KSx::Simple - Basic search engine.

    my $index = KSx::Simple->new(
        path     => '/path/to/index/'
        language => 'en',
    );

    while ( my ( $title, $content ) = each %source_docs ) {
        $index->add_doc({
            title    => $title,
            content  => $content,
        });
    }

    my $total_hits = $index->search( 
        query      => $query_string,
        offset     => 0,
        num_wanted => 10,
    );

    print "Total hits: $total_hits\n";
    while ( my $hit = $index->next ) {
        print "$hit->{title}\n",
    }

    my $index = KSx::Simple->new(
        path     => '/path/to/index/',
        language => 'en',
    );

    $index->add_doc({
        location => $url,
        title    => $title,
        content  => $content,
    });

    my $total_hits = $index->search( 
        query      => $query_string,    # required
        offset     => 40,               # default 0
        num_wanted => 20,               # default 10
    );

use strict;
use warnings;

package KSx::Simple;
use Carp;
use Scalar::Util qw( weaken reftype refaddr );

use KinoSearch::Plan::Schema;
use KinoSearch::Analysis::PolyAnalyzer;
use KinoSearch::Index::Indexer;
use KinoSearch::Search::IndexSearcher;

my %obj_cache;

sub new {
    my ( $either, %args ) = @_;
    my $path     = delete $args{path};
    my $language = lc( delete $args{language} );
    confess("Missing required parameter 'path'") unless defined $path;
    confess("Invalid language: '$language'")
        unless $language =~ /^(?:da|de|en|es|fi|fr|it|nl|no|pt|ru|sv)$/;
    my @remaining = keys %args;
    confess("Invalid params: @remaining") if @remaining;
    my $self = bless {
        type     => undef,
        schema   => undef,
        indexer  => undef,
        searcher => undef,
        hits     => undef,
        language => $language,
        path     => $path,
        },
        ref($either) || $either;

    # Get type and schema.
    my $analyzer
        = KinoSearch::Analysis::PolyAnalyzer->new( language => $language );
    $self->{type}
        = KinoSearch::Plan::FullTextType->new( analyzer => $analyzer, );
    my $schema = $self->{schema} = KinoSearch::Plan::Schema->new;

    # Cache the object for later clean-up.
    weaken( $obj_cache{ refaddr $self } = $self );

    return $self;
}

sub _lazily_create_indexer {
    my $self = shift;
    if ( !defined $self->{indexer} ) {
        $self->{indexer} = KinoSearch::Index::Indexer->new(
            schema => $self->{schema},
            index  => $self->{path},
        );
    }
}

sub add_doc {
    my ( $self, $hashref ) = @_;
    my $schema = $self->{schema};
    my $type   = $self->{type};
    croak("add_doc requires exactly one argument: a hashref")
        unless ( @_ == 2 and reftype($hashref) eq 'HASH' );
    $self->_lazily_create_indexer;
    $schema->spec_field( name => $_, type => $type ) for keys %$hashref;
    $self->{indexer}->add_doc($hashref);
}

sub _finish_indexing {
    my $self = shift;

    # Don't bother to throw an error if index not modified.
    if ( defined $self->{indexer} ) {
        $self->{indexer}->commit;

        # Trigger searcher and indexer refresh.
        undef $self->{indexer};
        undef $self->{searcher};
    }
}

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

    # Flush recent adds; lazily create searcher.
    $self->_finish_indexing;
    if ( !defined $self->{searcher} ) {
        $self->{searcher} = KinoSearch::Search::IndexSearcher->new(
            index => $self->{path} );
    }

    $self->{hits} = $self->{searcher}->hits(%args);

    return $self->{hits}->total_hits;
}

sub next {
    my $self = shift;
    return unless defined $self->{hits};

    # Get the hit, bail if hits are exhausted.
    my $hit = $self->{hits}->next;
    if ( !defined $hit ) {
        undef $self->{hits};
        return;
    }

    return $hit;
}

sub DESTROY {
    for (shift) {
        $_->_finish_indexing;
        delete $obj_cache{ refaddr $_ };
    }
}

END {
    # Finish indexing for any objects that still exist, since, if we wait
    # until global destruction, our Indexer might no longer exist,
    # (see bug #32689)
    $_->_finish_indexing for values %obj_cache;
}

1;

__END__

__POD__