3 * External storage in a file backend.
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.
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.
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
24 * File backend accessible external objects.
26 * In this system, each store "location" maps to the name of a file backend.
27 * The file backends must be defined in $wgFileBackends and must be global
28 * and fully qualified with a global "wikiId" prefix in the configuration.
30 * @ingroup ExternalStorage
33 class ExternalStoreMwstore
extends ExternalStoreMedium
{
35 * The URL returned is of the form of the form mwstore://backend/container/wiki/id
37 * @see ExternalStoreMedium::fetchFromURL()
41 public function fetchFromURL( $url ) {
42 $be = FileBackendGroup
::singleton()->backendFromPath( $url );
43 if ( $be instanceof FileBackend
) {
44 // We don't need "latest" since objects are immutable and
45 // backends should at least have "read-after-create" consistency.
46 return $be->getFileContents( [ 'src' => $url ] );
53 * Fetch data from given external store URLs.
54 * The URL returned is of the form of the form mwstore://backend/container/wiki/id
56 * @param array $urls An array of external store URLs
57 * @return array A map from url to stored content. Failed results are not represented.
59 public function batchFetchFromURLs( array $urls ) {
61 foreach ( $urls as $url ) {
62 $be = FileBackendGroup
::singleton()->backendFromPath( $url );
63 if ( $be instanceof FileBackend
) {
64 $pathsByBackend[$be->getName()][] = $url;
68 foreach ( $pathsByBackend as $backendName => $paths ) {
69 $be = FileBackendGroup
::singleton()->get( $backendName );
70 $blobs +
= $be->getFileContentsMulti( [ 'srcs' => $paths ] );
76 public function store( $backend, $data ) {
77 $be = FileBackendGroup
::singleton()->get( $backend );
78 if ( $be instanceof FileBackend
) {
79 // Get three random base 36 characters to act as shard directories
80 $rand = Wikimedia\base_convert
( mt_rand( 0, 46655 ), 10, 36, 3 );
81 // Make sure ID is roughly lexicographically increasing for performance
82 $id = str_pad( UIDGenerator
::newTimestampedUID128( 32 ), 26, '0', STR_PAD_LEFT
);
83 // Segregate items by wiki ID for the sake of bookkeeping
84 // @FIXME: this does not include the domain for b/c but it ideally should
85 $wiki = $this->params
['wiki'] ??
wfWikiID();
87 $url = $be->getContainerStoragePath( 'data' ) . '/' . rawurlencode( $wiki );
88 $url .= ( $be instanceof FSFileBackend
)
89 ?
"/{$rand[0]}/{$rand[1]}/{$rand[2]}/{$id}" // keep directories small
90 : "/{$rand[0]}/{$rand[1]}/{$id}"; // container sharding is only 2-levels
92 $be->prepare( [ 'dir' => dirname( $url ), 'noAccess' => 1, 'noListing' => 1 ] );
93 if ( $be->create( [ 'dst' => $url, 'content' => $data ] )->isOK() ) {
101 public function isReadOnly( $backend ) {
102 $be = FileBackendGroup
::singleton()->get( $backend );
104 return $be ?
$be->isReadOnly() : false;