Chris@76: <?php
Chris@76: 
Chris@76: /**
Chris@76:  * Simple Machines Forum (SMF)
Chris@76:  *
Chris@76:  * @package SMF
Chris@76:  * @author Simple Machines http://www.simplemachines.org
Chris@76:  * @copyright 2011 Simple Machines
Chris@76:  * @license http://www.simplemachines.org/about/smf/license.php BSD
Chris@76:  *
Chris@76:  * @version 2.0
Chris@76:  */
Chris@76: 
Chris@76: if (!defined('SMF'))
Chris@76: 	die('Hacking attempt...');
Chris@76: 
Chris@76: /*
Chris@76: 	int searchSort(string $wordA, string $wordB)
Chris@76: 		- callback function for usort used to sort the fulltext results.
Chris@76: 		- the order of sorting is: large words, small words, large words that
Chris@76: 		  are excluded from the search, small words that are excluded.
Chris@76: */
Chris@76: 
Chris@76: class fulltext_search
Chris@76: {
Chris@76: 	// This is the last version of SMF that this was tested on, to protect against API changes.
Chris@76: 	public $version_compatible = 'SMF 2.0';
Chris@76: 	// This won't work with versions of SMF less than this.
Chris@76: 	public $min_smf_version = 'SMF 2.0 Beta 2';
Chris@76: 	// Is it supported?
Chris@76: 	public $is_supported = true;
Chris@76: 
Chris@76: 	// Can we do a boolean search - tested on construct.
Chris@76: 	protected $canDoBooleanSearch = false;
Chris@76: 	// What words are banned?
Chris@76: 	protected $bannedWords = array();
Chris@76: 	// What is the minimum word length?
Chris@76: 	protected $min_word_length = 4;
Chris@76: 	// What databases support the fulltext index?
Chris@76: 	protected $supported_databases = array('mysql');
Chris@76: 
Chris@76: 	public function __construct()
Chris@76: 	{
Chris@76: 		global $smcFunc, $db_connection, $modSettings, $db_type;
Chris@76: 
Chris@76: 		// Is this database supported?
Chris@76: 		if (!in_array($db_type, $this->supported_databases))
Chris@76: 		{
Chris@76: 			$this->is_supported = false;
Chris@76: 			return;
Chris@76: 		}
Chris@76: 
Chris@76: 		// Some MySQL versions are superior to others :P.
Chris@76: 		$this->canDoBooleanSearch = version_compare($smcFunc['db_server_info']($db_connection), '4.0.1', '>=');
Chris@76: 
Chris@76: 		$this->bannedWords = empty($modSettings['search_banned_words']) ? array() : explode(',', $modSettings['search_banned_words']);
Chris@76: 		$this->min_word_length = $this->_getMinWordLength();
Chris@76: 	}
Chris@76: 
Chris@76: 	// Check whether the method can be performed by this API.
Chris@76: 	public function supportsMethod($methodName, $query_params = null)
Chris@76: 	{
Chris@76: 		switch ($methodName)
Chris@76: 		{
Chris@76: 			case 'searchSort':
Chris@76: 			case 'prepareIndexes':
Chris@76: 			case 'indexedWordQuery':
Chris@76: 				return true;
Chris@76: 			break;
Chris@76: 
Chris@76: 			default:
Chris@76: 				return false;
Chris@76: 			break;
Chris@76: 		}
Chris@76: 	}
Chris@76: 
Chris@76: 	// What is the minimum word length full text supports?
Chris@76: 	protected function _getMinWordLength()
Chris@76: 	{
Chris@76: 		global $smcFunc;
Chris@76: 
Chris@76: 		// Try to determine the minimum number of letters for a fulltext search.
Chris@76: 		$request = $smcFunc['db_search_query']('max_fulltext_length', '
Chris@76: 			SHOW VARIABLES
Chris@76: 			LIKE {string:fulltext_minimum_word_length}',
Chris@76: 			array(
Chris@76: 				'fulltext_minimum_word_length' => 'ft_min_word_len',
Chris@76: 			)
Chris@76: 		);
Chris@76: 		if ($request !== false && $smcFunc['db_num_rows']($request) == 1)
Chris@76: 		{
Chris@76: 			list (, $min_word_length) = $smcFunc['db_fetch_row']($request);
Chris@76: 			$smcFunc['db_free_result']($request);
Chris@76: 		}
Chris@76: 		// 4 is the MySQL default...
Chris@76: 		else
Chris@76: 			$min_word_length = 4;
Chris@76: 
Chris@76: 		return $min_word_length;
Chris@76: 	}
Chris@76: 
Chris@76: 	// This function compares the length of two strings plus a little.
