first commit

27 files changed, 4950 insertions, 0 deletions

diff --git a/www/wiki/includes/search/AugmentPageProps.php b/www/wiki/includes/search/AugmentPageProps.php
new file mode 100644
index 00000000..29bd463d
--- /dev/null
+++ b/www/wiki/includes/search/AugmentPageProps.php
@@ -0,0 +1,20 @@
+<?php
+
+/**
+ * Augment search result set with values of certain page props.
+ */
+class AugmentPageProps implements ResultSetAugmentor {
+	/**
+	 * @var array List of properties.
+	 */
+	private $propnames;
+
+	public function __construct( $propnames ) {
+		$this->propnames = $propnames;
+	}
+
+	public function augmentAll( SearchResultSet $resultSet ) {
+		$titles = $resultSet->extractTitles();
+		return PageProps::getInstance()->getProperties( $titles, $this->propnames );
+	}
+}
diff --git a/www/wiki/includes/search/DummySearchIndexFieldDefinition.php b/www/wiki/includes/search/DummySearchIndexFieldDefinition.php
new file mode 100644
index 00000000..3ee3ed5a
--- /dev/null
+++ b/www/wiki/includes/search/DummySearchIndexFieldDefinition.php
@@ -0,0 +1,30 @@
+<?php
+
+/**
+ * Dummy implementation of SearchIndexFieldDefinition for testing purposes.
+ *
+ * @since 1.28
+ */
+class DummySearchIndexFieldDefinition extends SearchIndexFieldDefinition {
+
+	/**
+	 * @param SearchEngine $engine
+	 *
+	 * @return array
+	 */
+	public function getMapping( SearchEngine $engine ) {
+		$mapping = [
+			'name' => $this->name,
+			'type' => $this->type,
+			'flags' => $this->flags,
+			'subfields' => []
+		];
+
+		foreach ( $this->subfields as $subfield ) {
+			$mapping['subfields'][] = $subfield->getMapping( $engine );
+		}
+
+		return $mapping;
+	}
+
+}
diff --git a/www/wiki/includes/search/NullIndexField.php b/www/wiki/includes/search/NullIndexField.php
new file mode 100644
index 00000000..ff1e8cbf
--- /dev/null
+++ b/www/wiki/includes/search/NullIndexField.php
@@ -0,0 +1,52 @@
+<?php
+
+/**
+ * Null index field - means search engine does not implement this field.
+ */
+class NullIndexField implements SearchIndexField {
+
+	/**
+	 * Get mapping for specific search engine
+	 * @param SearchEngine $engine
+	 * @return array|null Null means this field does not map to anything
+	 */
+	public function getMapping( SearchEngine $engine ) {
+		return null;
+	}
+
+	/**
+	 * Set global flag for this field.
+	 *
+	 * @param int $flag Bit flag to set/unset
+	 * @param bool $unset True if flag should be unset, false by default
+	 * @return $this
+	 */
+	public function setFlag( $flag, $unset = false ) {
+	}
+
+	/**
+	 * Check if flag is set.
+	 * @param int $flag
+	 * @return int 0 if unset, !=0 if set
+	 */
+	public function checkFlag( $flag ) {
+		return 0;
+	}
+
+	/**
+	 * Merge two field definitions if possible.
+	 *
+	 * @param SearchIndexField $that
+	 * @return SearchIndexField|false New definition or false if not mergeable.
+	 */
+	public function merge( SearchIndexField $that ) {
+		return $that;
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public function getEngineHints( SearchEngine $engine ) {
+		return [];
+	}
+}
diff --git a/www/wiki/includes/search/ParserOutputSearchDataExtractor.php b/www/wiki/includes/search/ParserOutputSearchDataExtractor.php
new file mode 100644
index 00000000..4b60a0c5
--- /dev/null
+++ b/www/wiki/includes/search/ParserOutputSearchDataExtractor.php
@@ -0,0 +1,96 @@
+<?php
+
+namespace MediaWiki\Search;
+
+use Category;
+use ParserOutput;
+use Title;
+
+/**
+ * Extracts data from ParserOutput for indexing in the search engine.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @since 1.28
+ */
+class ParserOutputSearchDataExtractor {
+
+	/**
+	 * Get a list of categories, as an array with title text strings.
+	 *
+	 * @param ParserOutput $parserOutput
+	 * @return string[]
+	 */
+	public function getCategories( ParserOutput $parserOutput ) {
+		$categories = [];
+
+		foreach ( $parserOutput->getCategoryLinks() as $key ) {
+			$categories[] = Category::newFromName( $key )->getTitle()->getText();
+		}
+
+		return $categories;
+	}
+
+	/**
+	 * Get a list of external links from ParserOutput, as an array of strings.
+	 *
+	 * @param ParserOutput $parserOutput
+	 * @return string[]
+	 */
+	public function getExternalLinks( ParserOutput $parserOutput ) {
+		return array_keys( $parserOutput->getExternalLinks() );
+	}
+
+	/**
+	 * Get a list of outgoing wiki links (including interwiki links), as
+	 * an array of prefixed title strings.
+	 *
+	 * @param ParserOutput $parserOutput
+	 * @return string[]
+	 */
+	public function getOutgoingLinks( ParserOutput $parserOutput ) {
+		$outgoingLinks = [];
+
+		foreach ( $parserOutput->getLinks() as $linkedNamespace => $namespaceLinks ) {
+			foreach ( array_keys( $namespaceLinks ) as $linkedDbKey ) {
+				$outgoingLinks[] =
+					Title::makeTitle( $linkedNamespace, $linkedDbKey )->getPrefixedDBkey();
+			}
+		}
+
+		return $outgoingLinks;
+	}
+
+	/**
+	 * Get a list of templates used in the ParserOutput content, as prefixed title strings
+	 *
+	 * @param ParserOutput $parserOutput
+	 * @return string[]
+	 */
+	public function getTemplates( ParserOutput $parserOutput ) {
+		$templates = [];
+
+		foreach ( $parserOutput->getTemplates() as $tNS => $templatesInNS ) {
+			foreach ( array_keys( $templatesInNS ) as $tDbKey ) {
+				$templateTitle = Title::makeTitle( $tNS, $tDbKey );
+				$templates[] = $templateTitle->getPrefixedText();
+			}
+		}
+
+		return $templates;
+	}
+
+}
diff --git a/www/wiki/includes/search/PerRowAugmentor.php b/www/wiki/includes/search/PerRowAugmentor.php
new file mode 100644
index 00000000..a3979f7b
--- /dev/null
+++ b/www/wiki/includes/search/PerRowAugmentor.php
@@ -0,0 +1,37 @@
+<?php
+
+/**
+ * Perform augmentation of each row and return composite result,
+ * indexed by ID.
+ */
+class PerRowAugmentor implements ResultSetAugmentor {
+
+	/**
+	 * @var ResultAugmentor
+	 */
+	private $rowAugmentor;
+
+	/**
+	 * @param ResultAugmentor $augmentor Per-result augmentor to use.
+	 */
+	public function __construct( ResultAugmentor $augmentor ) {
+		$this->rowAugmentor = $augmentor;
+	}
+
+	/**
+	 * Produce data to augment search result set.
+	 * @param SearchResultSet $resultSet
+	 * @return array Data for all results
+	 */
+	public function augmentAll( SearchResultSet $resultSet ) {
+		$data = [];
+		foreach ( $resultSet->extractResults() as $result ) {
+			$id = $result->getTitle()->getArticleID();
+			if ( !$id ) {
+				continue;
+			}
+			$data[$id] = $this->rowAugmentor->augment( $result );
+		}
+		return $data;
+	}
+}
diff --git a/www/wiki/includes/search/ResultAugmentor.php b/www/wiki/includes/search/ResultAugmentor.php
new file mode 100644
index 00000000..df58e71a
--- /dev/null
+++ b/www/wiki/includes/search/ResultAugmentor.php
@@ -0,0 +1,13 @@
+<?php
+
+/**
+ * Augment search results.
+ */
+interface ResultAugmentor {
+	/**
+	 * Produce data to augment search result set.
+	 * @param SearchResult $result
+	 * @return mixed Data for this result
+	 */
+	public function augment( SearchResult $result );
+}
diff --git a/www/wiki/includes/search/ResultSetAugmentor.php b/www/wiki/includes/search/ResultSetAugmentor.php
new file mode 100644
index 00000000..e2d79a9c
--- /dev/null
+++ b/www/wiki/includes/search/ResultSetAugmentor.php
@@ -0,0 +1,13 @@
+<?php
+
+/**
+ * Augment search results.
+ */
+interface ResultSetAugmentor {
+	/**
+	 * Produce data to augment search result set.
+	 * @param SearchResultSet $resultSet
+	 * @return array Data for all results
+	 */
+	public function augmentAll( SearchResultSet $resultSet );
+}
diff --git a/www/wiki/includes/search/SearchDatabase.php b/www/wiki/includes/search/SearchDatabase.php
new file mode 100644
index 00000000..643c2c13
--- /dev/null
+++ b/www/wiki/includes/search/SearchDatabase.php
@@ -0,0 +1,61 @@
+<?php
+/**
+ * Database search engine
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @ingroup Search
+ */
+
+use Wikimedia\Rdbms\IDatabase;
+
+/**
+ * Base search engine base class for database-backed searches
+ * @ingroup Search
+ * @since 1.23
+ */
+class SearchDatabase extends SearchEngine {
+	/**
+	 * @var IDatabase Slave database for reading from for results
+	 */
+	protected $db;
+
+	/**
+	 * @param IDatabase $db The database to search from
+	 */
+	public function __construct( IDatabase $db = null ) {
+		if ( $db ) {
+			$this->db = $db;
+		} else {
+			$this->db = wfGetDB( DB_REPLICA );
+		}
+	}
+
+	/**
+	 * Return a 'cleaned up' search string
+	 *
+	 * @param string $text
+	 * @return string
+	 */
+	protected function filter( $text ) {
+		// List of chars allowed in the search query.
+		// This must include chars used in the search syntax.
+		// Usually " (phrase) or * (wildcards) if supported by the engine
+		$lc = $this->legalSearchChars( self::CHARS_ALL );
+		return trim( preg_replace( "/[^{$lc}]/", " ", $text ) );
+	}
+}
diff --git a/www/wiki/includes/search/SearchEngine.php b/www/wiki/includes/search/SearchEngine.php
new file mode 100644
index 00000000..bfcfb598
--- /dev/null
+++ b/www/wiki/includes/search/SearchEngine.php
@@ -0,0 +1,812 @@
+<?php
+/**
+ * Basic search engine
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @ingroup Search
+ */
+
+/**
+ * @defgroup Search Search
+ */
+
+use MediaWiki\MediaWikiServices;
+
+/**
+ * Contain a class for special pages
+ * @ingroup Search
+ */
+abstract class SearchEngine {
+	/** @var string */
+	public $prefix = '';
+
+	/** @var int[]|null */
+	public $namespaces = [ NS_MAIN ];
+
+	/** @var int */
+	protected $limit = 10;
+
+	/** @var int */
+	protected $offset = 0;
+
+	/** @var array|string */
+	protected $searchTerms = [];
+
+	/** @var bool */
+	protected $showSuggestion = true;
+	private $sort = 'relevance';
+
+	/** @var array Feature values */
+	protected $features = [];
+
+	/** @const string profile type for completionSearch */
+	const COMPLETION_PROFILE_TYPE = 'completionSearchProfile';
+
+	/** @const string profile type for query independent ranking features */
+	const FT_QUERY_INDEP_PROFILE_TYPE = 'fulltextQueryIndepProfile';
+
+	/** @const int flag for legalSearchChars: includes all chars allowed in a search query */
+	const CHARS_ALL = 1;
+
+	/** @const int flag for legalSearchChars: includes all chars allowed in a search term */
+	const CHARS_NO_SYNTAX = 2;
+
+	/**
+	 * Perform a full text search query and return a result set.
+	 * If full text searches are not supported or disabled, return null.
+	 * STUB
+	 *
+	 * @param string $term Raw search term
+	 * @return SearchResultSet|Status|null
+	 */
+	function searchText( $term ) {
+		return null;
+	}
+
+	/**
+	 * Perform a title search in the article archive.
+	 * NOTE: these results still should be filtered by
+	 * matching against PageArchive, permissions checks etc
+	 * The results returned by this methods are only sugegstions and
+	 * may not end up being shown to the user.
+	 *
+	 * @param string $term Raw search term
+	 * @return Status<Title[]>
+	 * @since 1.29
+	 */
+	function searchArchiveTitle( $term ) {
+		return Status::newGood( [] );
+	}
+
+	/**
+	 * Perform a title-only search query and return a result set.
+	 * If title searches are not supported or disabled, return null.
+	 * STUB
+	 *
+	 * @param string $term Raw search term
+	 * @return SearchResultSet|null
+	 */
+	function searchTitle( $term ) {
+		return null;
+	}
+
+	/**
+	 * @since 1.18
+	 * @param string $feature
+	 * @return bool
+	 */
+	public function supports( $feature ) {
+		switch ( $feature ) {
+			case 'search-update':
+				return true;
+			case 'title-suffix-filter':
+			default:
+				return false;
+		}
+	}
+
+	/**
+	 * Way to pass custom data for engines
+	 * @since 1.18
+	 * @param string $feature
+	 * @param mixed $data
+	 */
+	public function setFeatureData( $feature, $data ) {
+		$this->features[$feature] = $data;
+	}
+
+	/**
+	 * Way to retrieve custom data set by setFeatureData
+	 * or by the engine itself.
+	 * @since 1.29
+	 * @param string $feature feature name
+	 * @return mixed the feature value or null if unset
+	 */
+	public function getFeatureData( $feature ) {
+		if ( isset( $this->features[$feature] ) ) {
+			return $this->features[$feature];
+		}
+		return null;
+	}
+
+	/**
+	 * When overridden in derived class, performs database-specific conversions
+	 * on text to be used for searching or updating search index.
+	 * Default implementation does nothing (simply returns $string).
+	 *
+	 * @param string $string String to process
+	 * @return string
+	 */
+	public function normalizeText( $string ) {
+		global $wgContLang;
+
+		// Some languages such as Chinese require word segmentation
+		return $wgContLang->segmentByWord( $string );
+	}
+
+	/**
+	 * Transform search term in cases when parts of the query came as different
+	 * GET params (when supported), e.g. for prefix queries:
+	 * search=test&prefix=Main_Page/Archive -> test prefix:Main Page/Archive
+	 * @param string $term
+	 * @return string
+	 */
+	public function transformSearchTerm( $term ) {
+		return $term;
+	}
+
+	/**
+	 * Get service class to finding near matches.
+	 * @param Config $config Configuration to use for the matcher.
+	 * @return SearchNearMatcher
+	 */
+	public function getNearMatcher( Config $config ) {
+		global $wgContLang;
+		return new SearchNearMatcher( $config, $wgContLang );
+	}
+
+	/**
+	 * Get near matcher for default SearchEngine.
+	 * @return SearchNearMatcher
+	 */
+	protected static function defaultNearMatcher() {
+		$config = MediaWikiServices::getInstance()->getMainConfig();
+		return MediaWikiServices::getInstance()->newSearchEngine()->getNearMatcher( $config );
+	}
+
+	/**
+	 * If an exact title match can be found, or a very slightly close match,
+	 * return the title. If no match, returns NULL.
+	 * @deprecated since 1.27; Use SearchEngine::getNearMatcher()
+	 * @param string $searchterm
+	 * @return Title
+	 */
+	public static function getNearMatch( $searchterm ) {
+		return static::defaultNearMatcher()->getNearMatch( $searchterm );
+	}
+
+	/**
+	 * Do a near match (see SearchEngine::getNearMatch) and wrap it into a
+	 * SearchResultSet.
+	 * @deprecated since 1.27; Use SearchEngine::getNearMatcher()
+	 * @param string $searchterm
+	 * @return SearchResultSet
+	 */
+	public static function getNearMatchResultSet( $searchterm ) {
+		return static::defaultNearMatcher()->getNearMatchResultSet( $searchterm );
+	}
+
+	/**
+	 * Get chars legal for search
+	 * NOTE: usage as static is deprecated and preserved only as BC measure
+	 * @param int $type type of search chars (see self::CHARS_ALL
+	 * and self::CHARS_NO_SYNTAX). Defaults to CHARS_ALL
+	 * @return string
+	 */
+	public static function legalSearchChars( $type = self::CHARS_ALL ) {
+		return "A-Za-z_'.0-9\\x80-\\xFF\\-";
+	}
+
+	/**
+	 * Set the maximum number of results to return
+	 * and how many to skip before returning the first.
+	 *
+	 * @param int $limit
+	 * @param int $offset
+	 */
+	function setLimitOffset( $limit, $offset = 0 ) {
+		$this->limit = intval( $limit );
+		$this->offset = intval( $offset );
+	}
+
+	/**
+	 * Set which namespaces the search should include.
+	 * Give an array of namespace index numbers.
+	 *
+	 * @param int[]|null $namespaces
+	 */
+	function setNamespaces( $namespaces ) {
+		if ( $namespaces ) {
+			// Filter namespaces to only keep valid ones
+			$validNs = $this->searchableNamespaces();
+			$namespaces = array_filter( $namespaces, function ( $ns ) use( $validNs ) {
+				return $ns < 0 || isset( $validNs[$ns] );
+			} );
+		} else {
+			$namespaces = [];
+		}
+		$this->namespaces = $namespaces;
+	}
+
+	/**
+	 * Set whether the searcher should try to build a suggestion.  Note: some searchers
+	 * don't support building a suggestion in the first place and others don't respect
+	 * this flag.
+	 *
+	 * @param bool $showSuggestion Should the searcher try to build suggestions
+	 */
+	function setShowSuggestion( $showSuggestion ) {
+		$this->showSuggestion = $showSuggestion;
+	}
+
+	/**
+	 * Get the valid sort directions.  All search engines support 'relevance' but others
+	 * might support more. The default in all implementations should be 'relevance.'
+	 *
+	 * @since 1.25
+	 * @return string[] the valid sort directions for setSort
+	 */
+	public function getValidSorts() {
+		return [ 'relevance' ];
+	}
+
+	/**
+	 * Set the sort direction of the search results. Must be one returned by
+	 * SearchEngine::getValidSorts()
+	 *
+	 * @since 1.25
+	 * @throws InvalidArgumentException
+	 * @param string $sort sort direction for query result
+	 */
+	public function setSort( $sort ) {
+		if ( !in_array( $sort, $this->getValidSorts() ) ) {
+			throw new InvalidArgumentException( "Invalid sort: $sort. " .
+				"Must be one of: " . implode( ', ', $this->getValidSorts() ) );
+		}
+		$this->sort = $sort;
+	}
+
+	/**
+	 * Get the sort direction of the search results
+	 *
+	 * @since 1.25
+	 * @return string
+	 */
+	public function getSort() {
+		return $this->sort;
+	}
+
+	/**
+	 * Parse some common prefixes: all (search everything)
+	 * or namespace names and set the list of namespaces
+	 * of this class accordingly.
