# Auto-generated file -- DO NOT EDIT!!!!!

=head1 NAME

KinoSearch::Index::Segment - Warehouse for information about one segment of an inverted index.

=head1 SYNOPSIS

    # Index-time.
    package MyDataWriter;
    use base qw( KinoSearch::Index::DataWriter );

    sub finish {
        my $self     = shift;
        my $segment  = $self->get_segment;
        my $metadata = $self->SUPER::metadata();
        $metadata->{foo} = $self->get_foo;
        $segment->store_metadata(
            key       => 'my_component',
            metadata  => $metadata
        );
    }

    # Search-time.
    package MyDataReader;
    use base qw( KinoSearch::Index::DataReader );

    sub new {
        my $self     = shift->SUPER::new(@_);
        my $segment  = $self->get_segment;
        my $metadata = $segment->fetch_metadata('my_component');
        if ($metadata) {
            $self->set_foo( $metadata->{foo} );
            ...
        }
        return $self;
    }



=head1 DESCRIPTION

Warehouse for information about one segment of an inverted index.

KinoSearch's indexes are made up of individual "segments", each of which is
is an independent inverted index.  On the file system, each segment is a
directory within the main index directory whose name starts with "seg_":
"seg_2", "seg_5a", etc.

Each Segment object keeps track of information about an index segment: its
fields, document count, and so on.  The Segment object itself writes one
file, C<< segmeta.json >>; besides storing info needed by Segment
itself, the "segmeta" file serves as a central repository for metadata
generated by other index components -- relieving them of the burden of
storing metadata themselves.



=head1 METHODS

=head2 add_field(field)

Register a new field and assign it a field number.  If the field was
already known, nothing happens.

=over

=item *

B<field> - Field name.

=back

Returns: the field's field number, which is a positive integer.

=head2 store_metadata( I<[labeled params]> )

Store arbitrary information in the segment's metadata Hash, to be
serialized later.  Throws an error if C<< key >> is used twice.

=over

=item *

B<key> - String identifying an index component.

=item *

B<metadata> - JSON-izable data structure.

=back

=head2 fetch_metadata(key)

Fetch a value from the Segment's metadata hash.

=head2 field_num(field)

Given a field name, return its field number for this segment (which
may differ from its number in other segments).  Return 0 (an invalid
field number) if the field name can't be found.

=over

=item *

B<field> - Field name.

=back

=head2 field_name(field_num)

Given a field number, return the name of its field, or undef if the
field name can't be found.

=head2 get_name()

Getter for the object's seg name.

=head2 get_number()

Getter for the segment number.

=head2 set_count(count)

Setter for the object's document count.

=head2 get_count()

Getter for the object's document count.





=head1 INHERITANCE

KinoSearch::Index::Segment isa L<KinoSearch::Obj>.


=head1 COPYRIGHT AND LICENSE

Copyright 2005-2009 Marvin Humphrey

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

=cut