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 // @codeCoverageIgnoreStart
  26 require_once __DIR__ . '/Maintenance.php';
  27 // @codeCoverageIgnoreEnd
  28
  29 use MediaWiki\MainConfigNames;
  30 use MediaWiki\Maintenance\Maintenance;
  31 use MediaWiki\Settings\SettingsBuilder;
  32 use MediaWiki\Storage\BlobAccessException;
  33 use MediaWiki\Storage\BlobStore;
  34 use MediaWiki\Storage\SqlBlobStore;
  35
  36 /**
  37  * Maintenance script used to fetch page text in a subprocess.
  38  *
  39  * @ingroup Maintenance
  40  */
  41 class FetchText extends Maintenance {
  42
  43         public function __construct() {
  44                 parent::__construct();
  45                 $this->addDescription( "Fetch the raw revision blob from a blob address.\n" .
  46                         "Integer IDs are interpreted as referring to text.old_id for backwards compatibility.\n" .
  47                         "NOTE: Export transformations are NOT applied. " .
  48                         "This is left to dumpTextPass.php"
  49                 );
  50         }
  51
  52         public function finalSetup( SettingsBuilder $settingsBuilder ) {
  53                 // This script should always try to run all db queries in the 'dump' group if such
  54                 // a group exists, just like the BackupDumper and TextPassDumper modules.
  55                 // To account for parts of MediaWiki that get their own db connection outside of
  56                 // Maintenance::getDB(), we set this global variable so that they will attempt
  57                 // to use this group.
  58                 $settingsBuilder->putConfigValue( MainConfigNames::DBDefaultGroup, 'dump' );
  59                 // do this last so that options can override
  60
  61                 parent::finalSetup( $settingsBuilder );
  62         }
  63
  64         /**
  65          * @return BlobStore
  66          */
  67         private function getBlobStore() {
  68                 return $this->getServiceContainer()->getBlobStore();
  69         }
  70
  71         /**
  72          * returns a string containing the following in order:
  73          *   textid
  74          *   \n
  75          *   length of text (-1 on error = failure to retrieve/unserialize/gunzip/etc)
  76          *   \n
  77          *   text  (may be empty)
  78          *
  79          * note that the text string itself is *not* followed by newline
  80          */
  81         public function execute() {
  82                 $stdin = $this->getStdin();
  83                 while ( !feof( $stdin ) ) {
  84                         $line = fgets( $stdin );
  85                         if ( $line === false ) {
  86                                 // We appear to have lost contact...
  87                                 break;
  88                         }
  89                         $blobAddress = trim( $line );
  90
  91                         // Plain integers are supported for backwards compatibility with pre-MCR dumps.
  92                         if ( strpos( $blobAddress, ':' ) === false && is_numeric( $blobAddress ) ) {
  93                                 $blobAddress = SqlBlobStore::makeAddressFromTextId( intval( $blobAddress ) );
  94                         }
  95
  96                         try {
  97                                 $text = $this->getBlobStore()->getBlob( $blobAddress );
  98                                 $textLen = strlen( $text );
  99                         } catch ( BlobAccessException | InvalidArgumentException $ex ) {
 100                                 // XXX: log $ex to stderr?
 101                                 $textLen = '-1';
 102                                 $text = '';
 103                         }
 104
 105                         $this->output( $blobAddress . "\n" . $textLen . "\n" . $text );
 106                 }
 107         }
 108
 109 }
 110
 111 // @codeCoverageIgnoreStart
 112 $maintClass = FetchText::class;
 113 require_once RUN_MAINTENANCE_IF_MAIN;
 114 // @codeCoverageIgnoreEnd