php-phpbb/phpBB/includes/search/fulltext_sphinx.php

<?php
/**
*
* @package search
* @copyright (c) 2005 phpBB Group
* @license http://opensource.org/licenses/gpl-2.0.php GNU General Public License v2
*
*/

/**
*/
if (!defined('IN_PHPBB'))
{
	exit;
}

/**
* @ignore
*/
/**
* This statement is necessary as this file is sometimes included from within a
* function and the variables used are in global space.
*/
global $phpbb_root_path, $phpEx, $table_prefix;
require($phpbb_root_path . "includes/sphinxapi-0.9.8." . $phpEx);

define('SPHINX_MAX_MATCHES', 20000);
define('SPHINX_CONNECT_RETRIES', 3);
define('SPHINX_CONNECT_WAIT_TIME', 300);

/**
* fulltext_sphinx
* Fulltext search based on the sphinx search deamon
* @package search
*/
class phpbb_search_fulltext_sphinx
{
	private $stats = array();
	private $split_words = array();
	private $id;
	private $indexes;
	private $sphinx;
	public $word_length = array();
	public $search_query;
	public $common_words = array();

	/**
	 * Constructor
	 * Creates a new phpbb_search_fulltext_postgres, which is used as a search backend.
	 *
	 * @param string|bool $error Any error that occurs is passed on through this reference variable otherwise false
	 */
	public function __construct(&$error)
	{
		global $config;

		$this->id = $config['avatar_salt'];
		$this->indexes = 'index_phpbb_' . $this->id . '_delta;index_phpbb_' . $this->id . '_main';

		$this->sphinx = new SphinxClient();

		if (!empty($config['fulltext_sphinx_configured']))
		{
			// we only support localhost for now
			$this->sphinx->SetServer('localhost', (isset($config['fulltext_sphinx_port']) && $config['fulltext_sphinx_port']) ? (int) $config['fulltext_sphinx_port'] : 3312);
		}

		$config['fulltext_sphinx_min_word_len'] = 2;
		$config['fulltext_sphinx_max_word_len'] = 400;

		$error = false;
	}
	
	/**
	* Returns the name of this search backend to be displayed to administrators
	*
	* @return string Name
	*
	* @access public
	*/
	public function get_name()
	{
		return 'Sphinx Fulltext';
	}

	/**
	* Checks permissions and paths, if everything is correct it generates the config file
	*
	* @return string|bool Language key of the error/incompatiblity occured
	*
	* @access public
	*/
	function init()
	{
		global $db, $user, $config;

		if ($db->sql_layer != 'mysql' && $db->sql_layer != 'mysql4' && $db->sql_layer != 'mysqli')
		{
			return $user->lang['FULLTEXT_SPHINX_WRONG_DATABASE'];
		}

		if ($error = $this->config_updated())
		{
			return $error;
		}

		// move delta to main index each hour
		set_config('search_gc', 3600);

		return false;
	}

	/**
	 * Updates the config file sphinx.conf and generates the same in case autoconf is selected
	 *
	 * @return string|bool Language key of the error/incompatiblity occured otherwise false
	 *
	 * @access private
	 */
	function config_updated()
	{
		global $db, $user, $config, $phpbb_root_path, $phpEx;

			include ($phpbb_root_path . 'config.' . $phpEx);

			// now that we're sure everything was entered correctly, generate a config for the index
			// we misuse the avatar_salt for this, as it should be unique ;-)
			$config_object = new phpbb_search_sphinx_config($config['fulltext_sphinx_config_path'] . 'sphinx.conf');