+	 *
+	 * @param string $query
+	 * @return string
+	 */
+	function replacePrefixes( $query ) {
+		$queryAndNs = self::parseNamespacePrefixes( $query );
+		if ( $queryAndNs === false ) {
+			return $query;
+		}
+		$this->namespaces = $queryAndNs[1];
+		return $queryAndNs[0];
+	}
+
+	/**
+	 * Parse some common prefixes: all (search everything)
+	 * or namespace names
+	 *
+	 * @param string $query
+	 * @return false|array false if no namespace was extracted, an array
+	 * with the parsed query at index 0 and an array of namespaces at index
+	 * 1 (or null for all namespaces).
+	 */
+	public static function parseNamespacePrefixes( $query ) {
+		global $wgContLang;
+
+		$parsed = $query;
+		if ( strpos( $query, ':' ) === false ) { // nothing to do
+			return false;
+		}
+		$extractedNamespace = null;
+
+		$allkeyword = wfMessage( 'searchall' )->inContentLanguage()->text() . ":";
+		if ( strncmp( $query, $allkeyword, strlen( $allkeyword ) ) == 0 ) {
+			$extractedNamespace = null;
+			$parsed = substr( $query, strlen( $allkeyword ) );
+		} elseif ( strpos( $query, ':' ) !== false ) {
+			// TODO: should we unify with PrefixSearch::extractNamespace ?
+			$prefix = str_replace( ' ', '_', substr( $query, 0, strpos( $query, ':' ) ) );
+			$index = $wgContLang->getNsIndex( $prefix );
+			if ( $index !== false ) {
+				$extractedNamespace = [ $index ];
+				$parsed = substr( $query, strlen( $prefix ) + 1 );
+			} else {
+				return false;
+			}
+		}
+
+		if ( trim( $parsed ) == '' ) {
+			$parsed = $query; // prefix was the whole query
+		}
+
+		return [ $parsed, $extractedNamespace ];
+	}
+
+	/**
+	 * Find snippet highlight settings for all users
+	 * @return array Contextlines, contextchars
+	 */
+	public static function userHighlightPrefs() {
+		$contextlines = 2; // Hardcode this. Old defaults sucked. :)
+		$contextchars = 75; // same as above.... :P
+		return [ $contextlines, $contextchars ];
+	}
+
+	/**
+	 * Create or update the search index record for the given page.
+	 * Title and text should be pre-processed.
+	 * STUB
+	 *
+	 * @param int $id
+	 * @param string $title
+	 * @param string $text
+	 */
+	function update( $id, $title, $text ) {
+		// no-op
+	}
+
+	/**
+	 * Update a search index record's title only.
+	 * Title should be pre-processed.
+	 * STUB
+	 *
+	 * @param int $id
+	 * @param string $title
+	 */
+	function updateTitle( $id, $title ) {
+		// no-op
+	}
+
+	/**
+	 * Delete an indexed page
+	 * Title should be pre-processed.
+	 * STUB
+	 *
+	 * @param int $id Page id that was deleted
+	 * @param string $title Title of page that was deleted
+	 */
+	function delete( $id, $title ) {
+		// no-op
+	}
+
+	/**
+	 * Get the raw text for updating the index from a content object
+	 * Nicer search backends could possibly do something cooler than
+	 * just returning raw text
+	 *
+	 * @todo This isn't ideal, we'd really like to have content-specific handling here
+	 * @param Title $t Title we're indexing
+	 * @param Content $c Content of the page to index
+	 * @return string
+	 */
+	public function getTextFromContent( Title $t, Content $c = null ) {
+		return $c ? $c->getTextForSearchIndex() : '';
+	}
+
+	/**
+	 * If an implementation of SearchEngine handles all of its own text processing
+	 * in getTextFromContent() and doesn't require SearchUpdate::updateText()'s
+	 * rather silly handling, it should return true here instead.
+	 *
+	 * @return bool
+	 */
+	public function textAlreadyUpdatedForIndex() {
+		return false;
+	}
+
+	/**
+	 * Makes search simple string if it was namespaced.
+	 * Sets namespaces of the search to namespaces extracted from string.
+	 * @param string $search
+	 * @return string Simplified search string
+	 */
+	protected function normalizeNamespaces( $search ) {
+		// Find a Title which is not an interwiki and is in NS_MAIN
+		$title = Title::newFromText( $search );
+		$ns = $this->namespaces;
+		if ( $title && !$title->isExternal() ) {
+			$ns = [ $title->getNamespace() ];
+			if ( $title->getNamespace() !== NS_MAIN ) {
+				$search = substr( $search, strpos( $search, ':' ) + 1 );
+			}
+			if ( $ns[0] == NS_MAIN ) {
+				$ns = $this->namespaces; // no explicit prefix, use default namespaces
+				Hooks::run( 'PrefixSearchExtractNamespace', [ &$ns, &$search ] );
+			}
+		} else {
+			$title = Title::newFromText( $search . 'Dummy' );
+			if ( $title && $title->getText() == 'Dummy'
+					&& $title->getNamespace() != NS_MAIN
+					&& !$title->isExternal()
+			) {
+				$ns = [ $title->getNamespace() ];
+				$search = '';
+			} else {
+				Hooks::run( 'PrefixSearchExtractNamespace', [ &$ns, &$search ] );
+			}
+		}
+
+		$ns = array_map( function ( $space ) {
+			return $space == NS_MEDIA ? NS_FILE : $space;
+		}, $ns );
+
+		$this->setNamespaces( $ns );
+		return $search;
+	}
+
+	/**
+	 * Perform a completion search.
+	 * Does not resolve namespaces and does not check variants.
+	 * Search engine implementations may want to override this function.
+	 * @param string $search
+	 * @return SearchSuggestionSet
+	 */
+	protected function completionSearchBackend( $search ) {
+		$results = [];
+
+		$search = trim( $search );
+
+		if ( !in_array( NS_SPECIAL, $this->namespaces ) && // We do not run hook on Special: search
+			 !Hooks::run( 'PrefixSearchBackend',
+				[ $this->namespaces, $search, $this->limit, &$results, $this->offset ]
+		) ) {
+			// False means hook worked.
+			// FIXME: Yes, the API is weird. That's why it is going to be deprecated.
+
+			return SearchSuggestionSet::fromStrings( $results );
+		} else {
+			// Hook did not do the job, use default simple search
+			$results = $this->simplePrefixSearch( $search );
+			return SearchSuggestionSet::fromTitles( $results );
+		}
+	}
+
+	/**
+	 * Perform a completion search.
+	 * @param string $search
+	 * @return SearchSuggestionSet
+	 */
+	public function completionSearch( $search ) {
+		if ( trim( $search ) === '' ) {
+			return SearchSuggestionSet::emptySuggestionSet(); // Return empty result
+		}
+		$search = $this->normalizeNamespaces( $search );
+		return $this->processCompletionResults( $search, $this->completionSearchBackend( $search ) );
+	}
+
+	/**
+	 * Perform a completion search with variants.
+	 * @param string $search
+	 * @return SearchSuggestionSet
+	 */
+	public function completionSearchWithVariants( $search ) {
+		if ( trim( $search ) === '' ) {
+			return SearchSuggestionSet::emptySuggestionSet(); // Return empty result
+		}
+		$search = $this->normalizeNamespaces( $search );
+
+		$results = $this->completionSearchBackend( $search );
+		$fallbackLimit = $this->limit - $results->getSize();
+		if ( $fallbackLimit > 0 ) {
+			global $wgContLang;
+
+			$fallbackSearches = $wgContLang->autoConvertToAllVariants( $search );
+			$fallbackSearches = array_diff( array_unique( $fallbackSearches ), [ $search ] );
+
+			foreach ( $fallbackSearches as $fbs ) {
+				$this->setLimitOffset( $fallbackLimit );
+				$fallbackSearchResult = $this->completionSearch( $fbs );
+				$results->appendAll( $fallbackSearchResult );
+				$fallbackLimit -= $fallbackSearchResult->getSize();
+				if ( $fallbackLimit <= 0 ) {
+					break;
+				}
+			}
+		}
+		return $this->processCompletionResults( $search, $results );
+	}
+
+	/**
+	 * Extract titles from completion results
+	 * @param SearchSuggestionSet $completionResults
+	 * @return Title[]
+	 */
+	public function extractTitles( SearchSuggestionSet $completionResults ) {
+		return $completionResults->map( function ( SearchSuggestion $sugg ) {
+			return $sugg->getSuggestedTitle();
+		} );
+	}
+
+	/**
+	 * Process completion search results.
+	 * Resolves the titles and rescores.
+	 * @param string $search
+	 * @param SearchSuggestionSet $suggestions
+	 * @return SearchSuggestionSet
+	 */
+	protected function processCompletionResults( $search, SearchSuggestionSet $suggestions ) {
+		$search = trim( $search );
+		// preload the titles with LinkBatch
+		$titles = $suggestions->map( function ( SearchSuggestion $sugg ) {
+			return $sugg->getSuggestedTitle();
+		} );
+		$lb = new LinkBatch( $titles );
+		$lb->setCaller( __METHOD__ );
+		$lb->execute();
+
+		$results = $suggestions->map( function ( SearchSuggestion $sugg ) {
+			return $sugg->getSuggestedTitle()->getPrefixedText();
+		} );
+
+		if ( $this->offset === 0 ) {
+			// Rescore results with an exact title match
+			// NOTE: in some cases like cross-namespace redirects
+			// (frequently used as shortcuts e.g. WP:WP on huwiki) some
+			// backends like Cirrus will return no results. We should still
+			// try an exact title match to workaround this limitation
+			$rescorer = new SearchExactMatchRescorer();
+			$rescoredResults = $rescorer->rescore( $search, $this->namespaces, $results, $this->limit );
+		} else {
+			// No need to rescore if offset is not 0
+			// The exact match must have been returned at position 0
+			// if it existed.
+			$rescoredResults = $results;
+		}
+
+		if ( count( $rescoredResults ) > 0 ) {
+			$found = array_search( $rescoredResults[0], $results );
+			if ( $found === false ) {
+				// If the first result is not in the previous array it
+				// means that we found a new exact match
+				$exactMatch = SearchSuggestion::fromTitle( 0, Title::newFromText( $rescoredResults[0] ) );
+				$suggestions->prepend( $exactMatch );
+				$suggestions->shrink( $this->limit );
+			} else {
+				// if the first result is not the same we need to rescore
+				if ( $found > 0 ) {
+					$suggestions->rescore( $found );
+				}
+			}
+		}
+
+		return $suggestions;
+	}
+
+	/**
+	 * Simple prefix search for subpages.
+	 * @param string $search
+	 * @return Title[]
+	 */
+	public function defaultPrefixSearch( $search ) {
+		if ( trim( $search ) === '' ) {
+			return [];
+		}
+
+		$search = $this->normalizeNamespaces( $search );
+		return $this->simplePrefixSearch( $search );
+	}
+
+	/**
+	 * Call out to simple search backend.
+	 * Defaults to TitlePrefixSearch.
+	 * @param string $search
+	 * @return Title[]
+	 */
+	protected function simplePrefixSearch( $search ) {
+		// Use default database prefix search
+		$backend = new TitlePrefixSearch;
+		return $backend->defaultSearchBackend( $this->namespaces, $search, $this->limit, $this->offset );
+	}
+
+	/**
+	 * Make a list of searchable namespaces and their canonical names.
+	 * @deprecated since 1.27; use SearchEngineConfig::searchableNamespaces()
+	 * @return array
+	 */
+	public static function searchableNamespaces() {
+		return MediaWikiServices::getInstance()->getSearchEngineConfig()->searchableNamespaces();
+	}
+
+	/**
+	 * Extract default namespaces to search from the given user's
+	 * settings, returning a list of index numbers.
+	 * @deprecated since 1.27; use SearchEngineConfig::userNamespaces()
+	 * @param user $user
+	 * @return array
+	 */
+	public static function userNamespaces( $user ) {
+		return MediaWikiServices::getInstance()->getSearchEngineConfig()->userNamespaces( $user );
+	}
+
+	/**
+	 * An array of namespaces indexes to be searched by default
+	 * @deprecated since 1.27; use SearchEngineConfig::defaultNamespaces()
+	 * @return array
+	 */
+	public static function defaultNamespaces() {
+		return MediaWikiServices::getInstance()->getSearchEngineConfig()->defaultNamespaces();
+	}
+
+	/**
+	 * Get a list of namespace names useful for showing in tooltips
+	 * and preferences
+	 * @deprecated since 1.27; use SearchEngineConfig::namespacesAsText()
+	 * @param array $namespaces
+	 * @return array
+	 */
+	public static function namespacesAsText( $namespaces ) {
+		return MediaWikiServices::getInstance()->getSearchEngineConfig()->namespacesAsText( $namespaces );
+	}
+
+	/**
+	 * Load up the appropriate search engine class for the currently
+	 * active database backend, and return a configured instance.
+	 * @deprecated since 1.27; Use SearchEngineFactory::create
+	 * @param string $type Type of search backend, if not the default
+	 * @return SearchEngine
+	 */
+	public static function create( $type = null ) {
+		return MediaWikiServices::getInstance()->getSearchEngineFactory()->create( $type );
+	}
+
+	/**
+	 * Return the search engines we support. If only $wgSearchType
+	 * is set, it'll be an array of just that one item.
+	 * @deprecated since 1.27; use SearchEngineConfig::getSearchTypes()
+	 * @return array
+	 */
+	public static function getSearchTypes() {
+		return MediaWikiServices::getInstance()->getSearchEngineConfig()->getSearchTypes();
+	}
+
+	/**
+	 * Get a list of supported profiles.
+	 * Some search engine implementations may expose specific profiles to fine-tune
+	 * its behaviors.
+	 * The profile can be passed as a feature data with setFeatureData( $profileType, $profileName )
+	 * The array returned by this function contains the following keys:
+	 * - name: the profile name to use with setFeatureData
+	 * - desc-message: the i18n description
+	 * - default: set to true if this profile is the default
+	 *
+	 * @since 1.28
+	 * @param string $profileType the type of profiles
+	 * @param User|null $user the user requesting the list of profiles
+	 * @return array|null the list of profiles or null if none available
+	 */
+	public function getProfiles( $profileType, User $user = null ) {
+		return null;
+	}
+
+	/**
+	 * Create a search field definition.
+	 * Specific search engines should override this method to create search fields.
+	 * @param string $name
+	 * @param int $type One of the types in SearchIndexField::INDEX_TYPE_*
+	 * @return SearchIndexField
+	 * @since 1.28
+	 */
+	public function makeSearchFieldMapping( $name, $type ) {
+		return new NullIndexField();
+	}
+
+	/**
+	 * Get fields for search index
+	 * @since 1.28
+	 * @return SearchIndexField[] Index field definitions for all content handlers
+	 */
+	public function getSearchIndexFields() {
+		$models = ContentHandler::getContentModels();
+		$fields = [];
+		$seenHandlers = new SplObjectStorage();
+		foreach ( $models as $model ) {
+			try {
+				$handler = ContentHandler::getForModelID( $model );
+			}
+			catch ( MWUnknownContentModelException $e ) {
+				// If we can find no handler, ignore it
+				continue;
+			}
+			// Several models can have the same handler, so avoid processing it repeatedly
+			if ( $seenHandlers->contains( $handler ) ) {
+				// We already did this one
+				continue;
+			}
+			$seenHandlers->attach( $handler );
+			$handlerFields = $handler->getFieldsForSearchIndex( $this );
+			foreach ( $handlerFields as $fieldName => $fieldData ) {
+				if ( empty( $fields[$fieldName] ) ) {
+					$fields[$fieldName] = $fieldData;
+				} else {
+					// TODO: do we allow some clashes with the same type or reject all of them?
+					$mergeDef = $fields[$fieldName]->merge( $fieldData );
+					if ( !$mergeDef ) {
+						throw new InvalidArgumentException( "Duplicate field $fieldName for model $model" );
+					}
+					$fields[$fieldName] = $mergeDef;
+				}
+			}
+		}
+		// Hook to allow extensions to produce search mapping fields
+		Hooks::run( 'SearchIndexFields', [ &$fields, $this ] );
+		return $fields;
+	}
+
+	/**
+	 * Augment search results with extra data.
+	 *
+	 * @param SearchResultSet $resultSet
+	 */
+	public function augmentSearchResults( SearchResultSet $resultSet ) {
+		$setAugmentors = [];
+		$rowAugmentors = [];
+		Hooks::run( "SearchResultsAugment", [ &$setAugmentors, &$rowAugmentors ] );
+
+		if ( !$setAugmentors && !$rowAugmentors ) {
+			// We're done here
+			return;
+		}
+
+		// Convert row augmentors to set augmentor
+		foreach ( $rowAugmentors as $name => $row ) {
+			if ( isset( $setAugmentors[$name] ) ) {
+				throw new InvalidArgumentException( "Both row and set augmentors are defined for $name" );
+			}
+			$setAugmentors[$name] = new PerRowAugmentor( $row );
+		}
+
+		foreach ( $setAugmentors as $name => $augmentor ) {
+			$data = $augmentor->augmentAll( $resultSet );
+			if ( $data ) {
+				$resultSet->setAugmentedData( $name, $data );
+			}
+		}
+	}
+}
+
+/**
+ * Dummy class to be used when non-supported Database engine is present.
+ * @todo FIXME: Dummy class should probably try something at least mildly useful,
+ * such as a LIKE search through titles.
+ * @ingroup Search
+ */
+class SearchEngineDummy extends SearchEngine {
+	// no-op
+}
diff --git a/www/wiki/includes/search/SearchEngineConfig.php b/www/wiki/includes/search/SearchEngineConfig.php
new file mode 100644
index 00000000..90f85c3d
--- /dev/null
+++ b/www/wiki/includes/search/SearchEngineConfig.php
@@ -0,0 +1,117 @@
+<?php
+
+/**
+ * Configuration handling class for SearchEngine.
+ * Provides added service over plain configuration.
+ *
+ * @since 1.27
+ */
+class SearchEngineConfig {
+
+	/**
+	 * Config object from which the settings will be derived.
+	 * @var Config
+	 */
+	private $config;
+
+	/**
+	 * Current language
+	 * @var Language
+	 */
+	private $language;
+
+	public function __construct( Config $config, Language $lang ) {
+		$this->config = $config;
+		$this->language = $lang;
+	}
+
+	/**
+	 * Retrieve original config.
+	 * @return Config
+	 */
+	public function getConfig() {
+		return $this->config;
+	}
+
+	/**
+	 * Make a list of searchable namespaces and their canonical names.
+	 * @return array Namespace ID => name
+	 */
+	public function searchableNamespaces() {
+		$arr = [];
+		foreach ( $this->language->getNamespaces() as $ns => $name ) {
+			if ( $ns >= NS_MAIN ) {
+				$arr[$ns] = $name;
+			}
+		}
+
+		Hooks::run( 'SearchableNamespaces', [ &$arr ] );
+		return $arr;
+	}
+
+	/**
+	 * Extract default namespaces to search from the given user's
+	 * settings, returning a list of index numbers.
+	 *
+	 * @param user $user
+	 * @return int[]
+	 */
+	public function userNamespaces( $user ) {
+		$arr = [];
+		foreach ( $this->searchableNamespaces() as $ns => $name ) {
+			if ( $user->getOption( 'searchNs' . $ns ) ) {
+				$arr[] = $ns;
+			}
+		}
+
+		return $arr;
+	}
+
+	/**
+	 * An array of namespaces indexes to be searched by default
+	 *
+	 * @return int[] Namespace IDs
+	 */
+	public function defaultNamespaces() {
+		return array_keys( $this->config->get( 'NamespacesToBeSearchedDefault' ), true );
+	}
+
+	/**
+	 * Return the search engines we support. If only $wgSearchType
+	 * is set, it'll be an array of just that one item.