Chris@76: 	public function searchSort($a, $b)
Chris@76: 	{
Chris@76: 		global $modSettings, $excludedWords;
Chris@76: 
Chris@76: 		$x = strlen($a) - (in_array($a, $excludedWords) ? 1000 : 0);
Chris@76: 		$y = strlen($b) - (in_array($b, $excludedWords) ? 1000 : 0);
Chris@76: 
Chris@76: 		return $x < $y ? 1 : ($x > $y ? -1 : 0);
Chris@76: 	}
Chris@76: 
Chris@76: 	// Do we have to do some work with the words we are searching for to prepare them?
Chris@76: 	public function prepareIndexes($word, &$wordsSearch, &$wordsExclude, $isExcluded)
Chris@76: 	{
Chris@76: 		global $modSettings;
Chris@76: 
Chris@76: 		$subwords = text2words($word, null, false);
Chris@76: 
Chris@76: 		if (!$this->canDoBooleanSearch && count($subwords) > 1 && empty($modSettings['search_force_index']))
Chris@76: 			$wordsSearch['words'][] = $word;
Chris@76: 
Chris@76: 		if ($this->canDoBooleanSearch)
Chris@76: 		{
Chris@76: 			$fulltextWord = count($subwords) === 1 ? $word : '"' . $word . '"';
Chris@76: 			$wordsSearch['indexed_words'][] = $fulltextWord;
Chris@76: 			if ($isExcluded)
Chris@76: 				$wordsExclude[] = $fulltextWord;
Chris@76: 		}
Chris@76: 		// Excluded phrases don't benefit from being split into subwords.
Chris@76: 		elseif (count($subwords) > 1 && $isExcluded)
Chris@76: 			return;
Chris@76: 		else
Chris@76: 		{
Chris@76: 			$relyOnIndex = true;
Chris@76: 			foreach ($subwords as $subword)
Chris@76: 			{
Chris@76: 				if (($smcFunc['strlen']($subword) >= $this->min_word_length) && !in_array($subword, $this->bannedWords))
Chris@76: 				{
Chris@76: 					$wordsSearch['indexed_words'][] = $subword;
Chris@76: 					if ($isExcluded)
Chris@76: 						$wordsExclude[] = $subword;
Chris@76: 				}
Chris@76: 				elseif (!in_array($subword, $this->bannedWords))
Chris@76: 					$relyOnIndex = false;
Chris@76: 			}
Chris@76: 
Chris@76: 			if ($this->canDoBooleanSearch && !$relyOnIndex && empty($modSettings['search_force_index']))
Chris@76: 				$wordsSearch['words'][] = $word;
Chris@76: 		}
Chris@76: 	}
Chris@76: 
Chris@76: 	// Search for indexed words.
Chris@76: 	public function indexedWordQuery($words, $search_data)
Chris@76: 	{
Chris@76: 		global $modSettings, $smcFunc;
Chris@76: 
Chris@76: 		$query_select = array(
Chris@76: 			'id_msg' => 'm.id_msg',
Chris@76: 		);
Chris@76: 		$query_where = array();
Chris@76: 		$query_params = $search_data['params'];
Chris@76: 
Chris@76: 		if ($query_params['id_search'])
Chris@76: 			$query_select['id_search'] = '{int:id_search}';
Chris@76: 
Chris@76: 		$count = 0;
Chris@76: 		if (empty($modSettings['search_simple_fulltext']))
Chris@76: 			foreach ($words['words'] as $regularWord)
Chris@76: 			{
Chris@76: 				$query_where[] = 'm.body' . (in_array($regularWord, $query_params['excluded_words']) ? ' NOT' : '') . (empty($modSettings['search_match_words']) || $no_regexp ? ' LIKE ' : 'RLIKE') . '{string:complex_body_' . $count . '}';
Chris@76: 				$query_params['complex_body_' . $count++] = empty($modSettings['search_match_words']) || $no_regexp ? '%' . strtr($regularWord, array('_' => '\\_', '%' => '\\%')) . '%' : '[[:<:]]' . addcslashes(preg_replace(array('/([\[\]$.+*?|{}()])/'), array('[$1]'), $regularWord), '\\\'') . '[[:>:]]';
Chris@76: 			}
Chris@76: 
Chris@76: 		if ($query_params['user_query'])
Chris@76: 			$query_where[] = '{raw:user_query}';
Chris@76: 		if ($query_params['board_query'])
Chris@76: 			$query_where[] = 'm.id_board {raw:board_query}';
Chris@76: 
Chris@76: 		if ($query_params['topic'])
Chris@76: 			$query_where[] = 'm.id_topic = {int:topic}';
Chris@76: 		if ($query_params['min_msg_id'])
Chris@76: 			$query_where[] = 'm.id_msg >= {int:min_msg_id}';
