Move FileBackendStore and FileOp classes to /libs

Change-Id: If490f64bec282e5dfcdaf7feb1cbf46d3dce1064

3 files changed, 0 insertions, 3037 deletions

diff --git a/includes/filebackend/FileBackendStore.php b/includes/filebackend/FileBackendStore.php
deleted file mode 100644
index 66f0737e222e..000000000000
--- a/includes/filebackend/FileBackendStore.php
+++ /dev/null
@@ -1,1977 +0,0 @@
-<?php
-/**
- * Base class for all backends using particular storage medium.
- *
- * 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
- * @ingroup FileBackend
- * @author Aaron Schulz
- */
-
-/**
- * @brief Base class for all backends using particular storage medium.
- *
- * This class defines the methods as abstract that subclasses must implement.
- * Outside callers should *not* use functions with "Internal" in the name.
- *
- * The FileBackend operations are implemented using basic functions
- * such as storeInternal(), copyInternal(), deleteInternal() and the like.
- * This class is also responsible for path resolution and sanitization.
- *
- * @ingroup FileBackend
- * @since 1.19
- */
-abstract class FileBackendStore extends FileBackend {
-	/** @var WANObjectCache */
-	protected $memCache;
-	/** @var ProcessCacheLRU Map of paths to small (RAM/disk) cache items */
-	protected $cheapCache;
-	/** @var ProcessCacheLRU Map of paths to large (RAM/disk) cache items */
-	protected $expensiveCache;
-
-	/** @var array Map of container names to sharding config */
-	protected $shardViaHashLevels = [];
-
-	/** @var callable Method to get the MIME type of files */
-	protected $mimeCallback;
-
-	protected $maxFileSize = 4294967296; // integer bytes (4GiB)
-
-	const CACHE_TTL = 10; // integer; TTL in seconds for process cache entries
-	const CACHE_CHEAP_SIZE = 500; // integer; max entries in "cheap cache"
-	const CACHE_EXPENSIVE_SIZE = 5; // integer; max entries in "expensive cache"
-
-	/**
-	 * @see FileBackend::__construct()
-	 * Additional $config params include:
-	 *   - wanCache     : WANObjectCache object to use for persistent caching.
-	 *   - mimeCallback : Callback that takes (storage path, content, file system path) and
-	 *                    returns the MIME type of the file or 'unknown/unknown'. The file
-	 *                    system path parameter should be used if the content one is null.
-	 *
-	 * @param array $config
-	 */
-	public function __construct( array $config ) {
-		parent::__construct( $config );
-		$this->mimeCallback = isset( $config['mimeCallback'] )
-			? $config['mimeCallback']
-			: null;
-		$this->memCache = WANObjectCache::newEmpty(); // disabled by default
-		$this->cheapCache = new ProcessCacheLRU( self::CACHE_CHEAP_SIZE );
-		$this->expensiveCache = new ProcessCacheLRU( self::CACHE_EXPENSIVE_SIZE );
-	}
-
-	/**
-	 * Get the maximum allowable file size given backend
-	 * medium restrictions and basic performance constraints.
-	 * Do not call this function from places outside FileBackend and FileOp.
-	 *
-	 * @return int Bytes
-	 */
-	final public function maxFileSizeInternal() {
-		return $this->maxFileSize;
-	}
-
-	/**
-	 * Check if a file can be created or changed at a given storage path.
-	 * FS backends should check if the parent directory exists, files can be
-	 * written under it, and that any file already there is writable.
-	 * Backends using key/value stores should check if the container exists.
-	 *
-	 * @param string $storagePath
-	 * @return bool
-	 */
-	abstract public function isPathUsableInternal( $storagePath );
-
-	/**
-	 * Create a file in the backend with the given contents.
-	 * This will overwrite any file that exists at the destination.
-	 * Do not call this function from places outside FileBackend and FileOp.
-	 *
-	 * $params include:
-	 *   - content     : the raw file contents
-	 *   - dst         : destination storage path
-	 *   - headers     : HTTP header name/value map
-	 *   - async       : StatusValue will be returned immediately if supported.
-	 *                   If the StatusValue is OK, then its value field will be
-	 *                   set to a FileBackendStoreOpHandle object.
-	 *   - dstExists   : Whether a file exists at the destination (optimization).
-	 *                   Callers can use "false" if no existing file is being changed.
-	 *
-	 * @param array $params
-	 * @return StatusValue
-	 */
-	final public function createInternal( array $params ) {
-		$ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
-		if ( strlen( $params['content'] ) > $this->maxFileSizeInternal() ) {
-			$status = $this->newStatus( 'backend-fail-maxsize',
-				$params['dst'], $this->maxFileSizeInternal() );
-		} else {
-			$status = $this->doCreateInternal( $params );
-			$this->clearCache( [ $params['dst'] ] );
-			if ( !isset( $params['dstExists'] ) || $params['dstExists'] ) {
-				$this->deleteFileCache( $params['dst'] ); // persistent cache
-			}
-		}
-
-		return $status;
-	}
-
-	/**
-	 * @see FileBackendStore::createInternal()
-	 * @param array $params
-	 * @return StatusValue
-	 */
-	abstract protected function doCreateInternal( array $params );
-
-	/**
-	 * Store a file into the backend from a file on disk.
-	 * This will overwrite any file that exists at the destination.
-	 * Do not call this function from places outside FileBackend and FileOp.
-	 *
-	 * $params include:
-	 *   - src         : source path on disk
-	 *   - dst         : destination storage path
-	 *   - headers     : HTTP header name/value map
-	 *   - async       : StatusValue will be returned immediately if supported.
-	 *                   If the StatusValue is OK, then its value field will be
-	 *                   set to a FileBackendStoreOpHandle object.
-	 *   - dstExists   : Whether a file exists at the destination (optimization).
-	 *                   Callers can use "false" if no existing file is being changed.
-	 *
-	 * @param array $params
-	 * @return StatusValue
-	 */
-	final public function storeInternal( array $params ) {
-		$ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
-		if ( filesize( $params['src'] ) > $this->maxFileSizeInternal() ) {
-			$status = $this->newStatus( 'backend-fail-maxsize',
-				$params['dst'], $this->maxFileSizeInternal() );
-		} else {
-			$status = $this->doStoreInternal( $params );
-			$this->clearCache( [ $params['dst'] ] );
-			if ( !isset( $params['dstExists'] ) || $params['dstExists'] ) {
-				$this->deleteFileCache( $params['dst'] ); // persistent cache
-			}
-		}
-
-		return $status;
-	}
-
-	/**
-	 * @see FileBackendStore::storeInternal()
-	 * @param array $params
-	 * @return StatusValue
-	 */
-	abstract protected function doStoreInternal( array $params );
-
-	/**
-	 * Copy a file from one storage path to another in the backend.
-	 * This will overwrite any file that exists at the destination.
-	 * Do not call this function from places outside FileBackend and FileOp.
-	 *
-	 * $params include:
-	 *   - src                 : source storage path
-	 *   - dst                 : destination storage path
-	 *   - ignoreMissingSource : do nothing if the source file does not exist
-	 *   - headers             : HTTP header name/value map
-	 *   - async               : StatusValue will be returned immediately if supported.
-	 *                           If the StatusValue is OK, then its value field will be
-	 *                           set to a FileBackendStoreOpHandle object.
-	 *   - dstExists           : Whether a file exists at the destination (optimization).
-	 *                           Callers can use "false" if no existing file is being changed.
-	 *
-	 * @param array $params
-	 * @return StatusValue
-	 */
-	final public function copyInternal( array $params ) {
-		$ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
-		$status = $this->doCopyInternal( $params );
-		$this->clearCache( [ $params['dst'] ] );
-		if ( !isset( $params['dstExists'] ) || $params['dstExists'] ) {
-			$this->deleteFileCache( $params['dst'] ); // persistent cache
-		}
-
-		return $status;
-	}
-
-	/**
-	 * @see FileBackendStore::copyInternal()
-	 * @param array $params
-	 * @return StatusValue
-	 */
-	abstract protected function doCopyInternal( array $params );
-
-	/**
-	 * Delete a file at the storage path.
-	 * Do not call this function from places outside FileBackend and FileOp.
-	 *
-	 * $params include:
-	 *   - src                 : source storage path
-	 *   - ignoreMissingSource : do nothing if the source file does not exist
-	 *   - async               : StatusValue will be returned immediately if supported.
-	 *                           If the StatusValue is OK, then its value field will be
-	 *                           set to a FileBackendStoreOpHandle object.
-	 *
-	 * @param array $params
-	 * @return StatusValue
-	 */
-	final public function deleteInternal( array $params ) {
-		$ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
-		$status = $this->doDeleteInternal( $params );
-		$this->clearCache( [ $params['src'] ] );
-		$this->deleteFileCache( $params['src'] ); // persistent cache
-		return $status;
-	}
-
-	/**
-	 * @see FileBackendStore::deleteInternal()
-	 * @param array $params
-	 * @return StatusValue
-	 */
-	abstract protected function doDeleteInternal( array $params );
-
-	/**
-	 * Move a file from one storage path to another in the backend.
-	 * This will overwrite any file that exists at the destination.