			$config_data = array(
				'source source_phpbb_' . $this->id . '_main' => array(
					array('type',						'mysql'),
					array('sql_host',					$dbhost),
					array('sql_user',					$dbuser),
					array('sql_pass',					$dbpasswd),
					array('sql_db',						$dbname),
					array('sql_port',					$dbport),
					array('sql_query_pre',				'SET NAMES utf8'),
					array('sql_query_pre',				'REPLACE INTO ' . SPHINX_TABLE . ' SELECT 1, MAX(post_id) FROM ' . POSTS_TABLE . ''),
					array('sql_query_range',			'SELECT MIN(post_id), MAX(post_id) FROM ' . POSTS_TABLE . ''),
					array('sql_range_step',				'5000'),
					array('sql_query',					'SELECT
							p.post_id AS id,
							p.forum_id,
							p.topic_id,
							p.poster_id,
							IF(p.post_id = t.topic_first_post_id, 1, 0) as topic_first_post,
							p.post_time,
							p.post_subject,
							p.post_subject as title,
							p.post_text as data,
							t.topic_last_post_time,
							0 as deleted
						FROM ' . POSTS_TABLE . ' p, ' . TOPICS_TABLE . ' t
						WHERE
							p.topic_id = t.topic_id
							AND p.post_id >= $start AND p.post_id <= $end'),
					array('sql_query_post',				''),
					array('sql_query_post_index',		'REPLACE INTO ' . SPHINX_TABLE . ' ( counter_id, max_doc_id ) VALUES ( 1, $maxid )'),
					array('sql_query_info',				'SELECT * FROM ' . POSTS_TABLE . ' WHERE post_id = $id'),
					array('sql_attr_uint',				'forum_id'),
					array('sql_attr_uint',				'topic_id'),
					array('sql_attr_uint',				'poster_id'),
					array('sql_attr_bool',				'topic_first_post'),
					array('sql_attr_bool',				'deleted'),
					array('sql_attr_timestamp'	,		'post_time'),
					array('sql_attr_timestamp'	,		'topic_last_post_time'),
					array('sql_attr_str2ordinal',		'post_subject'),
				),
				'source source_phpbb_' . $this->id . '_delta : source_phpbb_' . $this->id . '_main' => array(
					array('sql_query_pre',				''),
					array('sql_query_range',			''),
					array('sql_range_step',				''),
					array('sql_query',					'SELECT
							p.post_id AS id,
							p.forum_id,
							p.topic_id,
							p.poster_id,
							IF(p.post_id = t.topic_first_post_id, 1, 0) as topic_first_post,
							p.post_time,
							p.post_subject,
							p.post_subject as title,
							p.post_text as data,
							t.topic_last_post_time,
							0 as deleted
						FROM ' . POSTS_TABLE . ' p, ' . TOPICS_TABLE . ' t
						WHERE
							p.topic_id = t.topic_id
							AND p.post_id >=  ( SELECT max_doc_id FROM ' . SPHINX_TABLE . ' WHERE counter_id=1 )'),
				),
				'index index_phpbb_' . $this->id . '_main' => array(
					array('path',						$config['fulltext_sphinx_data_path'] . 'index_phpbb_' . $this->id . '_main'),
					array('source',						'source_phpbb_' . $this->id . '_main'),
					array('docinfo',					'extern'),
					array('morphology',					'none'),
					array('stopwords',					$config['fulltext_sphinx_stopwords'] ? $config['fulltext_sphinx_config_path'] . 'sphinx_stopwords.txt' : ''),
					array('min_word_len',				'2'),
					array('charset_type',				'utf-8'),
					array('charset_table',				'U+FF10..U+FF19->0..9, 0..9, U+FF41..U+FF5A->a..z, U+FF21..U+FF3A->a..z, A..Z->a..z, a..z, U+0149, U+017F, U+0138, U+00DF, U+00FF, U+00C0..U+00D6->U+00E0..U+00F6, U+00E0..U+00F6, U+00D8..U+00DE->U+00F8..U+00FE, U+00F8..U+00FE, U+0100->U+0101, U+0101, U+0102->U+0103, U+0103, U+0104->U+0105, U+0105, U+0106->U+0107, U+0107, U+0108->U+0109, U+0109, U+010A->U+010B, U+010B, U+010C->U+010D, U+010D, U+010E->U+010F, U+010F, U+0110->U+0111, U+0111, U+0112->U+0113, U+0113, U+0114->U+0115, U+0115, U+0116->U+0117, U+0117, U+0118->U+0119, U+0119, U+011A->U+011B, U+011B, U+011C->U+011D, U+011D, U+011E->U+011F, U+011F, U+0130->U+0131, U+0131, U+0132->U+0133, U+0133, U+0134->U+0135, U+0135, U+0136->U+0137, U+0137, U+0139->U+013A, U+013A, U+013B->U+013C, U+013C, U+013D->U+013E, U+013E, U+013F->U+0140, U+0140, U+0141->U+0142, U+0142, U+0143->U+0144, U+0144, U+0145->U+0146, U+0146, U+0147->U+0148, U+0148, U+014A->U+014B, U+014B, U+014C->U+014D, U+014D, U+014E->U+014F, U+014F, U+0150->U+0151, U+0151, U+0152->U+0153, U+0153, U+0154->U+0155, U+0155, U+0156->U+0157, U+0157, U+0158->U+0159, U+0159, U+015A->U+015B, U+015B, U+015C->U+015D, U+015D, U+015E->U+015F, U+015F, U+0160->U+0161, U+0161, U+0162->U+0163, U+0163, U+0164->U+0165, U+0165, U+0166->U+0167, U+0167, U+0168->U+0169, U+0169, U+016A->U+016B, U+016B, U+016C->U+016D, U+016D, U+016E->U+016F, U+016F, U+0170->U+0171, U+0171, U+0172->U+0173, U+0173, U+0174->U+0175, U+0175, U+0176->U+0177, U+0177, U+0178->U+00FF, U+00FF, U+0179->U+017A, U+017A, U+017B->U+017C, U+017C, U+017D->U+017E, U+017E, U+0410..U+042F->U+0430..U+044F, U+0430..U+044F, U+4E00..U+9FFF'),
					array('min_prefix_len',				'0'),
					array('min_infix_len',				'0'),
				),
				'index index_phpbb_' . $this->id . '_delta : index_phpbb_' . $this->id . '_main' => array(
					array('path',						$config['fulltext_sphinx_data_path'] . 'index_phpbb_' . $this->id . '_delta'),
					array('source',						'source_phpbb_' . $this->id . '_delta'),
				),
				'indexer' => array(
					array('mem_limit',					$config['fulltext_sphinx_indexer_mem_limit'] . 'M'),
				),
				'searchd' => array(
					array('compat_sphinxql_magics'	,	'0'),
					array('listen'	,					'127.0.0.1'),
					array('port',						($config['fulltext_sphinx_port']) ? $config['fulltext_sphinx_port'] : '3312'),
					array('log',						$config['fulltext_sphinx_data_path'] . "log/searchd.log"),
					array('query_log',					$config['fulltext_sphinx_data_path'] . "log/sphinx-query.log"),
					array('read_timeout',				'5'),
					array('max_children',				'30'),
					array('pid_file',					$config['fulltext_sphinx_data_path'] . "searchd.pid"),
					array('max_matches',				(string) SPHINX_MAX_MATCHES),
					array('binlog_path',				$config['fulltext_sphinx_data_path']),
				),
			);

