includes/externalstore/ExternalStoreMedium.php

   1 <?php
   2 /**
   3  * External storage in some particular medium.
   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 ExternalStorage
  22  */
  23
  24 /**
  25  * Accessable external objects in a particular storage medium
  26  *
  27  * @ingroup ExternalStorage
  28  * @since 1.21
  29  */
  30 abstract class ExternalStoreMedium {
  31         /** @var array */
  32         protected $params = [];
  33
  34         /**
  35          * @param array $params Options
  36          */
  37         public function __construct( array $params = [] ) {
  38                 $this->params = $params;
  39         }
  40
  41         /**
  42          * Fetch data from given external store URL
  43          *
  44          * @param string $url An external store URL
  45          * @return string|bool The text stored or false on error
  46          * @throws MWException
  47          */
  48         abstract public function fetchFromURL( $url );
  49
  50         /**
  51          * Fetch data from given external store URLs.
  52          *
  53          * @param array $urls A list of external store URLs
  54          * @return array Map from the url to the text stored. Unfound data is not represented
  55          */
  56         public function batchFetchFromURLs( array $urls ) {
  57                 $retval = [];
  58                 foreach ( $urls as $url ) {
  59                         $data = $this->fetchFromURL( $url );
  60                         // Dont return when false to allow for simpler implementations.
  61                         // errored urls are handled in ExternalStore::batchFetchFromURLs
  62                         if ( $data !== false ) {
  63                                 $retval[$url] = $data;
  64                         }
  65                 }
  66
  67                 return $retval;
  68         }
  69
  70         /**
  71          * Insert a data item into a given location
  72          *
  73          * @param string $location The location name
  74          * @param string $data The data item
  75          * @return string|bool The URL of the stored data item, or false on error
  76          * @throws MWException
  77          */
  78         abstract public function store( $location, $data );
  79
  80         /**
  81          * Check if a given location is read-only
  82          *
  83          * @param string $location The location name
  84          * @return bool Whether this location is read-only
  85          * @since 1.31
  86          */
  87         public function isReadOnly( $location ) {
  88                 return false;
  89         }
  90 }