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58a9e587 | 1 | ######################################################################## |
a73f4a71 JRT |
2 | # $URL$ |
3 | # $Date$ | |
4 | # $Author$ | |
5 | # $Revision$ | |
5bf96118 CD |
6 | ######################################################################## |
7 | ||
8 | package Perl::Critic::Document; | |
9 | ||
5bf96118 | 10 | use strict; |
58a9e587 | 11 | use warnings; |
5bf96118 CD |
12 | use PPI::Document; |
13 | ||
58a9e587 JRT |
14 | #---------------------------------------------------------------------------- |
15 | ||
b22c8627 JRT |
16 | our $VERSION = '0.18_01'; |
17 | $VERSION = eval $VERSION; ## no critic | |
5bf96118 CD |
18 | |
19 | #---------------------------------------------------------------------------- | |
20 | ||
21 | our $AUTOLOAD; | |
22 | sub AUTOLOAD { ## no critic(ProhibitAutoloading) | |
23 | my ( $function_name ) = $AUTOLOAD =~ m/ ([^:\']+) \z /xms; | |
24 | return if $function_name eq 'DESTROY'; | |
25 | my $self = shift; | |
26 | return $self->{_doc}->$function_name(@_); | |
27 | } | |
28 | ||
58a9e587 | 29 | #---------------------------------------------------------------------------- |
5bf96118 | 30 | |
58a9e587 JRT |
31 | sub new { |
32 | my ($class, $doc) = @_; | |
5bf96118 CD |
33 | return bless { _doc => $doc }, $class; |
34 | } | |
35 | ||
58a9e587 JRT |
36 | #---------------------------------------------------------------------------- |
37 | ||
5bf96118 | 38 | sub find { |
58a9e587 | 39 | my ($self, $wanted) = @_; |
5bf96118 | 40 | |
58a9e587 JRT |
41 | # This method can only find elements by their class names. For |
42 | # other types of searches, delegate to the PPI::Document | |
5bf96118 CD |
43 | if ( ( ref $wanted ) || !$wanted || $wanted !~ m/ \A PPI:: /xms ) { |
44 | return $self->{_doc}->find($wanted, @_); | |
45 | } | |
58a9e587 JRT |
46 | |
47 | # Build the class cache if it doesn't exist. This happens at most | |
48 | # once per Perl::Critic::Document instance. %elements of will be | |
49 | # populated as a side-effect of calling the $finder_sub coderef | |
50 | # that is produced by the caching_finder() closure. | |
5bf96118 | 51 | if ( !$self->{_elements_of} ) { |
58a9e587 JRT |
52 | my %cache = ( 'PPI::Document' => [ $self ] ); |
53 | my $finder_coderef = _caching_finder( \%cache ); | |
54 | $self->{_doc}->find( $finder_coderef ); | |
55 | $self->{_elements_of} = \%cache; | |
56 | } | |
57 | ||
58 | # find() must return false-but-defined on fail | |
59 | return $self->{_elements_of}->{$wanted} || q{}; | |
60 | } | |
61 | ||
62 | #---------------------------------------------------------------------------- | |
63 | ||
fb21e21e CD |
64 | sub find_first { |
65 | my ($self, $wanted) = @_; | |
66 | ||
67 | # This method can only find elements by their class names. For | |
68 | # other types of searches, delegate to the PPI::Document | |
69 | if ( ( ref $wanted ) || !$wanted || $wanted !~ m/ \A PPI:: /xms ) { | |
70 | return $self->{_doc}->find_first($wanted, @_); | |
71 | } | |
72 | ||
73 | my $result = $self->find($wanted); | |
74 | return $result ? $result->[0] : $result; | |
75 | } | |
76 | ||
77 | #---------------------------------------------------------------------------- | |
78 | ||
58a9e587 JRT |
79 | sub _caching_finder { |
80 | ||
81 | my $cache_ref = shift; # These vars will persist for the life | |
82 | my %isa_cache = (); # of the code ref that this sub returns | |
83 | ||
84 | ||
85 | # Gather up all the PPI elements and sort by @ISA. Note: if any | |
86 | # instances used multiple inheritance, this implementation would | |
87 | # lead to multiple copies of $element in the $elements_of lists. | |