			$non_unique = array('sql_query_pre' => true, 'sql_attr_uint' => true, 'sql_attr_timestamp' => true, 'sql_attr_str2ordinal' => true, 'sql_attr_bool' => true);
			$delete = array('sql_group_column' => true, 'sql_date_column' => true, 'sql_str2ordinal_column' => true);

			foreach ($config_data as $section_name => $section_data)
			{
				$section = $config_object->get_section_by_name($section_name);
				if (!$section)
				{
					$section = $config_object->add_section($section_name);
				}

				foreach ($delete as $key => $void)
				{
					$section->delete_variables_by_name($key);
				}

				foreach ($non_unique as $key => $void)
				{
					$section->delete_variables_by_name($key);
				}

				foreach ($section_data as $entry)
				{
					$key = $entry[0];
					$value = $entry[1];

					if (!isset($non_unique[$key]))
					{
						$variable = $section->get_variable_by_name($key);
						if (!$variable)
						{
							$variable = $section->create_variable($key, $value);
						}
						else
						{
							$variable->set_value($value);
						}
					}
					else
					{
						$variable = $section->create_variable($key, $value);
					}
				}
			}

		set_config('fulltext_sphinx_configured', '1');

		$this->tidy();

		return false;
	}

	/**
	* Splits keywords entered by a user into an array of words stored in $this->split_words
	* Stores the tidied search query in $this->search_query
	*
	* @param string $keywords Contains the keyword as entered by the user
	* @param string $terms is either 'all' or 'any'
	* @return false if no valid keywords were found and otherwise true
	*
	* @access public
	*/
	function split_keywords(&$keywords, $terms)
	{
		global $config;

		if ($terms == 'all')
		{
			$match		= array('#\sand\s#i', '#\sor\s#i', '#\snot\s#i', '#\+#', '#-#', '#\|#', '#@#');
			$replace	= array(' & ', ' | ', '  - ', ' +', ' -', ' |', '');

