--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/forum/Sources/SearchAPI-Fulltext.php	Sun Jul 07 11:25:48 2013 +0200
@@ -0,0 +1,241 @@
+<?php
+
+/**
+ * Simple Machines Forum (SMF)
+ *
+ * @package SMF
+ * @author Simple Machines http://www.simplemachines.org
+ * @copyright 2011 Simple Machines
+ * @license http://www.simplemachines.org/about/smf/license.php BSD
+ *
+ * @version 2.0
+ */
+
+if (!defined('SMF'))
+	die('Hacking attempt...');
+
+/*
+	int searchSort(string $wordA, string $wordB)
+		- callback function for usort used to sort the fulltext results.
+		- the order of sorting is: large words, small words, large words that
+		  are excluded from the search, small words that are excluded.
+*/
+
+class fulltext_search
+{
+	// This is the last version of SMF that this was tested on, to protect against API changes.
+	public $version_compatible = 'SMF 2.0';
+	// This won't work with versions of SMF less than this.
+	public $min_smf_version = 'SMF 2.0 Beta 2';
+	// Is it supported?
+	public $is_supported = true;
+
+	// Can we do a boolean search - tested on construct.
+	protected $canDoBooleanSearch = false;
+	// What words are banned?
+	protected $bannedWords = array();
+	// What is the minimum word length?
+	protected $min_word_length = 4;
+	// What databases support the fulltext index?
+	protected $supported_databases = array('mysql');
+
+	public function __construct()
+	{
+		global $smcFunc, $db_connection, $modSettings, $db_type;
+
+		// Is this database supported?
+		if (!in_array($db_type, $this->supported_databases))
+		{
+			$this->is_supported = false;
+			return;
+		}
+
+		// Some MySQL versions are superior to others :P.
+		$this->canDoBooleanSearch = version_compare($smcFunc['db_server_info']($db_connection), '4.0.1', '>=');
+
+		$this->bannedWords = empty($modSettings['search_banned_words']) ? array() : explode(',', $modSettings['search_banned_words']);
+		$this->min_word_length = $this->_getMinWordLength();
+	}
+
+	// Check whether the method can be performed by this API.
+	public function supportsMethod($methodName, $query_params = null)
+	{
+		switch ($methodName)
+		{
+			case 'searchSort':
+			case 'prepareIndexes':
+			case 'indexedWordQuery':
+				return true;
+			break;
+
+			default:
+				return false;
+			break;
+		}
+	}
+
+	// What is the minimum word length full text supports?
+	protected function _getMinWordLength()
+	{
+		global $smcFunc;
+
+		// Try to determine the minimum number of letters for a fulltext search.
+		$request = $smcFunc['db_search_query']('max_fulltext_length', '
+			SHOW VARIABLES
+			LIKE {string:fulltext_minimum_word_length}',
+			array(
+				'fulltext_minimum_word_length' => 'ft_min_word_len',
+			)
+		);
+		if ($request !== false && $smcFunc['db_num_rows']($request) == 1)
+		{
+			list (, $min_word_length) = $smcFunc['db_fetch_row']($request);
+			$smcFunc['db_free_result']($request);
+		}
+		// 4 is the MySQL default...
+		else
+			$min_word_length = 4;
+
+		return $min_word_length;
+	}
+
+	// This function compares the length of two strings plus a little.
+	public function searchSort($a, $b)
+	{
+		global $modSettings, $excludedWords;
+
+		$x = strlen($a) - (in_array($a, $excludedWords) ? 1000 : 0);
+		$y = strlen($b) - (in_array($b, $excludedWords) ? 1000 : 0);
+
+		return $x < $y ? 1 : ($x > $y ? -1 : 0);
+	}
+
+	// Do we have to do some work with the words we are searching for to prepare them?
+	public function prepareIndexes($word, &$wordsSearch, &$wordsExclude, $isExcluded)
+	{
+		global $modSettings;
+
+		$subwords = text2words($word, null, false);
+
+		if (!$this->canDoBooleanSearch && count($subwords) > 1 && empty($modSettings['search_force_index']))
+			$wordsSearch['words'][] = $word;
+
+		if ($this->canDoBooleanSearch)
+		{
+			$fulltextWord = count($subwords) === 1 ? $word : '"' . $word . '"';
+			$wordsSearch['indexed_words'][] = $fulltextWord;
+			if ($isExcluded)
+				$wordsExclude[] = $fulltextWord;
+		}
+		// Excluded phrases don't benefit from being split into subwords.
+		elseif (count($subwords) > 1 && $isExcluded)
+			return;
+		else
+		{
+			$relyOnIndex = true;
+			foreach ($subwords as $subword)
+			{
+				if (($smcFunc['strlen']($subword) >= $this->min_word_length) && !in_array($subword, $this->bannedWords))
+				{
+					$wordsSearch['indexed_words'][] = $subword;
+					if ($isExcluded)
+						$wordsExclude[] = $subword;
+				}
+				elseif (!in_array($subword, $this->bannedWords))
+					$relyOnIndex = false;
+			}
+
+			if ($this->canDoBooleanSearch && !$relyOnIndex && empty($modSettings['search_force_index']))
+				$wordsSearch['words'][] = $word;
+		}
+	}
+
+	// Search for indexed words.
