#!/usr/bin/perl
package KiokuDB::Backend::Role::Scan;
use Moose::Role;
sub entries_to_ids {
my $stream = shift;
$stream->filter(sub {[ map { $_->id } @$_ ]});
}
use namespace::clean -except => 'meta';
requires "all_entries";
sub root_entries {
my $self = shift;
return $self->all_entries->filter(sub {[ grep { $_->root } @$_ ]});
}
sub child_entries {
my $self = shift;
return $self->all_entries->filter(sub {[ grep { not $_->root } @$_ ]});
}
sub all_entry_ids {
my $self = shift;
entries_to_ids($self->all_entries);
}
sub root_entry_ids {
my $self = shift;
entries_to_ids($self->root_entries);
}
sub child_entry_ids {
my $self = shift;
entries_to_ids($self->child_entries);
}
__PACKAGE__
__END__
=pod
=head1 NAME
KiokuDB::Backend::Role::Scan - Root set iteration
=head1 SYNOPSIS
with qw(KiokuDB::Backend::Role::Scan);
sub all_entries {
my $self = shift;
# return all root set entries
return Data::Stream::Bulk::Foo->new(...);
}
=head1 DESCRIPTION
This is a role for iterative scanning of all entries in a backend.
It is used for database backups, and various other tasks.
=head1 REQUIRED METHODS
=over 4
=item all_entries
Should return a L<Data::Stream::Bulk> stream enumerating all entries in the
database.
=back
=head1 OPTIONAL METHODS
These method have default implementations defined in terms of C<all_entries>
but maybe overridden if there is a more optimal solution than just filtering
that stream.
=over 4
=item root_entries
Should return a L<Data::Stream::Bulk> of just the root entries.
=item child_entries
Should return a L<Data::Stream::Bulk> of everything but the root entries.
=back
=cut