			$replacements = 0;
			$keywords = preg_replace($match, $replace, $keywords);
			$this->sphinx->SetMatchMode(SPH_MATCH_EXTENDED);
		}
		else
		{
			$this->sphinx->SetMatchMode(SPH_MATCH_ANY);
		}

		// Keep quotes and new lines
		$keywords = str_replace(array('&quot;', "\n"), array('"', ' '), trim($keywords));

		if (strlen($keywords) > 0)
		{
			$this->search_query = str_replace('"', '&quot;', $keywords);
			return true;
		}

		return false;
	}

	/**
	* Performs a search on keywords depending on display specific params. You have to run split_keywords() first.
	*
	* @param	string		$type				contains either posts or topics depending on what should be searched for
	* @param	string		$fields				contains either titleonly (topic titles should be searched), msgonly (only message bodies should be searched), firstpost (only subject and body of the first post should be searched) or all (all post bodies and subjects should be searched)
	* @param	string		$terms				is either 'all' (use query as entered, words without prefix should default to "have to be in field") or 'any' (ignore search query parts and just return all posts that contain any of the specified words)
	* @param	array		$sort_by_sql		contains SQL code for the ORDER BY part of a query
	* @param	string		$sort_key			is the key of $sort_by_sql for the selected sorting
	* @param	string		$sort_dir			is either a or d representing ASC and DESC
	* @param	string		$sort_days			specifies the maximum amount of days a post may be old
	* @param	array		$ex_fid_ary			specifies an array of forum ids which should not be searched
	* @param	array		$m_approve_fid_ary	specifies an array of forum ids in which the searcher is allowed to view unapproved posts
	* @param	int			$topic_id			is set to 0 or a topic id, if it is not 0 then only posts in this topic should be searched
	* @param	array		$author_ary			an array of author ids if the author should be ignored during the search the array is empty
	* @param	string		$author_name		specifies the author match, when ANONYMOUS is also a search-match
	* @param	array		&$id_ary			passed by reference, to be filled with ids for the page specified by $start and $per_page, should be ordered
	* @param	int			$start				indicates the first index of the page
	* @param	int			$per_page			number of ids each page is supposed to contain
	* @return	boolean|int						total number of results
	*
	* @access	public
	*/
	function keyword_search($type, $fields, $terms, $sort_by_sql, $sort_key, $sort_dir, $sort_days, $ex_fid_ary, $m_approve_fid_ary, $topic_id, $author_ary, $author_name, &$id_ary, $start, $per_page)
	{
		global $config, $db, $auth;

		// No keywords? No posts.
		if (!strlen($this->search_query) && !sizeof($author_ary))
		{
			return false;
		}

		$id_ary = array();

		$join_topic = ($type == 'posts') ? false : true;

		// sorting

		if ($type == 'topics')
		{
			switch ($sort_key)
			{
				case 'a':
					$this->sphinx->SetGroupBy('topic_id', SPH_GROUPBY_ATTR, 'poster_id ' . (($sort_dir == 'a') ? 'ASC' : 'DESC'));
				break;
				case 'f':
					$this->sphinx->SetGroupBy('topic_id', SPH_GROUPBY_ATTR, 'forum_id ' . (($sort_dir == 'a') ? 'ASC' : 'DESC'));
				break;
				case 'i':
				case 's':
					$this->sphinx->SetGroupBy('topic_id', SPH_GROUPBY_ATTR, 'post_subject ' . (($sort_dir == 'a') ? 'ASC' : 'DESC'));
				break;
				case 't':
				default:
					$this->sphinx->SetGroupBy('topic_id', SPH_GROUPBY_ATTR, 'topic_last_post_time ' . (($sort_dir == 'a') ? 'ASC' : 'DESC'));
				break;
			}
		}
		else
		{
			switch ($sort_key)
			{
				case 'a':
					$this->sphinx->SetSortMode(($sort_dir == 'a') ? SPH_SORT_ATTR_ASC : SPH_SORT_ATTR_DESC, 'poster_id');
				break;
				case 'f':
					$this->sphinx->SetSortMode(($sort_dir == 'a') ? SPH_SORT_ATTR_ASC : SPH_SORT_ATTR_DESC, 'forum_id');
				break;
				case 'i':
				case 's':
					$this->sphinx->SetSortMode(($sort_dir == 'a') ? SPH_SORT_ATTR_ASC : SPH_SORT_ATTR_DESC, 'post_subject');
				break;
				case 't':
				default:
					$this->sphinx->SetSortMode(($sort_dir == 'a') ? SPH_SORT_ATTR_ASC : SPH_SORT_ATTR_DESC, 'post_time');
				break;
			}
		}

