includes/search/SearchPostgres.php

   1 <?php
   2 /**
   3  * PostgreSQL search engine
   4  *
   5  * Copyright © 2006-2007 Greg Sabino Mullane <greg@turnstep.com>
   6  * https://www.mediawiki.org/
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License along
  19  * with this program; if not, write to the Free Software Foundation, Inc.,
  20  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  21  * http://www.gnu.org/copyleft/gpl.html
  22  *
  23  * @file
  24  * @ingroup Search
  25  */
  26 use MediaWiki\MediaWikiServices;
  27 use MediaWiki\Revision\SlotRecord;
  28 use Wikimedia\Rdbms\IDatabase;
  29
  30 /**
  31  * Search engine hook base class for Postgres
  32  * @ingroup Search
  33  */
  34 class SearchPostgres extends SearchDatabase {
  35         /**
  36          * Perform a full text search query via tsearch2 and return a result set.
  37          * Currently searches a page's current title (page.page_title) and
  38          * latest revision article text (text.old_text)
  39          *
  40          * @param string $term Raw search term
  41          * @return SqlSearchResultSet
  42          */
  43         protected function doSearchTitleInDB( $term ) {
  44                 $q = $this->searchQuery( $term, 'titlevector' );
  45                 $olderror = error_reporting( E_ERROR );
  46                 $dbr = $this->dbProvider->getReplicaDatabase();
  47                 // The real type is still IDatabase, but IReplicaDatabase is used for safety.
  48                 '@phan-var IDatabase $dbr';
  49                 // phpcs:ignore MediaWiki.Usage.DbrQueryUsage.DbrQueryFound
  50                 $resultSet = $dbr->query( $q, 'SearchPostgres', IDatabase::QUERY_SILENCE_ERRORS );
  51                 error_reporting( $olderror );
  52                 return new SqlSearchResultSet( $resultSet, $this->searchTerms );
  53         }
  54
  55         protected function doSearchTextInDB( $term ) {
  56                 $q = $this->searchQuery( $term, 'textvector' );
  57                 $olderror = error_reporting( E_ERROR );
  58                 $dbr = $this->dbProvider->getReplicaDatabase();
  59                 // The real type is still IDatabase, but IReplicaDatabase is used for safety.
  60                 '@phan-var IDatabase $dbr';
  61                 // phpcs:ignore MediaWiki.Usage.DbrQueryUsage.DbrQueryFound
  62                 $resultSet = $dbr->query( $q, 'SearchPostgres', IDatabase::QUERY_SILENCE_ERRORS );
  63                 error_reporting( $olderror );
  64                 return new SqlSearchResultSet( $resultSet, $this->searchTerms );
  65         }
  66
  67         /**
  68          * Transform the user's search string into a better form for tsearch2
  69          * Returns an SQL fragment consisting of quoted text to search for.
  70          *
  71          * @param string $term
  72          *
  73          * @return string
  74          */
  75         private function parseQuery( $term ) {
  76                 wfDebug( "parseQuery received: $term" );
  77
  78                 // No backslashes allowed
  79                 $term = preg_replace( '/\\\\/', '', $term );
  80
  81                 // Collapse parens into nearby words:
  82                 $term = preg_replace( '/\s*\(\s*/', ' (', $term );
  83                 $term = preg_replace( '/\s*\)\s*/', ') ', $term );
  84
  85                 // Treat colons as word separators:
  86                 $term = preg_replace( '/:/', ' ', $term );
  87
  88                 $searchstring = '';
  89                 $m = [];
  90                 if ( preg_match_all( '/([-!]?)(\S+)\s*/', $term, $m, PREG_SET_ORDER ) ) {
  91                         foreach ( $m as $terms ) {
  92                                 if ( strlen( $terms[1] ) ) {
  93                                         $searchstring .= ' & !';
  94                                 }
  95                                 if ( strtolower( $terms[2] ) === 'and' ) {
  96                                         $searchstring .= ' & ';
  97                                 } elseif ( strtolower( $terms[2] ) === 'or' || $terms[2] === '|' ) {
  98                                         $searchstring .= ' | ';
  99                                 } elseif ( strtolower( $terms[2] ) === 'not' ) {
 100                                         $searchstring .= ' & !';
 101                                 } else {
 102                                         $searchstring .= " & $terms[2]";
 103                                 }
 104                         }
 105                 }
 106
 107                 // Strip out leading junk
 108                 $searchstring = preg_replace( '/^[\s\&\|]+/', '', $searchstring );
 109
 110                 // Remove any doubled-up operators
 111                 $searchstring = preg_replace( '/([\!\&\|]) +(?:[\&\|] +)+/', "$1 ", $searchstring );
 112
 113                 // Remove any non-spaced operators (e.g. "Zounds!")
 114                 $searchstring = preg_replace( '/([^ ])[\!\&\|]/', "$1", $searchstring );
 115
 116                 // Remove any trailing whitespace or operators
 117                 $searchstring = preg_replace( '/[\s\!\&\|]+$/', '', $searchstring );
 118
 119                 // Remove unnecessary quotes around everything
 120                 $searchstring = preg_replace( '/^[\'"](.*)[\'"]$/', "$1", $searchstring );
 121
 122                 // Quote the whole thing
 123                 $dbr = $this->dbProvider->getReplicaDatabase();
 124                 $searchstring = $dbr->addQuotes( $searchstring );
 125
 126                 wfDebug( "parseQuery returned: $searchstring" );
 127
 128                 return $searchstring;
 129         }
 130
 131         /**
 132          * Construct the full SQL query to do the search.
