Bug 1350466 - Uplift bug 1342832 to bmo for performance and other reasons

1 files changed, 142 insertions, 0 deletions

diff --git a/Bugzilla/CPAN.pm b/Bugzilla/CPAN.pm
new file mode 100644
index 000000000..f044e45bc
--- /dev/null
+++ b/Bugzilla/CPAN.pm
@@ -0,0 +1,142 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+#
+# This Source Code Form is "Incompatible With Secondary Licenses", as
+# defined by the Mozilla Public License, v. 2.0.
+
+package Bugzilla::CPAN;
+
+use 5.10.1;
+use strict;
+use warnings;
+
+use Bugzilla::Constants qw(bz_locations);
+use Bugzilla::Install::Requirements qw(check_cpan_feature);
+
+BEGIN {
+    my $json_xs_ok = eval {
+        require JSON::XS;
+        require JSON;
+        JSON->VERSION("2.5");
+        1;
+    };
+    if ($json_xs_ok) {
+        $ENV{PERL_JSON_BACKEND} = 'JSON::XS';
+    }
+}
+
+use constant _CAN_HAS_FEATURE => eval {
+    require CPAN::Meta::Prereqs;
+    require CPAN::Meta::Requirements;
+    require Module::Metadata;
+    require Module::Runtime;
+    CPAN::Meta::Prereqs->VERSION('2.132830');
+    CPAN::Meta::Requirements->VERSION('2.121');
+    Module::Metadata->VERSION('1.000019');
+    1;
+};
+
+my (%FEATURE, %FEATURE_LOADED);
+
+sub cpan_meta {
+    my ($class) = @_;
+    my $dir  = bz_locations()->{libpath};
+    my $file = File::Spec->catfile($dir, 'MYMETA.json');
+    state $CPAN_META;
+
+    return $CPAN_META if $CPAN_META;
+
+    if (-f $file) {
+        open my $meta_fh, '<', $file or die "unable to open $file: $!";
+        my $str = do { local $/ = undef; scalar <$meta_fh> };
+        # detaint
+        $str =~ /^(.+)$/s; $str = $1;
+        close $meta_fh;
+
+        return $CPAN_META = CPAN::Meta->load_json_string($str);
+    }
+    else {
+        require Bugzilla::Error;
+        Bugzilla::Error::ThrowCodeError('cpan_meta_missing');
+    }
+}
+
+sub cpan_requirements {
+    my ($class, $prereqs) = @_;
+    if ($prereqs->can('merged_requirements')) {
+        return $prereqs->merged_requirements( [ 'configure', 'runtime' ], ['requires'] );
+    }
+    else {
+        my $req = CPAN::Meta::Requirements->new;
+        $req->add_requirements( $prereqs->requirements_for('configure', 'requires') );
+        $req->add_requirements( $prereqs->requirements_for('runtime', 'requires') );
+        return $req;
+    }
+}
+
+sub has_feature {
+    my ($class, $feature_name) = @_;
+
+    return 0 unless _CAN_HAS_FEATURE;
+    return $FEATURE{$feature_name} if exists $FEATURE{ $feature_name };
+
+    my $meta = $class->cpan_meta;
+    my $feature = eval { $meta->feature($feature_name) }
+      or ThrowCodeError('invalid_feature', { feature => $feature_name });
+
+    return $FEATURE{$feature_name} = check_cpan_feature($feature)->{ok};
+}
+
+
+# Bugzilla expects this will also load all the modules.. so we have to do that.
+# Later we should put a deprecation warning here, and favor calling has_feature().
+sub feature {
+    my ($class, $feature_name) = @_;
+    return 0 unless _CAN_HAS_FEATURE;
+    return 1 if $FEATURE_LOADED{$feature_name};
+    return 0 unless $class->has_feature($feature_name);
+ 
+    my $meta = $class->cpan_meta;
+    my $feature = $meta->feature($feature_name);
+    my @modules = $feature->prereqs->merged_requirements->required_modules;
+    Module::Runtime::require_module($_) foreach @modules;
+    return $FEATURE_LOADED{$feature_name} = 1;
+}
+
+1;
+
+__END__
+
+
+=head1 NAME
+
+Bugzilla::CPAN - Methods relating to Bugzilla's CPAN metadata (including features)
+
+=head1 SYNOPSIS
+
+  use Bugzilla;
+  Bugzilla->cpan_meta;
+  Bugzilla->feature('psgi');
+  Bugzilla->has_feature('psgi');
+
+=head1 DESCRIPTION
+
+You most likely never need to use this module directly, as the Bugzilla factory class inherits all of these class methods.
+It exists so that cpan metadata can be read in before the rest of Bugzilla.pm is loaded in checksetup.pl
+
+=head1 CLASS METHODS
+
+=head2 C<feature>
+
+Wrapper around C<has_feature()> that also loads all of required modules into the runtime.
+
+=head2 C<has_feature>
+
+Consults F<MYMETA.yml> for optional Bugzilla features and returns true if all the requirements
+are installed.
+
+=head2 C<cpan_meta>
+
+Returns a L<CPAN::Meta> from the contents of MYMETA.json in the bugzilla directory.
+