		// most narrow filters first
		if ($topic_id)
		{
			$this->sphinx->SetFilter('topic_id', array($topic_id));
		}

		$search_query_prefix = '';

		switch($fields)
		{
			case 'titleonly':
				// only search the title
				if ($terms == 'all')
				{
					$search_query_prefix = '@title ';
				}
				$this->sphinx->SetFieldWeights(array("title" => 5, "data" => 1)); // weight for the title
				$this->sphinx->SetFilter('topic_first_post', array(1)); // 1 is first_post, 0 is not first post
			break;

			case 'msgonly':
				// only search the body
				if ($terms == 'all')
				{
					$search_query_prefix = '@data ';
				}
				$this->sphinx->SetFieldWeights(array("title" => 1, "data" => 5)); // weight for the body
			break;

			case 'firstpost':
				$this->sphinx->SetFieldWeights(array("title" => 5, "data" => 1)); // more relative weight for the title, also search the body
				$this->sphinx->SetFilter('topic_first_post', array(1)); // 1 is first_post, 0 is not first post
			break;

			default:
				$this->sphinx->SetFieldWeights(array("title" => 5, "data" => 1)); // more relative weight for the title, also search the body
			break;
		}

		if (sizeof($author_ary))
		{
			$this->sphinx->SetFilter('poster_id', $author_ary);
		}

		if (sizeof($ex_fid_ary))
		{
			// All forums that a user is allowed to access
			$fid_ary = array_unique(array_intersect(array_keys($auth->acl_getf('f_read', true)), array_keys($auth->acl_getf('f_search', true))));
			// All forums that the user wants to and can search in
			$search_forums = array_diff($fid_ary, $ex_fid_ary);

			if (sizeof($search_forums))
			{
				$this->sphinx->SetFilter('forum_id', $search_forums);
			}
		}

		$this->sphinx->SetFilter('deleted', array(0));

		$this->sphinx->SetLimits($start, (int) $per_page, SPHINX_MAX_MATCHES);
		$result = $this->sphinx->Query($search_query_prefix . str_replace('&quot;', '"', $this->search_query), $this->indexes);

		// could be connection to localhost:3312 failed (errno=111, msg=Connection refused) during rotate, retry if so
		$retries = SPHINX_CONNECT_RETRIES;
		while (!$result && (strpos($this->sphinx->_error, "errno=111,") !== false) && $retries--)
		{
			usleep(SPHINX_CONNECT_WAIT_TIME);
			$result = $this->sphinx->Query($search_query_prefix . str_replace('&quot;', '"', $this->search_query), $this->indexes);
		}

		$id_ary = array();
		if (isset($result['matches']))
		{
			if ($type == 'posts')
			{
				$id_ary = array_keys($result['matches']);
			}
			else
			{
				foreach($result['matches'] as $key => $value)
				{
					$id_ary[] = $value['attrs']['topic_id'];
				}
			}
		}
		else
		{
			return false;
		}

		$result_count = $result['total_found'];