+	 *
+	 * @return array
+	 */
+	public function getSearchTypes() {
+		$alternatives = $this->config->get( 'SearchTypeAlternatives' ) ?: [];
+		array_unshift( $alternatives, $this->config->get( 'SearchType' ) );
+
+		return $alternatives;
+	}
+
+	/**
+	 * Return the search engine configured in $wgSearchType, etc.
+	 *
+	 * @return string|null
+	 */
+	public function getSearchType() {
+		return $this->config->get( 'SearchType' );
+	}
+
+	/**
+	 * Get a list of namespace names useful for showing in tooltips
+	 * and preferences.
+	 *
+	 * @param int[] $namespaces
+	 * @return string[] List of names
+	 */
+	public function namespacesAsText( $namespaces ) {
+		$formatted = array_map( [ $this->language, 'getFormattedNsText' ], $namespaces );
+		foreach ( $formatted as $key => $ns ) {
+			if ( empty( $ns ) ) {
+				$formatted[$key] = wfMessage( 'blanknamespace' )->text();
+			}
+		}
+		return $formatted;
+	}
+}
diff --git a/www/wiki/includes/search/SearchEngineFactory.php b/www/wiki/includes/search/SearchEngineFactory.php
new file mode 100644
index 00000000..8cdca571
--- /dev/null
+++ b/www/wiki/includes/search/SearchEngineFactory.php
@@ -0,0 +1,65 @@
+<?php
+
+use Wikimedia\Rdbms\IDatabase;
+
+/**
+ * Factory class for SearchEngine.
+ * Allows to create engine of the specific type.
+ */
+class SearchEngineFactory {
+	/**
+	 * Configuration for SearchEngine classes.
+	 * @var SearchEngineConfig
+	 */
+	private $config;
+
+	public function __construct( SearchEngineConfig $config ) {
+		$this->config = $config;
+	}
+
+	/**
+	 * Create SearchEngine of the given type.
+	 * @param string $type
+	 * @return SearchEngine
+	 */
+	public function create( $type = null ) {
+		$dbr = null;
+
+		$configType = $this->config->getSearchType();
+		$alternatives = $this->config->getSearchTypes();
+
+		if ( $type && in_array( $type, $alternatives ) ) {
+			$class = $type;
+		} elseif ( $configType !== null ) {
+			$class = $configType;
+		} else {
+			$dbr = wfGetDB( DB_REPLICA );
+			$class = self::getSearchEngineClass( $dbr );
+		}
+
+		$search = new $class( $dbr );
+		return $search;
+	}
+
+	/**
+	 * @param IDatabase $db
+	 * @return string SearchEngine subclass name
+	 * @since 1.28
+	 */
+	public static function getSearchEngineClass( IDatabase $db ) {
+		switch ( $db->getType() ) {
+			case 'sqlite':
+				return SearchSqlite::class;
+			case 'mysql':
+				return SearchMySQL::class;
+			case 'postgres':
+				return SearchPostgres::class;
+			case 'mssql':
+				return SearchMssql::class;
+			case 'oracle':
+				return SearchOracle::class;
+			default:
+				return SearchEngineDummy::class;
+		}
+	}
+}
diff --git a/www/wiki/includes/search/SearchExactMatchRescorer.php b/www/wiki/includes/search/SearchExactMatchRescorer.php
new file mode 100644
index 00000000..354b3909
--- /dev/null
+++ b/www/wiki/includes/search/SearchExactMatchRescorer.php
@@ -0,0 +1,144 @@
+<?php
+/**
+ * Rescores results from a prefix search/opensearch to make sure the
+ * exact match is the first result.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ */
+
+/**
+ * An utility class to rescore search results by looking for an exact match
+ * in the db and add the page found to the first position.
+ *
+ * NOTE: extracted from TitlePrefixSearch
+ * @ingroup Search
+ */
+class SearchExactMatchRescorer {
+	/**
+	 * Default search backend does proper prefix searching, but custom backends
+	 * may sort based on other algorithms that may cause the exact title match
+	 * to not be in the results or be lower down the list.
+	 * @param string $search the query
+	 * @param int[] $namespaces
+	 * @param string[] $srchres results
+	 * @param int $limit the max number of results to return
+	 * @return string[] munged results
+	 */
+	public function rescore( $search, $namespaces, $srchres, $limit ) {
+		// Pick namespace (based on PrefixSearch::defaultSearchBackend)
+		$ns = in_array( NS_MAIN, $namespaces ) ? NS_MAIN : reset( $namespaces );
+		$t = Title::newFromText( $search, $ns );
+		if ( !$t || !$t->exists() ) {
+			// No exact match so just return the search results
+			return $srchres;
+		}
+		$string = $t->getPrefixedText();
+		$key = array_search( $string, $srchres );
+		if ( $key !== false ) {
+			// Exact match was in the results so just move it to the front
+			return $this->pullFront( $key, $srchres );
+		}
+		// Exact match not in the search results so check for some redirect handling cases
+		if ( $t->isRedirect() ) {
+			$target = $this->getRedirectTarget( $t );
+			$key = array_search( $target, $srchres );
+			if ( $key !== false ) {
+				// Exact match is a redirect to one of the returned matches so pull the
+				// returned match to the front.  This might look odd but the alternative
+				// is to put the redirect in front and drop the match.  The name of the
+				// found match is often more descriptive/better formed than the name of
+				// the redirect AND by definition they share a prefix.  Hopefully this
+				// choice is less confusing and more helpful.  But it might not be.  But
+				// it is the choice we're going with for now.
+				return $this->pullFront( $key, $srchres );
+			}
+			$redirectTargetsToRedirect = $this->redirectTargetsToRedirect( $srchres );
+			if ( isset( $redirectTargetsToRedirect[$target] ) ) {
+				// The exact match and something in the results list are both redirects
+				// to the same thing!  In this case we'll pull the returned match to the
+				// top following the same logic above.  Again, it might not be a perfect
+				// choice but it'll do.
+				return $this->pullFront( $redirectTargetsToRedirect[$target], $srchres );
+			}
+		} else {
+			$redirectTargetsToRedirect = $this->redirectTargetsToRedirect( $srchres );
+			if ( isset( $redirectTargetsToRedirect[$string] ) ) {
+				// The exact match is the target of a redirect already in the results list so remove
+				// the redirect from the results list and push the exact match to the front
+				array_splice( $srchres, $redirectTargetsToRedirect[$string], 1 );
+				array_unshift( $srchres, $string );
+				return $srchres;
+			}
+		}
+
+		// Exact match is totally unique from the other results so just add it to the front
+		array_unshift( $srchres, $string );
+		// And roll one off the end if the results are too long
+		if ( count( $srchres ) > $limit ) {
+			array_pop( $srchres );
+		}
+		return $srchres;
+	}
+
+	/**
+	 * @param string[] $titles
+	 * @return array redirect target prefixedText to index of title in titles
+	 *   that is a redirect to it.
+	 */
+	private function redirectTargetsToRedirect( array $titles ) {
+		$result = [];
+		foreach ( $titles as $key => $titleText ) {
+			$title = Title::newFromText( $titleText );
+			if ( !$title || !$title->isRedirect() ) {
+				continue;
+			}
+			$target = $this->getRedirectTarget( $title );
+			if ( !$target ) {
+				continue;
+			}
+			$result[$target] = $key;
+		}
+		return $result;
+	}
+
+	/**
+	 * Returns an array where the element of $array at index $key becomes
+	 * the first element.
+	 * @param int $key key to pull to the front
+	 * @return array $array with the item at $key pulled to the front
+	 */
+	private function pullFront( $key, array $array ) {
+		$cut = array_splice( $array, $key, 1 );
+		array_unshift( $array, $cut[0] );
+		return $array;
+	}
+
+	/**
+	 * Get a redirect's destination from a title
+	 * @param Title $title A title to redirect. It may not redirect or even exist
+	 * @return null|string If title exists and redirects, get the destination's prefixed name
+	 */
+	private function getRedirectTarget( $title ) {
+		$page = WikiPage::factory( $title );
+		if ( !$page->exists() ) {
+			return null;
+		}
+		$redir = $page->getRedirectTarget();
+		return $redir ? $redir->getPrefixedText() : null;
+	}
+}
diff --git a/www/wiki/includes/search/SearchHighlighter.php b/www/wiki/includes/search/SearchHighlighter.php
new file mode 100644
index 00000000..20462cf1
--- /dev/null
+++ b/www/wiki/includes/search/SearchHighlighter.php
@@ -0,0 +1,566 @@
+<?php
+/**
+ * Basic search engine highlighting
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @ingroup Search
+ */
+
+/**
+ * Highlight bits of wikitext
+ *
+ * @ingroup Search
+ */
+class SearchHighlighter {
+	protected $mCleanWikitext = true;
+
+	/**
+	 * @warning If you pass false to this constructor, then
+	 *  the caller is responsible for HTML escaping.
+	 * @param bool $cleanupWikitext
+	 */
+	function __construct( $cleanupWikitext = true ) {
+		$this->mCleanWikitext = $cleanupWikitext;
+	}
+
+	/**
+	 * Wikitext highlighting when $wgAdvancedSearchHighlighting = true
+	 *
+	 * @param string $text
+	 * @param array $terms Terms to highlight (not html escaped but
+	 *   regex escaped via SearchDatabase::regexTerm())
+	 * @param int $contextlines
+	 * @param int $contextchars
+	 * @return string
+	 */
+	public function highlightText( $text, $terms, $contextlines, $contextchars ) {
+		global $wgContLang, $wgSearchHighlightBoundaries;
+
+		if ( $text == '' ) {
+			return '';
+		}
+
+		// spli text into text + templates/links/tables
+		$spat = "/(\\{\\{)|(\\[\\[[^\\]:]+:)|(\n\\{\\|)";
+		// first capture group is for detecting nested templates/links/tables/references
+		$endPatterns = [
+			1 => '/(\{\{)|(\}\})/', // template
+			2 => '/(\[\[)|(\]\])/', // image
+			3 => "/(\n\\{\\|)|(\n\\|\\})/" ]; // table
+
+		// @todo FIXME: This should prolly be a hook or something
+		// instead of hardcoding a class name from the Cite extension
+		if ( class_exists( 'Cite' ) ) {
+			$spat .= '|(<ref>)'; // references via cite extension
+			$endPatterns[4] = '/(<ref>)|(<\/ref>)/';
+		}
+		$spat .= '/';
+		$textExt = []; // text extracts
+		$otherExt = []; // other extracts
+		$start = 0;
+		$textLen = strlen( $text );
+		$count = 0; // sequence number to maintain ordering
+		while ( $start < $textLen ) {
+			// find start of template/image/table
+			if ( preg_match( $spat, $text, $matches, PREG_OFFSET_CAPTURE, $start ) ) {
+				$epat = '';
+				foreach ( $matches as $key => $val ) {
+					if ( $key > 0 && $val[1] != -1 ) {
+						if ( $key == 2 ) {
+							// see if this is an image link
+							$ns = substr( $val[0], 2, -1 );
+							if ( $wgContLang->getNsIndex( $ns ) != NS_FILE ) {
+								break;
+							}
+
+						}
+						$epat = $endPatterns[$key];
+						$this->splitAndAdd( $textExt, $count, substr( $text, $start, $val[1] - $start ) );
+						$start = $val[1];
+						break;
+					}
+				}
+				if ( $epat ) {
+					// find end (and detect any nested elements)
+					$level = 0;
+					$offset = $start + 1;
+					$found = false;
+					while ( preg_match( $epat, $text, $endMatches, PREG_OFFSET_CAPTURE, $offset ) ) {
+						if ( array_key_exists( 2, $endMatches ) ) {
+							// found end
+							if ( $level == 0 ) {
+								$len = strlen( $endMatches[2][0] );
+								$off = $endMatches[2][1];
+								$this->splitAndAdd( $otherExt, $count,
+									substr( $text, $start, $off + $len - $start ) );
+								$start = $off + $len;
+								$found = true;
+								break;
+							} else {
+								// end of nested element
+								$level -= 1;
+							}
+						} else {
+							// nested
+							$level += 1;
+						}
+						$offset = $endMatches[0][1] + strlen( $endMatches[0][0] );
+					}
+					if ( !$found ) {
+						// couldn't find appropriate closing tag, skip
+						$this->splitAndAdd( $textExt, $count, substr( $text, $start, strlen( $matches[0][0] ) ) );
+						$start += strlen( $matches[0][0] );
+					}
+					continue;
+				}
+			}
+			// else: add as text extract
+			$this->splitAndAdd( $textExt, $count, substr( $text, $start ) );
+			break;
+		}
+
+		$all = $textExt + $otherExt; // these have disjunct key sets
+
+		// prepare regexps
+		foreach ( $terms as $index => $term ) {
+			// manually do upper/lowercase stuff for utf-8 since PHP won't do it
+			if ( preg_match( '/[\x80-\xff]/', $term ) ) {
+				$terms[$index] = preg_replace_callback(
+					'/./us',
+					[ $this, 'caseCallback' ],
+					$terms[$index]
+				);
+			} else {
+				$terms[$index] = $term;
+			}
+		}
+		$anyterm = implode( '|', $terms );
+		$phrase = implode( "$wgSearchHighlightBoundaries+", $terms );
+		// @todo FIXME: A hack to scale contextchars, a correct solution
+		// would be to have contextchars actually be char and not byte
+		// length, and do proper utf-8 substrings and lengths everywhere,
+		// but PHP is making that very hard and unclean to implement :(
+		$scale = strlen( $anyterm ) / mb_strlen( $anyterm );
+		$contextchars = intval( $contextchars * $scale );
+
+		$patPre = "(^|$wgSearchHighlightBoundaries)";
+		$patPost = "($wgSearchHighlightBoundaries|$)";
+
+		$pat1 = "/(" . $phrase . ")/ui";
+		$pat2 = "/$patPre(" . $anyterm . ")$patPost/ui";
+
+		$left = $contextlines;
+
+		$snippets = [];
+		$offsets = [];
+
+		// show beginning only if it contains all words
+		$first = 0;
+		$firstText = '';
+		foreach ( $textExt as $index => $line ) {
+			if ( strlen( $line ) > 0 && $line[0] != ';' && $line[0] != ':' ) {
+				$firstText = $this->extract( $line, 0, $contextchars * $contextlines );
+				$first = $index;
+				break;
+			}
+		}
+		if ( $firstText ) {
+			$succ = true;
+			// check if first text contains all terms
+			foreach ( $terms as $term ) {
+				if ( !preg_match( "/$patPre" . $term . "$patPost/ui", $firstText ) ) {
+					$succ = false;
+					break;
+				}
+			}
+			if ( $succ ) {
+				$snippets[$first] = $firstText;
+				$offsets[$first] = 0;
+			}
+		}
+		if ( !$snippets ) {
+			// match whole query on text
+			$this->process( $pat1, $textExt, $left, $contextchars, $snippets, $offsets );
+			// match whole query on templates/tables/images
+			$this->process( $pat1, $otherExt, $left, $contextchars, $snippets, $offsets );
+			// match any words on text
+			$this->process( $pat2, $textExt, $left, $contextchars, $snippets, $offsets );
+			// match any words on templates/tables/images
+			$this->process( $pat2, $otherExt, $left, $contextchars, $snippets, $offsets );
+
+			ksort( $snippets );
+		}
+
+		// add extra chars to each snippet to make snippets constant size
+		$extended = [];
+		if ( count( $snippets ) == 0 ) {
+			// couldn't find the target words, just show beginning of article
+			if ( array_key_exists( $first, $all ) ) {
+				$targetchars = $contextchars * $contextlines;
+				$snippets[$first] = '';
+				$offsets[$first] = 0;
+			}
+		} else {
+			// if begin of the article contains the whole phrase, show only that !!