-	 * Do not call this function from places outside FileBackend and FileOp.
-	 *
-	 * $params include:
-	 *   - src                 : source storage path
-	 *   - dst                 : destination storage path
-	 *   - ignoreMissingSource : do nothing if the source file does not exist
-	 *   - headers             : HTTP header name/value map
-	 *   - async               : StatusValue will be returned immediately if supported.
-	 *                           If the StatusValue is OK, then its value field will be
-	 *                           set to a FileBackendStoreOpHandle object.
-	 *   - dstExists           : Whether a file exists at the destination (optimization).
-	 *                           Callers can use "false" if no existing file is being changed.
-	 *
-	 * @param array $params
-	 * @return StatusValue
-	 */
-	final public function moveInternal( array $params ) {
-		$ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
-		$status = $this->doMoveInternal( $params );
-		$this->clearCache( [ $params['src'], $params['dst'] ] );
-		$this->deleteFileCache( $params['src'] ); // persistent cache
-		if ( !isset( $params['dstExists'] ) || $params['dstExists'] ) {
-			$this->deleteFileCache( $params['dst'] ); // persistent cache
-		}
-
-		return $status;
-	}
-
-	/**
-	 * @see FileBackendStore::moveInternal()
-	 * @param array $params
-	 * @return StatusValue
-	 */
-	protected function doMoveInternal( array $params ) {
-		unset( $params['async'] ); // two steps, won't work here :)
-		$nsrc = FileBackend::normalizeStoragePath( $params['src'] );
-		$ndst = FileBackend::normalizeStoragePath( $params['dst'] );
-		// Copy source to dest
-		$status = $this->copyInternal( $params );
-		if ( $nsrc !== $ndst && $status->isOK() ) {
-			// Delete source (only fails due to races or network problems)
-			$status->merge( $this->deleteInternal( [ 'src' => $params['src'] ] ) );
-			$status->setResult( true, $status->value ); // ignore delete() errors
-		}
-
-		return $status;
-	}
-
-	/**
-	 * Alter metadata for a file at the storage path.
-	 * Do not call this function from places outside FileBackend and FileOp.
-	 *
-	 * $params include:
-	 *   - src           : source storage path
-	 *   - headers       : HTTP header name/value map
-	 *   - async         : StatusValue will be returned immediately if supported.
-	 *                     If the StatusValue is OK, then its value field will be
-	 *                     set to a FileBackendStoreOpHandle object.
-	 *
-	 * @param array $params
-	 * @return StatusValue
-	 */
-	final public function describeInternal( array $params ) {
-		$ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
-		if ( count( $params['headers'] ) ) {
-			$status = $this->doDescribeInternal( $params );
-			$this->clearCache( [ $params['src'] ] );
-			$this->deleteFileCache( $params['src'] ); // persistent cache
-		} else {
-			$status = $this->newStatus(); // nothing to do
-		}
-
-		return $status;
-	}
-
-	/**
-	 * @see FileBackendStore::describeInternal()
-	 * @param array $params
-	 * @return StatusValue
-	 */
-	protected function doDescribeInternal( array $params ) {
-		return $this->newStatus();
-	}
-
-	/**
-	 * No-op file operation that does nothing.
-	 * Do not call this function from places outside FileBackend and FileOp.
-	 *
-	 * @param array $params
-	 * @return StatusValue
-	 */
-	final public function nullInternal( array $params ) {
-		return $this->newStatus();
-	}
-
-	final public function concatenate( array $params ) {
-		$ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
-		$status = $this->newStatus();
-
-		// Try to lock the source files for the scope of this function
-		$scopeLockS = $this->getScopedFileLocks( $params['srcs'], LockManager::LOCK_UW, $status );
-		if ( $status->isOK() ) {
-			// Actually do the file concatenation...
-			$start_time = microtime( true );
-			$status->merge( $this->doConcatenate( $params ) );
-			$sec = microtime( true ) - $start_time;
-			if ( !$status->isOK() ) {
-				$this->logger->error( get_class( $this ) . "-{$this->name}" .
-					" failed to concatenate " . count( $params['srcs'] ) . " file(s) [$sec sec]" );
-			}
-		}
-
-		return $status;
-	}
-
-	/**
-	 * @see FileBackendStore::concatenate()
-	 * @param array $params
-	 * @return StatusValue
-	 */
-	protected function doConcatenate( array $params ) {
-		$status = $this->newStatus();
-		$tmpPath = $params['dst']; // convenience
-		unset( $params['latest'] ); // sanity
-
-		// Check that the specified temp file is valid...
-		MediaWiki\suppressWarnings();
-		$ok = ( is_file( $tmpPath ) && filesize( $tmpPath ) == 0 );
-		MediaWiki\restoreWarnings();
-		if ( !$ok ) { // not present or not empty
-			$status->fatal( 'backend-fail-opentemp', $tmpPath );
-
-			return $status;
-		}
-
-		// Get local FS versions of the chunks needed for the concatenation...
-		$fsFiles = $this->getLocalReferenceMulti( $params );
-		foreach ( $fsFiles as $path => &$fsFile ) {
-			if ( !$fsFile ) { // chunk failed to download?
-				$fsFile = $this->getLocalReference( [ 'src' => $path ] );
-				if ( !$fsFile ) { // retry failed?
-					$status->fatal( 'backend-fail-read', $path );
-
-					return $status;
-				}
-			}
-		}
-		unset( $fsFile ); // unset reference so we can reuse $fsFile
-
-		// Get a handle for the destination temp file
-		$tmpHandle = fopen( $tmpPath, 'ab' );
-		if ( $tmpHandle === false ) {
-			$status->fatal( 'backend-fail-opentemp', $tmpPath );
-
-			return $status;
-		}
-
-		// Build up the temp file using the source chunks (in order)...
-		foreach ( $fsFiles as $virtualSource => $fsFile ) {
-			// Get a handle to the local FS version
-			$sourceHandle = fopen( $fsFile->getPath(), 'rb' );
-			if ( $sourceHandle === false ) {
-				fclose( $tmpHandle );
-				$status->fatal( 'backend-fail-read', $virtualSource );
-
-				return $status;
-			}
-			// Append chunk to file (pass chunk size to avoid magic quotes)
-			if ( !stream_copy_to_stream( $sourceHandle, $tmpHandle ) ) {
-				fclose( $sourceHandle );
-				fclose( $tmpHandle );
-				$status->fatal( 'backend-fail-writetemp', $tmpPath );
-
-				return $status;
-			}
-			fclose( $sourceHandle );
-		}
-		if ( !fclose( $tmpHandle ) ) {
-			$status->fatal( 'backend-fail-closetemp', $tmpPath );
-
-			return $status;
-		}
-
-		clearstatcache(); // temp file changed
-
-		return $status;
-	}
-
-	final protected function doPrepare( array $params ) {
-		$ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
-		$status = $this->newStatus();
-
-		list( $fullCont, $dir, $shard ) = $this->resolveStoragePath( $params['dir'] );
-		if ( $dir === null ) {
-			$status->fatal( 'backend-fail-invalidpath', $params['dir'] );
-
-			return $status; // invalid storage path
-		}
-
-		if ( $shard !== null ) { // confined to a single container/shard
-			$status->merge( $this->doPrepareInternal( $fullCont, $dir, $params ) );
-		} else { // directory is on several shards
-			$this->logger->debug( __METHOD__ . ": iterating over all container shards.\n" );
-			list( , $shortCont, ) = self::splitStoragePath( $params['dir'] );
-			foreach ( $this->getContainerSuffixes( $shortCont ) as $suffix ) {
-				$status->merge( $this->doPrepareInternal( "{$fullCont}{$suffix}", $dir, $params ) );
-			}
-		}
-
-		return $status;
-	}
-
-	/**
-	 * @see FileBackendStore::doPrepare()
-	 * @param string $container
-	 * @param string $dir
-	 * @param array $params
-	 * @return StatusValue
-	 */
-	protected function doPrepareInternal( $container, $dir, array $params ) {
-		return $this->newStatus();
-	}
-
-	final protected function doSecure( array $params ) {
-		$ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
-		$status = $this->newStatus();
-
-		list( $fullCont, $dir, $shard ) = $this->resolveStoragePath( $params['dir'] );
-		if ( $dir === null ) {
-			$status->fatal( 'backend-fail-invalidpath', $params['dir'] );
-
-			return $status; // invalid storage path
-		}
-
-		if ( $shard !== null ) { // confined to a single container/shard
-			$status->merge( $this->doSecureInternal( $fullCont, $dir, $params ) );
-		} else { // directory is on several shards
-			$this->logger->debug( __METHOD__ . ": iterating over all container shards.\n" );
-			list( , $shortCont, ) = self::splitStoragePath( $params['dir'] );
-			foreach ( $this->getContainerSuffixes( $shortCont ) as $suffix ) {
-				$status->merge( $this->doSecureInternal( "{$fullCont}{$suffix}", $dir, $params ) );
-			}
-		}
-
-		return $status;
-	}
-
-	/**
-	 * @see FileBackendStore::doSecure()
-	 * @param string $container
-	 * @param string $dir
-	 * @param array $params
-	 * @return StatusValue
-	 */
-	protected function doSecureInternal( $container, $dir, array $params ) {
-		return $this->newStatus();
-	}
-
-	final protected function doPublish( array $params ) {
-		$ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
-		$status = $this->newStatus();
-
-		list( $fullCont, $dir, $shard ) = $this->resolveStoragePath( $params['dir'] );
-		if ( $dir === null ) {
-			$status->fatal( 'backend-fail-invalidpath', $params['dir'] );
-
-			return $status; // invalid storage path
-		}
-
-		if ( $shard !== null ) { // confined to a single container/shard
-			$status->merge( $this->doPublishInternal( $fullCont, $dir, $params ) );
-		} else { // directory is on several shards
-			$this->logger->debug( __METHOD__ . ": iterating over all container shards.\n" );
-			list( , $shortCont, ) = self::splitStoragePath( $params['dir'] );
-			foreach ( $this->getContainerSuffixes( $shortCont ) as $suffix ) {
-				$status->merge( $this->doPublishInternal( "{$fullCont}{$suffix}", $dir, $params ) );
-			}
-		}
-
-		return $status;
-	}
-
-	/**
-	 * @see FileBackendStore::doPublish()
-	 * @param string $container
-	 * @param string $dir
-	 * @param array $params
-	 * @return StatusValue
-	 */
-	protected function doPublishInternal( $container, $dir, array $params ) {
-		return $this->newStatus();
-	}
-
-	final protected function doClean( array $params ) {
-		$ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
-		$status = $this->newStatus();
-
-		// Recursive: first delete all empty subdirs recursively
-		if ( !empty( $params['recursive'] ) && !$this->directoriesAreVirtual() ) {
-			$subDirsRel = $this->getTopDirectoryList( [ 'dir' => $params['dir'] ] );
-			if ( $subDirsRel !== null ) { // no errors
-				foreach ( $subDirsRel as $subDirRel ) {
-					$subDir = $params['dir'] . "/{$subDirRel}"; // full path
-					$status->merge( $this->doClean( [ 'dir' => $subDir ] + $params ) );
-				}
-				unset( $subDirsRel ); // free directory for rmdir() on Windows (for FS backends)
-			}
-		}
-
-		list( $fullCont, $dir, $shard ) = $this->resolveStoragePath( $params['dir'] );
-		if ( $dir === null ) {
-			$status->fatal( 'backend-fail-invalidpath', $params['dir'] );
-
-			return $status; // invalid storage path
-		}
-
-		// Attempt to lock this directory...
