maintenance/fetchText.php

   1 <?php
   2 /**
   3  * Communications protocol.
   4  * This is used by dumpTextPass.php when the --spawn option is present.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  19  * http://www.gnu.org/copyleft/gpl.html
  20  *
  21  * @file
  22  * @ingroup Maintenance
  23  */
  24
  25 require_once __DIR__ . '/Maintenance.php';
  26
  27 /**
  28  * Maintenance script used to fetch page text in a subprocess.
  29  *
  30  * @ingroup Maintenance
  31  */
  32 class FetchText extends Maintenance {
  33         public function __construct() {
  34                 parent::__construct();
  35                 $this->addDescription( "Fetch the raw revision blob from an old_id.\n" .
  36                         "NOTE: Export transformations are NOT applied. " .
  37                         "This is left to backupTextPass.php"
  38                 );
  39         }
  40
  41         /**
  42          * returns a string containing the following in order:
  43          *   textid
  44          *   \n
  45          *   length of text (-1 on error = failure to retrieve/unserialize/gunzip/etc)
  46          *   \n
  47          *   text  (may be empty)
  48          *
  49          * note that the text string itself is *not* followed by newline
  50          */
  51         public function execute() {
  52                 $db = $this->getDB( DB_REPLICA );
  53                 $stdin = $this->getStdin();
  54                 while ( !feof( $stdin ) ) {
  55                         $line = fgets( $stdin );
  56                         if ( $line === false ) {
  57                                 // We appear to have lost contact...
  58                                 break;
  59                         }
  60                         $textId = intval( $line );
  61                         $text = $this->doGetText( $db, $textId );
  62                         if ( $text === false ) {
  63                                 # actual error, not zero-length text
  64                                 $textLen = "-1";
  65                         } else {
  66                                 $textLen = strlen( $text );
  67                         }
  68                         $this->output( $textId . "\n" . $textLen . "\n" . $text );
  69                 }
  70         }
  71
  72         /**
  73          * May throw a database error if, say, the server dies during query.
  74          * @param Database $db
  75          * @param int $id The old_id
  76          * @return string
  77          */
  78         private function doGetText( $db, $id ) {
  79                 $id = intval( $id );
  80                 $row = $db->selectRow( 'text',
  81                         [ 'old_text', 'old_flags' ],
  82                         [ 'old_id' => $id ],
  83                         __METHOD__ );
  84                 $text = Revision::getRevisionText( $row );
  85                 if ( $text === false ) {
  86                         return false;
  87                 }
  88
  89                 return $text;
  90         }
  91 }
  92
  93 $maintClass = "FetchText";
  94 require_once RUN_MAINTENANCE_IF_MAIN;