 | elsif ($package =~ /\A[0-9A-Z_a-z]+(?:::[0-9A-Z_a-z]+)*\z/) { |
44 | return bless { |
45 | 'package' => $package, |
46 | }, $class; |
47 | } |
48 | else { |
ed131e41 |
49 | confess "$package is not a module name"; |
50 | } |
774f4f10 |
51 | |
f10f6217 |
52 | } |
53 | |
54 | sub name { |
2905fb35 |
55 | confess "Can't call name as a class method" |
56 | unless blessed($_[0]); |
91a61819 |
57 | confess "Can't get the name of an anonymous package" |
58 | unless defined($_[0]->{package}); |
f10f6217 |
59 | return $_[0]->{package}; |
60 | } |
61 | |
62 | sub namespace { |
2905fb35 |
63 | confess "Can't call namespace as a class method" |
64 | unless blessed($_[0]); |
eb53b1bd |
65 | |
36cbfbad |
66 | if (BROKEN_WEAK_STASH) { |
eb53b1bd |
67 | no strict 'refs'; |
36cbfbad |
68 | return \%{$_[0]->name . '::'}; |
eb53b1bd |
69 | } |
36cbfbad |
70 | else { |
71 | return $_[0]->{namespace} if defined $_[0]->{namespace}; |
eb53b1bd |
72 | |
36cbfbad |
73 | { |
74 | no strict 'refs'; |
75 | $_[0]->{namespace} = \%{$_[0]->name . '::'}; |
76 | } |
77 | |
78 | weaken($_[0]->{namespace}); |
eb53b1bd |
79 | |
36cbfbad |
80 | return $_[0]->{namespace}; |
81 | } |
f10f6217 |
82 | } |
83 | |
84 | { |
85 | my %SIGIL_MAP = ( |
86 | '$' => 'SCALAR', |
87 | '@' => 'ARRAY', |
88 | '%' => 'HASH', |
89 | '&' => 'CODE', |
56a29840 |
90 | '' => 'IO', |
f10f6217 |
91 | ); |
92 | |
93 | sub _deconstruct_variable_name { |
94 | my ($self, $variable) = @_; |
95 | |
6a42a16c |
96 | my @ret; |
97 | if (ref($variable) eq 'HASH') { |
98 | @ret = @{$variable}{qw[name sigil type]}; |
99 | } |
100 | else { |
101 | (defined $variable && length $variable) |
102 | || confess "You must pass a variable name"; |
103 | |
104 | my $sigil = substr($variable, 0, 1, ''); |
105 | |
106 | if (exists $SIGIL_MAP{$sigil}) { |
107 | @ret = ($variable, $sigil, $SIGIL_MAP{$sigil}); |
108 | } |
109 | else { |
110 | @ret = ("${sigil}${variable}", '', $SIGIL_MAP{''}); |
111 | } |
112 | } |
f10f6217 |
113 | |
875d2d1d |
114 | # XXX in pure perl, this will access things in inner packages, |
115 | # in xs, this will segfault - probably look more into this at |
116 | # some point |
6a42a16c |
117 | ($ret[0] !~ /::/) |
875d2d1d |
118 | || confess "Variable names may not contain ::"; |
119 | |
6a42a16c |
120 | return @ret; |
f10f6217 |
121 | } |
122 | } |
123 | |
3634ce60 |
124 | sub _valid_for_type { |
125 | my $self = shift; |
126 | my ($value, $type) = @_; |
127 | if ($type eq 'HASH' || $type eq 'ARRAY' |
128 | || $type eq 'IO' || $type eq 'CODE') { |
129 | return reftype($value) eq $type; |
130 | } |
131 | else { |
132 | my $ref = reftype($value); |
d173d3a3 |
133 | return !defined($ref) || $ref eq 'SCALAR' || $ref eq 'REF' || $ref eq 'LVALUE' || $ref eq 'REGEXP' || $ref eq 'VSTRING'; |
3634ce60 |
134 | } |
135 | } |
136 | |
2905fb35 |
137 | sub add_symbol { |
640de369 |
138 | my ($self, $variable, $initial_value, %opts) = @_; |
f10f6217 |
139 | |
6a42a16c |
140 | my ($name, $sigil, $type) = $self->_deconstruct_variable_name($variable); |
f10f6217 |
141 | |
3634ce60 |
142 | if (@_ > 2) { |