-		$filesLockEx = [ $params['dir'] ];
-		$scopedLockE = $this->getScopedFileLocks( $filesLockEx, LockManager::LOCK_EX, $status );
-		if ( !$status->isOK() ) {
-			return $status; // abort
-		}
-
-		if ( $shard !== null ) { // confined to a single container/shard
-			$status->merge( $this->doCleanInternal( $fullCont, $dir, $params ) );
-			$this->deleteContainerCache( $fullCont ); // purge cache
-		} else { // directory is on several shards
-			$this->logger->debug( __METHOD__ . ": iterating over all container shards.\n" );
-			list( , $shortCont, ) = self::splitStoragePath( $params['dir'] );
-			foreach ( $this->getContainerSuffixes( $shortCont ) as $suffix ) {
-				$status->merge( $this->doCleanInternal( "{$fullCont}{$suffix}", $dir, $params ) );
-				$this->deleteContainerCache( "{$fullCont}{$suffix}" ); // purge cache
-			}
-		}
-
-		return $status;
-	}
-
-	/**
-	 * @see FileBackendStore::doClean()
-	 * @param string $container
-	 * @param string $dir
-	 * @param array $params
-	 * @return StatusValue
-	 */
-	protected function doCleanInternal( $container, $dir, array $params ) {
-		return $this->newStatus();
-	}
-
-	final public function fileExists( array $params ) {
-		$ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
-		$stat = $this->getFileStat( $params );
-
-		return ( $stat === null ) ? null : (bool)$stat; // null => failure
-	}
-
-	final public function getFileTimestamp( array $params ) {
-		$ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
-		$stat = $this->getFileStat( $params );
-
-		return $stat ? $stat['mtime'] : false;
-	}
-
-	final public function getFileSize( array $params ) {
-		$ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
-		$stat = $this->getFileStat( $params );
-
-		return $stat ? $stat['size'] : false;
-	}
-
-	final public function getFileStat( array $params ) {
-		$path = self::normalizeStoragePath( $params['src'] );
-		if ( $path === null ) {
-			return false; // invalid storage path
-		}
-		$ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
-		$latest = !empty( $params['latest'] ); // use latest data?
-		if ( !$latest && !$this->cheapCache->has( $path, 'stat', self::CACHE_TTL ) ) {
-			$this->primeFileCache( [ $path ] ); // check persistent cache
-		}
-		if ( $this->cheapCache->has( $path, 'stat', self::CACHE_TTL ) ) {
-			$stat = $this->cheapCache->get( $path, 'stat' );
-			// If we want the latest data, check that this cached
-			// value was in fact fetched with the latest available data.
-			if ( is_array( $stat ) ) {
-				if ( !$latest || $stat['latest'] ) {
-					return $stat;
-				}
-			} elseif ( in_array( $stat, [ 'NOT_EXIST', 'NOT_EXIST_LATEST' ] ) ) {
-				if ( !$latest || $stat === 'NOT_EXIST_LATEST' ) {
-					return false;
-				}
-			}
-		}
-		$stat = $this->doGetFileStat( $params );
-		if ( is_array( $stat ) ) { // file exists
-			// Strongly consistent backends can automatically set "latest"
-			$stat['latest'] = isset( $stat['latest'] ) ? $stat['latest'] : $latest;
-			$this->cheapCache->set( $path, 'stat', $stat );
-			$this->setFileCache( $path, $stat ); // update persistent cache
-			if ( isset( $stat['sha1'] ) ) { // some backends store SHA-1 as metadata
-				$this->cheapCache->set( $path, 'sha1',
-					[ 'hash' => $stat['sha1'], 'latest' => $latest ] );
-			}
-			if ( isset( $stat['xattr'] ) ) { // some backends store headers/metadata
-				$stat['xattr'] = self::normalizeXAttributes( $stat['xattr'] );
-				$this->cheapCache->set( $path, 'xattr',
-					[ 'map' => $stat['xattr'], 'latest' => $latest ] );
-			}
-		} elseif ( $stat === false ) { // file does not exist
-			$this->cheapCache->set( $path, 'stat', $latest ? 'NOT_EXIST_LATEST' : 'NOT_EXIST' );
-			$this->cheapCache->set( $path, 'xattr', [ 'map' => false, 'latest' => $latest ] );
-			$this->cheapCache->set( $path, 'sha1', [ 'hash' => false, 'latest' => $latest ] );
-			$this->logger->debug( __METHOD__ . ": File $path does not exist.\n" );
-		} else { // an error occurred
-			$this->logger->warning( __METHOD__ . ": Could not stat file $path.\n" );
-		}
-
-		return $stat;
-	}
-
-	/**
-	 * @see FileBackendStore::getFileStat()
-	 */
-	abstract protected function doGetFileStat( array $params );
-
-	public function getFileContentsMulti( array $params ) {
-		$ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
-
-		$params = $this->setConcurrencyFlags( $params );
-		$contents = $this->doGetFileContentsMulti( $params );
-
-		return $contents;
-	}
-
-	/**
-	 * @see FileBackendStore::getFileContentsMulti()
-	 * @param array $params
-	 * @return array
-	 */
-	protected function doGetFileContentsMulti( array $params ) {
-		$contents = [];
-		foreach ( $this->doGetLocalReferenceMulti( $params ) as $path => $fsFile ) {
-			MediaWiki\suppressWarnings();
-			$contents[$path] = $fsFile ? file_get_contents( $fsFile->getPath() ) : false;
-			MediaWiki\restoreWarnings();
-		}
-
-		return $contents;
-	}
-
-	final public function getFileXAttributes( array $params ) {
-		$path = self::normalizeStoragePath( $params['src'] );
-		if ( $path === null ) {
-			return false; // invalid storage path
-		}
-		$ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
-		$latest = !empty( $params['latest'] ); // use latest data?
-		if ( $this->cheapCache->has( $path, 'xattr', self::CACHE_TTL ) ) {
-			$stat = $this->cheapCache->get( $path, 'xattr' );
-			// If we want the latest data, check that this cached
-			// value was in fact fetched with the latest available data.
-			if ( !$latest || $stat['latest'] ) {
-				return $stat['map'];
-			}
-		}
-		$fields = $this->doGetFileXAttributes( $params );
-		$fields = is_array( $fields ) ? self::normalizeXAttributes( $fields ) : false;
-		$this->cheapCache->set( $path, 'xattr', [ 'map' => $fields, 'latest' => $latest ] );
-
-		return $fields;
-	}
-
-	/**
-	 * @see FileBackendStore::getFileXAttributes()
-	 * @return bool|string
-	 */
-	protected function doGetFileXAttributes( array $params ) {
-		return [ 'headers' => [], 'metadata' => [] ]; // not supported
-	}
-
-	final public function getFileSha1Base36( array $params ) {
-		$path = self::normalizeStoragePath( $params['src'] );
-		if ( $path === null ) {
-			return false; // invalid storage path
-		}
-		$ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
-		$latest = !empty( $params['latest'] ); // use latest data?
