mroonga.php

<?php
/*
Plugin Name: Mroonga
Plugin URI: https://github.com/mroonga/wordpress-mroonga
Description: This plugin provides fast and rich full text search features based on Mroonga. Mroonga is a MySQL/MariaDB plugin. You don't need to add a new server only for full text search. You can use existing MySQL/MariaDB server. It reduces maintainance cost.
Version: 0.1.2
Author: Yasuhiro Horimoto
Author URI: https://www.clear-code.com/
License: GPL2 or later
*/

class MroongaSearch
{

  private $textdomain = "mroonga";
  private $mroonga_install_doc = "http://mroonga.org/docs/install.html";

  public function table_name()
  {
    global $wpdb;

    return $wpdb->prefix . "mrn_posts";
  }

  public function __construct()
  {
    load_plugin_textdomain( $this->textdomain, false, dirname( plugin_basename( __FILE__ ) ) . "/languages"  );
  }

  public function activate()
  {
    $this->ensure_mroonga();
    $this->create_table();
    $this->copy_data();
    $this->create_index();
  }

  public function deactivate()
  {
    $this->drop_table();
  }

  private function ensure_mroonga()
  {
    global $wpdb;

    $is_mroonga_installed =
      $wpdb->get_var( "SELECT COUNT(*) FROM INFORMATION_SCHEMA.PLUGINS "
                      . " WHERE PLUGIN_NAME = 'Mroonga'" );
    if ( ! $is_mroonga_installed ) {
      $message  = __( "Mroonga is not installed on your DB Server.",
                      $this->textdomain );
      $message .= " ";
      $message .= sprintf( __( "Please install Mroonga refer to %s.",
                               $this->textdomain ),
                           $this->mroonga_install_doc );
      exit( $messagee );
    }
  }

  private function create_table()
  {
    global $wpdb;

    $wpdb->query("CREATE TABLE {$this->table_name()} ( "
                 . "`post_id` bigint(20) unsigned PRIMARY KEY, "
                 . "`post_title` text COLLATE utf8mb4_unicode_ci, "
                 . "`post_content` longtext COLLATE utf8mb4_unicode_ci"
                 . ") ENGINE=Mroonga "
                 . "DEFAULT CHARSET=utf8mb4 "
                 . "COLLATE=utf8mb4_unicode_ci;");
  }

  private function copy_data()
  {
    global $wpdb;

    if ( $post_types = $this->get_search_post_types() ) {
      $post_types = esc_sql( $post_types );
      $post_type_in_string = "'" . implode( "','", $post_types ) . "'";
      $wpdb->query("INSERT INTO {$this->table_name()} "
                   . "(post_id, post_title, post_content) "
                   . "SELECT ID, post_title, post_content "
                   . "FROM {$wpdb->posts} "
                   . "WHERE post_status IN ('publish', 'private') "
                   . "AND post_type IN ($post_type_in_string)");
    }
  }

  private function create_index()
  {
    global $wpdb;

    $wpdb->query("ALTER TABLE {$this->table_name()} "
                 . "ADD FULLTEXT INDEX "
                 . "(post_title, post_content) "
                 . "COMMENT 'normalizer \"NormalizerAuto\"'");
  }

  private function drop_table()
  {
    global $wpdb;

    $wpdb->query("DROP TABLE IF EXISTS {$this->table_name()}");
  }

  private function get_search_post_types ()
  {
    $post_types = get_post_types( array( "exclude_from_search" => false ) );
    return apply_filters( "mroonga_search_post_types", $post_types );
  }

  public function update_post($post_id, $post)
  {
    global $wpdb;

    if ( in_array( $post->post_status, array( "publish", "private" ) ) && in_array( $post->post_type, $this->get_search_post_types() ) ) {
      $wpdb->replace($this->table_name(),
        array(
          "post_id" => $post_id,
          "post_title" => $post->post_title,
          "post_content" => $post->post_content
        )
      );
    }
  }

  public function fulltext_search($search, $wp_query)
  {
    return "";
  }

  public function fulltext_search_join($join, $wp_query)
  {
    global $wpdb;

    $search_query = $wp_query->get("s");
    if (strlen($search_query) > 0)
    {
      $boolean_mode_query = "*D+W1:10,2:1 $search_query";
      $join .= $wpdb->prepare(" INNER JOIN (SELECT post_id, "
                              . "MATCH (post_title, post_content) "
                              . "AGAINST (%s IN BOOLEAN MODE) AS score "
                              . "FROM {$this->table_name()} WHERE "
                              . "MATCH (post_title, post_content) "
                              . "AGAINST (%s IN BOOLEAN MODE)) AS matched_posts "
                              . "ON {$wpdb->posts}.ID = matched_posts.post_id",
                              $boolean_mode_query,
                              $boolean_mode_query);
    }
    return $join;
  }

  public function fulltext_search_orderby($orderby, $wp_query)
  {
    global $wpdb;

    $search_query = $wp_query->get("s");
    if (strlen($search_query) > 0)
    {
      $orderby = "score DESC";
    }
    return $orderby;
  }

  public function after_delete_post ( $post_id )
  {
    global $wpdb;
    $wpdb->delete( $this->table_name(), array( "post_id" => $post_id ) );
  }

}

$MroongaSearch = new MroongaSearch();

register_activation_hook(__FILE__, array($MroongaSearch, "activate"));
register_deactivation_hook(__FILE__, array($MroongaSearch, "deactivate"));

add_action("wp_insert_post", array($MroongaSearch, "update_post"), 10, 2);
add_filter("posts_search", array($MroongaSearch, "fulltext_search"), 10, 2);
add_filter("posts_join", array($MroongaSearch, "fulltext_search_join"), 10, 2);
add_filter("posts_search_orderby", array($MroongaSearch, "fulltext_search_orderby"), 10, 2);

add_action("after_delete_post", array($MroongaSearch, "after_delete_post"), 100, 1 );