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+<?php
+# Copyright (C) 2006-2007 Greg Sabino Mullane <greg@turnstep.com>
+# http://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 SearchEngine {
+
+ function __construct( $db ) {
+ $this->db = $db;
+ }
+
+ /**
+ * 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 $term String: raw search term
+ * @return PostgresSearchResultSet
+ */
+ function searchTitle( $term ) {
+ $q = $this->searchQuery( $term , 'titlevector', 'page_title' );
+ $olderror = error_reporting(E_ERROR);
+ $resultSet = $this->db->resultObject( $this->db->query( $q, 'SearchPostgres', true ) );
+ error_reporting($olderror);
+ if (!$resultSet) {
+ // Needed for "Query requires full scan, GIN doesn't support it"
+ return new SearchResultTooMany();
+ }
+ return new PostgresSearchResultSet( $resultSet, $this->searchTerms );
+ }
+ function searchText( $term ) {
+ $q = $this->searchQuery( $term, 'textvector', 'old_text' );
+ $olderror = error_reporting(E_ERROR);
+ $resultSet = $this->db->resultObject( $this->db->query( $q, 'SearchPostgres', true ) );
+ error_reporting($olderror);
+ if (!$resultSet) {
+ return new SearchResultTooMany();
+ }
+ return new PostgresSearchResultSet( $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.
+ */
+ 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 = array();
+ 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') {
+ $searchstring .= ' & ';
+ }
+ else if (strtolower($terms[2]) === 'or' or $terms[2] === '|') {
+ $searchstring .= ' | ';
+ }
+ else if (strtolower($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 $filteredTerm String
+ * @param $fulltext String
+ */
+ function searchQuery( $term, $fulltext, $colname ) {
+ global $wgDBversion;
+
+ if ( !isset( $wgDBversion ) ) {
+ $this->db->getServerVersion();
+ $wgDBversion = $this->db->numeric_version;
+ }
+ $prefix = $wgDBversion < 8.3 ? "'default'," : '';
+
+ # 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
+ $SQL = "SELECT to_tsquery($prefix $searchstring)";
+ $res = $this->db->doQuery($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");
+ }
+ $top = pg_fetch_result($res,0,0);
+
+ 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 = array();
+ if( preg_match_all("/'([^']+)'/", $top, $m, PREG_SET_ORDER ) ) {
+ foreach( $m as $terms ) {
+ $this->searchTerms[$terms[1]] = $terms[1];
+ }
+ }
+
+ $rankscore = $wgDBversion > 8.2 ? 5 : 1;
+ $rank = $wgDBversion < 8.3 ? 'rank' : 'ts_rank';
+ $query = "SELECT page_id, page_namespace, page_title, ".
+ "$rank($fulltext, to_tsquery($prefix $searchstring), $rankscore) 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 $fulltext @@ to_tsquery($prefix $searchstring)";
+ }
+
+ ## Redirects
+ if (! $this->showRedirects)
+ $query .= ' AND page_is_redirect = 0';
+
+ ## Namespaces - defaults to 0
+ if( !is_null($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 old_id IN ".
+ "(SELECT rev_text_id FROM revision WHERE rev_page = " . intval( $pageid ) .
+ " ORDER BY rev_text_id DESC OFFSET 1)";
+ $this->db->doQuery($SQL);
+ return true;
+ }
+
+ function updateTitle( $id, $title ) {
+ return true;
+ }
+
+} ## end of the SearchPostgres class
+
+/**
+ * @ingroup Search
+ */
+class PostgresSearchResult extends SearchResult {
+ function __construct( $row ) {
+ parent::__construct($row);
+ $this->score = $row->score;
+ }
+ function getScore() {
+ return $this->score;
+ }
+}
+
+/**
+ * @ingroup Search
+ */
+class PostgresSearchResultSet extends SqlSearchResultSet {
+ function __construct( $resultSet, $terms ) {
+ parent::__construct( $resultSet, $terms );
+ }
+
+ function next() {
+ $row = $this->mResultSet->fetchObject();
+ if( $row === false ) {
+ return false;
+ } else {
+ return new PostgresSearchResult( $row );
+ }
+ }
+}