+			if ( array_key_exists( $first, $snippets ) && preg_match( $pat1, $snippets[$first] )
+				&& $offsets[$first] < $contextchars * 2 ) {
+				$snippets = [ $first => $snippets[$first] ];
+			}
+
+			// calc by how much to extend existing snippets
+			$targetchars = intval( ( $contextchars * $contextlines ) / count( $snippets ) );
+		}
+
+		foreach ( $snippets as $index => $line ) {
+			$extended[$index] = $line;
+			$len = strlen( $line );
+			if ( $len < $targetchars - 20 ) {
+				// complete this line
+				if ( $len < strlen( $all[$index] ) ) {
+					$extended[$index] = $this->extract(
+						$all[$index],
+						$offsets[$index],
+						$offsets[$index] + $targetchars,
+						$offsets[$index]
+					);
+					$len = strlen( $extended[$index] );
+				}
+
+				// add more lines
+				$add = $index + 1;
+				while ( $len < $targetchars - 20
+						&& array_key_exists( $add, $all )
+						&& !array_key_exists( $add, $snippets ) ) {
+					$offsets[$add] = 0;
+					$tt = "\n" . $this->extract( $all[$add], 0, $targetchars - $len, $offsets[$add] );
+					$extended[$add] = $tt;
+					$len += strlen( $tt );
+					$add++;
+				}
+			}
+		}
+
+		// $snippets = array_map( 'htmlspecialchars', $extended );
+		$snippets = $extended;
+		$last = -1;
+		$extract = '';
+		foreach ( $snippets as $index => $line ) {
+			if ( $last == -1 ) {
+				$extract .= $line; // first line
+			} elseif ( $last + 1 == $index
+				&& $offsets[$last] + strlen( $snippets[$last] ) >= strlen( $all[$last] )
+			) {
+				$extract .= " " . $line; // continous lines
+			} else {
+				$extract .= '<b> ... </b>' . $line;
+			}
+
+			$last = $index;
+		}
+		if ( $extract ) {
+			$extract .= '<b> ... </b>';
+		}
+
+		$processed = [];
+		foreach ( $terms as $term ) {
+			if ( !isset( $processed[$term] ) ) {
+				$pat3 = "/$patPre(" . $term . ")$patPost/ui"; // highlight word
+				$extract = preg_replace( $pat3,
+					"\\1<span class='searchmatch'>\\2</span>\\3", $extract );
+				$processed[$term] = true;
+			}
+		}
+
+		return $extract;
+	}
+
+	/**
+	 * Split text into lines and add it to extracts array
+	 *
+	 * @param array &$extracts Index -> $line
+	 * @param int &$count
+	 * @param string $text
+	 */
+	function splitAndAdd( &$extracts, &$count, $text ) {
+		$split = explode( "\n", $this->mCleanWikitext ? $this->removeWiki( $text ) : $text );
+		foreach ( $split as $line ) {
+			$tt = trim( $line );
+			if ( $tt ) {
+				$extracts[$count++] = $tt;
+			}
+		}
+	}
+
+	/**
+	 * Do manual case conversion for non-ascii chars
+	 *
+	 * @param array $matches
+	 * @return string
+	 */
+	function caseCallback( $matches ) {
+		global $wgContLang;
+		if ( strlen( $matches[0] ) > 1 ) {
+			return '[' . $wgContLang->lc( $matches[0] ) . $wgContLang->uc( $matches[0] ) . ']';
+		} else {
+			return $matches[0];
+		}
+	}
+
+	/**
+	 * Extract part of the text from start to end, but by
+	 * not chopping up words
+	 * @param string $text
+	 * @param int $start
+	 * @param int $end
+	 * @param int &$posStart (out) actual start position
+	 * @param int &$posEnd (out) actual end position
+	 * @return string
+	 */
+	function extract( $text, $start, $end, &$posStart = null, &$posEnd = null ) {
+		if ( $start != 0 ) {
+			$start = $this->position( $text, $start, 1 );
+		}
+		if ( $end >= strlen( $text ) ) {
+			$end = strlen( $text );
+		} else {
+			$end = $this->position( $text, $end );
+		}
+
+		if ( !is_null( $posStart ) ) {
+			$posStart = $start;
+		}
+		if ( !is_null( $posEnd ) ) {
+			$posEnd = $end;
+		}
+
+		if ( $end > $start ) {
+			return substr( $text, $start, $end - $start );
+		} else {
+			return '';
+		}
+	}
+
+	/**
+	 * Find a nonletter near a point (index) in the text
+	 *
+	 * @param string $text
+	 * @param int $point
+	 * @param int $offset Offset to found index
+	 * @return int Nearest nonletter index, or beginning of utf8 char if none
+	 */
+	function position( $text, $point, $offset = 0 ) {
+		$tolerance = 10;
+		$s = max( 0, $point - $tolerance );
+		$l = min( strlen( $text ), $point + $tolerance ) - $s;
+		$m = [];
+
+		if ( preg_match(
+			'/[ ,.!?~!@#$%^&*\(\)+=\-\\\|\[\]"\'<>]/',
+			substr( $text, $s, $l ),
+			$m,
+			PREG_OFFSET_CAPTURE
+		) ) {
+			return $m[0][1] + $s + $offset;
+		} else {
+			// check if point is on a valid first UTF8 char
+			$char = ord( $text[$point] );
+			while ( $char >= 0x80 && $char < 0xc0 ) {
+				// skip trailing bytes
+				$point++;
+				if ( $point >= strlen( $text ) ) {
+					return strlen( $text );
+				}
+				$char = ord( $text[$point] );
+			}
+
+			return $point;
+
+		}
+	}
+
+	/**
+	 * Search extracts for a pattern, and return snippets
+	 *
+	 * @param string $pattern Regexp for matching lines
+	 * @param array $extracts Extracts to search
+	 * @param int &$linesleft Number of extracts to make
+	 * @param int &$contextchars Length of snippet
+	 * @param array &$out Map for highlighted snippets
+	 * @param array &$offsets Map of starting points of snippets
+	 * @protected
+	 */
+	function process( $pattern, $extracts, &$linesleft, &$contextchars, &$out, &$offsets ) {
+		if ( $linesleft == 0 ) {
+			return; // nothing to do
+		}
+		foreach ( $extracts as $index => $line ) {
+			if ( array_key_exists( $index, $out ) ) {
+				continue; // this line already highlighted
+			}
+
+			$m = [];
+			if ( !preg_match( $pattern, $line, $m, PREG_OFFSET_CAPTURE ) ) {
+				continue;
+			}
+
+			$offset = $m[0][1];
+			$len = strlen( $m[0][0] );
+			if ( $offset + $len < $contextchars ) {
+				$begin = 0;
+			} elseif ( $len > $contextchars ) {
+				$begin = $offset;
+			} else {
+				$begin = $offset + intval( ( $len - $contextchars ) / 2 );
+			}
+
+			$end = $begin + $contextchars;
+
+			$posBegin = $begin;
+			// basic snippet from this line
+			$out[$index] = $this->extract( $line, $begin, $end, $posBegin );
+			$offsets[$index] = $posBegin;
+			$linesleft--;
+			if ( $linesleft == 0 ) {
+				return;
+			}
+		}
+	}
+
+	/**
+	 * Basic wikitext removal
+	 * @protected
+	 * @param string $text
+	 * @return mixed
+	 */
+	function removeWiki( $text ) {
+		$text = preg_replace( "/\\{\\{([^|]+?)\\}\\}/", "", $text );
+		$text = preg_replace( "/\\{\\{([^|]+\\|)(.*?)\\}\\}/", "\\2", $text );
+		$text = preg_replace( "/\\[\\[([^|]+?)\\]\\]/", "\\1", $text );
+		$text = preg_replace_callback(
+			"/\\[\\[([^|]+\\|)(.*?)\\]\\]/",
+			[ $this, 'linkReplace' ],
+			$text
+		);
+		$text = preg_replace( "/<\/?[^>]+>/", "", $text );
+		$text = preg_replace( "/'''''/", "", $text );
+		$text = preg_replace( "/('''|<\/?[iIuUbB]>)/", "", $text );
+		$text = preg_replace( "/''/", "", $text );
+
+		// Note, the previous /<\/?[^>]+>/ is insufficient
+		// for XSS safety as the HTML tag can span multiple
+		// search results (T144845).
+		$text = Sanitizer::escapeHtmlAllowEntities( $text );
+		return $text;
+	}
+
+	/**
+	 * callback to replace [[target|caption]] kind of links, if
+	 * the target is category or image, leave it
+	 *
+	 * @param array $matches
+	 * @return string
+	 */
+	function linkReplace( $matches ) {
+		$colon = strpos( $matches[1], ':' );
+		if ( $colon === false ) {
+			return $matches[2]; // replace with caption
+		}
+		global $wgContLang;
+		$ns = substr( $matches[1], 0, $colon );
+		$index = $wgContLang->getNsIndex( $ns );
+		if ( $index !== false && ( $index == NS_FILE || $index == NS_CATEGORY ) ) {
+			return $matches[0]; // return the whole thing
+		} else {
+			return $matches[2];
+		}
+	}
+
+	/**
+	 * Simple & fast snippet extraction, but gives completely unrelevant
+	 * snippets
+	 *
+	 * Used when $wgAdvancedSearchHighlighting is false.
+	 *
+	 * @param string $text
+	 * @param array $terms Escaped for regex by SearchDatabase::regexTerm()
+	 * @param int $contextlines
+	 * @param int $contextchars
+	 * @return string
+	 */
+	public function highlightSimple( $text, $terms, $contextlines, $contextchars ) {
+		global $wgContLang;
+
+		$lines = explode( "\n", $text );
+
+		$terms = implode( '|', $terms );
+		$max = intval( $contextchars ) + 1;
+		$pat1 = "/(.*)($terms)(.{0,$max})/i";
+
+		$lineno = 0;
+
+		$extract = "";
+		foreach ( $lines as $line ) {
+			if ( 0 == $contextlines ) {
+				break;
+			}
+			++$lineno;
+			$m = [];
+			if ( !preg_match( $pat1, $line, $m ) ) {
+				continue;
+			}
+			--$contextlines;
+			// truncate function changes ... to relevant i18n message.
+			$pre = $wgContLang->truncate( $m[1], - $contextchars, '...', false );
+
+			if ( count( $m ) < 3 ) {
+				$post = '';
+			} else {
+				$post = $wgContLang->truncate( $m[3], $contextchars, '...', false );
+			}
+
+			$found = $m[2];
+
+			$line = htmlspecialchars( $pre . $found . $post );
+			$pat2 = '/(' . $terms . ")/i";
+			$line = preg_replace( $pat2, "<span class='searchmatch'>\\1</span>", $line );
+
+			$extract .= "${line}\n";
+		}
+
+		return $extract;
+	}
+
+	/**
+	 * Returns the first few lines of the text
+	 *
+	 * @param string $text
+	 * @param int $contextlines Max number of returned lines
+	 * @param int $contextchars Average number of characters per line
+	 * @return string
+	 */
+	public function highlightNone( $text, $contextlines, $contextchars ) {
+		$match = [];
+		$text = ltrim( $text ) . "\n"; // make sure the preg_match may find the last line
+		$text = str_replace( "\n\n", "\n", $text ); // remove empty lines
+		preg_match( "/^(.*\n){0,$contextlines}/", $text, $match );
+
+		// Trim and limit to max number of chars
+		$text = htmlspecialchars( substr( trim( $match[0] ), 0, $contextlines * $contextchars ) );
+		return str_replace( "\n", '<br>', $text );
+	}
+}
diff --git a/www/wiki/includes/search/SearchIndexField.php b/www/wiki/includes/search/SearchIndexField.php
new file mode 100644
index 00000000..6f3b2078
--- /dev/null
+++ b/www/wiki/includes/search/SearchIndexField.php
@@ -0,0 +1,98 @@
+<?php
+/**
+ * Definition of a mapping for the search index field.
+ * @since 1.28
+ */
+interface SearchIndexField {
+	/**
+	 * Field types
+	 */
+	const INDEX_TYPE_TEXT = 0;
+	const INDEX_TYPE_KEYWORD = 1;
+	const INDEX_TYPE_INTEGER = 2;
+	const INDEX_TYPE_NUMBER = 3;
+	const INDEX_TYPE_DATETIME = 4;
+	const INDEX_TYPE_NESTED = 5;
+	const INDEX_TYPE_BOOL = 6;
+
+	/**
+	 * SHORT_TEXT is meant to be used with short text made of mostly ascii
+	 * technical information. Generally a language agnostic analysis chain
+	 * is used and aggressive splitting to increase recall.
+	 * E.g suited for mime/type
+	 */
+	const INDEX_TYPE_SHORT_TEXT = 7;
+
+	/**
+	 * Generic field flags.
+	 */
+	/**
+	 * This field is case-insensitive.
+	 */
+	const FLAG_CASEFOLD = 1;
+
+	/**
+	 * This field contains secondary information, which is
+	 * already present in other fields, but can be used for
+	 * scoring.
+	 */
+	const FLAG_SCORING = 2;
+
+	/**
+	 * This field does not need highlight handling.
+	 */
+	const FLAG_NO_HIGHLIGHT = 4;
+
+	/**
+	 * Do not index this field, just store it.
+	 */
+	const FLAG_NO_INDEX = 8;
+
+	/**
+	 * Get mapping for specific search engine
+	 * @param SearchEngine $engine
+	 * @return array|null Null means this field does not map to anything
+	 */
+	public function getMapping( SearchEngine $engine );
+
+	/**
+	 * Set global flag for this field.
+	 *
+	 * @param int $flag Bit flag to set/unset
+	 * @param bool $unset True if flag should be unset, false by default
+	 * @return $this
+	 */
+	public function setFlag( $flag, $unset = false );
+
+	/**
+	 * Check if flag is set.
+	 * @param int $flag
+	 * @return int 0 if unset, !=0 if set
+	 */
+	public function checkFlag( $flag );
+
+	/**
+	 * Merge two field definitions if possible.
+	 *
+	 * @param SearchIndexField $that
+	 * @return SearchIndexField|false New definition or false if not mergeable.
+	 */
+	public function merge( SearchIndexField $that );
+
+	/**
+	 * A list of search engine hints for this field.
+	 * Hints are usually specific to a search engine implementation
+	 * and allow to fine control how the search engine will handle this
+	 * particular field.
+	 *
+	 * For example some search engine permits some optimizations
+	 * at index time by ignoring an update if the updated value
+	 * does not change by more than X% on a numeric value.
+	 *
+	 * @param SearchEngine $engine
+	 * @return array an array of hints generally indexed by hint name. The type of
+	 * values is search engine specific
+	 * @since 1.30
+	 */
+	public function getEngineHints( SearchEngine $engine );
+}
diff --git a/www/wiki/includes/search/SearchIndexFieldDefinition.php b/www/wiki/includes/search/SearchIndexFieldDefinition.php
new file mode 100644
index 00000000..a11dff9f
--- /dev/null
+++ b/www/wiki/includes/search/SearchIndexFieldDefinition.php
@@ -0,0 +1,153 @@
+<?php
+
+/**
+ * Basic infrastructure of the field definition.
+ *
+ * Specific engines should extend this class and at at least,
+ * override the getMapping method, but can reuse other parts.
+ *
+ * @since 1.28
+ */
+abstract class SearchIndexFieldDefinition implements SearchIndexField {
+
+	/**
+	 * Name of the field
+	 *
+	 * @var string
+	 */
+	protected $name;
+
+	/**
+	 * Type of the field, one of the constants above
+	 *
+	 * @var int
+	 */
+	protected $type;
+
+	/**
+	 * Bit flags for the field.
+	 *
+	 * @var int
+	 */
+	protected $flags = 0;
+
+	/**
+	 * Subfields
+	 * @var SearchIndexFieldDefinition[]
+	 */
+	protected $subfields = [];
+
+	/**
+	 * @var callable
+	 */
+	private $mergeCallback;
+
+	/**
+	 * @param string $name Field name
+	 * @param int $type Index type
+	 */
+	public function __construct( $name, $type ) {
+		$this->name = $name;
+		$this->type = $type;
+	}
+
+	/**
+	 * Get field name
+	 * @return string
+	 */
+	public function getName() {
+		return $this->name;
+	}
+
+	/**
+	 * Get index type
+	 * @return int
+	 */
+	public function getIndexType() {
+		return $this->type;
+	}
+
+	/**
+	 * Set global flag for this field.
+	 *
+	 * @param int $flag Bit flag to set/unset
+	 * @param bool $unset True if flag should be unset, false by default
+	 * @return $this
+	 */
+	public function setFlag( $flag, $unset = false ) {
+		if ( $unset ) {
+			$this->flags &= ~$flag;
+		} else {
+			$this->flags |= $flag;
+		}
+		return $this;
+	}
+
+	/**
+	 * Check if flag is set.
+	 * @param int $flag
+	 * @return int 0 if unset, !=0 if set
+	 */
+	public function checkFlag( $flag ) {
+		return $this->flags & $flag;
+	}
+
+	/**
+	 * Merge two field definitions if possible.
+	 *
+	 * @param SearchIndexField $that
+	 * @return SearchIndexField|false New definition or false if not mergeable.
+	 */
+	public function merge( SearchIndexField $that ) {
+		if ( !empty( $this->mergeCallback ) ) {
+			return call_user_func( $this->mergeCallback, $this, $that );
+		}
+		// TODO: which definitions may be compatible?
+		if ( ( $that instanceof self ) && $this->type === $that->type &&
+			$this->flags === $that->flags && $this->type !== self::INDEX_TYPE_NESTED
+		) {
+			return $that;
+		}
+		return false;
+	}
+
+	/**
+	 * Get subfields
+	 * @return SearchIndexFieldDefinition[]
+	 */
+	public function getSubfields() {
+		return $this->subfields;
+	}
+
+	/**
+	 * Set subfields
+	 * @param SearchIndexFieldDefinition[] $subfields
+	 * @return $this
+	 */
+	public function setSubfields( array $subfields ) {
+		$this->subfields = $subfields;
+		return $this;
+	}
+
+	/**
+	 * @param SearchEngine $engine
+	 *
+	 * @return array
+	 */
+	abstract public function getMapping( SearchEngine $engine );
+
+	/**
+	 * Set field-specific merge strategy.
+	 * @param callable $callback
+	 */
+	public function setMergeCallback( $callback ) {
+		$this->mergeCallback = $callback;
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public function getEngineHints( SearchEngine $engine ) {
+		return [];
+	}
+}
diff --git a/www/wiki/includes/search/SearchMssql.php b/www/wiki/includes/search/SearchMssql.php
new file mode 100644
index 00000000..57ca06e3
--- /dev/null
+++ b/www/wiki/includes/search/SearchMssql.php
@@ -0,0 +1,210 @@
+<?php
+/**
+ * Mssql search engine
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @ingroup Search
+ */
+
+/**
+ * Search engine hook base class for Mssql (ConText).
+ * @ingroup Search
+ */
+class SearchMssql extends SearchDatabase {
+	/**
+	 * Perform a full text search query and return a result set.
+	 *
+	 * @param string $term Raw search term
+	 * @return SqlSearchResultSet
+	 * @access public
+	 */
+	function searchText( $term ) {
+		$resultSet = $this->db->query( $this->getQuery( $this->filter( $term ), true ) );
+		return new SqlSearchResultSet( $resultSet, $this->searchTerms );
+	}
+
+	/**
+	 * Perform a title-only search query and return a result set.
+	 *
+	 * @param string $term Raw search term
+	 * @return SqlSearchResultSet
+	 * @access public
+	 */
+	function searchTitle( $term ) {
+		$resultSet = $this->db->query( $this->getQuery( $this->filter( $term ), false ) );
+		return new SqlSearchResultSet( $resultSet, $this->searchTerms );
+	}
+
+	/**
+	 * Return a partial WHERE clause to limit the search to the given namespaces
+	 *
+	 * @return string
+	 * @private
+	 */
+	function queryNamespaces() {
+		$namespaces = implode( ',', $this->namespaces );
+		if ( $namespaces == '' ) {
+			$namespaces = '0';
+		}
+		return 'AND page_namespace IN (' . $namespaces . ')';
+	}
+
+	/**
+	 * Return a LIMIT clause to limit results on the query.
+	 *
+	 * @param string $sql
+	 *
+	 * @return string
+	 */
+	function queryLimit( $sql ) {
+		return $this->db->limitResult( $sql, $this->limit, $this->offset );
+	}
+
+	/**
+	 * Does not do anything for generic search engine
+	 * subclasses may define this though
+	 *
+	 * @param string $filteredTerm
+	 * @param bool $fulltext
+	 * @return string
+	 */
+	function queryRanking( $filteredTerm, $fulltext ) {
+		return ' ORDER BY ftindex.[RANK] DESC'; // return ' ORDER BY score(1)';
+	}
+
+	/**
+	 * Construct the full SQL query to do the search.
+	 * The guts shoulds be constructed in queryMain()
+	 *
+	 * @param string $filteredTerm
+	 * @param bool $fulltext
+	 * @return string
+	 */
+	function getQuery( $filteredTerm, $fulltext ) {
+		return $this->queryLimit( $this->queryMain( $filteredTerm, $fulltext ) . ' ' .
+			$this->queryNamespaces() . ' ' .
+			$this->queryRanking( $filteredTerm, $fulltext ) . ' ' );
+	}
+
+	/**
+	 * Picks which field to index on, depending on what type of query.
+	 *
+	 * @param bool $fulltext
+	 * @return string
+	 */
+	function getIndexField( $fulltext ) {
+		return $fulltext ? 'si_text' : 'si_title';
+	}
+
+	/**
+	 * Get the base part of the search query.
+	 *
+	 * @param string $filteredTerm
+	 * @param bool $fulltext
+	 * @return string
+	 * @private
+	 */
+	function queryMain( $filteredTerm, $fulltext ) {
+		$match = $this->parseQuery( $filteredTerm, $fulltext );
+		$page = $this->db->tableName( 'page' );
+		$searchindex = $this->db->tableName( 'searchindex' );
+
+		return 'SELECT page_id, page_namespace, page_title, ftindex.[RANK]' .
+			"FROM $page,FREETEXTTABLE($searchindex , $match, LANGUAGE 'English') as ftindex " .