		$id_ary = array_slice($id_ary, 0, (int) $per_page);

		return $result_count;
	}

	/**
	* Performs a search on an author's posts without caring about message contents. Depends on display specific params
	*
	* @param	string		$type				contains either posts or topics depending on what should be searched for
	* @param	boolean		$firstpost_only		if true, only topic starting posts will be considered
	* @param	array		$sort_by_sql		contains SQL code for the ORDER BY part of a query
	* @param	string		$sort_key			is the key of $sort_by_sql for the selected sorting
	* @param	string		$sort_dir			is either a or d representing ASC and DESC
	* @param	string		$sort_days			specifies the maximum amount of days a post may be old
	* @param	array		$ex_fid_ary			specifies an array of forum ids which should not be searched
	* @param	array		$m_approve_fid_ary	specifies an array of forum ids in which the searcher is allowed to view unapproved posts
	* @param	int			$topic_id			is set to 0 or a topic id, if it is not 0 then only posts in this topic should be searched
	* @param	array		$author_ary			an array of author ids
	* @param	string		$author_name		specifies the author match, when ANONYMOUS is also a search-match
	* @param	array		&$id_ary			passed by reference, to be filled with ids for the page specified by $start and $per_page, should be ordered
	* @param	int			$start				indicates the first index of the page
	* @param	int			$per_page			number of ids each page is supposed to contain
	* @return	boolean|int						total number of results
	*
	* @access	public
	*/
	function author_search($type, $firstpost_only, $sort_by_sql, $sort_key, $sort_dir, $sort_days, $ex_fid_ary, $m_approve_fid_ary, $topic_id, $author_ary, $author_name, &$id_ary, $start, $per_page)
	{
		$this->search_query = '';

		$this->sphinx->SetMatchMode(SPH_MATCH_FULLSCAN);
		$fields = ($firstpost_only) ? 'firstpost' : 'all';
		$terms = 'all';
		return $this->keyword_search($type, $fields, $terms, $sort_by_sql, $sort_key, $sort_dir, $sort_days, $ex_fid_ary, $m_approve_fid_ary, $topic_id, $author_ary, $author_name, $id_ary, $start, $per_page);
	}

	/**
	 * Updates wordlist and wordmatch tables when a message is posted or changed
	 *
	 * @param	string	$mode	Contains the post mode: edit, post, reply, quote
	 * @param	int	$post_id	The id of the post which is modified/created
	 * @param	string	&$message	New or updated post content
	 * @param	string	&$subject	New or updated post subject
	 * @param	int	$poster_id	Post author's user id
	 * @param	int	$forum_id	The id of the forum in which the post is located
	 *
	 * @access public
	 */
	function index($mode, $post_id, &$message, &$subject, $poster_id, $forum_id)
	{
		global $config, $db;

		if ($mode == 'edit')
		{
			$this->sphinx->UpdateAttributes($this->indexes, array('forum_id', 'poster_id'), array((int)$post_id => array((int)$forum_id, (int)$poster_id)));
		}
		else if ($mode != 'post' && $post_id)
		{
			// Update topic_last_post_time for full topic
			$sql_array = array(
				'SELECT'	=> 'p1.post_id',
				'FROM'		=> array(
					POSTS_TABLE	=> 'p1',
				),
				'LEFT_JOIN'	=> array(array(
					'FROM'	=> array(
						POSTS_TABLE	=> 'p2'
					),
					'ON'	=> 'p1.topic_id = p2.topic_id',
				)),
			);

			$sql = $db->sql_build_query('SELECT', $sql_array);
			$result = $db->sql_query($sql);

			$post_updates = array();
			$post_time = time();
			while ($row = $db->sql_fetchrow($result))
			{
				$post_updates[(int)$row['post_id']] = array($post_time);
			}
			$db->sql_freeresult($result);

			if (sizeof($post_updates))
			{
				$this->sphinx->UpdateAttributes($this->indexes, array('topic_last_post_time'), $post_updates);
			}
		}
	}

	/**
	* Delete a post from the index after it was deleted
	*
	* @access public
	*/
	function index_remove($post_ids, $author_ids, $forum_ids)
	{
		$values = array();
		foreach ($post_ids as $post_id)
		{
			$values[$post_id] = array(1);
		}

		$this->sphinx->UpdateAttributes($this->indexes, array('deleted'), $values);
	}

	/**
	* Destroy old cache entries
	*
	* @access public
	*/
	function tidy($create = false)
	{
		global $config;

		set_config('search_last_gc', time(), true);
	}

	/**
	* Create sphinx table
	*
	* @return string|bool error string is returned incase of errors otherwise false
	*
	* @access public
	*/
	function create_index($acp_module, $u_action)
	{
		global $db, $user, $config;

		if (!isset($config['fulltext_sphinx_configured']) || !$config['fulltext_sphinx_configured'])
		{
			return $user->lang['FULLTEXT_SPHINX_CONFIGURE_FIRST'];
		}

		if (!$this->index_created())
		{
			$sql = 'CREATE TABLE IF NOT EXISTS ' . SPHINX_TABLE . ' (
				counter_id INT NOT NULL PRIMARY KEY,
				max_doc_id INT NOT NULL
			)';
			$db->sql_query($sql);

