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+<?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 SearchEngine {
+ // Cached because SearchUpdate keeps recreating our class
+ private static $fulltextSupported = null;
+
+ /**
+ * Creates an instance of this class
+ * @param $db DatabaseSqlite: database object
+ */
+ function __construct( $db ) {
+ $this->db = $db;
+ }
+
+ /**
+ * Whether fulltext search is supported by current schema
+ * @return Boolean
+ */
+ function fulltextSearchSupported() {
+ if ( self::$fulltextSupported === null ) {
+ self::$fulltextSupported = $this->db->selectField(
+ 'updatelog',
+ 'ul_key',
+ array( 'ul_key' => 'fts3' ),
+ __METHOD__ ) !== false;
+ }
+ return self::$fulltextSupported;
+ }
+
+ /**
+ * Parse the user's query and transform it into an SQL fragment which will
+ * become part of a WHERE clause
+ */
+ function parseQuery( $filteredText, $fulltext ) {
+ global $wgContLang;
+ $lc = SearchEngine::legalSearchChars(); // Minus format chars
+ $searchon = '';
+ $this->searchTerms = array();
+
+ $m = array();
+ if( preg_match_all( '/([-+<>~]?)(([' . $lc . ']+)(\*?)|"[^"]*")/',
+ $filteredText, $m, PREG_SET_ORDER ) ) {
+ foreach( $m as $bits ) {
+ @list( /* all */, $modifier, $term, $nonQuoted, $wildcard ) = $bits;
+
+ 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 = array( $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(
+ array( $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->strencode( $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() {
+ return "\"*" . parent::legalSearchChars();
+ }
+
+ /**
+ * Perform a full text search query and return a result set.
+ *
+ * @param $term String: raw search term
+ * @return SqliteSearchResultSet
+ */
+ function searchText( $term ) {
+ return $this->searchInternal( $term, true );
+ }
+
+ /**
+ * Perform a title-only search query and return a result set.
+ *
+ * @param $term String: raw search term
+ * @return SqliteSearchResultSet
+ */
+ function searchTitle( $term ) {
+ return $this->searchInternal( $term, false );
+ }
+
+ protected function searchInternal( $term, $fulltext ) {
+ global $wgCountTotalSearchHits, $wgContLang;
+
+ if ( !$this->fulltextSearchSupported() ) {
+ return null;
+ }
+
+ $filteredTerm = $this->filter( $wgContLang->lc( $term ) );
+ $resultSet = $this->db->query( $this->getQuery( $filteredTerm, $fulltext ) );
+
+ $total = null;
+ if( $wgCountTotalSearchHits ) {
+ $totalResult = $this->db->query( $this->getCountQuery( $filteredTerm, $fulltext ) );
+ $row = $totalResult->fetchObject();
+ if( $row ) {
+ $total = intval( $row->c );
+ }
+ $totalResult->free();
+ }
+
+ return new SqliteSearchResultSet( $resultSet, $this->searchTerms, $total );
+ }
+
+
+ /**
+ * Return a partial WHERE clause to exclude redirects, if so set
+ * @return String
+ */
+ function queryRedirect() {
+ if( $this->showRedirects ) {
+ return '';
+ } else {
+ return 'AND page_is_redirect=0';
+ }
+ }
+
+ /**
+ * Return a partial WHERE clause to limit the search to the given namespaces
+ * @return String
+ */
+ function queryNamespaces() {
+ if( is_null($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 $sql String:
+ * @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 $filteredTerm String
+ * @param $fulltext Boolean
+ */
+ function getQuery( $filteredTerm, $fulltext ) {
+ return $this->limitResult(
+ $this->queryMain( $filteredTerm, $fulltext ) . ' ' .
+ $this->queryRedirect() . ' ' .
+ $this->queryNamespaces()
+ );
+ }
+
+ /**
+ * Picks which field to index on, depending on what type of query.
+ * @param $fulltext Boolean
+ * @return String
+ */
+ function getIndexField( $fulltext ) {
+ return $fulltext ? 'si_text' : 'si_title';
+ }
+
+ /**
+ * Get the base part of the search query.
+ *
+ * @param $filteredTerm String
+ * @param $fulltext Boolean
+ * @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->queryRedirect() . ' ' .
+ $this->queryNamespaces();
+ }
+
+ /**
+ * Create or update the search index record for the given page.
+ * Title and text should be pre-processed.
+ *
+ * @param $id Integer
+ * @param $title String
+ * @param $text String
+ */
+ 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', array( 'rowid' => $id ), __METHOD__ );
+
+ $dbw->insert( 'searchindex',
+ array(
+ 'rowid' => $id,
+ 'si_title' => $title,
+ 'si_text' => $text
+ ), __METHOD__ );
+ }
+
+ /**
+ * Update a search index record's title only.
+ * Title should be pre-processed.
+ *
+ * @param $id Integer
+ * @param $title String
+ */
+ function updateTitle( $id, $title ) {
+ if ( !$this->fulltextSearchSupported() ) {
+ return;
+ }
+ $dbw = wfGetDB( DB_MASTER );
+
+ $dbw->update( 'searchindex',
+ array( 'si_title' => $title ),
+ array( 'rowid' => $id ),
+ __METHOD__ );
+ }
+}
+
+/**
+ * @ingroup Search
+ */
+class SqliteSearchResultSet extends SqlSearchResultSet {
+ function SqliteSearchResultSet( $resultSet, $terms, $totalHits=null ) {
+ parent::__construct( $resultSet, $terms );
+ $this->mTotalHits = $totalHits;
+ }
+
+ function getTotalHits() {
+ return $this->mTotalHits;
+ }
+} \ No newline at end of file
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