+	public function indexedWordQuery($words, $search_data)
+	{
+		global $modSettings, $smcFunc;
+
+		$query_select = array(
+			'id_msg' => 'm.id_msg',
+		);
+		$query_where = array();
+		$query_params = $search_data['params'];
+
+		if ($query_params['id_search'])
+			$query_select['id_search'] = '{int:id_search}';
+
+		$count = 0;
+		if (empty($modSettings['search_simple_fulltext']))
+			foreach ($words['words'] as $regularWord)
+			{
+				$query_where[] = 'm.body' . (in_array($regularWord, $query_params['excluded_words']) ? ' NOT' : '') . (empty($modSettings['search_match_words']) || $no_regexp ? ' LIKE ' : 'RLIKE') . '{string:complex_body_' . $count . '}';
+				$query_params['complex_body_' . $count++] = empty($modSettings['search_match_words']) || $no_regexp ? '%' . strtr($regularWord, array('_' => '\\_', '%' => '\\%')) . '%' : '[[:<:]]' . addcslashes(preg_replace(array('/([\[\]$.+*?|{}()])/'), array('[$1]'), $regularWord), '\\\'') . '[[:>:]]';
+			}
+
+		if ($query_params['user_query'])
+			$query_where[] = '{raw:user_query}';
+		if ($query_params['board_query'])
+			$query_where[] = 'm.id_board {raw:board_query}';
+
+		if ($query_params['topic'])
+			$query_where[] = 'm.id_topic = {int:topic}';
+		if ($query_params['min_msg_id'])
+			$query_where[] = 'm.id_msg >= {int:min_msg_id}';
+		if ($query_params['max_msg_id'])
+			$query_where[] = 'm.id_msg <= {int:max_msg_id}';
+
+		$count = 0;
+		if (!empty($query_params['excluded_phrases']) && empty($modSettings['search_force_index']))
+			foreach ($query_params['excluded_phrases'] as $phrase)
+			{
+				$query_where[] = 'subject NOT ' . (empty($modSettings['search_match_words']) || $no_regexp ? ' LIKE ' : 'RLIKE') . '{string:exclude_subject_phrase_' . $count . '}';
+				$query_params['exclude_subject_phrase_' . $count++] = empty($modSettings['search_match_words']) || $no_regexp ? '%' . strtr($phrase, array('_' => '\\_', '%' => '\\%')) . '%' : '[[:<:]]' . addcslashes(preg_replace(array('/([\[\]$.+*?|{}()])/'), array('[$1]'), $phrase), '\\\'') . '[[:>:]]';
+			}
+		$count = 0;
+		if (!empty($query_params['excluded_subject_words']) && empty($modSettings['search_force_index']))
+			foreach ($query_params['excluded_subject_words'] as $excludedWord)
+			{
+				$query_where[] = 'subject NOT ' . (empty($modSettings['search_match_words']) || $no_regexp ? ' LIKE ' : 'RLIKE') . '{string:exclude_subject_words_' . $count . '}';
+				$query_params['exclude_subject_words_' . $count++] = empty($modSettings['search_match_words']) || $no_regexp ? '%' . strtr($excludedWord, array('_' => '\\_', '%' => '\\%')) . '%' : '[[:<:]]' . addcslashes(preg_replace(array('/([\[\]$.+*?|{}()])/'), array('[$1]'), $excludedWord), '\\\'') . '[[:>:]]';
+			}
+
+		if (!empty($modSettings['search_simple_fulltext']))
+		{
+			$query_where[] = 'MATCH (body) AGAINST ({string:body_match})';
+			$query_params['body_match'] = implode(' ', array_diff($words['indexed_words'], $query_params['excluded_index_words']));
+		}
+		elseif ($this->canDoBooleanSearch)
+		{
+			$query_params['boolean_match'] = '';
+			foreach ($words['indexed_words'] as $fulltextWord)
+				$query_params['boolean_match'] .= (in_array($fulltextWord, $query_params['excluded_index_words']) ? '-' : '+') . $fulltextWord . ' ';
+			$query_params['boolean_match'] = substr($query_params['boolean_match'], 0, -1);
+
+			$query_where[] = 'MATCH (body) AGAINST ({string:boolean_match} IN BOOLEAN MODE)';
+		}
+		else
+		{
+			$count = 0;
+			foreach ($words['indexed_words'] as $fulltextWord)
+			{
+				$query_where[] = (in_array($fulltextWord, $query_params['excluded_index_words']) ? 'NOT ' : '') . 'MATCH (body) AGAINST ({string:fulltext_match_' . $count . '})';
+				$query_params['fulltext_match_' . $count++] = $fulltextWord;
+			}
+		}
+
+		$ignoreRequest = $smcFunc['db_search_query']('insert_into_log_messages_fulltext', ($smcFunc['db_support_ignore'] ? ( '
+			INSERT IGNORE INTO {db_prefix}' . $search_data['insert_into'] . '
+				(' . implode(', ', array_keys($query_select)) . ')') : '') . '
+			SELECT ' . implode(', ', $query_select) . '
+			FROM {db_prefix}messages AS m
+			WHERE ' . implode('
+				AND ', $query_where) . (empty($search_data['max_results']) ? '' : '
+			LIMIT ' . ($search_data['max_results'] - $search_data['indexed_results'])),
+			$query_params
+		);
+
+		return $ignoreRequest;
+	}
+}
+
+?>
\ No newline at end of file