Current File : //usr/local/share/perl5/CPAN/Distroprefs.pm
# -*- Mode: cperl; coding: utf-8; cperl-indent-level: 4 -*-
# vim: ts=4 sts=4 sw=4:
use 5.006;
use strict;
package CPAN::Distroprefs;
use vars qw($VERSION);
$VERSION = '6.0001';
package CPAN::Distroprefs::Result;
use File::Spec;
sub new { bless $_[1] || {} => $_[0] }
sub abs { File::Spec->catfile($_[0]->dir, $_[0]->file) }
sub __cloner {
my ($class, $name, $newclass) = @_;
$newclass = 'CPAN::Distroprefs::Result::' . $newclass;
no strict 'refs';
*{$class . '::' . $name} = sub {
$newclass->new({
%{ $_[0] },
%{ $_[1] },
});
};
}
BEGIN { __PACKAGE__->__cloner(as_warning => 'Warning') }
BEGIN { __PACKAGE__->__cloner(as_fatal => 'Fatal') }
BEGIN { __PACKAGE__->__cloner(as_success => 'Success') }
sub __accessor {
my ($class, $key) = @_;
no strict 'refs';
*{$class . '::' . $key} = sub { $_[0]->{$key} };
}
BEGIN { __PACKAGE__->__accessor($_) for qw(type file ext dir) }
sub is_warning { 0 }
sub is_fatal { 0 }
sub is_success { 0 }
package CPAN::Distroprefs::Result::Error;
use vars qw(@ISA);
BEGIN { @ISA = 'CPAN::Distroprefs::Result' } ## no critic
BEGIN { __PACKAGE__->__accessor($_) for qw(msg) }
sub as_string {
my ($self) = @_;
if ($self->msg) {
return sprintf $self->fmt_reason, $self->file, $self->msg;
} else {
return sprintf $self->fmt_unknown, $self->file;
}
}
package CPAN::Distroprefs::Result::Warning;
use vars qw(@ISA);
BEGIN { @ISA = 'CPAN::Distroprefs::Result::Error' } ## no critic
sub is_warning { 1 }
sub fmt_reason { "Error reading distroprefs file %s, skipping: %s" }
sub fmt_unknown { "Unknown error reading distroprefs file %s, skipping." }
package CPAN::Distroprefs::Result::Fatal;
use vars qw(@ISA);
BEGIN { @ISA = 'CPAN::Distroprefs::Result::Error' } ## no critic
sub is_fatal { 1 }
sub fmt_reason { "Error reading distroprefs file %s: %s" }
sub fmt_unknown { "Unknown error reading distroprefs file %s." }
package CPAN::Distroprefs::Result::Success;
use vars qw(@ISA);
BEGIN { @ISA = 'CPAN::Distroprefs::Result' } ## no critic
BEGIN { __PACKAGE__->__accessor($_) for qw(prefs extension) }
sub is_success { 1 }
package CPAN::Distroprefs::Iterator;
sub new { bless $_[1] => $_[0] }
sub next { $_[0]->() }
package CPAN::Distroprefs;
use Carp ();
use DirHandle;
sub _load_method {
my ($self, $loader, $result) = @_;
return '_load_yaml' if $loader eq 'CPAN' or $loader =~ /^YAML(::|$)/;
return '_load_' . $result->ext;
}
sub _load_yaml {
my ($self, $loader, $result) = @_;
my $data = eval {
$loader eq 'CPAN'
? $loader->_yaml_loadfile($result->abs)
: [ $loader->can('LoadFile')->($result->abs) ]
};
if (my $err = $@) {
die $result->as_warning({
msg => $err,
});
} elsif (!$data) {
die $result->as_warning;
} else {
return @$data;
}
}
sub _load_dd {
my ($self, $loader, $result) = @_;
my @data;
{
package CPAN::Eval;
# this caused a die in CPAN.pm, and I am leaving it 'fatal', though I'm
# not sure why we wouldn't just skip the file as we do for all other
# errors. -- hdp
my $abs = $result->abs;
open FH, "<$abs" or die $result->as_fatal(msg => "$!");
local $/;
my $eval = <FH>;
close FH;
no strict;
eval $eval;
if (my $err = $@) {
die $result->as_warning({ msg => $err });
}
my $i = 1;
while (${"VAR$i"}) {
push @data, ${"VAR$i"};
$i++;
}
}
return @data;
}
sub _load_st {
my ($self, $loader, $result) = @_;
# eval because Storable is never forward compatible
my @data = eval { @{scalar $loader->can('retrieve')->($result->abs) } };
if (my $err = $@) {
die $result->as_warning({ msg => $err });
}
return @data;
}
sub _build_file_list {
if (@_ > 3) {