-		if ( $this->cheapCache->has( $path, 'sha1', self::CACHE_TTL ) ) {
-			$stat = $this->cheapCache->get( $path, 'sha1' );
-			// If we want the latest data, check that this cached
-			// value was in fact fetched with the latest available data.
-			if ( !$latest || $stat['latest'] ) {
-				return $stat['hash'];
-			}
-		}
-		$hash = $this->doGetFileSha1Base36( $params );
-		$this->cheapCache->set( $path, 'sha1', [ 'hash' => $hash, 'latest' => $latest ] );
-
-		return $hash;
-	}
-
-	/**
-	 * @see FileBackendStore::getFileSha1Base36()
-	 * @param array $params
-	 * @return bool|string
-	 */
-	protected function doGetFileSha1Base36( array $params ) {
-		$fsFile = $this->getLocalReference( $params );
-		if ( !$fsFile ) {
-			return false;
-		} else {
-			return $fsFile->getSha1Base36();
-		}
-	}
-
-	final public function getFileProps( array $params ) {
-		$ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
-		$fsFile = $this->getLocalReference( $params );
-		$props = $fsFile ? $fsFile->getProps() : FSFile::placeholderProps();
-
-		return $props;
-	}
-
-	final public function getLocalReferenceMulti( array $params ) {
-		$ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
-
-		$params = $this->setConcurrencyFlags( $params );
-
-		$fsFiles = []; // (path => FSFile)
-		$latest = !empty( $params['latest'] ); // use latest data?
-		// Reuse any files already in process cache...
-		foreach ( $params['srcs'] as $src ) {
-			$path = self::normalizeStoragePath( $src );
-			if ( $path === null ) {
-				$fsFiles[$src] = null; // invalid storage path
-			} elseif ( $this->expensiveCache->has( $path, 'localRef' ) ) {
-				$val = $this->expensiveCache->get( $path, 'localRef' );
-				// If we want the latest data, check that this cached
-				// value was in fact fetched with the latest available data.
-				if ( !$latest || $val['latest'] ) {
-					$fsFiles[$src] = $val['object'];
-				}
-			}
-		}
-		// Fetch local references of any remaning files...
-		$params['srcs'] = array_diff( $params['srcs'], array_keys( $fsFiles ) );
-		foreach ( $this->doGetLocalReferenceMulti( $params ) as $path => $fsFile ) {
-			$fsFiles[$path] = $fsFile;
-			if ( $fsFile ) { // update the process cache...
-				$this->expensiveCache->set( $path, 'localRef',
-					[ 'object' => $fsFile, 'latest' => $latest ] );
-			}
-		}
-
-		return $fsFiles;
-	}
-
-	/**
-	 * @see FileBackendStore::getLocalReferenceMulti()
-	 * @param array $params
-	 * @return array
-	 */
-	protected function doGetLocalReferenceMulti( array $params ) {
-		return $this->doGetLocalCopyMulti( $params );
-	}
-
-	final public function getLocalCopyMulti( array $params ) {
-		$ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
-
-		$params = $this->setConcurrencyFlags( $params );
-		$tmpFiles = $this->doGetLocalCopyMulti( $params );
-
-		return $tmpFiles;
-	}
-
-	/**
-	 * @see FileBackendStore::getLocalCopyMulti()
-	 * @param array $params
-	 * @return array
-	 */
-	abstract protected function doGetLocalCopyMulti( array $params );
-
-	/**
-	 * @see FileBackend::getFileHttpUrl()
-	 * @param array $params
-	 * @return string|null
-	 */
-	public function getFileHttpUrl( array $params ) {
-		return null; // not supported
-	}
-
-	final public function streamFile( array $params ) {
-		$ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
-		$status = $this->newStatus();
-
-		// Always set some fields for subclass convenience
-		$params['options'] = isset( $params['options'] ) ? $params['options'] : [];
-		$params['headers'] = isset( $params['headers'] ) ? $params['headers'] : [];
-
-		// Don't stream it out as text/html if there was a PHP error
-		if ( ( empty( $params['headless'] ) || $params['headers'] ) && headers_sent() ) {
-			print "Headers already sent, terminating.\n";
-			$status->fatal( 'backend-fail-stream', $params['src'] );
-			return $status;
-		}
-
-		$status->merge( $this->doStreamFile( $params ) );
-
-		return $status;
-	}
-
-	/**
-	 * @see FileBackendStore::streamFile()
-	 * @param array $params
-	 * @return StatusValue
-	 */
-	protected function doStreamFile( array $params ) {
-		$status = $this->newStatus();
-
-		$flags = 0;
-		$flags |= !empty( $params['headless'] ) ? HTTPFileStreamer::STREAM_HEADLESS : 0;
-		$flags |= !empty( $params['allowOB'] ) ? HTTPFileStreamer::STREAM_ALLOW_OB : 0;
-
-		$fsFile = $this->getLocalReference( $params );
-		if ( $fsFile ) {
-			$streamer = new HTTPFileStreamer(
-				$fsFile->getPath(),
-				[
-					'obResetFunc' => $this->obResetFunc,
-					'streamMimeFunc' => $this->streamMimeFunc
-				]
-			);
-			$res = $streamer->stream( $params['headers'], true, $params['options'], $flags );
-		} else {
-			$res = false;
-			HTTPFileStreamer::send404Message( $params['src'], $flags );
-		}
-
-		if ( !$res ) {
-			$status->fatal( 'backend-fail-stream', $params['src'] );
-		}
-
-		return $status;
-	}
-
-	final public function directoryExists( array $params ) {
-		list( $fullCont, $dir, $shard ) = $this->resolveStoragePath( $params['dir'] );
-		if ( $dir === null ) {
-			return false; // invalid storage path
-		}
-		if ( $shard !== null ) { // confined to a single container/shard
-			return $this->doDirectoryExists( $fullCont, $dir, $params );
-		} else { // directory is on several shards
-			$this->logger->debug( __METHOD__ . ": iterating over all container shards.\n" );
-			list( , $shortCont, ) = self::splitStoragePath( $params['dir'] );
-			$res = false; // response
-			foreach ( $this->getContainerSuffixes( $shortCont ) as $suffix ) {
-				$exists = $this->doDirectoryExists( "{$fullCont}{$suffix}", $dir, $params );
-				if ( $exists ) {
-					$res = true;
-					break; // found one!
-				} elseif ( $exists === null ) { // error?
-					$res = null; // if we don't find anything, it is indeterminate
-				}
-			}
-
-			return $res;
-		}
-	}
-
-	/**
-	 * @see FileBackendStore::directoryExists()
-	 *
-	 * @param string $container Resolved container name
-	 * @param string $dir Resolved path relative to container
-	 * @param array $params
-	 * @return bool|null
-	 */
-	abstract protected function doDirectoryExists( $container, $dir, array $params );
-
-	final public function getDirectoryList( array $params ) {
-		list( $fullCont, $dir, $shard ) = $this->resolveStoragePath( $params['dir'] );
-		if ( $dir === null ) { // invalid storage path
-			return null;
-		}
-		if ( $shard !== null ) {
-			// File listing is confined to a single container/shard
-			return $this->getDirectoryListInternal( $fullCont, $dir, $params );
-		} else {
-			$this->logger->debug( __METHOD__ . ": iterating over all container shards.\n" );
-			// File listing spans multiple containers/shards
-			list( , $shortCont, ) = self::splitStoragePath( $params['dir'] );
-
-			return new FileBackendStoreShardDirIterator( $this,
-				$fullCont, $dir, $this->getContainerSuffixes( $shortCont ), $params );
-		}
-	}
-
-	/**
-	 * Do not call this function from places outside FileBackend
-	 *
-	 * @see FileBackendStore::getDirectoryList()
-	 *
-	 * @param string $container Resolved container name
-	 * @param string $dir Resolved path relative to container
-	 * @param array $params
-	 * @return Traversable|array|null Returns null on failure
-	 */
-	abstract public function getDirectoryListInternal( $container, $dir, array $params );
-
-	final public function getFileList( array $params ) {
-		list( $fullCont, $dir, $shard ) = $this->resolveStoragePath( $params['dir'] );
-		if ( $dir === null ) { // invalid storage path
-			return null;
-		}
-		if ( $shard !== null ) {
-			// File listing is confined to a single container/shard
-			return $this->getFileListInternal( $fullCont, $dir, $params );
-		} else {
-			$this->logger->debug( __METHOD__ . ": iterating over all container shards.\n" );
-			// File listing spans multiple containers/shards
-			list( , $shortCont, ) = self::splitStoragePath( $params['dir'] );
-
-			return new FileBackendStoreShardFileIterator( $this,
-				$fullCont, $dir, $this->getContainerSuffixes( $shortCont ), $params );
-		}
-	}
-
-	/**
-	 * Do not call this function from places outside FileBackend
-	 *
-	 * @see FileBackendStore::getFileList()
-	 *
-	 * @param string $container Resolved container name
-	 * @param string $dir Resolved path relative to container
-	 * @param array $params
-	 * @return Traversable|array|null Returns null on failure
-	 */
-	abstract public function getFileListInternal( $container, $dir, array $params );
-
-	/**
-	 * Return a list of FileOp objects from a list of operations.
