KiokuDB::Backend::Role::Scan - Root set iteration

KiokuDB documentation Contained in the KiokuDB distribution.

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NAME

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KiokuDB::Backend::Role::Scan - Root set iteration

SYNOPSIS

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    with qw(KiokuDB::Backend::Role::Scan);

    sub all_entries {
        my $self = shift;

        # return all root set entries
        return Data::Stream::Bulk::Foo->new(...);
    }

DESCRIPTION

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This is a role for iterative scanning of all entries in a backend.

It is used for database backups, and various other tasks.

REQUIRED METHODS

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all_entries

Should return a Data::Stream::Bulk stream enumerating all entries in the database.

OPTIONAL METHODS

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These method have default implementations defined in terms of all_entries but maybe overridden if there is a more optimal solution than just filtering that stream.

root_entries

Should return a Data::Stream::Bulk of just the root entries.

child_entries

Should return a Data::Stream::Bulk of everything but the root entries.

KiokuDB documentation Contained in the KiokuDB distribution. 
#!/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__