die "_build_file_list should be called with 3 arguments, was called with more. First argument is '$_[0]'.";
}
my ($dir, $dir1, $ext_re) = @_;
my @list;
my $dh;
unless (opendir($dh, $dir)) {
$CPAN::Frontend->mywarn("ignoring prefs directory '$dir': $!");
return @list;
}
while (my $fn = readdir $dh) {
next if $fn eq '.' || $fn eq '..';
if (-d "$dir/$fn") {
next if $fn =~ /^[._]/; # prune .svn, .git, .hg, _darcs and what the user wants to hide
push @list, _build_file_list("$dir/$fn", "$dir1$fn/", $ext_re);
} else {
if ($fn =~ $ext_re) {
push @list, "$dir1$fn";
}
}
}
return @list;
}
sub find {
my ($self, $dir, $ext_map) = @_;
return CPAN::Distroprefs::Iterator->new(sub { return }) unless %$ext_map;
my $possible_ext = join "|", map { quotemeta } keys %$ext_map;
my $ext_re = qr/\.($possible_ext)$/;
my @files = _build_file_list($dir, '', $ext_re);
@files = sort @files if @files;
# label the block so that we can use redo in the middle
return CPAN::Distroprefs::Iterator->new(sub { LOOP: {
my $fn = shift @files;
return unless defined $fn;
my ($ext) = $fn =~ $ext_re;
my $loader = $ext_map->{$ext};
my $result = CPAN::Distroprefs::Result->new({
file => $fn, ext => $ext, dir => $dir
});
# copied from CPAN.pm; is this ever actually possible?
redo unless -f $result->abs;
my $load_method = $self->_load_method($loader, $result);
my @prefs = eval { $self->$load_method($loader, $result) };
if (my $err = $@) {
if (ref($err) && eval { $err->isa('CPAN::Distroprefs::Result') }) {
return $err;
}
# rethrow any exceptions that we did not generate
die $err;
} elsif (!@prefs) {
# the loader should have handled this, but just in case:
return $result->as_warning;
}
return $result->as_success({
prefs => [
map { CPAN::Distroprefs::Pref->new({ data => $_ }) } @prefs
],
});
} });
}
package CPAN::Distroprefs::Pref;
use Carp ();
sub new { bless $_[1] => $_[0] }
sub data { shift->{data} }
sub has_any_match { $_[0]->data->{match} ? 1 : 0 }
sub has_match {
my $match = $_[0]->data->{match} || return 0;
exists $match->{$_[1]} || exists $match->{"not_$_[1]"}
}
sub has_valid_subkeys {
grep { exists $_[0]->data->{match}{$_} }
map { $_, "not_$_" }
$_[0]->match_attributes
}
sub _pattern {
my $re = shift;
my $p = eval sprintf 'qr{%s}', $re;
if ($@) {
$@ =~ s/\n$//;
die "Error in Distroprefs pattern qr{$re}\n$@";
}
return $p;
}
sub _match_scalar {
my ($match, $data) = @_;
my $qr = _pattern($match);
return $data =~ /$qr/;
}
sub _match_hash {
my ($match, $data) = @_;
for my $mkey (keys %$match) {
(my $dkey = $mkey) =~ s/^not_//;
my $val = defined $data->{$dkey} ? $data->{$dkey} : '';
if (_match_scalar($match->{$mkey}, $val)) {
return 0 if $mkey =~ /^not_/;
}
else {
return 0 if $mkey !~ /^not_/;
}
}
return 1;
}
sub _match {
my ($self, $key, $data, $matcher) = @_;
my $m = $self->data->{match};
if (exists $m->{$key}) {
return 0 unless $matcher->($m->{$key}, $data);
}
if (exists $m->{"not_$key"}) {
return 0 if $matcher->($m->{"not_$key"}, $data);
}
return 1;
}
sub _scalar_match {
my ($self, $key, $data) = @_;
return $self->_match($key, $data, \&_match_scalar);
}
sub _hash_match {
my ($self, $key, $data) = @_;
return $self->_match($key, $data, \&_match_hash);
}
# do not take the order of C<keys %$match> because "module" is by far the
# slowest
sub match_attributes { qw(env distribution perl perlconfig module) }
sub match_module {
my ($self, $modules) = @_;
return $self->_match("module", $modules, sub {
my($match, $data) = @_;
my $qr = _pattern($match);
for my $module (@$data) {
return 1 if $module =~ /$qr/;
}
return 0;
});
}