-	 * Do not call this function from places outside FileBackend.
-	 *
-	 * The result must have the same number of items as the input.
-	 * An exception is thrown if an unsupported operation is requested.
-	 *
-	 * @param array $ops Same format as doOperations()
-	 * @return FileOp[] List of FileOp objects
-	 * @throws FileBackendError
-	 */
-	final public function getOperationsInternal( array $ops ) {
-		$supportedOps = [
-			'store' => 'StoreFileOp',
-			'copy' => 'CopyFileOp',
-			'move' => 'MoveFileOp',
-			'delete' => 'DeleteFileOp',
-			'create' => 'CreateFileOp',
-			'describe' => 'DescribeFileOp',
-			'null' => 'NullFileOp'
-		];
-
-		$performOps = []; // array of FileOp objects
-		// Build up ordered array of FileOps...
-		foreach ( $ops as $operation ) {
-			$opName = $operation['op'];
-			if ( isset( $supportedOps[$opName] ) ) {
-				$class = $supportedOps[$opName];
-				// Get params for this operation
-				$params = $operation;
-				// Append the FileOp class
-				$performOps[] = new $class( $this, $params, $this->logger );
-			} else {
-				throw new FileBackendError( "Operation '$opName' is not supported." );
-			}
-		}
-
-		return $performOps;
-	}
-
-	/**
-	 * Get a list of storage paths to lock for a list of operations
-	 * Returns an array with LockManager::LOCK_UW (shared locks) and
-	 * LockManager::LOCK_EX (exclusive locks) keys, each corresponding
-	 * to a list of storage paths to be locked. All returned paths are
-	 * normalized.
-	 *
-	 * @param array $performOps List of FileOp objects
-	 * @return array (LockManager::LOCK_UW => path list, LockManager::LOCK_EX => path list)
-	 */
-	final public function getPathsToLockForOpsInternal( array $performOps ) {
-		// Build up a list of files to lock...
-		$paths = [ 'sh' => [], 'ex' => [] ];
-		foreach ( $performOps as $fileOp ) {
-			$paths['sh'] = array_merge( $paths['sh'], $fileOp->storagePathsRead() );
-			$paths['ex'] = array_merge( $paths['ex'], $fileOp->storagePathsChanged() );
-		}
-		// Optimization: if doing an EX lock anyway, don't also set an SH one
-		$paths['sh'] = array_diff( $paths['sh'], $paths['ex'] );
-		// Get a shared lock on the parent directory of each path changed
-		$paths['sh'] = array_merge( $paths['sh'], array_map( 'dirname', $paths['ex'] ) );
-
-		return [
-			LockManager::LOCK_UW => $paths['sh'],
-			LockManager::LOCK_EX => $paths['ex']
-		];
-	}
-
-	public function getScopedLocksForOps( array $ops, StatusValue $status ) {
-		$paths = $this->getPathsToLockForOpsInternal( $this->getOperationsInternal( $ops ) );
-
-		return $this->getScopedFileLocks( $paths, 'mixed', $status );
-	}
-
-	final protected function doOperationsInternal( array $ops, array $opts ) {
-		$ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
-		$status = $this->newStatus();
-
-		// Fix up custom header name/value pairs...
-		$ops = array_map( [ $this, 'sanitizeOpHeaders' ], $ops );
-
-		// Build up a list of FileOps...
-		$performOps = $this->getOperationsInternal( $ops );
-
-		// Acquire any locks as needed...
-		if ( empty( $opts['nonLocking'] ) ) {
-			// Build up a list of files to lock...
-			$paths = $this->getPathsToLockForOpsInternal( $performOps );
-			// Try to lock those files for the scope of this function...
-
-			$scopeLock = $this->getScopedFileLocks( $paths, 'mixed', $status );
-			if ( !$status->isOK() ) {
-				return $status; // abort
-			}
-		}
-
-		// Clear any file cache entries (after locks acquired)
-		if ( empty( $opts['preserveCache'] ) ) {
-			$this->clearCache();
-		}
-
-		// Build the list of paths involved
-		$paths = [];
-		foreach ( $performOps as $op ) {
-			$paths = array_merge( $paths, $op->storagePathsRead() );
-			$paths = array_merge( $paths, $op->storagePathsChanged() );
-		}
-
-		// Enlarge the cache to fit the stat entries of these files
-		$this->cheapCache->resize( max( 2 * count( $paths ), self::CACHE_CHEAP_SIZE ) );
-
-		// Load from the persistent container caches
-		$this->primeContainerCache( $paths );
-		// Get the latest stat info for all the files (having locked them)
-		$ok = $this->preloadFileStat( [ 'srcs' => $paths, 'latest' => true ] );
-
-		if ( $ok ) {
-			// Actually attempt the operation batch...
-			$opts = $this->setConcurrencyFlags( $opts );
-			$subStatus = FileOpBatch::attempt( $performOps, $opts, $this->fileJournal );
-		} else {
-			// If we could not even stat some files, then bail out...
-			$subStatus = $this->newStatus( 'backend-fail-internal', $this->name );
-			foreach ( $ops as $i => $op ) { // mark each op as failed
-				$subStatus->success[$i] = false;
-				++$subStatus->failCount;
-			}
-			$this->logger->error( get_class( $this ) . "-{$this->name} " .
-				" stat failure; aborted operations: " . FormatJson::encode( $ops ) );
-		}
-
-		// Merge errors into StatusValue fields
-		$status->merge( $subStatus );
-		$status->success = $subStatus->success; // not done in merge()
-
-		// Shrink the stat cache back to normal size
-		$this->cheapCache->resize( self::CACHE_CHEAP_SIZE );
-
-		return $status;
-	}
-
-	final protected function doQuickOperationsInternal( array $ops ) {
-		$ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
-		$status = $this->newStatus();
-
-		// Fix up custom header name/value pairs...
-		$ops = array_map( [ $this, 'sanitizeOpHeaders' ], $ops );
-
-		// Clear any file cache entries
-		$this->clearCache();
-
-		$supportedOps = [ 'create', 'store', 'copy', 'move', 'delete', 'describe', 'null' ];
-		// Parallel ops may be disabled in config due to dependencies (e.g. needing popen())
-		$async = ( $this->parallelize === 'implicit' && count( $ops ) > 1 );
-		$maxConcurrency = $this->concurrency; // throttle
-		/** @var StatusValue[] $statuses */
-		$statuses = []; // array of (index => StatusValue)
-		$fileOpHandles = []; // list of (index => handle) arrays
-		$curFileOpHandles = []; // current handle batch
-		// Perform the sync-only ops and build up op handles for the async ops...
-		foreach ( $ops as $index => $params ) {
-			if ( !in_array( $params['op'], $supportedOps ) ) {
-				throw new FileBackendError( "Operation '{$params['op']}' is not supported." );
-			}
-			$method = $params['op'] . 'Internal'; // e.g. "storeInternal"
-			$subStatus = $this->$method( [ 'async' => $async ] + $params );
-			if ( $subStatus->value instanceof FileBackendStoreOpHandle ) { // async
-				if ( count( $curFileOpHandles ) >= $maxConcurrency ) {
-					$fileOpHandles[] = $curFileOpHandles; // push this batch
-					$curFileOpHandles = [];
-				}
-				$curFileOpHandles[$index] = $subStatus->value; // keep index
-			} else { // error or completed
-				$statuses[$index] = $subStatus; // keep index
-			}
-		}
-		if ( count( $curFileOpHandles ) ) {
-			$fileOpHandles[] = $curFileOpHandles; // last batch
-		}
-		// Do all the async ops that can be done concurrently...
-		foreach ( $fileOpHandles as $fileHandleBatch ) {
-			$statuses = $statuses + $this->executeOpHandlesInternal( $fileHandleBatch );
-		}
-		// Marshall and merge all the responses...
-		foreach ( $statuses as $index => $subStatus ) {
-			$status->merge( $subStatus );
-			if ( $subStatus->isOK() ) {
-				$status->success[$index] = true;
-				++$status->successCount;
-			} else {
-				$status->success[$index] = false;
-				++$status->failCount;
-			}
-		}
-
-		return $status;
-	}
-
-	/**
-	 * Execute a list of FileBackendStoreOpHandle handles in parallel.
-	 * The resulting StatusValue object fields will correspond
-	 * to the order in which the handles where given.
