don't invalidate the method map if we add a method object

[gitmo/Class-MOP.git] / lib / Class / MOP / Mixin / HasMethods.pm

package Class::MOP::Mixin::HasMethods;

use strict;
use warnings;

use Class::MOP::Method::Meta;

our $VERSION   = '1.11';
$VERSION = eval $VERSION;
our $AUTHORITY = 'cpan:STEVAN';

use Scalar::Util 'blessed';
use Carp         'confess';
use Sub::Name    'subname';

use base 'Class::MOP::Mixin';

sub method_metaclass         { $_[0]->{'method_metaclass'}            }
sub wrapped_method_metaclass { $_[0]->{'wrapped_method_metaclass'}    }
sub _meta_method_class       { 'Class::MOP::Method::Meta'             }

sub _add_meta_method {
    my $self = shift;
    my ($name) = @_;
    my $existing_method = $self->can('find_method_by_name')
                              ? $self->find_method_by_name($name)
                              : $self->get_method($name);
    return if $existing_method
           && $existing_method->isa($self->_meta_method_class);
    $self->add_method(
        $name => $self->_meta_method_class->wrap(
            name                 => $name,
            package_name         => $self->name,
            associated_metaclass => $self,
        )
    );
}

sub wrap_method_body {
    my ( $self, %args ) = @_;

    ( 'CODE' eq ref $args{body} )
        || confess "Your code block must be a CODE reference";

    $self->method_metaclass->wrap(
        package_name => $self->name,
        %args,
    );
}

sub add_method {
    my ( $self, $method_name, $method ) = @_;
    ( defined $method_name && length $method_name )
        || confess "You must define a method name";

    my $package_name = $self->name;

    my $body;
    if ( blessed($method) ) {
        $body = $method->body;
        if ( $method->package_name ne $package_name ) {
            $method = $method->clone(
                package_name => $package_name,
                name         => $method_name,
            ) if $method->can('clone');
        }

        $method->attach_to_class($self);
    }
    else {
        # If a raw code reference is supplied, its method object is not created.
        # The method object won't be created until required.
        $body = $method;
    }

    $self->_method_map->{$method_name} = $method;

    my ( $current_package, $current_name ) = Class::MOP::get_code_info($body);

    if ( !defined $current_name || $current_name =~ /^__ANON__/ ) {
        my $full_method_name = ( $package_name . '::' . $method_name );
        subname( $full_method_name => $body );
    }

    $self->add_package_symbol("&$method_name", $body);

    # if we added the actual method object to the method map, we're still valid
    $self->update_package_cache_flag
        if blessed($method);
}

sub _code_is_mine {
    my ( $self, $code ) = @_;

    my ( $code_package, $code_name ) = Class::MOP::get_code_info($code);

    return $code_package && $code_package eq $self->name
        || ( $code_package eq 'constant' && $code_name eq '__ANON__' );
}

sub has_method {
    my ( $self, $method_name ) = @_;

    ( defined $method_name && length $method_name )
        || confess "You must define a method name";

    my $method = $self->_get_maybe_raw_method($method_name)
        or return;

    return defined($self->_method_map->{$method_name} = $method);
}

sub get_method {
    my ( $self, $method_name ) = @_;

    ( defined $method_name && length $method_name )
        || confess "You must define a method name";

    my $method = $self->_get_maybe_raw_method($method_name)
        or return;

    return $method if blessed $method;

    return $self->_method_map->{$method_name} = $self->wrap_method_body(
        body                 => $method,
        name                 => $method_name,
        associated_metaclass => $self,
    );
}

sub _get_maybe_raw_method {
    my ( $self, $method_name ) = @_;

    my $map_entry = $self->_method_map->{$method_name};
    return $map_entry if defined $map_entry;

    my $code = $self->get_package_symbol("&$method_name");

    unless ($map_entry) {
        return unless $code && $self->_code_is_mine($code);
    }

    return $code;
}

sub remove_method {
    my ( $self, $method_name ) = @_;
    ( defined $method_name && length $method_name )
        || confess "You must define a method name";

    my $removed_method = delete $self->_method_map->{$method_name};

    $self->remove_package_symbol("&$method_name");

    $removed_method->detach_from_class
        if $removed_method && blessed $removed_method;

    # still valid, since we just removed the method from the map
    $self->update_package_cache_flag;

    return $removed_method;
}

sub get_method_list {
    my $self = shift;

    return keys %{ $self->_full_method_map };
}

# This should probably be what get_method_list actually does, instead of just
# returning names. This was created as a much faster alternative to
# $meta->get_method($_) for $meta->get_method_list
sub _get_local_methods {
    my $self = shift;

    return values %{ $self->_full_method_map };
}

sub _restore_metamethods_from {
    my $self = shift;
    my ($old_meta) = @_;

    for my $method ($old_meta->_get_local_methods) {
        $method->_make_compatible_with($self->method_metaclass);
        $self->add_method($method->name => $method);
    }
}

sub reset_package_cache_flag  { (shift)->{'_package_cache_flag'} = undef }
sub update_package_cache_flag {
    my $self = shift;
    # NOTE:
    # we can manually update the cache number
    # since we are actually adding the method
    # to our cache as well. This avoids us
    # having to regenerate the method_map.
    # - SL
    $self->{'_package_cache_flag'} = Class::MOP::check_package_cache_flag($self->name);
}

sub _full_method_map {
    my $self = shift;

    my $pkg_gen = Class::MOP::check_package_cache_flag($self->name);

    if (($self->{_package_cache_flag_full} || -1) != $pkg_gen) {
        # forcibly reify all method map entries
        $self->get_method($_)
            for $self->list_all_package_symbols('CODE');
        $self->{_package_cache_flag_full} = $pkg_gen;
    }

    return $self->_method_map;
}

1;

__END__

=pod

=head1 NAME

Class::MOP::Mixin::HasMethods - Methods for metaclasses which have methods

=head1 DESCRIPTION

This class implements methods for metaclasses which have methods
(L<Class::MOP::Package> and L<Moose::Meta::Role>). See L<Class::MOP::Package>
for API details.

=head1 AUTHORS

Dave Rolsky E<lt>autarch@urth.orgE<gt>

=head1 COPYRIGHT AND LICENSE

Copyright 2006-2010 by Infinity Interactive, Inc.

L<http://www.iinteractive.com>

This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself.

=cut