+			'WHERE page_id=ftindex.[KEY] ';
+	}
+
+	/** @todo document
+	 * @param string $filteredText
+	 * @param bool $fulltext
+	 * @return string
+	 */
+	function parseQuery( $filteredText, $fulltext ) {
+		global $wgContLang;
+		$lc = $this->legalSearchChars( self::CHARS_NO_SYNTAX );
+		$this->searchTerms = [];
+
+		# @todo FIXME: This doesn't handle parenthetical expressions.
+		$m = [];
+		$q = [];
+
+		if ( preg_match_all( '/([-+<>~]?)(([' . $lc . ']+)(\*?)|"[^"]*")/',
+			$filteredText, $m, PREG_SET_ORDER ) ) {
+			foreach ( $m as $terms ) {
+				$q[] = $terms[1] . $wgContLang->normalizeForSearch( $terms[2] );
+
+				if ( !empty( $terms[3] ) ) {
+					$regexp = preg_quote( $terms[3], '/' );
+					if ( $terms[4] ) {
+						$regexp .= "[0-9A-Za-z_]+";
+					}
+				} else {
+					$regexp = preg_quote( str_replace( '"', '', $terms[2] ), '/' );
+				}
+				$this->searchTerms[] = $regexp;
+			}
+		}
+
+		$searchon = $this->db->addQuotes( implode( ',', $q ) );
+		$field = $this->getIndexField( $fulltext );
+		return "$field, $searchon";
+	}
+
+	/**
+	 * Create or update the search index record for the given page.
+	 * Title and text should be pre-processed.
+	 *
+	 * @param int $id
+	 * @param string $title
+	 * @param string $text
+	 * @return bool|ResultWrapper
+	 */
+	function update( $id, $title, $text ) {
+		// We store the column data as UTF-8 byte order marked binary stream
+		// because we are invoking the plain text IFilter on it so that, and we want it
+		// to properly decode the stream as UTF-8.  SQL doesn't support UTF8 as a data type
+		// but the indexer will correctly handle it by this method.  Since all we are doing
+		// is passing this data to the indexer and never retrieving it via PHP, this will save space
+		$table = $this->db->tableName( 'searchindex' );
+		$utf8bom = '0xEFBBBF';
+		$si_title = $utf8bom . bin2hex( $title );
+		$si_text = $utf8bom . bin2hex( $text );
+		$sql = "DELETE FROM $table WHERE si_page = $id;";
+		$sql .= "INSERT INTO $table (si_page, si_title, si_text) VALUES ($id, $si_title, $si_text)";
+		return $this->db->query( $sql, 'SearchMssql::update' );
+	}
+
+	/**
+	 * Update a search index record's title only.
+	 * Title should be pre-processed.
+	 *
+	 * @param int $id
+	 * @param string $title
+	 * @return bool|ResultWrapper
+	 */
+	function updateTitle( $id, $title ) {
+		$table = $this->db->tableName( 'searchindex' );
+
+		// see update for why we are using the utf8bom
+		$utf8bom = '0xEFBBBF';
+		$si_title = $utf8bom . bin2hex( $title );
+		$sql = "DELETE FROM $table WHERE si_page = $id;";
+		$sql .= "INSERT INTO $table (si_page, si_title, si_text) VALUES ($id, $si_title, 0x00)";
+		return $this->db->query( $sql, 'SearchMssql::updateTitle' );
+	}
+}
diff --git a/www/wiki/includes/search/SearchMySQL.php b/www/wiki/includes/search/SearchMySQL.php
new file mode 100644
index 00000000..8e705c1f
--- /dev/null
+++ b/www/wiki/includes/search/SearchMySQL.php
@@ -0,0 +1,458 @@
+<?php
+/**
+ * MySQL search engine
+ *
+ * Copyright (C) 2004 Brion Vibber <brion@pobox.com>
+ * https://www.mediawiki.org/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @ingroup Search
+ */
+
+/**
+ * Search engine hook for MySQL 4+
+ * @ingroup Search
+ */
+class SearchMySQL extends SearchDatabase {
+	protected $strictMatching = true;
+
+	private static $mMinSearchLength;
+
+	/**
+	 * Parse the user's query and transform it into an SQL fragment which will
+	 * become part of a WHERE clause
+	 *
+	 * @param string $filteredText
+	 * @param string $fulltext
+	 *
+	 * @return string
+	 */
+	function parseQuery( $filteredText, $fulltext ) {
+		global $wgContLang;
+
+		$lc = $this->legalSearchChars( self::CHARS_NO_SYNTAX ); // Minus syntax chars (" and *)
+		$searchon = '';
+		$this->searchTerms = [];
+
+		# @todo FIXME: This doesn't handle parenthetical expressions.
+		$m = [];
+		if ( preg_match_all( '/([-+<>~]?)(([' . $lc . ']+)(\*?)|"[^"]*")/',
+				$filteredText, $m, PREG_SET_ORDER ) ) {
+			foreach ( $m as $bits ) {
+				Wikimedia\suppressWarnings();
+				list( /* all */, $modifier, $term, $nonQuoted, $wildcard ) = $bits;
+				Wikimedia\restoreWarnings();
+
+				if ( $nonQuoted != '' ) {
+					$term = $nonQuoted;
+					$quote = '';
+				} else {
+					$term = str_replace( '"', '', $term );
+					$quote = '"';
+				}
+
+				if ( $searchon !== '' ) {
+					$searchon .= ' ';
+				}
+				if ( $this->strictMatching && ( $modifier == '' ) ) {
+					// If we leave this out, boolean op defaults to OR which is rarely helpful.
+					$modifier = '+';
+				}
+
+				// Some languages such as Serbian store the input form in the search index,
+				// so we may need to search for matches in multiple writing system variants.
+				$convertedVariants = $wgContLang->autoConvertToAllVariants( $term );
+				if ( is_array( $convertedVariants ) ) {
+					$variants = array_unique( array_values( $convertedVariants ) );
+				} else {
+					$variants = [ $term ];
+				}
+
+				// The low-level search index does some processing on input to work
+				// around problems with minimum lengths and encoding in MySQL's
+				// fulltext engine.
+				// For Chinese this also inserts spaces between adjacent Han characters.
+				$strippedVariants = array_map(
+					[ $wgContLang, 'normalizeForSearch' ],
+					$variants );
+
+				// Some languages such as Chinese force all variants to a canonical
+				// form when stripping to the low-level search index, so to be sure
+				// let's check our variants list for unique items after stripping.
+				$strippedVariants = array_unique( $strippedVariants );
+
+				$searchon .= $modifier;
+				if ( count( $strippedVariants ) > 1 ) {
+					$searchon .= '(';
+				}
+				foreach ( $strippedVariants as $stripped ) {
+					$stripped = $this->normalizeText( $stripped );
+					if ( $nonQuoted && strpos( $stripped, ' ' ) !== false ) {
+						// Hack for Chinese: we need to toss in quotes for
+						// multiple-character phrases since normalizeForSearch()
+						// added spaces between them to make word breaks.
+						$stripped = '"' . trim( $stripped ) . '"';
+					}
+					$searchon .= "$quote$stripped$quote$wildcard ";
+				}
+				if ( count( $strippedVariants ) > 1 ) {
+					$searchon .= ')';
+				}
+
+				// Match individual terms or quoted phrase in result highlighting...
+				// Note that variants will be introduced in a later stage for highlighting!
+				$regexp = $this->regexTerm( $term, $wildcard );
+				$this->searchTerms[] = $regexp;
+			}
+			wfDebug( __METHOD__ . ": Would search with '$searchon'\n" );
+			wfDebug( __METHOD__ . ': Match with /' . implode( '|', $this->searchTerms ) . "/\n" );
+		} else {
+			wfDebug( __METHOD__ . ": Can't understand search query '{$filteredText}'\n" );
+		}
+
+		$searchon = $this->db->addQuotes( $searchon );
+		$field = $this->getIndexField( $fulltext );
+		return " MATCH($field) AGAINST($searchon IN BOOLEAN MODE) ";
+	}
+
+	function regexTerm( $string, $wildcard ) {
+		global $wgContLang;
+
+		$regex = preg_quote( $string, '/' );
+		if ( $wgContLang->hasWordBreaks() ) {
+			if ( $wildcard ) {
+				// Don't cut off the final bit!
+				$regex = "\b$regex";
+			} else {
+				$regex = "\b$regex\b";
+			}
+		} else {
+			// For Chinese, words may legitimately abut other words in the text literal.
+			// Don't add \b boundary checks... note this could cause false positives
+			// for latin chars.
+		}
+		return $regex;
+	}
+
+	public static function legalSearchChars( $type = self::CHARS_ALL ) {
+		$searchChars = parent::legalSearchChars( $type );
+		if ( $type === self::CHARS_ALL ) {
+			// " for phrase, * for wildcard
+			$searchChars = "\"*" . $searchChars;
+		}
+		return $searchChars;
+	}
+
+	/**
+	 * Perform a full text search query and return a result set.
+	 *
+	 * @param string $term Raw search term
+	 * @return SqlSearchResultSet
+	 */
+	function searchText( $term ) {
+		return $this->searchInternal( $term, true );
+	}
+
+	/**
+	 * Perform a title-only search query and return a result set.
+	 *
+	 * @param string $term Raw search term
+	 * @return SqlSearchResultSet
+	 */
+	function searchTitle( $term ) {
+		return $this->searchInternal( $term, false );
+	}
+
+	protected function searchInternal( $term, $fulltext ) {
+		// This seems out of place, why is this called with empty term?
+		if ( trim( $term ) === '' ) {
+			return null;
+		}
+
+		$filteredTerm = $this->filter( $term );
+		$query = $this->getQuery( $filteredTerm, $fulltext );
+		$resultSet = $this->db->select(
+			$query['tables'], $query['fields'], $query['conds'],
+			__METHOD__, $query['options'], $query['joins']
+		);
+
+		$total = null;
+		$query = $this->getCountQuery( $filteredTerm, $fulltext );
+		$totalResult = $this->db->select(
+			$query['tables'], $query['fields'], $query['conds'],
+			__METHOD__, $query['options'], $query['joins']
+		);
+
+		$row = $totalResult->fetchObject();
+		if ( $row ) {
+			$total = intval( $row->c );
+		}
+		$totalResult->free();
+
+		return new SqlSearchResultSet( $resultSet, $this->searchTerms, $total );
+	}
+
+	public function supports( $feature ) {
+		switch ( $feature ) {
+			case 'title-suffix-filter':
+				return true;
+			default:
+				return parent::supports( $feature );
+		}
+	}
+
+	/**
+	 * Add special conditions
+	 * @param array &$query
+	 * @since 1.18
+	 */
+	protected function queryFeatures( &$query ) {
+		foreach ( $this->features as $feature => $value ) {
+			if ( $feature === 'title-suffix-filter' && $value ) {
+				$query['conds'][] = 'page_title' . $this->db->buildLike( $this->db->anyString(), $value );
+			}
+		}
+	}
+
+	/**
+	 * Add namespace conditions
+	 * @param array &$query
+	 * @since 1.18 (changed)
+	 */
+	function queryNamespaces( &$query ) {
+		if ( is_array( $this->namespaces ) ) {
+			if ( count( $this->namespaces ) === 0 ) {
+				$this->namespaces[] = '0';
+			}
+			$query['conds']['page_namespace'] = $this->namespaces;
+		}
+	}
+
+	/**
+	 * Add limit options
+	 * @param array &$query
+	 * @since 1.18
+	 */
+	protected function limitResult( &$query ) {
+		$query['options']['LIMIT'] = $this->limit;
+		$query['options']['OFFSET'] = $this->offset;
+	}
+
+	/**
+	 * Construct the SQL query to do the search.
+	 * The guts shoulds be constructed in queryMain()
+	 * @param string $filteredTerm
+	 * @param bool $fulltext
+	 * @return array
+	 * @since 1.18 (changed)
+	 */
+	function getQuery( $filteredTerm, $fulltext ) {
+		$query = [
+			'tables' => [],
+			'fields' => [],
+			'conds' => [],
+			'options' => [],
+			'joins' => [],
+		];
+
+		$this->queryMain( $query, $filteredTerm, $fulltext );
+		$this->queryFeatures( $query );
+		$this->queryNamespaces( $query );
+		$this->limitResult( $query );
+
+		return $query;
+	}
+
+	/**
+	 * Picks which field to index on, depending on what type of query.
+	 * @param bool $fulltext
+	 * @return string
+	 */
+	function getIndexField( $fulltext ) {
+		return $fulltext ? 'si_text' : 'si_title';
+	}
+
+	/**
+	 * Get the base part of the search query.
+	 *
+	 * @param array &$query Search query array
+	 * @param string $filteredTerm
+	 * @param bool $fulltext
+	 * @since 1.18 (changed)
+	 */
+	function queryMain( &$query, $filteredTerm, $fulltext ) {
+		$match = $this->parseQuery( $filteredTerm, $fulltext );
+		$query['tables'][] = 'page';
+		$query['tables'][] = 'searchindex';
+		$query['fields'][] = 'page_id';
+		$query['fields'][] = 'page_namespace';
+		$query['fields'][] = 'page_title';
+		$query['conds'][] = 'page_id=si_page';
+		$query['conds'][] = $match;
+	}
+
+	/**
+	 * @since 1.18 (changed)
+	 * @param string $filteredTerm
+	 * @param bool $fulltext
+	 * @return array
+	 */
+	function getCountQuery( $filteredTerm, $fulltext ) {
+		$match = $this->parseQuery( $filteredTerm, $fulltext );
+
+		$query = [
+			'tables' => [ 'page', 'searchindex' ],
+			'fields' => [ 'COUNT(*) as c' ],
+			'conds' => [ 'page_id=si_page', $match ],
+			'options' => [],
+			'joins' => [],
+		];
+
+		$this->queryFeatures( $query );
+		$this->queryNamespaces( $query );
+
+		return $query;
+	}
+
+	/**
+	 * Create or update the search index record for the given page.
+	 * Title and text should be pre-processed.
+	 *
+	 * @param int $id
+	 * @param string $title
+	 * @param string $text
+	 */
+	function update( $id, $title, $text ) {
+		$dbw = wfGetDB( DB_MASTER );
+		$dbw->replace( 'searchindex',
+			[ 'si_page' ],
+			[
+				'si_page' => $id,
+				'si_title' => $this->normalizeText( $title ),
+				'si_text' => $this->normalizeText( $text )
+			], __METHOD__ );
+	}
+
+	/**
+	 * Update a search index record's title only.
+	 * Title should be pre-processed.
+	 *
+	 * @param int $id
+	 * @param string $title
+	 */
+	function updateTitle( $id, $title ) {
+		$dbw = wfGetDB( DB_MASTER );
+
+		$dbw->update( 'searchindex',
+			[ 'si_title' => $this->normalizeText( $title ) ],
+			[ 'si_page' => $id ],
+			__METHOD__,
+			[ $dbw->lowPriorityOption() ] );
+	}
+
+	/**
+	 * Delete an indexed page
+	 * Title should be pre-processed.
+	 *
+	 * @param int $id Page id that was deleted
+	 * @param string $title Title of page that was deleted
+	 */
+	function delete( $id, $title ) {
+		$dbw = wfGetDB( DB_MASTER );
+
+		$dbw->delete( 'searchindex', [ 'si_page' => $id ], __METHOD__ );
+	}
+
+	/**
+	 * Converts some characters for MySQL's indexing to grok it correctly,
+	 * and pads short words to overcome limitations.
+	 * @param string $string
+	 * @return mixed|string
+	 */
+	function normalizeText( $string ) {
+		global $wgContLang;
+
+		$out = parent::normalizeText( $string );
+
+		// MySQL fulltext index doesn't grok utf-8, so we
+		// need to fold cases and convert to hex
+		$out = preg_replace_callback(
+			"/([\\xc0-\\xff][\\x80-\\xbf]*)/",
+			[ $this, 'stripForSearchCallback' ],
+			$wgContLang->lc( $out ) );
+
+		// And to add insult to injury, the default indexing
+		// ignores short words... Pad them so we can pass them
+		// through without reconfiguring the server...
+		$minLength = $this->minSearchLength();
+		if ( $minLength > 1 ) {
+			$n = $minLength - 1;
+			$out = preg_replace(
+				"/\b(\w{1,$n})\b/",
+				"$1u800",
+				$out );
+		}
+
+		// Periods within things like hostnames and IP addresses
+		// are also important -- we want a search for "example.com"
+		// or "192.168.1.1" to work sanely.
+		// MySQL's search seems to ignore them, so you'd match on
+		// "example.wikipedia.com" and "192.168.83.1" as well.
+		$out = preg_replace(
+			"/(\w)\.(\w|\*)/u",
+			"$1u82e$2",
+			$out );
+
+		return $out;
+	}
+
+	/**
+	 * Armor a case-folded UTF-8 string to get through MySQL's
+	 * fulltext search without being mucked up by funny charset
+	 * settings or anything else of the sort.
+	 * @param array $matches
+	 * @return string
+	 */
+	protected function stripForSearchCallback( $matches ) {
+		return 'u8' . bin2hex( $matches[1] );
+	}
+
+	/**
+	 * Check MySQL server's ft_min_word_len setting so we know
+	 * if we need to pad short words...
+	 *
+	 * @return int
+	 */
+	protected function minSearchLength() {
+		if ( is_null( self::$mMinSearchLength ) ) {
+			$sql = "SHOW GLOBAL VARIABLES LIKE 'ft\\_min\\_word\\_len'";
+
+			$dbr = wfGetDB( DB_REPLICA );
+			$result = $dbr->query( $sql, __METHOD__ );
+			$row = $result->fetchObject();
+			$result->free();
+
+			if ( $row && $row->Variable_name == 'ft_min_word_len' ) {
+				self::$mMinSearchLength = intval( $row->Value );
+			} else {
+				self::$mMinSearchLength = 0;
+			}
+		}
+		return self::$mMinSearchLength;
+	}
+}
diff --git a/www/wiki/includes/search/SearchNearMatchResultSet.php b/www/wiki/includes/search/SearchNearMatchResultSet.php
new file mode 100644
index 00000000..31417974
--- /dev/null
+++ b/www/wiki/includes/search/SearchNearMatchResultSet.php
@@ -0,0 +1,30 @@
+<?php
+/**
+ * A SearchResultSet wrapper for SearchNearMatcher
+ */
+class SearchNearMatchResultSet extends SearchResultSet {
+	private $fetched = false;
+
+	/**
+	 * @param Title|null $match Title if matched, else null
+	 */
+	public function __construct( $match ) {
+		$this->result = $match;
+	}
+
+	public function numRows() {
+		return $this->result ? 1 : 0;
+	}
+
+	public function next() {
+		if ( $this->fetched || !$this->result ) {
+			return false;
+		}
+		$this->fetched = true;
+		return SearchResult::newFromTitle( $this->result, $this );
+	}
+
+	public function rewind() {
+		$this->fetched = false;
+	}
+}
diff --git a/www/wiki/includes/search/SearchNearMatcher.php b/www/wiki/includes/search/SearchNearMatcher.php
new file mode 100644
index 00000000..27046f31
--- /dev/null
+++ b/www/wiki/includes/search/SearchNearMatcher.php
@@ -0,0 +1,167 @@
+<?php
+
+/**
+ * Implementation of near match title search.
+ * TODO: split into service/implementation.
