includes/filebackend/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         /** @var bool Garbage collect the temp file */
  32         protected $canDelete = false;
  33
  34         /** @var array Active temp files to purge on shutdown */
  35         protected static $instances = array();
  36
  37         /**
  38          * Make a new temporary file on the file system.
  39          * Temporary files may be purged when the file object falls out of scope.
  40          *
  41          * @param string $prefix
  42          * @param string $extension
  43          * @return TempFSFile|null
  44          */
  45         public static function factory( $prefix, $extension = '' ) {
  46                 wfProfileIn( __METHOD__ );
  47                 $base = wfTempDir() . '/' . $prefix . wfRandomString( 12 );
  48                 $ext = ( $extension != '' ) ? ".{$extension}" : "";
  49                 for ( $attempt = 1; true; $attempt++ ) {
  50                         $path = "{$base}-{$attempt}{$ext}";
  51                         wfSuppressWarnings();
  52                         $newFileHandle = fopen( $path, 'x' );
  53                         wfRestoreWarnings();
  54                         if ( $newFileHandle ) {
  55                                 fclose( $newFileHandle );
  56                                 break; // got it
  57                         }
  58                         if ( $attempt >= 5 ) {
  59                                 wfProfileOut( __METHOD__ );
  60
  61                                 return null; // give up
  62                         }
  63                 }
  64                 $tmpFile = new self( $path );
  65                 $tmpFile->canDelete = true; // safely instantiated
  66                 wfProfileOut( __METHOD__ );
  67
  68                 return $tmpFile;
  69         }
  70
  71         /**
  72          * Purge this file off the file system
  73          *
  74          * @return bool Success
  75          */
  76         public function purge() {
  77                 $this->canDelete = false; // done
  78                 wfSuppressWarnings();
  79                 $ok = unlink( $this->path );
  80                 wfRestoreWarnings();
  81
  82                 return $ok;
  83         }
  84
  85         /**
  86          * Clean up the temporary file only after an object goes out of scope
  87          *
  88          * @param stdClass $object
  89          * @return TempFSFile This object
  90          */
  91         public function bind( $object ) {
  92                 if ( is_object( $object ) ) {
  93                         if ( !isset( $object->tempFSFileReferences ) ) {
  94                                 // Init first since $object might use __get() and return only a copy variable
  95                                 $object->tempFSFileReferences = array();
  96                         }
  97                         $object->tempFSFileReferences[] = $this;
  98                 }
  99
 100                 return $this;
 101         }
 102
 103         /**
 104          * Set flag to not clean up after the temporary file
 105          *
 106          * @return TempFSFile This object
 107          */
 108         public function preserve() {
 109                 $this->canDelete = false;
 110
 111                 return $this;
 112         }
 113
 114         /**
 115          * Set flag clean up after the temporary file
 116          *
 117          * @return TempFSFile This object
 118          */
 119         public function autocollect() {
 120                 $this->canDelete = true;
 121
 122                 return $this;
 123         }
 124
 125         /**
 126          * Cleans up after the temporary file by deleting it
 127          */
 128         function __destruct() {
 129                 if ( $this->canDelete ) {
 130                         wfSuppressWarnings();
 131                         unlink( $this->path );
 132                         wfRestoreWarnings();
 133                 }
 134         }
 135 }