-	 *
-	 * @param FileBackendStoreOpHandle[] $fileOpHandles
-	 *
-	 * @throws FileBackendError
-	 * @return StatusValue[] Map of StatusValue objects
-	 */
-	final public function executeOpHandlesInternal( array $fileOpHandles ) {
-		$ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
-
-		foreach ( $fileOpHandles as $fileOpHandle ) {
-			if ( !( $fileOpHandle instanceof FileBackendStoreOpHandle ) ) {
-				throw new InvalidArgumentException( "Got a non-FileBackendStoreOpHandle object." );
-			} elseif ( $fileOpHandle->backend->getName() !== $this->getName() ) {
-				throw new InvalidArgumentException(
-					"Got a FileBackendStoreOpHandle for the wrong backend." );
-			}
-		}
-		$res = $this->doExecuteOpHandlesInternal( $fileOpHandles );
-		foreach ( $fileOpHandles as $fileOpHandle ) {
-			$fileOpHandle->closeResources();
-		}
-
-		return $res;
-	}
-
-	/**
-	 * @see FileBackendStore::executeOpHandlesInternal()
-	 *
-	 * @param FileBackendStoreOpHandle[] $fileOpHandles
-	 *
-	 * @throws FileBackendError
-	 * @return StatusValue[] List of corresponding StatusValue objects
-	 */
-	protected function doExecuteOpHandlesInternal( array $fileOpHandles ) {
-		if ( count( $fileOpHandles ) ) {
-			throw new LogicException( "Backend does not support asynchronous operations." );
-		}
-
-		return [];
-	}
-
-	/**
-	 * Normalize and filter HTTP headers from a file operation
-	 *
-	 * This normalizes and strips long HTTP headers from a file operation.
-	 * Most headers are just numbers, but some are allowed to be long.
-	 * This function is useful for cleaning up headers and avoiding backend
-	 * specific errors, especially in the middle of batch file operations.
-	 *
-	 * @param array $op Same format as doOperation()
-	 * @return array
-	 */
-	protected function sanitizeOpHeaders( array $op ) {
-		static $longs = [ 'content-disposition' ];
-
-		if ( isset( $op['headers'] ) ) { // op sets HTTP headers
-			$newHeaders = [];
-			foreach ( $op['headers'] as $name => $value ) {
-				$name = strtolower( $name );
-				$maxHVLen = in_array( $name, $longs ) ? INF : 255;
-				if ( strlen( $name ) > 255 || strlen( $value ) > $maxHVLen ) {
-					trigger_error( "Header '$name: $value' is too long." );
-				} else {
-					$newHeaders[$name] = strlen( $value ) ? $value : ''; // null/false => ""
-				}
-			}
-			$op['headers'] = $newHeaders;
-		}
-
-		return $op;
-	}
-
-	final public function preloadCache( array $paths ) {
-		$fullConts = []; // full container names
-		foreach ( $paths as $path ) {
-			list( $fullCont, , ) = $this->resolveStoragePath( $path );
-			$fullConts[] = $fullCont;
-		}
-		// Load from the persistent file and container caches
-		$this->primeContainerCache( $fullConts );
-		$this->primeFileCache( $paths );
-	}
-
-	final public function clearCache( array $paths = null ) {
-		if ( is_array( $paths ) ) {
-			$paths = array_map( 'FileBackend::normalizeStoragePath', $paths );
-			$paths = array_filter( $paths, 'strlen' ); // remove nulls
-		}
-		if ( $paths === null ) {
-			$this->cheapCache->clear();
-			$this->expensiveCache->clear();
-		} else {
-			foreach ( $paths as $path ) {
-				$this->cheapCache->clear( $path );
-				$this->expensiveCache->clear( $path );
-			}
-		}
-		$this->doClearCache( $paths );
-	}
-
-	/**
-	 * Clears any additional stat caches for storage paths
-	 *
-	 * @see FileBackend::clearCache()
-	 *
-	 * @param array $paths Storage paths (optional)
-	 */
-	protected function doClearCache( array $paths = null ) {
-	}
-
-	final public function preloadFileStat( array $params ) {
-		$ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
-		$success = true; // no network errors
-
-		$params['concurrency'] = ( $this->parallelize !== 'off' ) ? $this->concurrency : 1;
-		$stats = $this->doGetFileStatMulti( $params );
-		if ( $stats === null ) {
-			return true; // not supported
-		}
-
-		$latest = !empty( $params['latest'] ); // use latest data?
-		foreach ( $stats as $path => $stat ) {
-			$path = FileBackend::normalizeStoragePath( $path );
-			if ( $path === null ) {
-				continue; // this shouldn't happen
-			}
-			if ( is_array( $stat ) ) { // file exists
-				// Strongly consistent backends can automatically set "latest"
-				$stat['latest'] = isset( $stat['latest'] ) ? $stat['latest'] : $latest;
-				$this->cheapCache->set( $path, 'stat', $stat );
-				$this->setFileCache( $path, $stat ); // update persistent cache
-				if ( isset( $stat['sha1'] ) ) { // some backends store SHA-1 as metadata
-					$this->cheapCache->set( $path, 'sha1',
-						[ 'hash' => $stat['sha1'], 'latest' => $latest ] );
-				}
-				if ( isset( $stat['xattr'] ) ) { // some backends store headers/metadata
-					$stat['xattr'] = self::normalizeXAttributes( $stat['xattr'] );
-					$this->cheapCache->set( $path, 'xattr',
-						[ 'map' => $stat['xattr'], 'latest' => $latest ] );
-				}
-			} elseif ( $stat === false ) { // file does not exist
-				$this->cheapCache->set( $path, 'stat',
-					$latest ? 'NOT_EXIST_LATEST' : 'NOT_EXIST' );
-				$this->cheapCache->set( $path, 'xattr',
-					[ 'map' => false, 'latest' => $latest ] );
-				$this->cheapCache->set( $path, 'sha1',
-					[ 'hash' => false, 'latest' => $latest ] );
-				$this->logger->debug( __METHOD__ . ": File $path does not exist.\n" );
-			} else { // an error occurred
-				$success = false;
-				$this->logger->warning( __METHOD__ . ": Could not stat file $path.\n" );
-			}
-		}
-
-		return $success;
-	}
-
-	/**
-	 * Get file stat information (concurrently if possible) for several files
-	 *
-	 * @see FileBackend::getFileStat()
-	 *
-	 * @param array $params Parameters include:
-	 *   - srcs        : list of source storage paths
-	 *   - latest      : use the latest available data
-	 * @return array|null Map of storage paths to array|bool|null (returns null if not supported)
-	 * @since 1.23
-	 */
-	protected function doGetFileStatMulti( array $params ) {
-		return null; // not supported
-	}
-
-	/**
-	 * Is this a key/value store where directories are just virtual?
-	 * Virtual directories exists in so much as files exists that are
-	 * prefixed with the directory path followed by a forward slash.
-	 *
-	 * @return bool
-	 */
-	abstract protected function directoriesAreVirtual();
-
-	/**
-	 * Check if a short container name is valid
-	 *
-	 * This checks for length and illegal characters.
-	 * This may disallow certain characters that can appear
-	 * in the prefix used to make the full container name.
-	 *
-	 * @param string $container
-	 * @return bool
-	 */
-	final protected static function isValidShortContainerName( $container ) {
-		// Suffixes like '.xxx' (hex shard chars) or '.seg' (file segments)
-		// might be used by subclasses. Reserve the dot character for sanity.
-		// The only way dots end up in containers (e.g. resolveStoragePath)
-		// is due to the wikiId container prefix or the above suffixes.
-		return self::isValidContainerName( $container ) && !preg_match( '/[.]/', $container );
-	}
-
-	/**
-	 * Check if a full container name is valid
-	 *
-	 * This checks for length and illegal characters.
-	 * Limiting the characters makes migrations to other stores easier.
-	 *
-	 * @param string $container
-	 * @return bool
-	 */
-	final protected static function isValidContainerName( $container ) {
-		// This accounts for NTFS, Swift, and Ceph restrictions
-		// and disallows directory separators or traversal characters.
-		// Note that matching strings URL encode to the same string;
-		// in Swift/Ceph, the length restriction is *after* URL encoding.
-		return (bool)preg_match( '/^[a-z0-9][a-z0-9-_.]{0,199}$/i', $container );
-	}
-
-	/**
-	 * Splits a storage path into an internal container name,
-	 * an internal relative file name, and a container shard suffix.
-	 * Any shard suffix is already appended to the internal container name.
-	 * This also checks that the storage path is valid and within this backend.
-	 *
-	 * If the container is sharded but a suffix could not be determined,
-	 * this means that the path can only refer to a directory and can only
-	 * be scanned by looking in all the container shards.
-	 *
-	 * @param string $storagePath
-	 * @return array (container, path, container suffix) or (null, null, null) if invalid
-	 */
-	final protected function resolveStoragePath( $storagePath ) {
-		list( $backend, $shortCont, $relPath ) = self::splitStoragePath( $storagePath );
-		if ( $backend === $this->name ) { // must be for this backend
-			$relPath = self::normalizeContainerPath( $relPath );
-			if ( $relPath !== null && self::isValidShortContainerName( $shortCont ) ) {
-				// Get shard for the normalized path if this container is sharded
-				$cShard = $this->getContainerShard( $shortCont, $relPath );
-				// Validate and sanitize the relative path (backend-specific)
-				$relPath = $this->resolveContainerPath( $shortCont, $relPath );
-				if ( $relPath !== null ) {
-					// Prepend any wiki ID prefix to the container name
-					$container = $this->fullContainerName( $shortCont );
-					if ( self::isValidContainerName( $container ) ) {
-						// Validate and sanitize the container name (backend-specific)
-						$container = $this->resolveContainerName( "{$container}{$cShard}" );
-						if ( $container !== null ) {
-							return [ $container, $relPath, $cShard ];
-						}
-					}
-				}
-			}
-		}
-
-		return [ null, null, null ];
-	}
-
-	/**
-	 * Like resolveStoragePath() except null values are returned if
-	 * the container is sharded and the shard could not be determined
-	 * or if the path ends with '/'. The latter case is illegal for FS
-	 * backends and can confuse listings for object store backends.