sub match_distribution { shift->_scalar_match(distribution => @_) }
sub match_perl { shift->_scalar_match(perl => @_) }
sub match_perlconfig { shift->_hash_match(perlconfig => @_) }
sub match_env { shift->_hash_match(env => @_) }
sub matches {
my ($self, $arg) = @_;
my $default_match = 0;
for my $key (grep { $self->has_match($_) } $self->match_attributes) {
unless (exists $arg->{$key}) {
Carp::croak "Can't match pref: missing argument key $key";
}
$default_match = 1;
my $val = $arg->{$key};
# make it possible to avoid computing things until we have to
if (ref($val) eq 'CODE') { $val = $val->() }
my $meth = "match_$key";
return 0 unless $self->$meth($val);
}
return $default_match;
}
1;
__END__
=head1 NAME
CPAN::Distroprefs -- read and match distroprefs
=head1 SYNOPSIS
use CPAN::Distroprefs;
my %info = (... distribution/environment info ...);
my $finder = CPAN::Distroprefs->find($prefs_dir, \%ext_map);
while (my $result = $finder->next) {
die $result->as_string if $result->is_fatal;
warn($result->as_string), next if $result->is_warning;
for my $pref (@{ $result->prefs }) {
if ($pref->matches(\%info)) {
return $pref;
}
}
}
=head1 DESCRIPTION
This module encapsulates reading L<Distroprefs|CPAN> and matching them against CPAN distributions.
=head1 INTERFACE
my $finder = CPAN::Distroprefs->find($dir, \%ext_map);
while (my $result = $finder->next) { ... }
Build an iterator which finds distroprefs files in the tree below the
given directory. Within the tree directories matching C<m/^[._]/> are
pruned.
C<%ext_map> is a hashref whose keys are file extensions and whose values are
modules used to load matching files:
{
'yml' => 'YAML::Syck',
'dd' => 'Data::Dumper',
...
}
Each time C<< $finder->next >> is called, the iterator returns one of two
possible values:
=over
=item * a CPAN::Distroprefs::Result object
=item * C<undef>, indicating that no prefs files remain to be found
=back
=head1 RESULTS
L<C<find()>|/INTERFACE> returns CPAN::Distroprefs::Result objects to
indicate success or failure when reading a prefs file.
=head2 Common
All results share some common attributes:
=head3 type
C<success>, C<warning>, or C<fatal>
=head3 file
the file from which these prefs were read, or to which this error refers (relative filename)
=head3 ext
the file's extension, which determines how to load it
=head3 dir
the directory the file was read from
=head3 abs
the absolute path to the file
=head2 Errors
Error results (warning and fatal) contain:
=head3 msg
the error message (usually either C<$!> or a YAML error)
=head2 Successes
Success results contain:
=head3 prefs
an arrayref of CPAN::Distroprefs::Pref objects
=head1 PREFS
CPAN::Distroprefs::Pref objects represent individual distroprefs documents.
They are constructed automatically as part of C<success> results from C<find()>.
=head3 data
the pref information as a hashref, suitable for e.g. passing to Kwalify
=head3 match_attributes
returns a list of the valid match attributes (see the Distroprefs section in L<CPAN>)
currently: C<env perl perlconfig distribution module>
=head3 has_any_match
true if this pref has a 'match' attribute at all
=head3 has_valid_subkeys
true if this pref has a 'match' attribute and at least one valid match attribute
=head3 matches
if ($pref->matches(\%arg)) { ... }
true if this pref matches the passed-in hashref, which must have a value for
each of the C<match_attributes> (above)
=head1 LICENSE
This program is free software; you can redistribute it and/or modify it under
the same terms as Perl itself.
=cut
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