wikimedia/mediawiki-extensions-CirrusSearch

<?php

namespace CirrusSearch\Search;

use CirrusSearch\SearchConfig;
use SearchIndexField;

/**
 * Index field representing keyword.
 * Keywords use special analyzer.
 * @package CirrusSearch
 */
class KeywordIndexField extends CirrusIndexField {
    /**
     * Using text type here since it's better for our purposes than native
     * keyword type.
     * @var string
     */
    protected $typeName = 'text';
    /**
     * @var bool
     */
    private $caseSensitiveSubfield;

    public function __construct( $name, $type, SearchConfig $config, bool $caseSensitiveSubfield = false ) {
        parent::__construct( $name, $type, $config );
        if ( $caseSensitiveSubfield ) {
            $this->setFlag( SearchIndexField::FLAG_CASEFOLD );
        }
        $this->caseSensitiveSubfield = $caseSensitiveSubfield;
    }

    /**
     * Maximum number of characters allowed in keyword terms.
     */
    private const KEYWORD_IGNORE_ABOVE = 5000;

    public function getMapping( \SearchEngine $engine ) {
        $config = parent::getMapping( $engine );
        $config['analyzer'] =
            $this->checkFlag( self::FLAG_CASEFOLD ) ? 'lowercase_keyword' : 'keyword';
        $config += [
            'norms' => false,
            // Omit the length norm because there is only even one token
            'index_options' => 'docs',
        ];
        if ( $this->caseSensitiveSubfield ) {
            $config['fields']['keyword'] = [
                'type' => 'text',
                'analyzer' => 'keyword',
                'index_options' => 'docs',
                'norms' => false,
            ];
        }
        return $config;
    }
}