+ */
+class SearchNearMatcher {
+	/**
+	 * @var Config
+	 */
+	protected $config;
+
+	/**
+	 * Current language
+	 * @var Language
+	 */
+	private $language;
+
+	public function __construct( Config $config, Language $lang ) {
+		$this->config = $config;
+		$this->language = $lang;
+	}
+
+	/**
+	 * If an exact title match can be found, or a very slightly close match,
+	 * return the title. If no match, returns NULL.
+	 *
+	 * @param string $searchterm
+	 * @return Title
+	 */
+	public function getNearMatch( $searchterm ) {
+		$title = $this->getNearMatchInternal( $searchterm );
+
+		Hooks::run( 'SearchGetNearMatchComplete', [ $searchterm, &$title ] );
+		return $title;
+	}
+
+	/**
+	 * Do a near match (see SearchEngine::getNearMatch) and wrap it into a
+	 * SearchResultSet.
+	 *
+	 * @param string $searchterm
+	 * @return SearchResultSet
+	 */
+	public function getNearMatchResultSet( $searchterm ) {
+		return new SearchNearMatchResultSet( $this->getNearMatch( $searchterm ) );
+	}
+
+	/**
+	 * Really find the title match.
+	 * @param string $searchterm
+	 * @return null|Title
+	 */
+	protected function getNearMatchInternal( $searchterm ) {
+		$lang = $this->language;
+
+		$allSearchTerms = [ $searchterm ];
+
+		if ( $lang->hasVariants() ) {
+			$allSearchTerms = array_unique( array_merge(
+				$allSearchTerms,
+				$lang->autoConvertToAllVariants( $searchterm )
+			) );
+		}
+
+		$titleResult = null;
+		if ( !Hooks::run( 'SearchGetNearMatchBefore', [ $allSearchTerms, &$titleResult ] ) ) {
+			return $titleResult;
+		}
+
+		foreach ( $allSearchTerms as $term ) {
+			# Exact match? No need to look further.
+			$title = Title::newFromText( $term );
+			if ( is_null( $title ) ) {
+				return null;
+			}
+
+			# Try files if searching in the Media: namespace
+			if ( $title->getNamespace() == NS_MEDIA ) {
+				$title = Title::makeTitle( NS_FILE, $title->getText() );
+			}
+
+			if ( $title->isSpecialPage() || $title->isExternal() || $title->exists() ) {
+				return $title;
+			}
+
+			# See if it still otherwise has content is some sane sense
+			$page = WikiPage::factory( $title );
+			if ( $page->hasViewableContent() ) {
+				return $title;
+			}
+
+			if ( !Hooks::run( 'SearchAfterNoDirectMatch', [ $term, &$title ] ) ) {
+				return $title;
+			}
+
+			# Now try all lower case (i.e. first letter capitalized)
+			$title = Title::newFromText( $lang->lc( $term ) );
+			if ( $title && $title->exists() ) {
+				return $title;
+			}
+
+			# Now try capitalized string
+			$title = Title::newFromText( $lang->ucwords( $term ) );
+			if ( $title && $title->exists() ) {
+				return $title;
+			}
+
+			# Now try all upper case
+			$title = Title::newFromText( $lang->uc( $term ) );
+			if ( $title && $title->exists() ) {
+				return $title;
+			}
+
+			# Now try Word-Caps-Breaking-At-Word-Breaks, for hyphenated names etc
+			$title = Title::newFromText( $lang->ucwordbreaks( $term ) );
+			if ( $title && $title->exists() ) {
+				return $title;
+			}
+
+			// Give hooks a chance at better match variants
+			$title = null;
+			if ( !Hooks::run( 'SearchGetNearMatch', [ $term, &$title ] ) ) {
+				return $title;
+			}
+		}
+
+		$title = Title::newFromText( $searchterm );
+
+		# Entering an IP address goes to the contributions page
+		if ( $this->config->get( 'EnableSearchContributorsByIP' ) ) {
+			if ( ( $title->getNamespace() == NS_USER && User::isIP( $title->getText() ) )
+				|| User::isIP( trim( $searchterm ) ) ) {
+				return SpecialPage::getTitleFor( 'Contributions', $title->getDBkey() );
+			}
+		}
+
+		# Entering a user goes to the user page whether it's there or not
+		if ( $title->getNamespace() == NS_USER ) {
+			return $title;
+		}
+
+		# Go to images that exist even if there's no local page.
+		# There may have been a funny upload, or it may be on a shared
+		# file repository such as Wikimedia Commons.
+		if ( $title->getNamespace() == NS_FILE ) {
+			$image = wfFindFile( $title );
+			if ( $image ) {
+				return $title;
+			}
+		}
+
+		# MediaWiki namespace? Page may be "implied" if not customized.
+		# Just return it, with caps forced as the message system likes it.
+		if ( $title->getNamespace() == NS_MEDIAWIKI ) {
+			return Title::makeTitle( NS_MEDIAWIKI, $lang->ucfirst( $title->getText() ) );
+		}
+
+		# Quoted term? Try without the quotes...
+		$matches = [];
+		if ( preg_match( '/^"([^"]+)"$/', $searchterm, $matches ) ) {
+			return self::getNearMatch( $matches[1] );
+		}
+
+		return null;
+	}
+}
diff --git a/www/wiki/includes/search/SearchOracle.php b/www/wiki/includes/search/SearchOracle.php
new file mode 100644
index 00000000..8bcd78fa
--- /dev/null
+++ b/www/wiki/includes/search/SearchOracle.php
@@ -0,0 +1,276 @@
+<?php
+/**
+ * Oracle search engine
+ *
+ * Copyright © 2004 Brion Vibber <brion@pobox.com>
+ * https://www.mediawiki.org/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @ingroup Search
+ */
+
+/**
+ * Search engine hook base class for Oracle (ConText).
+ * @ingroup Search
+ */
+class SearchOracle extends SearchDatabase {
+	private $reservedWords = [
+		'ABOUT' => 1,
+		'ACCUM' => 1,
+		'AND' => 1,
+		'BT' => 1,
+		'BTG' => 1,
+		'BTI' => 1,
+		'BTP' => 1,
+		'FUZZY' => 1,
+		'HASPATH' => 1,
+		'INPATH' => 1,
+		'MINUS' => 1,
+		'NEAR' => 1,
+		'NOT' => 1,
+		'NT' => 1,
+		'NTG' => 1,
+		'NTI' => 1,
+		'NTP' => 1,
+		'OR' => 1,
+		'PT' => 1,
+		'RT' => 1,
+		'SQE' => 1,
+		'SYN' => 1,
+		'TR' => 1,
+		'TRSYN' => 1,
+		'TT' => 1,
+		'WITHIN' => 1,
+	];
+
+	/**
+	 * Perform a full text search query and return a result set.
+	 *
+	 * @param string $term Raw search term
+	 * @return SqlSearchResultSet
+	 */
+	function searchText( $term ) {
+		if ( $term == '' ) {
+			return new SqlSearchResultSet( false, '' );
+		}
+
+		$resultSet = $this->db->query( $this->getQuery( $this->filter( $term ), true ) );
+		return new SqlSearchResultSet( $resultSet, $this->searchTerms );
+	}
+
+	/**
+	 * Perform a title-only search query and return a result set.
+	 *
+	 * @param string $term Raw search term
+	 * @return SqlSearchResultSet
+	 */
+	function searchTitle( $term ) {
+		if ( $term == '' ) {
+			return new SqlSearchResultSet( false, '' );
+		}
+
+		$resultSet = $this->db->query( $this->getQuery( $this->filter( $term ), false ) );
+		return new SqlSearchResultSet( $resultSet, $this->searchTerms );
+	}
+
+	/**
+	 * Return a partial WHERE clause to limit the search to the given namespaces
+	 * @return string
+	 */
+	function queryNamespaces() {
+		if ( is_null( $this->namespaces ) ) {
+			return '';
+		}
+		if ( !count( $this->namespaces ) ) {
+			$namespaces = '0';
+		} else {
+			$namespaces = $this->db->makeList( $this->namespaces );
+		}
+		return 'AND page_namespace IN (' . $namespaces . ')';
+	}
+
+	/**
+	 * Return a LIMIT clause to limit results on the query.
+	 *
+	 * @param string $sql
+	 *
+	 * @return string
+	 */
+	function queryLimit( $sql ) {
+		return $this->db->limitResult( $sql, $this->limit, $this->offset );
+	}
+
+	/**
+	 * Does not do anything for generic search engine
+	 * subclasses may define this though
+	 *
+	 * @param string $filteredTerm
+	 * @param bool $fulltext
+	 * @return string
+	 */
+	function queryRanking( $filteredTerm, $fulltext ) {
+		return ' ORDER BY score(1)';
+	}
+
+	/**
+	 * Construct the full SQL query to do the search.
+	 * The guts shoulds be constructed in queryMain()
+	 * @param string $filteredTerm
+	 * @param bool $fulltext
+	 * @return string
+	 */
+	function getQuery( $filteredTerm, $fulltext ) {
+		return $this->queryLimit( $this->queryMain( $filteredTerm, $fulltext ) . ' ' .
+			$this->queryNamespaces() . ' ' .
+			$this->queryRanking( $filteredTerm, $fulltext ) . ' ' );
+	}
+
+	/**
+	 * Picks which field to index on, depending on what type of query.
+	 * @param bool $fulltext
+	 * @return string
+	 */
+	function getIndexField( $fulltext ) {
+		return $fulltext ? 'si_text' : 'si_title';
+	}
+
+	/**
+	 * Get the base part of the search query.
+	 *
+	 * @param string $filteredTerm
+	 * @param bool $fulltext
+	 * @return string
+	 */
+	function queryMain( $filteredTerm, $fulltext ) {
+		$match = $this->parseQuery( $filteredTerm, $fulltext );
+		$page = $this->db->tableName( 'page' );
+		$searchindex = $this->db->tableName( 'searchindex' );
+		return 'SELECT page_id, page_namespace, page_title ' .
+			"FROM $page,$searchindex " .
+			'WHERE page_id=si_page AND ' . $match;
+	}
+
+	/**
+	 * Parse a user input search string, and return an SQL fragment to be used
+	 * as part of a WHERE clause
+	 * @param string $filteredText
+	 * @param bool $fulltext
+	 * @return string
+	 */
+	function parseQuery( $filteredText, $fulltext ) {
+		global $wgContLang;
+		$lc = $this->legalSearchChars( self::CHARS_NO_SYNTAX );
+		$this->searchTerms = [];
+
+		# @todo FIXME: This doesn't handle parenthetical expressions.
+		$m = [];
+		$searchon = '';
+		if ( preg_match_all( '/([-+<>~]?)(([' . $lc . ']+)(\*?)|"[^"]*")/',
+				$filteredText, $m, PREG_SET_ORDER ) ) {
+			foreach ( $m as $terms ) {
+				// Search terms in all variant forms, only
+				// apply on wiki with LanguageConverter
+				$temp_terms = $wgContLang->autoConvertToAllVariants( $terms[2] );
+				if ( is_array( $temp_terms ) ) {
+					$temp_terms = array_unique( array_values( $temp_terms ) );
+					foreach ( $temp_terms as $t ) {
+						$searchon .= ( $terms[1] == '-' ? ' ~' : ' & ' ) . $this->escapeTerm( $t );
+					}
+				} else {
+					$searchon .= ( $terms[1] == '-' ? ' ~' : ' & ' ) . $this->escapeTerm( $terms[2] );
+				}
+				if ( !empty( $terms[3] ) ) {
+					$regexp = preg_quote( $terms[3], '/' );
+					if ( $terms[4] ) {
+						$regexp .= "[0-9A-Za-z_]+";
+					}
+				} else {
+					$regexp = preg_quote( str_replace( '"', '', $terms[2] ), '/' );
+				}
+				$this->searchTerms[] = $regexp;
+			}
+		}
+
+		$searchon = $this->db->addQuotes( ltrim( $searchon, ' &' ) );
+		$field = $this->getIndexField( $fulltext );
+		return " CONTAINS($field, $searchon, 1) > 0 ";
+	}
+
+	private function escapeTerm( $t ) {
+		global $wgContLang;
+		$t = $wgContLang->normalizeForSearch( $t );
+		$t = isset( $this->reservedWords[strtoupper( $t )] ) ? '{' . $t . '}' : $t;
+		$t = preg_replace( '/^"(.*)"$/', '($1)', $t );
+		$t = preg_replace( '/([-&|])/', '\\\\$1', $t );
+		return $t;
+	}
+
+	/**
+	 * Create or update the search index record for the given page.
+	 * Title and text should be pre-processed.
+	 *
+	 * @param int $id
+	 * @param string $title
+	 * @param string $text
+	 */
+	function update( $id, $title, $text ) {
+		$dbw = wfGetDB( DB_MASTER );
+		$dbw->replace( 'searchindex',
+			[ 'si_page' ],
+			[
+				'si_page' => $id,
+				'si_title' => $title,
+				'si_text' => $text
+			], 'SearchOracle::update' );
+
+		// Sync the index
+		// We need to specify the DB name (i.e. user/schema) here so that
+		// it can work from the installer, where
+		//     ALTER SESSION SET CURRENT_SCHEMA = ...
+		// was used.
+		$dbw->query( "CALL ctx_ddl.sync_index(" .
+			$dbw->addQuotes( $dbw->getDBname() . '.' . $dbw->tableName( 'si_text_idx', 'raw' ) ) . ")" );
+		$dbw->query( "CALL ctx_ddl.sync_index(" .
+			$dbw->addQuotes( $dbw->getDBname() . '.' . $dbw->tableName( 'si_title_idx', 'raw' ) ) . ")" );
+	}
+
+	/**
+	 * Update a search index record's title only.
+	 * Title should be pre-processed.
+	 *
+	 * @param int $id
+	 * @param string $title
+	 */
+	function updateTitle( $id, $title ) {
+		$dbw = wfGetDB( DB_MASTER );
+
+		$dbw->update( 'searchindex',
+			[ 'si_title' => $title ],
+			[ 'si_page' => $id ],
+			'SearchOracle::updateTitle',
+			[] );
+	}
+
+	public static function legalSearchChars( $type = self::CHARS_ALL ) {
+		$searchChars = parent::legalSearchChars( $type );
+		if ( $type === self::CHARS_ALL ) {
+			$searchChars = "\"" . $searchChars;
+		}
+		return $searchChars;
+	}
+}
diff --git a/www/wiki/includes/search/SearchPostgres.php b/www/wiki/includes/search/SearchPostgres.php
new file mode 100644
index 00000000..5a50b176
--- /dev/null
+++ b/www/wiki/includes/search/SearchPostgres.php
@@ -0,0 +1,192 @@
+<?php
+/**
+ * PostgreSQL search engine
+ *
+ * Copyright © 2006-2007 Greg Sabino Mullane <greg@turnstep.com>
+ * https://www.mediawiki.org/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @ingroup Search
+ */
+
+/**
+ * Search engine hook base class for Postgres
+ * @ingroup Search
+ */
+class SearchPostgres extends SearchDatabase {
+	/**
+	 * Perform a full text search query via tsearch2 and return a result set.
+	 * Currently searches a page's current title (page.page_title) and
+	 * latest revision article text (pagecontent.old_text)
+	 *
+	 * @param string $term Raw search term
+	 * @return SqlSearchResultSet
+	 */
+	function searchTitle( $term ) {
+		$q = $this->searchQuery( $term, 'titlevector', 'page_title' );
+		$olderror = error_reporting( E_ERROR );
+		$resultSet = $this->db->query( $q, 'SearchPostgres', true );
+		error_reporting( $olderror );
+		return new SqlSearchResultSet( $resultSet, $this->searchTerms );
+	}
+
+	function searchText( $term ) {
+		$q = $this->searchQuery( $term, 'textvector', 'old_text' );
+		$olderror = error_reporting( E_ERROR );
+		$resultSet = $this->db->query( $q, 'SearchPostgres', true );
+		error_reporting( $olderror );
+		return new SqlSearchResultSet( $resultSet, $this->searchTerms );
+	}
+
+	/**
+	 * Transform the user's search string into a better form for tsearch2
+	 * Returns an SQL fragment consisting of quoted text to search for.
+	 *
+	 * @param string $term
+	 *
+	 * @return string
+	 */
+	function parseQuery( $term ) {
+		wfDebug( "parseQuery received: $term \n" );
+
+		# # No backslashes allowed
+		$term = preg_replace( '/\\\/', '', $term );
+
+		# # Collapse parens into nearby words:
+		$term = preg_replace( '/\s*\(\s*/', ' (', $term );
+		$term = preg_replace( '/\s*\)\s*/', ') ', $term );
+
+		# # Treat colons as word separators:
+		$term = preg_replace( '/:/', ' ', $term );
+
+		$searchstring = '';
+		$m = [];
+		if ( preg_match_all( '/([-!]?)(\S+)\s*/', $term, $m, PREG_SET_ORDER ) ) {
+			foreach ( $m as $terms ) {
+				if ( strlen( $terms[1] ) ) {
+					$searchstring .= ' & !';
+				}
+				if ( strtolower( $terms[2] ) === 'and' ) {
+					$searchstring .= ' & ';
+				} elseif ( strtolower( $terms[2] ) === 'or' || $terms[2] === '|' ) {
+					$searchstring .= ' | ';
+				} elseif ( strtolower( $terms[2] ) === 'not' ) {
+					$searchstring .= ' & !';
+				} else {
+					$searchstring .= " & $terms[2]";
+				}
+			}
+		}
+
+		# # Strip out leading junk
+		$searchstring = preg_replace( '/^[\s\&\|]+/', '', $searchstring );
+
+		# # Remove any doubled-up operators
+		$searchstring = preg_replace( '/([\!\&\|]) +(?:[\&\|] +)+/', "$1 ", $searchstring );
+
+		# # Remove any non-spaced operators (e.g. "Zounds!")
+		$searchstring = preg_replace( '/([^ ])[\!\&\|]/', "$1", $searchstring );
+
+		# # Remove any trailing whitespace or operators
+		$searchstring = preg_replace( '/[\s\!\&\|]+$/', '', $searchstring );
+
+		# # Remove unnecessary quotes around everything
+		$searchstring = preg_replace( '/^[\'"](.*)[\'"]$/', "$1", $searchstring );
+
+		# # Quote the whole thing
+		$searchstring = $this->db->addQuotes( $searchstring );
+
+		wfDebug( "parseQuery returned: $searchstring \n" );
+
+		return $searchstring;
+	}
+
+	/**
+	 * Construct the full SQL query to do the search.
+	 * @param string $term
+	 * @param string $fulltext
+	 * @param string $colname
+	 * @return string
+	 */
+	function searchQuery( $term, $fulltext, $colname ) {
+		# Get the SQL fragment for the given term
+		$searchstring = $this->parseQuery( $term );
+
+		# # We need a separate query here so gin does not complain about empty searches
+		$sql = "SELECT to_tsquery($searchstring)";
+		$res = $this->db->query( $sql );
+		if ( !$res ) {
+			# # TODO: Better output (example to catch: one 'two)
+			die( "Sorry, that was not a valid search string. Please go back and try again" );
+		}
+		$top = $res->fetchRow()[0];
+
+		$this->searchTerms = [];
+		if ( $top === "" ) { # # e.g. if only stopwords are used XXX return something better
+			$query = "SELECT page_id, page_namespace, page_title, 0 AS score " .
