---
name: "LucyX::Index::ByteBufDocWriter"
section: "3pm"
platform: "linux"
package: "liblucy-perl"
version: "0.3.3-7+b1"
release: "Debian 9 (Stretch)"
platforms: ["linux"]
url: "https://new.carta.tech/LucyX::Index::ByteBufDocWriter"
---

# LucyX::Index::ByteBufDocWriter(3pm)

Write a Doc as a fixed-width byte array.

## NAME

LucyX::Index::ByteBufDocWriter - Write a Doc as a fixed-width byte array.

## SYNOPSIS

Create an Architecture subclass which overrides *register\_doc\_writer()* and *register\_doc\_reader()*:

```
    package MyArchitecture;
    use base qw( Lucy::Plan::Architecture );
    use LucyX::Index::ByteBufDocReader;
    use LucyX::Index::ByteBufDocWriter;
    sub register_doc_writer {
        my ( $self, $seg_writer ) = @_;
        my $doc_writer = LucyX::Index::ByteBufDocWriter->new(
            width      => 16,
            field      => 'value',
            snapshot   => $seg_writer->get_snapshot,
            segment    => $seg_writer->get_segment,
            polyreader => $seg_writer->get_polyreader,
        );
        $seg_writer->register(
            api       => "Lucy::Index::DocReader",
            component => $doc_writer,
        );
        $seg_writer->add_writer($doc_writer);
    }
    sub register_doc_reader {
        my ( $self, $seg_reader ) = @_;
        my $doc_reader = LucyX::Index::ByteBufDocReader->new(
            width    => 16,
            field    => 'value',
            schema   => $seg_reader->get_schema,
            folder   => $seg_reader->get_folder,
            segments => $seg_reader->get_segments,
            seg_tick => $seg_reader->get_seg_tick,
            snapshot => $seg_reader->get_snapshot,
        );
        $seg_reader->register(
            api       => 'Lucy::Index::DocReader',
            component => $doc_reader,
        );
    }
    package MySchema;
    use base qw( Lucy::Plan::Schema );
    sub architecture { MyArchitecture->new }
```

Proceed as normal in your indexer app, making sure that every supplied document supplies a valid value for the field in question:

```
    $indexer->add_doc({
        title   => $title,
        content => $content,
        id      => $id,      # <---- Must meet spec.
    });
```

Then, in your search app:

```
    my $searcher = Lucy::Search::IndexSearcher->new(
        index => '/path/to/index',
    );
    my $hits = $searcher->hits( query => $query );
    while ( my $id = $hits->next ) {
        my $real_doc = $external_document_source->fetch( $doc->{value} );
        ...
    }
```

## DESCRIPTION

This is a proof-of-concept class to demonstrate alternate implementations for fetching documents.  It is unsupported.