 133          * @param string $term
 134          * @param string $fulltext
 135          * @return string
 136          */
 137         private function searchQuery( $term, $fulltext ) {
 138                 # Get the SQL fragment for the given term
 139                 $searchstring = $this->parseQuery( $term );
 140
 141                 // We need a separate query here so gin does not complain about empty searches
 142                 $sql = "SELECT to_tsquery($searchstring)";
 143                 $dbr = $this->dbProvider->getReplicaDatabase();
 144                 // The real type is still IDatabase, but IReplicaDatabase is used for safety.
 145                 '@phan-var IDatabase $dbr';
 146                 // phpcs:ignore MediaWiki.Usage.DbrQueryUsage.DbrQueryFound
 147                 $res = $dbr->query( $sql, __METHOD__ );
 148                 if ( !$res ) {
 149                         // TODO: Better output (example to catch: one 'two)
 150                         die( "Sorry, that was not a valid search string. Please go back and try again" );
 151                 }
 152                 $top = $res->fetchRow()[0];
 153
 154                 $this->searchTerms = [];
 155                 $slotRoleStore = MediaWikiServices::getInstance()->getSlotRoleStore();
 156                 if ( $top === "" ) { // e.g. if only stopwords are used XXX return something better
 157                         $query = "SELECT page_id, page_namespace, page_title, 0 AS score " .
 158                                 "FROM page p, revision r, slots s, content c, \"text\" pc " .
 159                                 "WHERE p.page_latest = r.rev_id " .
 160                                 "AND s.slot_revision_id = r.rev_id " .
 161                                 "AND s.slot_role_id = " .
 162                                         $dbr->addQuotes( $slotRoleStore->acquireId( SlotRecord::MAIN ) ) . " " .
 163                                 "AND c.content_id = s.slot_content_id " .
 164                                 "AND pc.old_id = substring( c.content_address from '^tt:([0-9]+)$' )::int " .
 165                                 "AND 1=0";
 166                 } else {
 167                         $m = [];
 168                         if ( preg_match_all( "/'([^']+)'/", $top, $m, PREG_SET_ORDER ) ) {
 169                                 foreach ( $m as $terms ) {
 170                                         $this->searchTerms[$terms[1]] = $terms[1];
 171                                 }
 172                         }
 173
 174                         $query = "SELECT page_id, page_namespace, page_title, " .
 175                                 "ts_rank($fulltext, to_tsquery($searchstring), 5) AS score " .
 176                                 "FROM page p, revision r, slots s, content c, \"text\" pc " .
 177                                 "WHERE p.page_latest = r.rev_id " .
 178                                 "AND s.slot_revision_id = r.rev_id " .
 179                                 "AND s.slot_role_id = " . $dbr->addQuotes(
 180                                         $slotRoleStore->acquireId( SlotRecord::MAIN ) ) . " " .
 181                                 "AND c.content_id = s.slot_content_id " .
 182                                 "AND pc.old_id = substring( c.content_address from '^tt:([0-9]+)$' )::int " .
 183                                 "AND $fulltext @@ to_tsquery($searchstring)";
 184                 }
 185                 // Namespaces - defaults to main
 186                 if ( $this->namespaces !== null ) { // null -> search all
 187                         if ( count( $this->namespaces ) < 1 ) {
 188                                 $query .= ' AND page_namespace = ' . NS_MAIN;
 189                         } else {
 190                                 $namespaces = $dbr->makeList( $this->namespaces );
 191                                 $query .= " AND page_namespace IN ($namespaces)";
 192                         }
 193                 }
 194
 195                 $query .= " ORDER BY score DESC, page_id DESC";
 196
 197                 $query .= $dbr->limitResult( '', $this->limit, $this->offset );
 198
 199                 wfDebug( "searchQuery returned: $query" );
 200
 201                 return $query;
 202         }
 203
 204         // Most of the work of these two functions are done automatically via triggers
 205
 206         public function update( $pageid, $title, $text ) {
 207                 // We don't want to index older revisions
 208                 $slotRoleStore = MediaWikiServices::getInstance()->getSlotRoleStore();
 209                 $dbw = $this->dbProvider->getPrimaryDatabase();
 210                 $sql = "UPDATE \"text\" SET textvector = NULL " .
 211                         "WHERE textvector IS NOT NULL " .
 212                         "AND old_id IN " .
 213                         "(SELECT DISTINCT substring( c.content_address from '^tt:([0-9]+)$' )::int AS old_rev_text_id " .
 214                         " FROM content c, slots s, revision r " .
 215                         " WHERE r.rev_page = $pageid " .
 216                         " AND s.slot_revision_id = r.rev_id " .
 217                         " AND s.slot_role_id = " .
 218                                 $dbw->addQuotes( $slotRoleStore->acquireId( SlotRecord::MAIN ) ) . " " .
 219                         " AND c.content_id = s.slot_content_id " .
 220                         " ORDER BY old_rev_text_id DESC OFFSET 1)";
 221
 222                 $dbw->query( $sql, __METHOD__ );
 223
 224                 return true;
 225         }
 226
 227         public function updateTitle( $id, $title ) {
 228                 return true;
 229         }
 230 }