			$sql = 'TRUNCATE TABLE ' . SPHINX_TABLE;
			$db->sql_query($sql);
		}

		// start indexing process
		$this->tidy(true);

		return false;
	}

	/**
	* Drop sphinx table
	*
	* @return string|bool error string is returned incase of errors otherwise false
	*
	* @access public
	*/
	function delete_index($acp_module, $u_action)
	{
		global $db, $config;

		if (!$this->index_created())
		{
			return false;
		}

		$sql = 'DROP TABLE ' . SPHINX_TABLE;
		$db->sql_query($sql);

		return false;
	}

	/**
	* Returns true if the sphinx table was created
	*
	* @return bool true if sphinx table was created
	*
	* @access public
	*/
	function index_created($allow_new_files = true)
	{
		global $db, $config;

		$sql = 'SHOW TABLES LIKE \'' . SPHINX_TABLE . '\'';
		$result = $db->sql_query($sql);
		$row = $db->sql_fetchrow($result);
		$db->sql_freeresult($result);

		$created = false;

		if ($row)
		{
			$created = true;
		}

		return $created;
	}

	/**
	* Returns an associative array containing information about the indexes
	*
	* @return string|bool Language string of error false otherwise
	*
	* @access public
	*/
	function index_stats()
	{
		global $user;

		if (empty($this->stats))
		{
			$this->get_stats();
		}

		return array(
			$user->lang['FULLTEXT_SPHINX_MAIN_POSTS']			=> ($this->index_created()) ? $this->stats['main_posts'] : 0,
			$user->lang['FULLTEXT_SPHINX_DELTA_POSTS']			=> ($this->index_created()) ? $this->stats['total_posts'] - $this->stats['main_posts'] : 0,
			$user->lang['FULLTEXT_MYSQL_TOTAL_POSTS']			=> ($this->index_created()) ? $this->stats['total_posts'] : 0,
			$user->lang['FULLTEXT_SPHINX_LAST_SEARCHES']		=> nl2br($this->stats['last_searches']),
		);
	}

	/**
	* Collects stats that can be displayed on the index maintenance page
	*
	* @access private
	*/
	function get_stats()
	{
		global $db, $config;

		if ($this->index_created())
		{
			$sql = 'SELECT COUNT(post_id) as total_posts
				FROM ' . POSTS_TABLE;
			$result = $db->sql_query($sql);
			$this->stats['total_posts'] = (int) $db->sql_fetchfield('total_posts');
			$db->sql_freeresult($result);

			$sql = 'SELECT COUNT(p.post_id) as main_posts
				FROM ' . POSTS_TABLE . ' p, ' . SPHINX_TABLE . ' m
				WHERE p.post_id <= m.max_doc_id
					AND m.counter_id = 1';
			$result = $db->sql_query($sql);
			$this->stats['main_posts'] = (int) $db->sql_fetchfield('main_posts');
			$db->sql_freeresult($result);
		}

		$this->stats['last_searches'] = '';
	}

	/**
	* Returns a list of options for the ACP to display
	*
	* @return associative array containing template and config variables
	*
	* @access public
	*/
	function acp()
	{
		global $user, $config;

		$config_vars = array(
			'fulltext_sphinx_config_path' => 'string',
			'fulltext_sphinx_data_path' => 'string',
			'fulltext_sphinx_bin_path' => 'string',
			'fulltext_sphinx_port' => 'int',
			'fulltext_sphinx_stopwords'	=> 'bool',
			'fulltext_sphinx_indexer_mem_limit' => 'int',
		);

		$defaults = array(
			'fulltext_sphinx_indexer_mem_limit' => '512',
			'fulltext_sphinx_stopwords' => '0',
		);

		foreach ($config_vars as $config_var => $type)
		{
			if (!isset($config[$config_var]))
			{
				$default = '';
				if (isset($defaults[$config_var]))
				{
					$default = $defaults[$config_var];
				}
				set_config($config_var, $default);
			}
		}

