wikimedia/mediawiki-extensions-CirrusSearch

<?php

namespace CirrusSearch;

/**
 * Represents an external index referenced by the OtherIndex functionality.
 * Typically sourced from $wgCirrusSearchExtraIndex.
 */
class ExternalIndex {
    /**
     * @var SearchConfig
     */
    private $config;

    /**
     * @var string replica group to write to, null if the index requested is hosted on the same
     * cluster group declared in as the default group in this SearchConfig $config.
     */
    private $crossClusterName;

    /**
     * @var string Name of index on external clusters
     */
    private $indexName;

    /**
     * @var string Name of index on external clusters. Can include a group prefix
     *  when required.
     */
    private $groupAndIndexName;

    /**
     * @param Searchconfig $config
     * @param string $indexName Name of index on external clusters. Can include a group prefix
     * (e.g. "cluster_group:index_name")
     */
    public function __construct( SearchConfig $config, $indexName ) {
        $this->config = $config;
        $this->groupAndIndexName = $indexName;
        $groupAndIndex = explode( ':', $indexName, 2 );
        if ( count( $groupAndIndex ) === 2 ) {
            $currentGroup = $config->getClusterAssignment()->getCrossClusterName();
            $this->crossClusterName = $currentGroup !== $groupAndIndex[0] ? $groupAndIndex[0] : null;
            $this->indexName = $groupAndIndex[1];
        } else {
            $this->indexName = $indexName;
        }
    }

    /**
     * @return string Name of index on external clusters. Can include a group prefix
     *  when required.
     */
    public function getGroupAndIndexName() {
        return $this->groupAndIndexName;
    }

    /**
     * @return string The name of the external index.
     */
    public function getIndexName() {
        return $this->indexName;
    }

    /**
     * @return string|null The group external index writes must be sent to, null to send to current group.
     */
    public function getCrossClusterName() {
        return $this->crossClusterName;
    }

    /**
     * @param string|null $sourceCrossClusterName Name of the cluster as configured in the cross-cluster
     * search settings, null for simple&deprecated configs.
     * @return string The name of the index to search. Includes
     *   cross-cluster identifier if necessary.
     */
    public function getSearchIndex( $sourceCrossClusterName ) {
        $currentGroup = $this->crossClusterName ?? $this->config->getClusterAssignment()->getCrossClusterName();

        return $sourceCrossClusterName === $currentGroup || $currentGroup === null
            ? $this->indexName
            : "{$currentGroup}:{$this->indexName}";
    }

    /**
     * @return array Two item array first containing a wiki name and second a map
     *  from template name to weight for that template.
     */
    public function getBoosts() {
        $boosts = $this->config->getElement( 'CirrusSearchExtraIndexBoostTemplates', $this->indexName );
        if ( isset( $boosts['wiki'] ) ) {
            return [ $boosts['wiki'], $boosts['boosts'] ?? [] ];
        } else {
            return [ '', [] ];
        }
    }
}