MediaWiki 1.30.2

[autoinstallsdev/mediawiki.git] / includes / externalstore / ExternalStoreMwstore.php

diff --git a/includes/externalstore/ExternalStoreMwstore.php b/includes/externalstore/ExternalStoreMwstore.php
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+++ b/includes/externalstore/ExternalStoreMwstore.php
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+<?php
+/**
+ * External storage in a file backend.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ */
+
+/**
+ * File backend accessable external objects.
+ *
+ * In this system, each store "location" maps to the name of a file backend.
+ * The file backends must be defined in $wgFileBackends and must be global
+ * and fully qualified with a global "wikiId" prefix in the configuration.
+ *
+ * @ingroup ExternalStorage
+ * @since 1.21
+ */
+class ExternalStoreMwstore extends ExternalStoreMedium {
+       /**
+        * The URL returned is of the form of the form mwstore://backend/container/wiki/id
+        *
+        * @see ExternalStoreMedium::fetchFromURL()
+        * @param string $url
+        * @return bool
+        */
+       public function fetchFromURL( $url ) {
+               $be = FileBackendGroup::singleton()->backendFromPath( $url );
+               if ( $be instanceof FileBackend ) {
+                       // We don't need "latest" since objects are immutable and
+                       // backends should at least have "read-after-create" consistency.
+                       return $be->getFileContents( [ 'src' => $url ] );
+               }
+
+               return false;
+       }
+
+       /**
+        * Fetch data from given external store URLs.
+        * The URL returned is of the form of the form mwstore://backend/container/wiki/id
+        *
+        * @param array $urls An array of external store URLs
+        * @return array A map from url to stored content. Failed results are not represented.
+        */
+       public function batchFetchFromURLs( array $urls ) {
+               $pathsByBackend = [];
+               foreach ( $urls as $url ) {
+                       $be = FileBackendGroup::singleton()->backendFromPath( $url );
+                       if ( $be instanceof FileBackend ) {
+                               $pathsByBackend[$be->getName()][] = $url;
+                       }
+               }
+               $blobs = [];
+               foreach ( $pathsByBackend as $backendName => $paths ) {
+                       $be = FileBackendGroup::singleton()->get( $backendName );
+                       $blobs = $blobs + $be->getFileContentsMulti( [ 'srcs' => $paths ] );
+               }
+
+               return $blobs;
+       }
+
+       /**
+        * @see ExternalStoreMedium::store()
+        * @param string $backend
+        * @param string $data
+        * @return string|bool
+        * @throws MWException
+        */
+       public function store( $backend, $data ) {
+               $be = FileBackendGroup::singleton()->get( $backend );
+               if ( $be instanceof FileBackend ) {
+                       // Get three random base 36 characters to act as shard directories
+                       $rand = Wikimedia\base_convert( mt_rand( 0, 46655 ), 10, 36, 3 );
+                       // Make sure ID is roughly lexicographically increasing for performance
+                       $id = str_pad( UIDGenerator::newTimestampedUID128( 32 ), 26, '0', STR_PAD_LEFT );
+                       // Segregate items by wiki ID for the sake of bookkeeping
+                       $wiki = isset( $this->params['wiki'] ) ? $this->params['wiki'] : wfWikiID();
+
+                       $url = $be->getContainerStoragePath( 'data' ) . '/' . rawurlencode( $wiki );
+                       $url .= ( $be instanceof FSFileBackend )
+                               ? "/{$rand[0]}/{$rand[1]}/{$rand[2]}/{$id}" // keep directories small
+                               : "/{$rand[0]}/{$rand[1]}/{$id}"; // container sharding is only 2-levels
+
+                       $be->prepare( [ 'dir' => dirname( $url ), 'noAccess' => 1, 'noListing' => 1 ] );
+                       if ( $be->create( [ 'dst' => $url, 'content' => $data ] )->isOK() ) {
+                               return $url;
+                       }
+               }
+
+               return false;
+       }
+}