Chris@76: 		if ($query_params['max_msg_id'])
Chris@76: 			$query_where[] = 'm.id_msg <= {int:max_msg_id}';
Chris@76: 
Chris@76: 		$count = 0;
Chris@76: 		if (!empty($query_params['excluded_phrases']) && empty($modSettings['search_force_index']))
Chris@76: 			foreach ($query_params['excluded_phrases'] as $phrase)
Chris@76: 			{
Chris@76: 				$query_where[] = 'subject NOT ' . (empty($modSettings['search_match_words']) || $no_regexp ? ' LIKE ' : 'RLIKE') . '{string:exclude_subject_phrase_' . $count . '}';
Chris@76: 				$query_params['exclude_subject_phrase_' . $count++] = empty($modSettings['search_match_words']) || $no_regexp ? '%' . strtr($phrase, array('_' => '\\_', '%' => '\\%')) . '%' : '[[:<:]]' . addcslashes(preg_replace(array('/([\[\]$.+*?|{}()])/'), array('[$1]'), $phrase), '\\\'') . '[[:>:]]';
Chris@76: 			}
Chris@76: 		$count = 0;
Chris@76: 		if (!empty($query_params['excluded_subject_words']) && empty($modSettings['search_force_index']))
Chris@76: 			foreach ($query_params['excluded_subject_words'] as $excludedWord)
Chris@76: 			{
Chris@76: 				$query_where[] = 'subject NOT ' . (empty($modSettings['search_match_words']) || $no_regexp ? ' LIKE ' : 'RLIKE') . '{string:exclude_subject_words_' . $count . '}';
Chris@76: 				$query_params['exclude_subject_words_' . $count++] = empty($modSettings['search_match_words']) || $no_regexp ? '%' . strtr($excludedWord, array('_' => '\\_', '%' => '\\%')) . '%' : '[[:<:]]' . addcslashes(preg_replace(array('/([\[\]$.+*?|{}()])/'), array('[$1]'), $excludedWord), '\\\'') . '[[:>:]]';
Chris@76: 			}
Chris@76: 
Chris@76: 		if (!empty($modSettings['search_simple_fulltext']))
Chris@76: 		{
Chris@76: 			$query_where[] = 'MATCH (body) AGAINST ({string:body_match})';
Chris@76: 			$query_params['body_match'] = implode(' ', array_diff($words['indexed_words'], $query_params['excluded_index_words']));
Chris@76: 		}
Chris@76: 		elseif ($this->canDoBooleanSearch)
Chris@76: 		{
Chris@76: 			$query_params['boolean_match'] = '';
Chris@76: 			foreach ($words['indexed_words'] as $fulltextWord)
Chris@76: 				$query_params['boolean_match'] .= (in_array($fulltextWord, $query_params['excluded_index_words']) ? '-' : '+') . $fulltextWord . ' ';
Chris@76: 			$query_params['boolean_match'] = substr($query_params['boolean_match'], 0, -1);
Chris@76: 
Chris@76: 			$query_where[] = 'MATCH (body) AGAINST ({string:boolean_match} IN BOOLEAN MODE)';
Chris@76: 		}
Chris@76: 		else
Chris@76: 		{
Chris@76: 			$count = 0;
Chris@76: 			foreach ($words['indexed_words'] as $fulltextWord)
Chris@76: 			{
Chris@76: 				$query_where[] = (in_array($fulltextWord, $query_params['excluded_index_words']) ? 'NOT ' : '') . 'MATCH (body) AGAINST ({string:fulltext_match_' . $count . '})';
Chris@76: 				$query_params['fulltext_match_' . $count++] = $fulltextWord;
Chris@76: 			}
Chris@76: 		}
Chris@76: 
Chris@76: 		$ignoreRequest = $smcFunc['db_search_query']('insert_into_log_messages_fulltext', ($smcFunc['db_support_ignore'] ? ( '
Chris@76: 			INSERT IGNORE INTO {db_prefix}' . $search_data['insert_into'] . '
Chris@76: 				(' . implode(', ', array_keys($query_select)) . ')') : '') . '
Chris@76: 			SELECT ' . implode(', ', $query_select) . '
Chris@76: 			FROM {db_prefix}messages AS m
Chris@76: 			WHERE ' . implode('
Chris@76: 				AND ', $query_where) . (empty($search_data['max_results']) ? '' : '
Chris@76: 			LIMIT ' . ($search_data['max_results'] - $search_data['indexed_results'])),
Chris@76: 			$query_params
Chris@76: 		);
Chris@76: 
Chris@76: 		return $ignoreRequest;
Chris@76: 	}
Chris@76: }
Chris@76: 
Chris@76: ?>