143 | $self->_valid_for_type($initial_value, $type) |
144 | || confess "$initial_value is not of type $type"; |
3634ce60 |
145 | |
4ada57e0 |
146 | # cheap fail-fast check for PERLDBf_SUBLINE and '&' |
147 | if ($^P and $^P & 0x10 && $sigil eq '&') { |
640de369 |
148 | my $filename = $opts{filename}; |
149 | my $first_line_num = $opts{first_line_num}; |
4ada57e0 |
150 | |
640de369 |
151 | (undef, $filename, $first_line_num) = caller |
4ada57e0 |
152 | if not defined $filename; |
640de369 |
153 | |
154 | my $last_line_num = $opts{last_line_num} || ($first_line_num ||= 0); |
4ada57e0 |
155 | |
156 | # http://perldoc.perl.org/perldebguts.html#Debugger-Internals |
50419d91 |
157 | $DB::sub{$self->name . '::' . $name} = "$filename:$first_line_num-$last_line_num"; |
4ada57e0 |
158 | } |
159 | } |
f10f6217 |
160 | |
50419d91 |
161 | my $namespace = $self->namespace; |
c049a789 |
162 | $namespace->{$name} ||= *{ Symbol::gensym() }; |
0f40e41f |
163 | |
164 | if (@_ > 2) { |
165 | *{ $namespace->{$name} } = ref $initial_value |
166 | ? $initial_value : \$initial_value; |
167 | } |
f10f6217 |
168 | } |
169 | |
2905fb35 |
170 | sub remove_glob { |
f10f6217 |
171 | my ($self, $name) = @_; |
65b8253b |
172 | delete $self->namespace->{$name}; |
f10f6217 |
173 | } |
174 | |
2905fb35 |
175 | sub has_symbol { |
f10f6217 |
176 | my ($self, $variable) = @_; |
177 | |
6a42a16c |
178 | my ($name, $sigil, $type) = $self->_deconstruct_variable_name($variable); |
f10f6217 |
179 | |
180 | my $namespace = $self->namespace; |
181 | |
182 | return unless exists $namespace->{$name}; |
183 | |
184 | my $entry_ref = \$namespace->{$name}; |
185 | if (reftype($entry_ref) eq 'GLOB') { |
f7543739 |
186 | if ($type eq 'SCALAR') { |
7ef54f40 |
187 | if (BROKEN_SCALAR_INITIALIZATION) { |
188 | return defined ${ *{$entry_ref}{$type} }; |
189 | } |
190 | else { |
191 | return B::svref_2object($entry_ref)->SV->isa('B::SV'); |
192 | } |
f7543739 |
193 | } |
194 | else { |
195 | return defined *{$entry_ref}{$type}; |
196 | } |
f10f6217 |
197 | } |
198 | else { |
199 | # a symbol table entry can be -1 (stub), string (stub with prototype), |
200 | # or reference (constant) |
201 | return $type eq 'CODE'; |
202 | } |
203 | } |
204 | |
2905fb35 |
205 | sub get_symbol { |
e55803fc |
206 | my ($self, $variable, %opts) = @_; |
f10f6217 |
207 | |
6a42a16c |
208 | my ($name, $sigil, $type) = $self->_deconstruct_variable_name($variable); |
f10f6217 |
209 | |
210 | my $namespace = $self->namespace; |
211 | |
7486ccf3 |
212 | if (!exists $namespace->{$name}) { |
dc378b60 |
213 | if ($opts{vivify}) { |
214 | if ($type eq 'ARRAY') { |
215 | if (BROKEN_ISA_ASSIGNMENT) { |
2905fb35 |
216 | $self->add_symbol( |
dc378b60 |
217 | $variable, |
218 | $name eq 'ISA' ? () : ([]) |
219 | ); |
220 | } |
221 | else { |
2905fb35 |
222 | $self->add_symbol($variable, []); |
dc378b60 |
223 | } |
224 | } |
225 | elsif ($type eq 'HASH') { |
2905fb35 |
226 | $self->add_symbol($variable, {}); |
dc378b60 |
227 | } |
228 | elsif ($type eq 'SCALAR') { |
2905fb35 |
229 | $self->add_symbol($variable); |