+				"FROM page p, revision r, pagecontent c WHERE p.page_latest = r.rev_id " .
+				"AND r.rev_text_id = c.old_id AND 1=0";
+		} else {
+			$m = [];
+			if ( preg_match_all( "/'([^']+)'/", $top, $m, PREG_SET_ORDER ) ) {
+				foreach ( $m as $terms ) {
+					$this->searchTerms[$terms[1]] = $terms[1];
+				}
+			}
+
+			$query = "SELECT page_id, page_namespace, page_title, " .
+				"ts_rank($fulltext, to_tsquery($searchstring), 5) AS score " .
+				"FROM page p, revision r, pagecontent c WHERE p.page_latest = r.rev_id " .
+				"AND r.rev_text_id = c.old_id AND $fulltext @@ to_tsquery($searchstring)";
+		}
+
+		# # Namespaces - defaults to 0
+		if ( !is_null( $this->namespaces ) ) { // null -> search all
+			if ( count( $this->namespaces ) < 1 ) {
+				$query .= ' AND page_namespace = 0';
+			} else {
+				$namespaces = $this->db->makeList( $this->namespaces );
+				$query .= " AND page_namespace IN ($namespaces)";
+			}
+		}
+
+		$query .= " ORDER BY score DESC, page_id DESC";
+
+		$query .= $this->db->limitResult( '', $this->limit, $this->offset );
+
+		wfDebug( "searchQuery returned: $query \n" );
+
+		return $query;
+	}
+
+	# # Most of the work of these two functions are done automatically via triggers
+
+	function update( $pageid, $title, $text ) {
+		# # We don't want to index older revisions
+		$sql = "UPDATE pagecontent SET textvector = NULL WHERE textvector IS NOT NULL and old_id IN " .
+				"(SELECT DISTINCT rev_text_id FROM revision WHERE rev_page = " . intval( $pageid ) .
+				" ORDER BY rev_text_id DESC OFFSET 1)";
+		$this->db->query( $sql );
+		return true;
+	}
+
+	function updateTitle( $id, $title ) {
+		return true;
+	}
+
+}
diff --git a/www/wiki/includes/search/SearchResult.php b/www/wiki/includes/search/SearchResult.php
new file mode 100644
index 00000000..dc294c32
--- /dev/null
+++ b/www/wiki/includes/search/SearchResult.php
@@ -0,0 +1,283 @@
+<?php
+/**
+ * Search engine result
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @ingroup Search
+ */
+
+use MediaWiki\MediaWikiServices;
+
+/**
+ * @todo FIXME: This class is horribly factored. It would probably be better to
+ * have a useful base class to which you pass some standard information, then
+ * let the fancy self-highlighters extend that.
+ * @ingroup Search
+ */
+class SearchResult {
+
+	/**
+	 * @var Revision
+	 */
+	protected $mRevision = null;
+
+	/**
+	 * @var File
+	 */
+	protected $mImage = null;
+
+	/**
+	 * @var Title
+	 */
+	protected $mTitle;
+
+	/**
+	 * @var string
+	 */
+	protected $mText;
+
+	/**
+	 * @var SearchEngine
+	 */
+	protected $searchEngine;
+
+	/**
+	 * A set of extension data.
+	 * @var array[]
+	 */
+	protected $extensionData;
+
+	/**
+	 * Return a new SearchResult and initializes it with a title.
+	 *
+	 * @param Title $title
+	 * @param SearchResultSet $parentSet
+	 * @return SearchResult
+	 */
+	public static function newFromTitle( $title, SearchResultSet $parentSet = null ) {
+		$result = new static();
+		$result->initFromTitle( $title );
+		if ( $parentSet ) {
+			$parentSet->augmentResult( $result );
+		}
+		return $result;
+	}
+
+	/**
+	 * Initialize from a Title and if possible initializes a corresponding
+	 * Revision and File.
+	 *
+	 * @param Title $title
+	 */
+	protected function initFromTitle( $title ) {
+		$this->mTitle = $title;
+		if ( !is_null( $this->mTitle ) ) {
+			$id = false;
+			Hooks::run( 'SearchResultInitFromTitle', [ $title, &$id ] );
+			$this->mRevision = Revision::newFromTitle(
+				$this->mTitle, $id, Revision::READ_NORMAL );
+			if ( $this->mTitle->getNamespace() === NS_FILE ) {
+				$this->mImage = wfFindFile( $this->mTitle );
+			}
+		}
+		$this->searchEngine = MediaWikiServices::getInstance()->newSearchEngine();
+	}
+
+	/**
+	 * Check if this is result points to an invalid title
+	 *
+	 * @return bool
+	 */
+	function isBrokenTitle() {
+		return is_null( $this->mTitle );
+	}
+
+	/**
+	 * Check if target page is missing, happens when index is out of date
+	 *
+	 * @return bool
+	 */
+	function isMissingRevision() {
+		return !$this->mRevision && !$this->mImage;
+	}
+
+	/**
+	 * @return Title
+	 */
+	function getTitle() {
+		return $this->mTitle;
+	}
+
+	/**
+	 * Get the file for this page, if one exists
+	 * @return File|null
+	 */
+	function getFile() {
+		return $this->mImage;
+	}
+
+	/**
+	 * Lazy initialization of article text from DB
+	 */
+	protected function initText() {
+		if ( !isset( $this->mText ) ) {
+			if ( $this->mRevision != null ) {
+				$this->mText = $this->searchEngine->getTextFromContent(
+						$this->mTitle, $this->mRevision->getContent() );
+			} else { // TODO: can we fetch raw wikitext for commons images?
+				$this->mText = '';
+			}
+		}
+	}
+
+	/**
+	 * @param array $terms Terms to highlight
+	 * @return string Highlighted text snippet, null (and not '') if not supported
+	 */
+	function getTextSnippet( $terms ) {
+		global $wgAdvancedSearchHighlighting;
+		$this->initText();
+
+		// TODO: make highliter take a content object. Make ContentHandler a factory for SearchHighliter.
+		list( $contextlines, $contextchars ) = $this->searchEngine->userHighlightPrefs();
+
+		$h = new SearchHighlighter();
+		if ( count( $terms ) > 0 ) {
+			if ( $wgAdvancedSearchHighlighting ) {
+				return $h->highlightText( $this->mText, $terms, $contextlines, $contextchars );
+			} else {
+				return $h->highlightSimple( $this->mText, $terms, $contextlines, $contextchars );
+			}
+		} else {
+			return $h->highlightNone( $this->mText, $contextlines, $contextchars );
+		}
+	}
+
+	/**
+	 * @return string Highlighted title, '' if not supported
+	 */
+	function getTitleSnippet() {
+		return '';
+	}
+
+	/**
+	 * @return string Highlighted redirect name (redirect to this page), '' if none or not supported
+	 */
+	function getRedirectSnippet() {
+		return '';
+	}
+
+	/**
+	 * @return Title|null Title object for the redirect to this page, null if none or not supported
+	 */
+	function getRedirectTitle() {
+		return null;
+	}
+
+	/**
+	 * @return string Highlighted relevant section name, null if none or not supported
+	 */
+	function getSectionSnippet() {
+		return '';
+	}
+
+	/**
+	 * @return Title|null Title object (pagename+fragment) for the section,
+	 *  null if none or not supported
+	 */
+	function getSectionTitle() {
+		return null;
+	}
+
+	/**
+	 * @return string Highlighted relevant category name or '' if none or not supported
+	 */
+	public function getCategorySnippet() {
+		return '';
+	}
+
+	/**
+	 * @return string Timestamp
+	 */
+	function getTimestamp() {
+		if ( $this->mRevision ) {
+			return $this->mRevision->getTimestamp();
+		} elseif ( $this->mImage ) {
+			return $this->mImage->getTimestamp();
+		}
+		return '';
+	}
+
+	/**
+	 * @return int Number of words
+	 */
+	function getWordCount() {
+		$this->initText();
+		return str_word_count( $this->mText );
+	}
+
+	/**
+	 * @return int Size in bytes
+	 */
+	function getByteSize() {
+		$this->initText();
+		return strlen( $this->mText );
+	}
+
+	/**
+	 * @return string Interwiki prefix of the title (return iw even if title is broken)
+	 */
+	function getInterwikiPrefix() {
+		return '';
+	}
+
+	/**
+	 * @return string Interwiki namespace of the title (since we likely can't resolve it locally)
+	 */
+	function getInterwikiNamespaceText() {
+		return '';
+	}
+
+	/**
+	 * Did this match file contents (eg: PDF/DJVU)?
+	 * @return bool
+	 */
+	function isFileMatch() {
+		return false;
+	}
+
+	/**
+	 * Get the extension data as:
+	 * augmentor name => data
+	 * @return array[]
+	 */
+	public function getExtensionData() {
+		return $this->extensionData;
+	}
+
+	/**
+	 * Set extension data for this result.
+	 * The data is:
+	 * augmentor name => data
+	 * @param array[] $extensionData
+	 */
+	public function setExtensionData( array $extensionData ) {
+		$this->extensionData = $extensionData;
+	}
+
+}
diff --git a/www/wiki/includes/search/SearchResultSet.php b/www/wiki/includes/search/SearchResultSet.php
new file mode 100644
index 00000000..f25c7283
--- /dev/null
+++ b/www/wiki/includes/search/SearchResultSet.php
@@ -0,0 +1,279 @@
+<?php
+/**
+ * Search result sets
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @ingroup Search
+ */
+
+/**
+ * @ingroup Search
+ */
+class SearchResultSet {
+
+	/**
+	 * Types of interwiki results
+	 */
+	/**
+	 * Results that are displayed only together with existing main wiki results
+	 * @var int
+	 */
+	const SECONDARY_RESULTS = 0;
+	/**
+	 * Results that can displayed even if no existing main wiki results exist
+	 * @var int
+	 */
+	const INLINE_RESULTS = 1;
+
+	protected $containedSyntax = false;
+
+	/**
+	 * Cache of titles.
+	 * Lists titles of the result set, in the same order as results.
+	 * @var Title[]
+	 */
+	private $titles;
+
+	/**
+	 * Cache of results - serialization of the result iterator
+	 * as an array.
+	 * @var SearchResult[]
+	 */
+	private $results;
+
+	/**
+	 * Set of result's extra data, indexed per result id
+	 * and then per data item name.
+	 * The structure is:
+	 * PAGE_ID => [ augmentor name => data, ... ]
+	 * @var array[]
+	 */
+	protected $extraData = [];
+
+	public function __construct( $containedSyntax = false ) {
+		$this->containedSyntax = $containedSyntax;
+	}
+
+	/**
+	 * Fetch an array of regular expression fragments for matching
+	 * the search terms as parsed by this engine in a text extract.
+	 * STUB
+	 *
+	 * @return array
+	 */
+	function termMatches() {
+		return [];
+	}
+
+	function numRows() {
+		return 0;
+	}
+
+	/**
+	 * Some search modes return a total hit count for the query
+	 * in the entire article database. This may include pages
+	 * in namespaces that would not be matched on the given
+	 * settings.
+	 *
+	 * Return null if no total hits number is supported.
+	 *
+	 * @return int
+	 */
+	function getTotalHits() {
+		return null;
+	}
+
+	/**
+	 * Some search modes will run an alternative query that it thinks gives
+	 * a better result than the provided search. Returns true if this has
+	 * occured.
+	 *
+	 * @return bool
+	 */
+	function hasRewrittenQuery() {
+		return false;
+	}
+
+	/**
+	 * @return string|null The search the query was internally rewritten to,
+	 *  or null when the result of the original query was returned.
+	 */
+	function getQueryAfterRewrite() {
+		return null;
+	}
+
+	/**
+	 * @return string|null Same as self::getQueryAfterRewrite(), but in HTML
+	 *  and with changes highlighted. Null when the query was not rewritten.
+	 */
+	function getQueryAfterRewriteSnippet() {
+		return null;
+	}
+
+	/**
+	 * Some search modes return a suggested alternate term if there are
+	 * no exact hits. Returns true if there is one on this set.
+	 *
+	 * @return bool
+	 */
+	function hasSuggestion() {
+		return false;
+	}
+
+	/**
+	 * @return string|null Suggested query, null if none
+	 */
+	function getSuggestionQuery() {
+		return null;
+	}
+
+	/**
+	 * @return string HTML highlighted suggested query, '' if none
+	 */
+	function getSuggestionSnippet() {
+		return '';
+	}
+
+	/**
+	 * Return a result set of hits on other (multiple) wikis associated with this one
+	 *
+	 * @param int $type
+	 * @return SearchResultSet[]
+	 */
+	function getInterwikiResults( $type = self::SECONDARY_RESULTS ) {
+		return null;
+	}
+
+	/**
+	 * Check if there are results on other wikis
+	 *
+	 * @param int $type
+	 * @return bool
+	 */
+	function hasInterwikiResults( $type = self::SECONDARY_RESULTS ) {
+		return false;
+	}
+
+	/**
+	 * Fetches next search result, or false.
+	 * STUB
+	 * FIXME: refactor as iterator, so we could use nicer interfaces.
+	 * @return SearchResult|false
+	 */
+	function next() {
+		return false;
+	}
+
+	/**
+	 * Rewind result set back to beginning
+	 */
+	function rewind() {
+	}
+
+	/**
+	 * Frees the result set, if applicable.
+	 */
+	function free() {
+		// ...
+	}
+
+	/**
+	 * Did the search contain search syntax?  If so, Special:Search won't offer
+	 * the user a link to a create a page named by the search string because the
+	 * name would contain the search syntax.
+	 * @return bool
+	 */
+	public function searchContainedSyntax() {
+		return $this->containedSyntax;
+	}
+
+	/**
+	 * Extract all the results in the result set as array.
+	 * @return SearchResult[]
+	 */
+	public function extractResults() {
+		if ( is_null( $this->results ) ) {
+			$this->results = [];
+			if ( $this->numRows() == 0 ) {
+				// Don't bother if we've got empty result
+				return $this->results;
+			}
+			$this->rewind();
+			while ( ( $result = $this->next() ) != false ) {
+				$this->results[] = $result;
+			}
+			$this->rewind();
+		}
+		return $this->results;
+	}
+
+	/**
+	 * Extract all the titles in the result set.
+	 * @return Title[]
+	 */
+	public function extractTitles() {
+		if ( is_null( $this->titles ) ) {
+			if ( $this->numRows() == 0 ) {
+				// Don't bother if we've got empty result
+				$this->titles = [];
+			} else {
+				$this->titles = array_map(
+					function ( SearchResult $result ) {
+						return $result->getTitle();
+					},
+					$this->extractResults() );
+			}
+		}
+		return $this->titles;
+	}
+
+	/**
+	 * Sets augmented data for result set.
+	 * @param string $name Extra data item name
+	 * @param array[] $data Extra data as PAGEID => data
+	 */
+	public function setAugmentedData( $name, $data ) {
+		foreach ( $data as $id => $resultData ) {
+			$this->extraData[$id][$name] = $resultData;
+		}
+	}
+
+	/**
+	 * Returns extra data for specific result and store it in SearchResult object.
+	 * @param SearchResult $result
+	 * @return array|null List of data as name => value or null if none present.
+	 */
+	public function augmentResult( SearchResult $result ) {
+		$id = $result->getTitle()->getArticleID();
+		if ( !$id || !isset( $this->extraData[$id] ) ) {
+			return null;
+		}
+		$result->setExtensionData( $this->extraData[$id] );
+		return $this->extraData[$id];
+	}
+
+	/**
+	 * @return int|null The offset the current page starts at. Typically
+	 *  this should be null to allow the UI to decide on its own, but in
+	 *  special cases like interleaved AB tests specifying explicitly is
+	 *  necessary.
+	 */
+	public function getOffset() {
+		return null;
+	}
+}
diff --git a/www/wiki/includes/search/SearchSqlite.php b/www/wiki/includes/search/SearchSqlite.php
new file mode 100644
index 00000000..af29212b
--- /dev/null
+++ b/www/wiki/includes/search/SearchSqlite.php
@@ -0,0 +1,312 @@
+<?php
+/**
+ * SQLite search backend, based upon SearchMysql
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @ingroup Search
+ */
+
+/**
+ * Search engine hook for SQLite
+ * @ingroup Search
+ */
+class SearchSqlite extends SearchDatabase {
+	/**
+	 * Whether fulltext search is supported by current schema
+	 * @return bool
+	 */
+	function fulltextSearchSupported() {
+		return $this->db->checkForEnabledSearch();
+	}
+
+	/**
+	 * Parse the user's query and transform it into an SQL fragment which will
+	 * become part of a WHERE clause
+	 *
+	 * @param string $filteredText
+	 * @param bool $fulltext
+	 * @return string
+	 */
+	function parseQuery( $filteredText, $fulltext ) {
+		global $wgContLang;
+		$lc = $this->legalSearchChars( self::CHARS_NO_SYNTAX ); // Minus syntax chars (" and *)
+		$searchon = '';
+		$this->searchTerms = [];
+
+		$m = [];
+		if ( preg_match_all( '/([-+<>~]?)(([' . $lc . ']+)(\*?)|"[^"]*")/',
+				$filteredText, $m, PREG_SET_ORDER ) ) {
+			foreach ( $m as $bits ) {
+				Wikimedia\suppressWarnings();
+				list( /* all */, $modifier, $term, $nonQuoted, $wildcard ) = $bits;
+				Wikimedia\restoreWarnings();
+
+				if ( $nonQuoted != '' ) {
+					$term = $nonQuoted;
+					$quote = '';
+				} else {
+					$term = str_replace( '"', '', $term );
+					$quote = '"';
+				}
+
+				if ( $searchon !== '' ) {
+					$searchon .= ' ';
+				}
+
+				// Some languages such as Serbian store the input form in the search index,
+				// so we may need to search for matches in multiple writing system variants.
+				$convertedVariants = $wgContLang->autoConvertToAllVariants( $term );
+				if ( is_array( $convertedVariants ) ) {
+					$variants = array_unique( array_values( $convertedVariants ) );
+				} else {
+					$variants = [ $term ];
+				}
+
+				// The low-level search index does some processing on input to work
+				// around problems with minimum lengths and encoding in MySQL's
+				// fulltext engine.
+				// For Chinese this also inserts spaces between adjacent Han characters.
+				$strippedVariants = array_map(
+					[ $wgContLang, 'normalizeForSearch' ],
+					$variants );
+
+				// Some languages such as Chinese force all variants to a canonical
+				// form when stripping to the low-level search index, so to be sure
+				// let's check our variants list for unique items after stripping.
+				$strippedVariants = array_unique( $strippedVariants );
+
+				$searchon .= $modifier;
+				if ( count( $strippedVariants ) > 1 ) {
+					$searchon .= '(';
+				}
+				foreach ( $strippedVariants as $stripped ) {
+					if ( $nonQuoted && strpos( $stripped, ' ' ) !== false ) {
+						// Hack for Chinese: we need to toss in quotes for
+						// multiple-character phrases since normalizeForSearch()
+						// added spaces between them to make word breaks.
+						$stripped = '"' . trim( $stripped ) . '"';
+					}
+					$searchon .= "$quote$stripped$quote$wildcard ";
+				}
+				if ( count( $strippedVariants ) > 1 ) {
+					$searchon .= ')';
+				}
+
+				// Match individual terms or quoted phrase in result highlighting...