-	 *
-	 * This function is used when resolving paths that must be valid
-	 * locations for files. Directory and listing functions should
-	 * generally just use resolveStoragePath() instead.
-	 *
-	 * @see FileBackendStore::resolveStoragePath()
-	 *
-	 * @param string $storagePath
-	 * @return array (container, path) or (null, null) if invalid
-	 */
-	final protected function resolveStoragePathReal( $storagePath ) {
-		list( $container, $relPath, $cShard ) = $this->resolveStoragePath( $storagePath );
-		if ( $cShard !== null && substr( $relPath, -1 ) !== '/' ) {
-			return [ $container, $relPath ];
-		}
-
-		return [ null, null ];
-	}
-
-	/**
-	 * Get the container name shard suffix for a given path.
-	 * Any empty suffix means the container is not sharded.
-	 *
-	 * @param string $container Container name
-	 * @param string $relPath Storage path relative to the container
-	 * @return string|null Returns null if shard could not be determined
-	 */
-	final protected function getContainerShard( $container, $relPath ) {
-		list( $levels, $base, $repeat ) = $this->getContainerHashLevels( $container );
-		if ( $levels == 1 || $levels == 2 ) {
-			// Hash characters are either base 16 or 36
-			$char = ( $base == 36 ) ? '[0-9a-z]' : '[0-9a-f]';
-			// Get a regex that represents the shard portion of paths.
-			// The concatenation of the captures gives us the shard.
-			if ( $levels === 1 ) { // 16 or 36 shards per container
-				$hashDirRegex = '(' . $char . ')';
-			} else { // 256 or 1296 shards per container
-				if ( $repeat ) { // verbose hash dir format (e.g. "a/ab/abc")
-					$hashDirRegex = $char . '/(' . $char . '{2})';
-				} else { // short hash dir format (e.g. "a/b/c")
-					$hashDirRegex = '(' . $char . ')/(' . $char . ')';
-				}
-			}
-			// Allow certain directories to be above the hash dirs so as
-			// to work with FileRepo (e.g. "archive/a/ab" or "temp/a/ab").
-			// They must be 2+ chars to avoid any hash directory ambiguity.
-			$m = [];
-			if ( preg_match( "!^(?:[^/]{2,}/)*$hashDirRegex(?:/|$)!", $relPath, $m ) ) {
-				return '.' . implode( '', array_slice( $m, 1 ) );
-			}
-
-			return null; // failed to match
-		}
-
-		return ''; // no sharding
-	}
-
-	/**
-	 * Check if a storage path maps to a single shard.
-	 * Container dirs like "a", where the container shards on "x/xy",
-	 * can reside on several shards. Such paths are tricky to handle.
-	 *
-	 * @param string $storagePath Storage path
-	 * @return bool
-	 */
-	final public function isSingleShardPathInternal( $storagePath ) {
-		list( , , $shard ) = $this->resolveStoragePath( $storagePath );
-
-		return ( $shard !== null );
-	}
-
-	/**
-	 * Get the sharding config for a container.
-	 * If greater than 0, then all file storage paths within
-	 * the container are required to be hashed accordingly.
-	 *
-	 * @param string $container
-	 * @return array (integer levels, integer base, repeat flag) or (0, 0, false)
-	 */
-	final protected function getContainerHashLevels( $container ) {
-		if ( isset( $this->shardViaHashLevels[$container] ) ) {
-			$config = $this->shardViaHashLevels[$container];
-			$hashLevels = (int)$config['levels'];
-			if ( $hashLevels == 1 || $hashLevels == 2 ) {
-				$hashBase = (int)$config['base'];
-				if ( $hashBase == 16 || $hashBase == 36 ) {
-					return [ $hashLevels, $hashBase, $config['repeat'] ];
-				}
-			}
-		}
-
-		return [ 0, 0, false ]; // no sharding
-	}
-
-	/**
-	 * Get a list of full container shard suffixes for a container
-	 *
-	 * @param string $container
-	 * @return array
-	 */
-	final protected function getContainerSuffixes( $container ) {
-		$shards = [];
-		list( $digits, $base ) = $this->getContainerHashLevels( $container );
-		if ( $digits > 0 ) {
-			$numShards = pow( $base, $digits );
-			for ( $index = 0; $index < $numShards; $index++ ) {
-				$shards[] = '.' . Wikimedia\base_convert( $index, 10, $base, $digits );
-			}
-		}
-
-		return $shards;
-	}
-
-	/**
-	 * Get the full container name, including the wiki ID prefix
-	 *
-	 * @param string $container
-	 * @return string
-	 */
-	final protected function fullContainerName( $container ) {
-		if ( $this->domainId != '' ) {
-			return "{$this->domainId}-$container";
-		} else {
-			return $container;
-		}
-	}
-
-	/**
-	 * Resolve a container name, checking if it's allowed by the backend.
-	 * This is intended for internal use, such as encoding illegal chars.
-	 * Subclasses can override this to be more restrictive.
-	 *
-	 * @param string $container
-	 * @return string|null
-	 */
-	protected function resolveContainerName( $container ) {
-		return $container;
-	}
-
-	/**
-	 * Resolve a relative storage path, checking if it's allowed by the backend.
-	 * This is intended for internal use, such as encoding illegal chars or perhaps
-	 * getting absolute paths (e.g. FS based backends). Note that the relative path
-	 * may be the empty string (e.g. the path is simply to the container).
-	 *
-	 * @param string $container Container name
-	 * @param string $relStoragePath Storage path relative to the container
-	 * @return string|null Path or null if not valid
-	 */
-	protected function resolveContainerPath( $container, $relStoragePath ) {
-		return $relStoragePath;
-	}
-
-	/**
-	 * Get the cache key for a container
-	 *
-	 * @param string $container Resolved container name
-	 * @return string
-	 */
-	private function containerCacheKey( $container ) {
-		return "filebackend:{$this->name}:{$this->domainId}:container:{$container}";
-	}
-
-	/**
-	 * Set the cached info for a container
-	 *
-	 * @param string $container Resolved container name
-	 * @param array $val Information to cache
-	 */
-	final protected function setContainerCache( $container, array $val ) {
-		$this->memCache->set( $this->containerCacheKey( $container ), $val, 14 * 86400 );
-	}
-
-	/**
-	 * Delete the cached info for a container.
-	 * The cache key is salted for a while to prevent race conditions.
-	 *
-	 * @param string $container Resolved container name
-	 */
-	final protected function deleteContainerCache( $container ) {
-		if ( !$this->memCache->delete( $this->containerCacheKey( $container ), 300 ) ) {
-			trigger_error( "Unable to delete stat cache for container $container." );
-		}
-	}
-
-	/**
-	 * Do a batch lookup from cache for container stats for all containers
-	 * used in a list of container names or storage paths objects.
-	 * This loads the persistent cache values into the process cache.
-	 *
-	 * @param array $items
-	 */
-	final protected function primeContainerCache( array $items ) {
-		$ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
-
-		$paths = []; // list of storage paths
-		$contNames = []; // (cache key => resolved container name)
-		// Get all the paths/containers from the items...
-		foreach ( $items as $item ) {
-			if ( self::isStoragePath( $item ) ) {
-				$paths[] = $item;
-			} elseif ( is_string( $item ) ) { // full container name
-				$contNames[$this->containerCacheKey( $item )] = $item;
-			}
-		}
-		// Get all the corresponding cache keys for paths...
-		foreach ( $paths as $path ) {
-			list( $fullCont, , ) = $this->resolveStoragePath( $path );
-			if ( $fullCont !== null ) { // valid path for this backend
-				$contNames[$this->containerCacheKey( $fullCont )] = $fullCont;
-			}
-		}
-
-		$contInfo = []; // (resolved container name => cache value)
-		// Get all cache entries for these container cache keys...
-		$values = $this->memCache->getMulti( array_keys( $contNames ) );
-		foreach ( $values as $cacheKey => $val ) {
-			$contInfo[$contNames[$cacheKey]] = $val;
-		}
-
-		// Populate the container process cache for the backend...
-		$this->doPrimeContainerCache( array_filter( $contInfo, 'is_array' ) );
-	}
-
-	/**
-	 * Fill the backend-specific process cache given an array of
-	 * resolved container names and their corresponding cached info.
-	 * Only containers that actually exist should appear in the map.
-	 *
-	 * @param array $containerInfo Map of resolved container names to cached info
-	 */
-	protected function doPrimeContainerCache( array $containerInfo ) {
-	}
-
-	/**
-	 * Get the cache key for a file path
-	 *
-	 * @param string $path Normalized storage path
-	 * @return string
-	 */
-	private function fileCacheKey( $path ) {
-		return "filebackend:{$this->name}:{$this->domainId}:file:" . sha1( $path );
-	}
-
-	/**
-	 * Set the cached stat info for a file path.
-	 * Negatives (404s) are not cached. By not caching negatives, we can skip cache
-	 * salting for the case when a file is created at a path were there was none before.