dc378b60 |
230 | } |
231 | elsif ($type eq 'IO') { |
2905fb35 |
232 | $self->add_symbol($variable, Symbol::geniosym); |
dc378b60 |
233 | } |
234 | elsif ($type eq 'CODE') { |
235 | confess "Don't know how to vivify CODE variables"; |
236 | } |
237 | else { |
238 | confess "Unknown type $type in vivication"; |
239 | } |
5d3589c8 |
240 | } |
e55803fc |
241 | else { |
4723417a |
242 | return undef; |
e55803fc |
243 | } |
30d1a098 |
244 | } |
f10f6217 |
245 | |
246 | my $entry_ref = \$namespace->{$name}; |
247 | |
248 | if (ref($entry_ref) eq 'GLOB') { |
249 | return *{$entry_ref}{$type}; |
250 | } |
251 | else { |
252 | if ($type eq 'CODE') { |
d6213159 |
253 | # XXX we should really be able to support arbitrary anonymous |
254 | # stashes here... (not just via Package::Anon) |
255 | if (blessed($namespace) && $namespace->isa('Package::Anon')) { |
256 | # ->can will call gv_init for us |
257 | $namespace->bless(\(my $foo))->can($name); |
258 | return *{ $namespace->{$name} }{CODE}; |
259 | } |
260 | else { |
261 | no strict 'refs'; |
262 | return \&{ $self->name . '::' . $name }; |
263 | } |
f10f6217 |
264 | } |
265 | else { |
266 | return undef; |
267 | } |
268 | } |
269 | } |
270 | |
2905fb35 |
271 | sub get_or_add_symbol { |
e55803fc |
272 | my $self = shift; |
2905fb35 |
273 | $self->get_symbol(@_, vivify => 1); |
e55803fc |
274 | } |
275 | |
2905fb35 |
276 | sub remove_symbol { |
f10f6217 |
277 | my ($self, $variable) = @_; |
278 | |
6a42a16c |
279 | my ($name, $sigil, $type) = $self->_deconstruct_variable_name($variable); |
f10f6217 |
280 | |
281 | # FIXME: |
9a3d1390 |
282 | # no doubt this is grossly inefficient and |
f10f6217 |
283 | # could be done much easier and faster in XS |
284 | |
b1a00d0e |
285 | my ($scalar_desc, $array_desc, $hash_desc, $code_desc, $io_desc) = ( |
f10f6217 |
286 | { sigil => '$', type => 'SCALAR', name => $name }, |
287 | { sigil => '@', type => 'ARRAY', name => $name }, |
288 | { sigil => '%', type => 'HASH', name => $name }, |
289 | { sigil => '&', type => 'CODE', name => $name }, |
b1a00d0e |
290 | { sigil => '', type => 'IO', name => $name }, |
f10f6217 |
291 | ); |
292 | |
b1a00d0e |
293 | my ($scalar, $array, $hash, $code, $io); |
f10f6217 |
294 | if ($type eq 'SCALAR') { |
2905fb35 |
295 | $array = $self->get_symbol($array_desc) if $self->has_symbol($array_desc); |
296 | $hash = $self->get_symbol($hash_desc) if $self->has_symbol($hash_desc); |
297 | $code = $self->get_symbol($code_desc) if $self->has_symbol($code_desc); |
298 | $io = $self->get_symbol($io_desc) if $self->has_symbol($io_desc); |
f10f6217 |
299 | } |
300 | elsif ($type eq 'ARRAY') { |
7ef54f40 |
301 | $scalar = $self->get_symbol($scalar_desc) if $self->has_symbol($scalar_desc) || BROKEN_SCALAR_INITIALIZATION; |
2905fb35 |
302 | $hash = $self->get_symbol($hash_desc) if $self->has_symbol($hash_desc); |
303 | $code = $self->get_symbol($code_desc) if $self->has_symbol($code_desc); |
304 | $io = $self->get_symbol($io_desc) if $self->has_symbol($io_desc); |
f10f6217 |
305 | } |
306 | elsif ($type eq 'HASH') { |
