use strict;
use warnings;
package CPAN::Meta::Merge;
# VERSION
$CPAN::Meta::Merge::VERSION = '2.143240';
use Carp qw/croak/;
use Scalar::Util qw/blessed/;
use CPAN::Meta::Converter;
sub _identical {
my ($left, $right, $path) = @_;
croak sprintf "Can't merge attribute %s: '%s' does not equal '%s'", join('.', @{$path}), $left, $right unless $left eq $right;
return $left;
}
sub _merge {
my ($current, $next, $mergers, $path) = @_;
for my $key (keys %{$next}) {
if (not exists $current->{$key}) {
$current->{$key} = $next->{$key};
}
elsif (my $merger = $mergers->{$key}) {
$current->{$key} = $merger->($current->{$key}, $next->{$key}, [ @{$path}, $key ]);
}
elsif ($merger = $mergers->{':default'}) {
$current->{$key} = $merger->($current->{$key}, $next->{$key}, [ @{$path}, $key ]);
}
else {
croak sprintf "Can't merge unknown attribute '%s'", join '.', @{$path}, $key;
}
}
return $current;
}
sub _uniq {
my %seen = ();
return grep { not $seen{$_}++ } @_;
}
sub _set_addition {
my ($left, $right) = @_;
return [ +_uniq(@{$left}, @{$right}) ];
}
sub _uniq_map {
my ($left, $right, $path) = @_;
for my $key (keys %{$right}) {
if (not exists $left->{$key}) {
$left->{$key} = $right->{$key};
}
else {
croak 'Duplication of element ' . join '.', @{$path}, $key;
}
}
return $left;
}
sub _improvize {
my ($left, $right, $path) = @_;
my ($name) = reverse @{$path};
if ($name =~ /^x_/) {
if (ref($left) eq 'ARRAY') {
return _set_addition($left, $right, $path);
}
elsif (ref($left) eq 'HASH') {
return _uniq_map($left, $right, $path);
}
else {
return _identical($left, $right, $path);
}
}
croak sprintf "Can't merge '%s'", join '.', @{$path};
}
sub _optional_features {
my ($left, $right, $path) = @_;
for my $key (keys %{$right}) {
if (not exists $left->{$key}) {
$left->{$key} = $right->{$key};
}
else {
for my $subkey (keys %{ $right->{$key} }) {
next if $subkey eq 'prereqs';
if (not exists $left->{$key}{$subkey}) {
$left->{$key}{$subkey} = $right->{$key}{$subkey};
}
else {
Carp::croak "Cannot merge two optional_features named '$key' with different '$subkey' values"
if do { no warnings 'uninitialized'; $left->{$key}{$subkey} ne $right->{$key}{$subkey} };
}
}
require CPAN::Meta::Prereqs;
$left->{$key}{prereqs} =
CPAN::Meta::Prereqs->new($left->{$key}{prereqs})
->with_merged_prereqs(CPAN::Meta::Prereqs->new($right->{$key}{prereqs}))
->as_string_hash;
}
}
return $left;
}
my %default = (
abstract => \&_identical,
author => \&_set_addition,
dynamic_config => sub {
my ($left, $right) = @_;
return $left || $right;
},
generated_by => sub {
my ($left, $right) = @_;
return join ', ', _uniq(split(/, /, $left), split(/, /, $right));
},
license => \&_set_addition,
'meta-spec' => {
version => \&_identical,
url => \&_identical
},
name => \&_identical,
release_status => \&_identical,
version => \&_identical,
description => \&_identical,
keywords => \&_set_addition,
no_index => { map { ($_ => \&_set_addition) } qw/file directory package namespace/ },
optional_features => \&_optional_features,
prereqs => sub {
require CPAN::Meta::Prereqs;
my ($left, $right) = map { CPAN::Meta::Prereqs->new($_) } @_[0,1];
return $left->with_merged_prereqs($right)->as_string_hash;
},
provides => \&_uniq_map,
resources => {
license => \&_set_addition,
homepage => \&_identical,
bugtracker => \&_uniq_map,
repository => \&_uniq_map,
':default' => \&_improvize,
},
':default' => \&_improvize,
);
sub new {
my ($class, %arguments) = @_;
croak 'default version required' if not exists $arguments{default_version};
my %mapping = %default;
my %extra = %{ $arguments{extra_mappings} || {} };
for my $key (keys %extra) {
if (ref($mapping{$key}) eq 'HASH') {
$mapping{$key} = { %{ $mapping{$key} }, %{ $extra{$key} } };
}
else {
$mapping{$key} = $extra{$key};
}
}
return bless {
default_version => $arguments{default_version},
mapping => _coerce_mapping(\%mapping, []),
}, $class;
}
my %coderef_for = (
set_addition => \&_set_addition,
uniq_map => \&_uniq_map,
identical => \&_identical,
improvize => \&_improvize,
);
sub _coerce_mapping {
my ($orig, $map_path) = @_;
my %ret;
for my $key (keys %{$orig}) {
my $value = $orig->{$key};
if (ref($orig->{$key}) eq 'CODE') {
$ret{$key} = $value;
}
elsif (ref($value) eq 'HASH') {
my $mapping = _coerce_mapping($value, [ @{$map_path}, $key ]);
$ret{$key} = sub {
my ($left, $right, $path) = @_;
return _merge($left, $right, $mapping, [ @{$path} ]);
};
}
elsif ($coderef_for{$value}) {
$ret{$key} = $coderef_for{$value};
}
else {
croak "Don't know what to do with " . join '.', @{$map_path}, $key;
}
}
return \%ret;
}
sub merge {
my ($self, @items) = @_;
my $current = {};
for my $next (@items) {
if ( blessed($next) && $next->isa('CPAN::Meta') ) {
$next = $next->as_struct;
}
elsif ( ref($next) eq 'HASH' ) {
my $cmc = CPAN::Meta::Converter->new(
$next, default_version => $self->{default_version}
);
$next = $cmc->upgrade_fragment;
}
else {
croak "Don't know how to merge '$next'";
}
$current = _merge($current, $next, $self->{mapping}, []);
}
return $current;
}
1;
# ABSTRACT: Merging CPAN Meta fragments
__END__
=pod
=encoding UTF-8
=head1 NAME
CPAN::Meta::Merge - Merging CPAN Meta fragments
=head1 VERSION
version 2.143240
=head1 SYNOPSIS
my $merger = CPAN::Meta::Merge->new(default_version => "2");
my $meta = $merger->merge($base, @additional);
=head1 DESCRIPTION
=head1 METHODS
=head2 new
This creates a CPAN::Meta::Merge object. It takes one mandatory named
argument, C<version>, declaring the version of the meta-spec that must be
used for the merge. It can optionally take an C<extra_mappings> argument
that allows one to add additional merging functions for specific elements.
=head2 merge(@fragments)
Merge all C<@fragments> together. It will accept both CPAN::Meta objects and
(possibly incomplete) hashrefs of metadata.
=head1 AUTHORS
=over 4
=item *
David Golden <dagolden@cpan.org>
=item *
Ricardo Signes <rjbs@cpan.org>
=back
=head1 COPYRIGHT AND LICENSE
This software is copyright (c) 2010 by David Golden and Ricardo Signes.
This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.
=cut