3 * This program is free software; you can redistribute it and/or modify
4 * it under the terms of the GNU General Public License as published by
5 * the Free Software Foundation; either version 2 of the License, or
6 * (at your option) any later version.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
13 * You should have received a copy of the GNU General Public License along
14 * with this program; if not, write to the Free Software Foundation, Inc.,
15 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
16 * http://www.gnu.org/copyleft/gpl.html
19 * @ingroup FileBackend
23 * FileBackendStore helper function to handle listings that span container shards.
24 * Do not use this class from places outside of FileBackendStore.
26 * @ingroup FileBackend
28 abstract class FileBackendStoreShardListIterator
extends FilterIterator
{
29 /** @var FileBackendStore */
35 /** @var string Full container name */
38 /** @var string Resolved relative path */
42 protected $multiShardPaths = []; // (rel path => 1)
45 * @param FileBackendStore $backend
46 * @param string $container Full storage container name
47 * @param string $dir Storage directory relative to container
48 * @param array $suffixes List of container shard suffixes
49 * @param array $params
51 public function __construct(
52 FileBackendStore
$backend, $container, $dir, array $suffixes, array $params
54 $this->backend
= $backend;
55 $this->container
= $container;
56 $this->directory
= $dir;
57 $this->params
= $params;
59 $iter = new AppendIterator();
60 foreach ( $suffixes as $suffix ) {
61 $iter->append( $this->listFromShard( $this->container
. $suffix ) );
64 parent
::__construct( $iter );
67 public function accept() {
68 $rel = $this->getInnerIterator()->current(); // path relative to given directory
69 $path = $this->params
['dir'] . "/{$rel}"; // full storage path
70 if ( $this->backend
->isSingleShardPathInternal( $path ) ) {
71 return true; // path is only on one shard; no issue with duplicates
72 } elseif ( isset( $this->multiShardPaths
[$rel] ) ) {
73 // Don't keep listing paths that are on multiple shards
76 $this->multiShardPaths
[$rel] = 1;
82 public function rewind() {
84 $this->multiShardPaths
= [];
88 * Get the list for a given container shard
90 * @param string $container Resolved container name
93 abstract protected function listFromShard( $container );