7ef54f40 |
307 | $scalar = $self->get_symbol($scalar_desc) if $self->has_symbol($scalar_desc) || BROKEN_SCALAR_INITIALIZATION; |
2905fb35 |
308 | $array = $self->get_symbol($array_desc) if $self->has_symbol($array_desc); |
309 | $code = $self->get_symbol($code_desc) if $self->has_symbol($code_desc); |
310 | $io = $self->get_symbol($io_desc) if $self->has_symbol($io_desc); |
f10f6217 |
311 | } |
312 | elsif ($type eq 'CODE') { |
7ef54f40 |
313 | $scalar = $self->get_symbol($scalar_desc) if $self->has_symbol($scalar_desc) || BROKEN_SCALAR_INITIALIZATION; |
2905fb35 |
314 | $array = $self->get_symbol($array_desc) if $self->has_symbol($array_desc); |
315 | $hash = $self->get_symbol($hash_desc) if $self->has_symbol($hash_desc); |
316 | $io = $self->get_symbol($io_desc) if $self->has_symbol($io_desc); |
b1a00d0e |
317 | } |
318 | elsif ($type eq 'IO') { |
7ef54f40 |
319 | $scalar = $self->get_symbol($scalar_desc) if $self->has_symbol($scalar_desc) || BROKEN_SCALAR_INITIALIZATION; |
2905fb35 |
320 | $array = $self->get_symbol($array_desc) if $self->has_symbol($array_desc); |
321 | $hash = $self->get_symbol($hash_desc) if $self->has_symbol($hash_desc); |
322 | $code = $self->get_symbol($code_desc) if $self->has_symbol($code_desc); |
f10f6217 |
323 | } |
324 | else { |
325 | confess "This should never ever ever happen"; |
326 | } |
327 | |
2905fb35 |
328 | $self->remove_glob($name); |
f10f6217 |
329 | |
7ef54f40 |
330 | $self->add_symbol($scalar_desc => $scalar) if defined $scalar; |
2905fb35 |
331 | $self->add_symbol($array_desc => $array) if defined $array; |
332 | $self->add_symbol($hash_desc => $hash) if defined $hash; |
333 | $self->add_symbol($code_desc => $code) if defined $code; |
334 | $self->add_symbol($io_desc => $io) if defined $io; |
f10f6217 |
335 | } |
336 | |
2905fb35 |
337 | sub list_all_symbols { |
f10f6217 |
338 | my ($self, $type_filter) = @_; |
339 | |
340 | my $namespace = $self->namespace; |
341 | return keys %{$namespace} unless defined $type_filter; |
342 | |
343 | # NOTE: |
9a3d1390 |
344 | # or we can filter based on |
f10f6217 |
345 | # type (SCALAR|ARRAY|HASH|CODE) |
346 | if ($type_filter eq 'CODE') { |
347 | return grep { |
25c87f5c |
348 | # any non-typeglob in the symbol table is a constant or stub |
349 | ref(\$namespace->{$_}) ne 'GLOB' |
350 | # regular subs are stored in the CODE slot of the typeglob |
d1f721b3 |
351 | || defined(*{$namespace->{$_}}{CODE}) |
352 | } keys %{$namespace}; |
353 | } |
354 | elsif ($type_filter eq 'SCALAR') { |
355 | return grep { |
7ef54f40 |
356 | BROKEN_SCALAR_INITIALIZATION |
357 | ? (ref(\$namespace->{$_}) eq 'GLOB' |
358 | && defined(${*{$namespace->{$_}}{'SCALAR'}})) |
359 | : (do { |
360 | my $entry = \$namespace->{$_}; |
361 | ref($entry) eq 'GLOB' |
362 | && B::svref_2object($entry)->SV->isa('B::SV') |
363 | }) |
d1f721b3 |
364 | } keys %{$namespace}; |
365 | } |
366 | else { |
367 | return grep { |
368 | ref(\$namespace->{$_}) eq 'GLOB' |
369 | && defined(*{$namespace->{$_}}{$type_filter}) |
f10f6217 |
370 | } keys %{$namespace}; |
f10f6217 |
371 | } |
