includes/filerepo/backend/TempFSFile.php

   1 <?php
   2 /**
   3  * Location holder of files stored temporarily
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup FileBackend
  22  */
  23
  24 /**
  25  * This class is used to hold the location and do limited manipulation
  26  * of files stored temporarily (this will be whatever wfTempDir() returns)
  27  *
  28  * @ingroup FileBackend
  29  */
  30 class TempFSFile extends FSFile {
  31         protected $canDelete = false; // bool; garbage collect the temp file
  32
  33         /** @var Array of active temp files to purge on shutdown */
  34         protected static $instances = array();
  35
  36         /**
  37          * Make a new temporary file on the file system.
  38          * Temporary files may be purged when the file object falls out of scope.
  39          *
  40          * @param $prefix string
  41          * @param $extension string
  42          * @return TempFSFile|null
  43          */
  44         public static function factory( $prefix, $extension = '' ) {
  45                 $base = wfTempDir() . '/' . $prefix . dechex( mt_rand( 0, 99999999 ) );
  46                 $ext = ( $extension != '' ) ? ".{$extension}" : "";
  47                 for ( $attempt = 1; true; $attempt++ ) {
  48                         $path = "{$base}-{$attempt}{$ext}";
  49                         wfSuppressWarnings();
  50                         $newFileHandle = fopen( $path, 'x' );
  51                         wfRestoreWarnings();
  52                         if ( $newFileHandle ) {
  53                                 fclose( $newFileHandle );
  54                                 break; // got it
  55                         }
  56                         if ( $attempt >= 15 ) {
  57                                 return null; // give up
  58                         }
  59                 }
  60                 $tmpFile = new self( $path );
  61                 $tmpFile->canDelete = true; // safely instantiated
  62                 return $tmpFile;
  63         }
  64
  65         /**
  66          * Purge this file off the file system
  67          *
  68          * @return bool Success
  69          */
  70         public function purge() {
  71                 $this->canDelete = false; // done
  72                 wfSuppressWarnings();
  73                 $ok = unlink( $this->path );
  74                 wfRestoreWarnings();
  75                 return $ok;
  76         }
  77
  78         /**
  79          * Clean up the temporary file only after an object goes out of scope
  80          *
  81          * @param $object Object
  82          * @return void
  83          */
  84         public function bind( $object ) {
  85                 if ( is_object( $object ) ) {
  86                         $object->tempFSFileReferences[] = $this;
  87                 }
  88         }
  89
  90         /**
  91          * Set flag to not clean up after the temporary file
  92          *
  93          * @return void
  94          */
  95         public function preserve() {
  96                 $this->canDelete = false;
  97         }
  98
  99         /**
 100          * Cleans up after the temporary file by deleting it
 101          */
 102         function __destruct() {
 103                 if ( $this->canDelete ) {
 104                         wfSuppressWarnings();
 105                         unlink( $this->path );
 106                         wfRestoreWarnings();
 107                 }
 108         }
 109 }