+				// Note that variants will be introduced in a later stage for highlighting!
+				$regexp = $this->regexTerm( $term, $wildcard );
+				$this->searchTerms[] = $regexp;
+			}
+
+		} else {
+			wfDebug( __METHOD__ . ": Can't understand search query '{$filteredText}'\n" );
+		}
+
+		$searchon = $this->db->addQuotes( $searchon );
+		$field = $this->getIndexField( $fulltext );
+		return " $field MATCH $searchon ";
+	}
+
+	function regexTerm( $string, $wildcard ) {
+		global $wgContLang;
+
+		$regex = preg_quote( $string, '/' );
+		if ( $wgContLang->hasWordBreaks() ) {
+			if ( $wildcard ) {
+				// Don't cut off the final bit!
+				$regex = "\b$regex";
+			} else {
+				$regex = "\b$regex\b";
+			}
+		} else {
+			// For Chinese, words may legitimately abut other words in the text literal.
+			// Don't add \b boundary checks... note this could cause false positives
+			// for latin chars.
+		}
+		return $regex;
+	}
+
+	public static function legalSearchChars( $type = self::CHARS_ALL ) {
+		$searchChars = parent::legalSearchChars( $type );
+		if ( $type === self::CHARS_ALL ) {
+			// " for phrase, * for wildcard
+			$searchChars = "\"*" . $searchChars;
+		}
+		return $searchChars;
+	}
+
+	/**
+	 * Perform a full text search query and return a result set.
+	 *
+	 * @param string $term Raw search term
+	 * @return SqlSearchResultSet
+	 */
+	function searchText( $term ) {
+		return $this->searchInternal( $term, true );
+	}
+
+	/**
+	 * Perform a title-only search query and return a result set.
+	 *
+	 * @param string $term Raw search term
+	 * @return SqlSearchResultSet
+	 */
+	function searchTitle( $term ) {
+		return $this->searchInternal( $term, false );
+	}
+
+	protected function searchInternal( $term, $fulltext ) {
+		global $wgContLang;
+
+		if ( !$this->fulltextSearchSupported() ) {
+			return null;
+		}
+
+		$filteredTerm = $this->filter( $wgContLang->lc( $term ) );
+		$resultSet = $this->db->query( $this->getQuery( $filteredTerm, $fulltext ) );
+
+		$total = null;
+		$totalResult = $this->db->query( $this->getCountQuery( $filteredTerm, $fulltext ) );
+		$row = $totalResult->fetchObject();
+		if ( $row ) {
+			$total = intval( $row->c );
+		}
+		$totalResult->free();
+
+		return new SqlSearchResultSet( $resultSet, $this->searchTerms, $total );
+	}
+
+	/**
+	 * Return a partial WHERE clause to limit the search to the given namespaces
+	 * @return string
+	 */
+	function queryNamespaces() {
+		if ( is_null( $this->namespaces ) ) {
+			return '';  # search all
+		}
+		if ( !count( $this->namespaces ) ) {
+			$namespaces = '0';
+		} else {
+			$namespaces = $this->db->makeList( $this->namespaces );
+		}
+		return 'AND page_namespace IN (' . $namespaces . ')';
+	}
+
+	/**
+	 * Returns a query with limit for number of results set.
+	 * @param string $sql
+	 * @return string
+	 */
+	function limitResult( $sql ) {
+		return $this->db->limitResult( $sql, $this->limit, $this->offset );
+	}
+
+	/**
+	 * Construct the full SQL query to do the search.
+	 * The guts shoulds be constructed in queryMain()
+	 * @param string $filteredTerm
+	 * @param bool $fulltext
+	 * @return string
+	 */
+	function getQuery( $filteredTerm, $fulltext ) {
+		return $this->limitResult(
+			$this->queryMain( $filteredTerm, $fulltext ) . ' ' .
+			$this->queryNamespaces()
+		);
+	}
+
+	/**
+	 * Picks which field to index on, depending on what type of query.
+	 * @param bool $fulltext
+	 * @return string
+	 */
+	function getIndexField( $fulltext ) {
+		return $fulltext ? 'si_text' : 'si_title';
+	}
+
+	/**
+	 * Get the base part of the search query.
+	 *
+	 * @param string $filteredTerm
+	 * @param bool $fulltext
+	 * @return string
+	 */
+	function queryMain( $filteredTerm, $fulltext ) {
+		$match = $this->parseQuery( $filteredTerm, $fulltext );
+		$page = $this->db->tableName( 'page' );
+		$searchindex = $this->db->tableName( 'searchindex' );
+		return "SELECT $searchindex.rowid, page_namespace, page_title " .
+			"FROM $page,$searchindex " .
+			"WHERE page_id=$searchindex.rowid AND $match";
+	}
+
+	function getCountQuery( $filteredTerm, $fulltext ) {
+		$match = $this->parseQuery( $filteredTerm, $fulltext );
+		$page = $this->db->tableName( 'page' );
+		$searchindex = $this->db->tableName( 'searchindex' );
+		return "SELECT COUNT(*) AS c " .
+			"FROM $page,$searchindex " .
+			"WHERE page_id=$searchindex.rowid AND $match " .
+			$this->queryNamespaces();
+	}
+
+	/**
+	 * Create or update the search index record for the given page.
+	 * Title and text should be pre-processed.
+	 *
+	 * @param int $id
+	 * @param string $title
+	 * @param string $text
+	 */
+	function update( $id, $title, $text ) {
+		if ( !$this->fulltextSearchSupported() ) {
+			return;
+		}
+		// @todo find a method to do it in a single request,
+		// couldn't do it so far due to typelessness of FTS3 tables.
+		$dbw = wfGetDB( DB_MASTER );
+
+		$dbw->delete( 'searchindex', [ 'rowid' => $id ], __METHOD__ );
+
+		$dbw->insert( 'searchindex',
+			[
+				'rowid' => $id,
+				'si_title' => $title,
+				'si_text' => $text
+			], __METHOD__ );
+	}
+
+	/**
+	 * Update a search index record's title only.
+	 * Title should be pre-processed.
+	 *
+	 * @param int $id
+	 * @param string $title
+	 */
+	function updateTitle( $id, $title ) {
+		if ( !$this->fulltextSearchSupported() ) {
+			return;
+		}
+		$dbw = wfGetDB( DB_MASTER );
+
+		$dbw->update( 'searchindex',
+			[ 'si_title' => $title ],
+			[ 'rowid' => $id ],
+			__METHOD__ );
+	}
+}
diff --git a/www/wiki/includes/search/SearchSuggestion.php b/www/wiki/includes/search/SearchSuggestion.php
new file mode 100644
index 00000000..7f433db4
--- /dev/null
+++ b/www/wiki/includes/search/SearchSuggestion.php
@@ -0,0 +1,185 @@
+<?php
+
+/**
+ * Search suggestion
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+/**
+ * A search suggestion
+ */
+class SearchSuggestion {
+	/**
+	 * @var string the suggestion
+	 */
+	private $text;
+
+	/**
+	 * @var string the suggestion URL
+	 */
+	private $url;
+
+	/**
+	 * @var Title|null the suggested title
+	 */
+	private $suggestedTitle;
+
+	/**
+	 * NOTE: even if suggestedTitle is a redirect suggestedTitleID
+	 * is the ID of the target page.
+	 * @var int|null the suggested title ID
+	 */
+	private $suggestedTitleID;
+
+	/**
+	 * @var float|null The suggestion score
+	 */
+	private $score;
+
+	/**
+	 * Construct a new suggestion
+	 * @param float $score the suggestion score
+	 * @param string|null $text the suggestion text
+	 * @param Title|null $suggestedTitle the suggested title
+	 * @param int|null $suggestedTitleID the suggested title ID
+	 */
+	public function __construct( $score, $text = null, Title $suggestedTitle = null,
+			$suggestedTitleID = null ) {
+		$this->score = $score;
+		$this->text = $text;
+		if ( $suggestedTitle ) {
+			$this->setSuggestedTitle( $suggestedTitle );
+		}
+		$this->suggestedTitleID = $suggestedTitleID;
+	}
+
+	/**
+	 * The suggestion text
+	 * @return string
+	 */
+	public function getText() {
+		return $this->text;
+	}
+
+	/**
+	 * Set the suggestion text.
+	 * @param string $text
+	 * @param bool $setTitle Should we also update the title?
+	 */
+	public function setText( $text, $setTitle = true ) {
+		$this->text = $text;
+		if ( $setTitle && $text !== '' && $text !== null ) {
+			$this->setSuggestedTitle( Title::makeTitle( 0, $text ) );
+		}
+	}
+
+	/**
+	 * Title object in the case this suggestion is based on a title.
+	 * May return null if the suggestion is not a Title.
+	 * @return Title|null
+	 */
+	public function getSuggestedTitle() {
+		return $this->suggestedTitle;
+	}
+
+	/**
+	 * Set the suggested title
+	 * @param Title|null $title
+	 */
+	public function setSuggestedTitle( Title $title = null ) {
+		$this->suggestedTitle = $title;
+		if ( $title !== null ) {
+			$this->url = wfExpandUrl( $title->getFullURL(), PROTO_CURRENT );
+		}
+	}
+
+	/**
+	 * Title ID in the case this suggestion is based on a title.
+	 * May return null if the suggestion is not a Title.
+	 * @return int|null
+	 */
+	public function getSuggestedTitleID() {
+		return $this->suggestedTitleID;
+	}
+
+	/**
+	 * Set the suggested title ID
+	 * @param int|null $suggestedTitleID
+	 */
+	public function setSuggestedTitleID( $suggestedTitleID = null ) {
+		$this->suggestedTitleID = $suggestedTitleID;
+	}
+
+	/**
+	 * Suggestion score
+	 * @return float Suggestion score
+	 */
+	public function getScore() {
+		return $this->score;
+	}
+
+	/**
+	 * Set the suggestion score
+	 * @param float $score
+	 */
+	public function setScore( $score ) {
+		$this->score = $score;
+	}
+
+	/**
+	 * Suggestion URL, can be the link to the Title or maybe in the
+	 * future a link to the search results for this search suggestion.
+	 * @return string Suggestion URL
+	 */
+	public function getURL() {
+		return $this->url;
+	}
+
+	/**
+	 * Set the suggestion URL
+	 * @param string $url
+	 */
+	public function setURL( $url ) {
+		$this->url = $url;
+	}
+
+	/**
+	 * Create suggestion from Title
+	 * @param float $score Suggestions score
+	 * @param Title $title
+	 * @return SearchSuggestion
+	 */
+	public static function fromTitle( $score, Title $title ) {
+		return new self( $score, $title->getPrefixedText(), $title, $title->getArticleID() );
+	}
+
+	/**
+	 * Create suggestion from text
+	 * Will also create a title if text if not empty.
+	 * @param float $score Suggestions score
+	 * @param string $text
+	 * @return SearchSuggestion
+	 */
+	public static function fromText( $score, $text ) {
+		$suggestion = new self( $score, $text );
+		if ( $text ) {
+			$suggestion->setSuggestedTitle( Title::makeTitle( 0, $text ) );
+		}
+		return $suggestion;
+	}
+
+}
diff --git a/www/wiki/includes/search/SearchSuggestionSet.php b/www/wiki/includes/search/SearchSuggestionSet.php
new file mode 100644
index 00000000..aced5e18
--- /dev/null
+++ b/www/wiki/includes/search/SearchSuggestionSet.php
@@ -0,0 +1,212 @@
+<?php
+
+/**
+ * Search suggestion sets
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+/**
+ * A set of search suggestions.
+ * The set is always ordered by score, with the best match first.
+ */
+class SearchSuggestionSet {
+	/**
+	 * @var SearchSuggestion[]
+	 */
+	private $suggestions = [];
+
+	/**
+	 *
+	 * @var array
+	 */
+	private $pageMap = [];
+
+	/**
+	 * Builds a new set of suggestions.
+	 *
+	 * NOTE: the array should be sorted by score (higher is better),
+	 * in descending order.
+	 * SearchSuggestionSet will not try to re-order this input array.
+	 * Providing an unsorted input array is a mistake and will lead to
+	 * unexpected behaviors.
+	 *
+	 * @param SearchSuggestion[] $suggestions (must be sorted by score)
+	 */
+	public function __construct( array $suggestions ) {
+		foreach ( $suggestions as $suggestion ) {
+			$pageID = $suggestion->getSuggestedTitleID();
+			if ( $pageID && empty( $this->pageMap[$pageID] ) ) {
+				$this->pageMap[$pageID] = true;
+			}
+			$this->suggestions[] = $suggestion;
+		}
+	}
+
+	/**
+	 * Get the list of suggestions.
+	 * @return SearchSuggestion[]
+	 */
+	public function getSuggestions() {
+		return $this->suggestions;
+	}
+
+	/**
+	 * Call array_map on the suggestions array
+	 * @param callback $callback
+	 * @return array
+	 */
+	public function map( $callback ) {
+		return array_map( $callback, $this->suggestions );
+	}
+
+	/**
+	 * Add a new suggestion at the end.
+	 * If the score of the new suggestion is greater than the worst one,
+	 * the new suggestion score will be updated (worst - 1).
+	 *
+	 * @param SearchSuggestion $suggestion
+	 */
+	public function append( SearchSuggestion $suggestion ) {
+		$pageID = $suggestion->getSuggestedTitleID();
+		if ( $pageID && isset( $this->pageMap[$pageID] ) ) {
+			return;
+		}
+		if ( $this->getSize() > 0 && $suggestion->getScore() >= $this->getWorstScore() ) {
+			$suggestion->setScore( $this->getWorstScore() - 1 );
+		}
+		$this->suggestions[] = $suggestion;
+		if ( $pageID ) {
+			$this->pageMap[$pageID] = true;
+		}
+	}
+
+	/**
+	 * Add suggestion set to the end of the current one.
+	 * @param SearchSuggestionSet $set
+	 */
+	public function appendAll( SearchSuggestionSet $set ) {
+		foreach ( $set->getSuggestions() as $sugg ) {
+			$this->append( $sugg );
+		}
+	}
+
+	/**
+	 * Move the suggestion at index $key to the first position
+	 * @param string $key
+	 */
+	public function rescore( $key ) {
+		$removed = array_splice( $this->suggestions, $key, 1 );
+		unset( $this->pageMap[$removed[0]->getSuggestedTitleID()] );
+		$this->prepend( $removed[0] );
+	}
+
+	/**
+	 * Add a new suggestion at the top. If the new suggestion score
+	 * is lower than the best one its score will be updated (best + 1)
+	 * @param SearchSuggestion $suggestion
+	 */
+	public function prepend( SearchSuggestion $suggestion ) {
+		$pageID = $suggestion->getSuggestedTitleID();
+		if ( $pageID && isset( $this->pageMap[$pageID] ) ) {
+			return;
+		}
+		if ( $this->getSize() > 0 && $suggestion->getScore() <= $this->getBestScore() ) {
+			$suggestion->setScore( $this->getBestScore() + 1 );
+		}
+		array_unshift( $this->suggestions,  $suggestion );
+		if ( $pageID ) {
+			$this->pageMap[$pageID] = true;
+		}
+	}
+
+	/**
+	 * @return float the best score in this suggestion set
+	 */
+	public function getBestScore() {
+		if ( empty( $this->suggestions ) ) {
+			return 0;
+		}
+		return $this->suggestions[0]->getScore();
+	}
+
+	/**
+	 * @return float the worst score in this set
+	 */
+	public function getWorstScore() {
+		if ( empty( $this->suggestions ) ) {
+			return 0;
+		}
+		return end( $this->suggestions )->getScore();
+	}
+
+	/**
+	 * @return int the number of suggestion in this set
+	 */
+	public function getSize() {
+		return count( $this->suggestions );
+	}
+
+	/**
+	 * Remove any extra elements in the suggestions set
+	 * @param int $limit the max size of this set.
+	 */
+	public function shrink( $limit ) {
+		if ( count( $this->suggestions ) > $limit ) {
+			$this->suggestions = array_slice( $this->suggestions, 0, $limit );
+		}
+	}
+
+	/**
+	 * Builds a new set of suggestion based on a title array.
+	 * Useful when using a backend that supports only Titles.
+	 *
+	 * NOTE: Suggestion scores will be generated.
+	 *
+	 * @param Title[] $titles
+	 * @return SearchSuggestionSet
+	 */
+	public static function fromTitles( array $titles ) {
+		$score = count( $titles );
+		$suggestions = array_map( function ( $title ) use ( &$score ) {
+			return SearchSuggestion::fromTitle( $score--, $title );
+		}, $titles );
+		return new SearchSuggestionSet( $suggestions );
+	}
+
+	/**
+	 * Builds a new set of suggestion based on a string array.
+	 *
+	 * NOTE: Suggestion scores will be generated.
+	 *
+	 * @param string[] $titles
+	 * @return SearchSuggestionSet
+	 */
+	public static function fromStrings( array $titles ) {
+		$score = count( $titles );
+		$suggestions = array_map( function ( $title ) use ( &$score ) {
+			return SearchSuggestion::fromText( $score--, $title );
+		}, $titles );
+		return new SearchSuggestionSet( $suggestions );
+	}
+
+	/**
+	 * @return SearchSuggestionSet an empty suggestion set
+	 */
+	public static function emptySuggestionSet() {
+		return new SearchSuggestionSet( [] );
+	}
+}
diff --git a/www/wiki/includes/search/SqlSearchResultSet.php b/www/wiki/includes/search/SqlSearchResultSet.php
new file mode 100644
index 00000000..53d09e82
--- /dev/null
+++ b/www/wiki/includes/search/SqlSearchResultSet.php
@@ -0,0 +1,69 @@
+<?php
+
+use Wikimedia\Rdbms\ResultWrapper;
+
+/**
+ * This class is used for different SQL-based search engines shipped with MediaWiki
+ * @ingroup Search
+ */
+class SqlSearchResultSet extends SearchResultSet {
+	protected $resultSet;
+	protected $terms;
+	protected $totalHits;
+
+	function __construct( ResultWrapper $resultSet, $terms, $total = null ) {
+		$this->resultSet = $resultSet;
+		$this->terms = $terms;
+		$this->totalHits = $total;
+	}
+
+	function termMatches() {
+		return $this->terms;
+	}
+
+	function numRows() {
+		if ( $this->resultSet === false ) {
+			return false;
+		}
+
+		return $this->resultSet->numRows();
+	}
+
+	function next() {
+		if ( $this->resultSet === false ) {
+			return false;
+		}
+
+		$row = $this->resultSet->fetchObject();
+		if ( $row === false ) {
+			return false;
+		}
+
+		return SearchResult::newFromTitle(
+			Title::makeTitle( $row->page_namespace, $row->page_title ), $this
+		);
+	}
+
+	function rewind() {
+		if ( $this->resultSet ) {
+			$this->resultSet->rewind();
+		}
+	}
+
+	function free() {
+		if ( $this->resultSet === false ) {
+			return false;
+		}
+
+		$this->resultSet->free();
+	}
+
+	function getTotalHits() {
+		if ( !is_null( $this->totalHits ) ) {
+			return $this->totalHits;
+		} else {
+			// Special:Search expects a number here.
+			return $this->numRows();
+		}
+	}
+}