372 | } |
f4979588 |
373 | |
2905fb35 |
374 | sub get_all_symbols { |
375 | my ($self, $type_filter) = @_; |
376 | |
377 | my $namespace = $self->namespace; |
378 | return { %{$namespace} } unless defined $type_filter; |
379 | |
380 | return { |
381 | map { $_ => $self->get_symbol({name => $_, type => $type_filter}) } |
382 | $self->list_all_symbols($type_filter) |
383 | } |
384 | } |
385 | |
0992f4ec |
386 | =head1 BUGS |
387 | |
2905fb35 |
388 | =over 4 |
389 | |
2905fb35 |
390 | =item * remove_symbol also replaces the associated typeglob |
391 | |
392 | This can cause unexpected behavior when doing manipulation at compile time - |
393 | removing subroutines will still allow them to be called from within the package |
394 | as subroutines (although they will not be available as methods). This can be |
395 | considered a feature in some cases (this is how L<namespace::clean> works, for |
396 | instance), but should not be relied upon - use C<remove_glob> directly if you |
397 | want this behavior. |
398 | |
cdb543b5 |
399 | =item * Some minor memory leaks |
400 | |
401 | The pure perl implementation has a couple minor memory leaks (see the TODO |
402 | tests in t/20-leaks.t) that I'm having a hard time tracking down - these may be |
403 | core perl bugs, it's hard to tell. |
404 | |
2905fb35 |
405 | =back |
0992f4ec |
406 | |
407 | Please report any bugs through RT: email |
408 | C<bug-package-stash at rt.cpan.org>, or browse to |
409 | L<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Package-Stash>. |
410 | |
f4979588 |
411 | =head1 SEE ALSO |
412 | |
f4979588 |
413 | =over 4 |
414 | |
988beb41 |
415 | =item * L<Class::MOP::Package> |
f4979588 |
416 | |
988beb41 |
417 | This module is a factoring out of code that used to live here |
f4979588 |
418 | |
419 | =back |
420 | |
0992f4ec |
421 | =head1 SUPPORT |
422 | |
423 | You can find this documentation for this module with the perldoc command. |
424 | |
425 | perldoc Package::Stash |
426 | |
427 | You can also look for information at: |
428 | |
429 | =over 4 |
430 | |
431 | =item * AnnoCPAN: Annotated CPAN documentation |
432 | |
433 | L<http://annocpan.org/dist/Package-Stash> |
434 | |
435 | =item * CPAN Ratings |
436 | |
437 | L<http://cpanratings.perl.org/d/Package-Stash> |
438 | |
439 | =item * RT: CPAN's request tracker |
440 | |
441 | L<http://rt.cpan.org/NoAuth/Bugs.html?Dist=Package-Stash> |
442 | |
443 | =item * Search CPAN |
444 | |
445 | L<http://search.cpan.org/dist/Package-Stash> |
446 | |
447 | =back |
448 | |
449 | =head1 AUTHOR |
450 | |
451 | Jesse Luehrs <doy at tozt dot net> |
452 | |
453 | Mostly copied from code from L<Class::MOP::Package>, by Stevan Little and the |
454 | Moose Cabal. |
455 | |
a912fc4b |
456 | =begin Pod::Coverage |
457 | |
458 | BROKEN_ISA_ASSIGNMENT |
459 | add_symbol |
460 | get_all_symbols |
461 | get_or_add_symbol |
462 | get_symbol |
463 | has_symbol |
464 | list_all_symbols |
465 | name |
466 | namespace |
467 | new |
468 | remove_glob |
469 | |
470 | =end Pod::Coverage |
471 | |
f4979588 |
472 | =cut |
473 | |
474 | 1; |