		$tpl = '
		<span class="error">' . $user->lang['FULLTEXT_SPHINX_CONFIGURE_BEFORE']. '</span>
		<dl>
			<dt><label for="fulltext_sphinx_config_path">' . $user->lang['FULLTEXT_SPHINX_CONFIG_PATH'] . ':</label><br /><span>' . $user->lang['FULLTEXT_SPHINX_CONFIG_PATH_EXPLAIN'] . '</span></dt>
			<dd><input id="fulltext_sphinx_config_path" type="text" size="40" maxlength="255" name="config[fulltext_sphinx_config_path]" value="' . $config['fulltext_sphinx_config_path'] . '" /></dd>
		</dl>
		<dl>
			<dt><label for="fulltext_sphinx_bin_path">' . $user->lang['FULLTEXT_SPHINX_BIN_PATH'] . ':</label><br /><span>' . $user->lang['FULLTEXT_SPHINX_BIN_PATH_EXPLAIN'] . '</span></dt>
			<dd><input id="fulltext_sphinx_bin_path" type="text" size="40" maxlength="255" name="config[fulltext_sphinx_bin_path]" value="' . $bin_path . '" /></dd>
		</dl>
		<dl>
			<dt><label for="fulltext_sphinx_data_path">' . $user->lang['FULLTEXT_SPHINX_DATA_PATH'] . ':</label><br /><span>' . $user->lang['FULLTEXT_SPHINX_DATA_PATH_EXPLAIN'] . '</span></dt>
			<dd><input id="fulltext_sphinx_data_path" type="text" size="40" maxlength="255" name="config[fulltext_sphinx_data_path]" value="' . $config['fulltext_sphinx_data_path'] . '" /></dd>
		</dl>
		<dl>
			<dt><label for="fulltext_sphinx_stopwords">' . $user->lang['FULLTEXT_SPHINX_STOPWORDS_FILE'] . ':</label><br /><span>' . $user->lang['FULLTEXT_SPHINX_STOPWORDS_FILE_EXPLAIN'] . '</span></dt>
			<dd><label><input type="radio" id="fulltext_sphinx_stopwords" name="config[fulltext_sphinx_stopwords]" value="1"' . (($config['fulltext_sphinx_stopwords']) ? ' checked="checked"' : '') . ' class="radio" /> ' . $user->lang['YES'] . '</label><label><input type="radio" name="config[fulltext_sphinx_stopwords]" value="0"' . ((!$config['fulltext_sphinx_stopwords']) ? ' checked="checked"' : '') . ' class="radio" /> ' . $user->lang['NO'] . '</label></dd>
		</dl>
		<span class="error">' . $user->lang['FULLTEXT_SPHINX_CONFIGURE_AFTER']. '</span>
		<dl>
			<dt><label for="fulltext_sphinx_port">' . $user->lang['FULLTEXT_SPHINX_PORT'] . ':</label><br /><span>' . $user->lang['FULLTEXT_SPHINX_PORT_EXPLAIN'] . '</span></dt>
			<dd><input id="fulltext_sphinx_port" type="text" size="4" maxlength="10" name="config[fulltext_sphinx_port]" value="' . $config['fulltext_sphinx_port'] . '" /></dd>
		</dl>
		<dl>
			<dt><label for="fulltext_sphinx_indexer_mem_limit">' . $user->lang['FULLTEXT_SPHINX_INDEXER_MEM_LIMIT'] . ':</label><br /><span>' . $user->lang['FULLTEXT_SPHINX_INDEXER_MEM_LIMIT_EXPLAIN'] . '</span></dt>
			<dd><input id="fulltext_sphinx_indexer_mem_limit" type="text" size="4" maxlength="10" name="config[fulltext_sphinx_indexer_mem_limit]" value="' . $config['fulltext_sphinx_indexer_mem_limit'] . '" />' . $user->lang['MIB'] . '</dd>
		</dl>
		';

		// These are fields required in the config table
		return array(
			'tpl'		=> $tpl,
			'config'	=> $config_vars
		);
	}
}