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         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                 wfProfileIn( __METHOD__ );
  46                 $base = wfTempDir() . '/' . $prefix . wfRandomString( 12 );
  47                 $ext = ( $extension != '' ) ? ".{$extension}" : "";
  48                 for ( $attempt = 1; true; $attempt++ ) {
  49                         $path = "{$base}-{$attempt}{$ext}";
  50                         wfSuppressWarnings();
  51                         $newFileHandle = fopen( $path, 'x' );
  52                         wfRestoreWarnings();
  53                         if ( $newFileHandle ) {
  54                                 fclose( $newFileHandle );
  55                                 break; // got it
  56                         }
  57                         if ( $attempt >= 5 ) {
  58                                 wfProfileOut( __METHOD__ );
  59                                 return null; // give up
  60                         }
  61                 }
  62                 $tmpFile = new self( $path );
  63                 $tmpFile->canDelete = true; // safely instantiated
  64                 wfProfileOut( __METHOD__ );
  65                 return $tmpFile;
  66         }
  67
  68         /**
  69          * Purge this file off the file system
  70          *
  71          * @return bool Success
  72          */
  73         public function purge() {
  74                 $this->canDelete = false; // done
  75                 wfSuppressWarnings();
  76                 $ok = unlink( $this->path );
  77                 wfRestoreWarnings();
  78                 return $ok;
  79         }
  80
  81         /**
  82          * Clean up the temporary file only after an object goes out of scope
  83          *
  84          * @param $object Object
  85          * @return void
  86          */
  87         public function bind( $object ) {
  88                 if ( is_object( $object ) ) {
  89                         if ( !isset( $object->tempFSFileReferences ) ) {
  90                                 // Init first since $object might use __get() and return only a copy variable
  91                                 $object->tempFSFileReferences = array();
  92                         }
  93                         $object->tempFSFileReferences[] = $this;
  94                 }
  95         }
  96
  97         /**
  98          * Set flag to not clean up after the temporary file
  99          *
 100          * @return void
 101          */
 102         public function preserve() {
 103                 $this->canDelete = false;
 104         }
 105
 106         /**
 107          * Set flag clean up after the temporary file
 108          *
 109          * @return void
 110          */
 111         public function autocollect() {
 112                 $this->canDelete = true;
 113         }
 114
 115         /**
 116          * Cleans up after the temporary file by deleting it
 117          */
 118         function __destruct() {
 119                 if ( $this->canDelete ) {
 120                         wfSuppressWarnings();
 121                         unlink( $this->path );
 122                         wfRestoreWarnings();
 123                 }
 124         }
 125 }