88 | # However, PPI::* doesn't do multiple inheritance, so we are safe | |
89 | ||
90 | return sub { | |
91 | my $element = $_[1]; | |
92 | my $classes = $isa_cache{ref $element}; | |
93 | if ( !$classes ) { | |
94 | $classes = [ ref $element ]; | |
95 | # Use a C-style loop because we append to the classes array inside | |
96 | for ( my $i = 0; $i < @{$classes}; $i++ ) { ## no critic(ProhibitCStyleForLoops) | |
97 | no strict 'refs'; ## no critic(ProhibitNoStrict) | |
98 | push @{$classes}, @{"$classes->[$i]::ISA"}; | |
99 | $cache_ref->{$classes->[$i]} ||= []; | |
5bf96118 | 100 | } |
58a9e587 JRT |
101 | $isa_cache{$classes->[0]} = $classes; |
102 | } | |
5bf96118 | 103 | |
58a9e587 JRT |
104 | for my $class ( @{$classes} ) { |
105 | push @{$cache_ref->{$class}}, $element; | |
106 | } | |
5bf96118 | 107 | |
58a9e587 JRT |
108 | return 0; # 0 tells find() to keep traversing, but not to store this $element |
109 | }; | |
5bf96118 CD |
110 | } |
111 | ||
58a9e587 JRT |
112 | #---------------------------------------------------------------------------- |
113 | ||
5bf96118 | 114 | 1; |
58a9e587 | 115 | |
5bf96118 CD |
116 | __END__ |
117 | ||
a73f4a71 JRT |
118 | =pod |
119 | ||
120 | =for stopwords pre-caches | |
121 | ||
5bf96118 CD |
122 | =head1 NAME |
123 | ||
124 | Perl::Critic::Document - Caching wrapper around PPI::Document | |
125 | ||
126 | =head1 SYNOPSIS | |
127 | ||
128 | use PPI::Document; | |
129 | use Perl::Critic::Document; | |
130 | my $doc = PPI::Document->new('Foo.pm'); | |
131 | $doc = Perl::Critic::Document->new($doc); | |
132 | ## Then use the instance just like a PPI::Document | |
133 | ||
134 | =head1 DESCRIPTION | |
135 | ||
136 | Perl::Critic does a lot of iterations over the PPI document tree via | |
137 | the C<PPI::Document::find()> method. To save some time, this class | |
138 | pre-caches a lot of the common C<find()> calls in a single traversal. | |
139 | Then, on subsequent requests we return the cached data. | |
140 | ||
141 | This is implemented as a facade, where method calls are handed to the | |
142 | stored C<PPI::Document> instance. | |
143 | ||
144 | =head1 CAVEATS | |
145 | ||
146 | This facade does not implement the overloaded operators from | |
147 | L<PPI::Document> (that is, the C<use overload ...> work). Therefore, | |
148 | users of this facade must not rely on that syntactic sugar. So, for | |
149 | example, instead of C<my $source = "$doc";> you should write C<my | |
150 | $source = $doc->content();> | |
151 | ||
152 | Perhaps there is a CPAN module out there which implements a facade | |
153 | better than we do here? | |
154 | ||
155 | =head1 METHODS | |
156 | ||
157 | =over | |
158 | ||
7076e807 CD |
159 | =item $pkg->new($doc) |
160 | ||
161 | Create a new instance referencing a PPI::Document instance. | |
162 | ||
5bf96118 CD |
163 | =item $self->find($wanted) |
164 | ||
fb21e21e CD |
165 | =item $self->find_first($wanted) |
166 | ||
167 | If C<$wanted> is a simple PPI class name, then the cache is employed. | |
168 | Otherwise we forward the call to the C<find()> or C<find_first()> | |
169 | method of the C<PPI::Document> instance. | |
5bf96118 CD |
170 | |
171 | =back | |
172 | ||
173 | =head1 AUTHOR | |
174 | ||
175 | Chris Dolan <cdolan@cpan.org> | |
176 | ||
177 | =head1 COPYRIGHT | |
178 | ||
179 | Copyright (c) 2006 Chris Dolan. All rights reserved. | |
180 | ||
181 | This program is free software; you can redistribute it and/or modify | |
182 | it under the same terms as Perl itself. The full text of this license | |
183 | can be found in the LICENSE file included with this module. | |
184 | ||
185 | =cut |