includes/search/SearchPostgres.php
<?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
*/
use MediaWiki\MediaWikiServices;
use MediaWiki\Revision\SlotRecord;
use Wikimedia\Rdbms\IDatabase;
/**
* 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 (text.old_text)
*
* @param string $term Raw search term
* @return SqlSearchResultSet
*/
protected function doSearchTitleInDB( $term ) {
$q = $this->searchQuery( $term, 'titlevector' );
$olderror = error_reporting( E_ERROR );
$dbr = $this->dbProvider->getReplicaDatabase();
// The real type is still IDatabase, but IReplicaDatabase is used for safety.
'@phan-var IDatabase $dbr';
// phpcs:ignore MediaWiki.Usage.DbrQueryUsage.DbrQueryFound
$resultSet = $dbr->query( $q, 'SearchPostgres', IDatabase::QUERY_SILENCE_ERRORS );
error_reporting( $olderror );
return new SqlSearchResultSet( $resultSet, $this->searchTerms );
}
protected function doSearchTextInDB( $term ) {
$q = $this->searchQuery( $term, 'textvector' );
$olderror = error_reporting( E_ERROR );
$dbr = $this->dbProvider->getReplicaDatabase();
// The real type is still IDatabase, but IReplicaDatabase is used for safety.
'@phan-var IDatabase $dbr';
// phpcs:ignore MediaWiki.Usage.DbrQueryUsage.DbrQueryFound
$resultSet = $dbr->query( $q, 'SearchPostgres', IDatabase::QUERY_SILENCE_ERRORS );
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
*/
private function parseQuery( $term ) {
wfDebug( "parseQuery received: $term" );
// 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
$dbr = $this->dbProvider->getReplicaDatabase();
$searchstring = $dbr->addQuotes( $searchstring );
wfDebug( "parseQuery returned: $searchstring" );
return $searchstring;
}
/**
* Construct the full SQL query to do the search.
* @param string $term
* @param string $fulltext
* @return string
*/
private function searchQuery( $term, $fulltext ) {
# 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)";
$dbr = $this->dbProvider->getReplicaDatabase();
// The real type is still IDatabase, but IReplicaDatabase is used for safety.
'@phan-var IDatabase $dbr';
// phpcs:ignore MediaWiki.Usage.DbrQueryUsage.DbrQueryFound
$res = $dbr->query( $sql, __METHOD__ );
if ( !$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 = [];
$slotRoleStore = MediaWikiServices::getInstance()->getSlotRoleStore();
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, slots s, content c, \"text\" pc " .
"WHERE p.page_latest = r.rev_id " .
"AND s.slot_revision_id = r.rev_id " .
"AND s.slot_role_id = " .
$dbr->addQuotes( $slotRoleStore->acquireId( SlotRecord::MAIN ) ) . " " .
"AND c.content_id = s.slot_content_id " .
"AND pc.old_id = substring( c.content_address from '^tt:([0-9]+)$' )::int " .
"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, slots s, content c, \"text\" pc " .
"WHERE p.page_latest = r.rev_id " .
"AND s.slot_revision_id = r.rev_id " .
"AND s.slot_role_id = " . $dbr->addQuotes(
$slotRoleStore->acquireId( SlotRecord::MAIN ) ) . " " .
"AND c.content_id = s.slot_content_id " .
"AND pc.old_id = substring( c.content_address from '^tt:([0-9]+)$' )::int " .
"AND $fulltext @@ to_tsquery($searchstring)";
}
// Namespaces - defaults to main
if ( $this->namespaces !== null ) { // null -> search all
if ( count( $this->namespaces ) < 1 ) {
$query .= ' AND page_namespace = ' . NS_MAIN;
} else {
$namespaces = $dbr->makeList( $this->namespaces );
$query .= " AND page_namespace IN ($namespaces)";
}
}
$query .= " ORDER BY score DESC, page_id DESC";
$query .= $dbr->limitResult( '', $this->limit, $this->offset );
wfDebug( "searchQuery returned: $query" );
return $query;
}
// Most of the work of these two functions are done automatically via triggers
public function update( $pageid, $title, $text ) {
// We don't want to index older revisions
$slotRoleStore = MediaWikiServices::getInstance()->getSlotRoleStore();
$dbw = $this->dbProvider->getPrimaryDatabase();
$sql = "UPDATE \"text\" SET textvector = NULL " .
"WHERE textvector IS NOT NULL " .
"AND old_id IN " .
"(SELECT DISTINCT substring( c.content_address from '^tt:([0-9]+)$' )::int AS old_rev_text_id " .
" FROM content c, slots s, revision r " .
" WHERE r.rev_page = $pageid " .
" AND s.slot_revision_id = r.rev_id " .
" AND s.slot_role_id = " .
$dbw->addQuotes( $slotRoleStore->acquireId( SlotRecord::MAIN ) ) . " " .
" AND c.content_id = s.slot_content_id " .
" ORDER BY old_rev_text_id DESC OFFSET 1)";
$dbw->query( $sql, __METHOD__ );
return true;
}
public function updateTitle( $id, $title ) {
return true;
}
}