-	 *
-	 * @param string $path Storage path
-	 * @param array $val Stat information to cache
-	 */
-	final protected function setFileCache( $path, array $val ) {
-		$path = FileBackend::normalizeStoragePath( $path );
-		if ( $path === null ) {
-			return; // invalid storage path
-		}
-		$mtime = ConvertibleTimestamp::convert( TS_UNIX, $val['mtime'] );
-		$ttl = $this->memCache->adaptiveTTL( $mtime, 7 * 86400, 300, .1 );
-		$key = $this->fileCacheKey( $path );
-		// Set the cache unless it is currently salted.
-		$this->memCache->set( $key, $val, $ttl );
-	}
-
-	/**
-	 * Delete the cached stat info for a file path.
-	 * The cache key is salted for a while to prevent race conditions.
-	 * Since negatives (404s) are not cached, this does not need to be called when
-	 * a file is created at a path were there was none before.
-	 *
-	 * @param string $path Storage path
-	 */
-	final protected function deleteFileCache( $path ) {
-		$path = FileBackend::normalizeStoragePath( $path );
-		if ( $path === null ) {
-			return; // invalid storage path
-		}
-		if ( !$this->memCache->delete( $this->fileCacheKey( $path ), 300 ) ) {
-			trigger_error( "Unable to delete stat cache for file $path." );
-		}
-	}
-
-	/**
-	 * Do a batch lookup from cache for file stats for all paths
-	 * used in a list of storage paths or FileOp objects.
-	 * This loads the persistent cache values into the process cache.
-	 *
-	 * @param array $items List of storage paths
-	 */
-	final protected function primeFileCache( array $items ) {
-		$ps = $this->scopedProfileSection( __METHOD__ . "-{$this->name}" );
-
-		$paths = []; // list of storage paths
-		$pathNames = []; // (cache key => storage path)
-		// Get all the paths/containers from the items...
-		foreach ( $items as $item ) {
-			if ( self::isStoragePath( $item ) ) {
-				$paths[] = FileBackend::normalizeStoragePath( $item );
-			}
-		}
-		// Get rid of any paths that failed normalization...
-		$paths = array_filter( $paths, 'strlen' ); // remove nulls
-		// Get all the corresponding cache keys for paths...
-		foreach ( $paths as $path ) {
-			list( , $rel, ) = $this->resolveStoragePath( $path );
-			if ( $rel !== null ) { // valid path for this backend
-				$pathNames[$this->fileCacheKey( $path )] = $path;
-			}
-		}
-		// Get all cache entries for these file cache keys...
-		$values = $this->memCache->getMulti( array_keys( $pathNames ) );
-		foreach ( $values as $cacheKey => $val ) {
-			$path = $pathNames[$cacheKey];
-			if ( is_array( $val ) ) {
-				$val['latest'] = false; // never completely trust cache
-				$this->cheapCache->set( $path, 'stat', $val );
-				if ( isset( $val['sha1'] ) ) { // some backends store SHA-1 as metadata
-					$this->cheapCache->set( $path, 'sha1',
-						[ 'hash' => $val['sha1'], 'latest' => false ] );
-				}
-				if ( isset( $val['xattr'] ) ) { // some backends store headers/metadata
-					$val['xattr'] = self::normalizeXAttributes( $val['xattr'] );
-					$this->cheapCache->set( $path, 'xattr',
-						[ 'map' => $val['xattr'], 'latest' => false ] );
-				}
-			}
-		}
-	}
-
-	/**
-	 * Normalize file headers/metadata to the FileBackend::getFileXAttributes() format
-	 *
-	 * @param array $xattr
-	 * @return array
-	 * @since 1.22
-	 */
-	final protected static function normalizeXAttributes( array $xattr ) {
-		$newXAttr = [ 'headers' => [], 'metadata' => [] ];
-
-		foreach ( $xattr['headers'] as $name => $value ) {
-			$newXAttr['headers'][strtolower( $name )] = $value;
-		}
-
-		foreach ( $xattr['metadata'] as $name => $value ) {
-			$newXAttr['metadata'][strtolower( $name )] = $value;
-		}
-
-		return $newXAttr;
-	}
-
-	/**
-	 * Set the 'concurrency' option from a list of operation options
-	 *
-	 * @param array $opts Map of operation options
-	 * @return array
-	 */
-	final protected function setConcurrencyFlags( array $opts ) {
-		$opts['concurrency'] = 1; // off
-		if ( $this->parallelize === 'implicit' ) {
-			if ( !isset( $opts['parallelize'] ) || $opts['parallelize'] ) {
-				$opts['concurrency'] = $this->concurrency;
-			}
-		} elseif ( $this->parallelize === 'explicit' ) {
-			if ( !empty( $opts['parallelize'] ) ) {
-				$opts['concurrency'] = $this->concurrency;
-			}
-		}
-
-		return $opts;
-	}
-
-	/**
-	 * Get the content type to use in HEAD/GET requests for a file
-	 *
-	 * @param string $storagePath
-	 * @param string|null $content File data
-	 * @param string|null $fsPath File system path
-	 * @return string MIME type
-	 */
-	protected function getContentType( $storagePath, $content, $fsPath ) {
-		if ( $this->mimeCallback ) {
-			return call_user_func_array( $this->mimeCallback, func_get_args() );
-		}
-
-		$mime = null;
-		if ( $fsPath !== null && function_exists( 'finfo_file' ) ) {
-			$finfo = finfo_open( FILEINFO_MIME_TYPE );
-			$mime = finfo_file( $finfo, $fsPath );
-			finfo_close( $finfo );
-		}
-
-		return is_string( $mime ) ? $mime : 'unknown/unknown';
-	}
-}
-
-/**
- * FileBackendStore helper class for performing asynchronous file operations.
- *
- * For example, calling FileBackendStore::createInternal() with the "async"
- * param flag may result in a StatusValue that contains this object as a value.
- * This class is largely backend-specific and is mostly just "magic" to be
- * passed to FileBackendStore::executeOpHandlesInternal().
- */
-abstract class FileBackendStoreOpHandle {
-	/** @var array */
-	public $params = []; // params to caller functions
-	/** @var FileBackendStore */
-	public $backend;
-	/** @var array */
-	public $resourcesToClose = [];
-
-	public $call; // string; name that identifies the function called
-
-	/**
-	 * Close all open file handles
-	 */
-	public function closeResources() {
-		array_map( 'fclose', $this->resourcesToClose );
-	}
-}
-
-/**
- * FileBackendStore helper function to handle listings that span container shards.
- * Do not use this class from places outside of FileBackendStore.
- *
- * @ingroup FileBackend
- */
-abstract class FileBackendStoreShardListIterator extends FilterIterator {
-	/** @var FileBackendStore */
-	protected $backend;
-
-	/** @var array */
-	protected $params;
-
-	/** @var string Full container name */
-	protected $container;
-
-	/** @var string Resolved relative path */
-	protected $directory;
-
-	/** @var array */
-	protected $multiShardPaths = []; // (rel path => 1)
-
-	/**
-	 * @param FileBackendStore $backend
-	 * @param string $container Full storage container name
-	 * @param string $dir Storage directory relative to container
-	 * @param array $suffixes List of container shard suffixes
-	 * @param array $params
-	 */
-	public function __construct(
-		FileBackendStore $backend, $container, $dir, array $suffixes, array $params
-	) {
-		$this->backend = $backend;
-		$this->container = $container;
-		$this->directory = $dir;
-		$this->params = $params;
-
-		$iter = new AppendIterator();
-		foreach ( $suffixes as $suffix ) {
-			$iter->append( $this->listFromShard( $this->container . $suffix ) );
-		}
-
-		parent::__construct( $iter );
-	}
-
-	public function accept() {
-		$rel = $this->getInnerIterator()->current(); // path relative to given directory
-		$path = $this->params['dir'] . "/{$rel}"; // full storage path
-		if ( $this->backend->isSingleShardPathInternal( $path ) ) {
-			return true; // path is only on one shard; no issue with duplicates
-		} elseif ( isset( $this->multiShardPaths[$rel] ) ) {
-			// Don't keep listing paths that are on multiple shards
-			return false;
-		} else {
-			$this->multiShardPaths[$rel] = 1;
-
-			return true;
-		}
-	}
-
-	public function rewind() {
-		parent::rewind();
-		$this->multiShardPaths = [];
-	}
-
-	/**
-	 * Get the list for a given container shard
-	 *
-	 * @param string $container Resolved container name
-	 * @return Iterator
-	 */
-	abstract protected function listFromShard( $container );
-}
-
-/**
- * Iterator for listing directories
- */
-class FileBackendStoreShardDirIterator extends FileBackendStoreShardListIterator {
-	protected function listFromShard( $container ) {
-		$list = $this->backend->getDirectoryListInternal(
-			$container, $this->directory, $this->params );
-		if ( $list === null ) {
-			return new ArrayIterator( [] );
-		} else {
-			return is_array( $list ) ? new ArrayIterator( $list ) : $list;
-		}
-	}
-}
-
-/**
- * Iterator for listing regular files
- */
-class FileBackendStoreShardFileIterator extends FileBackendStoreShardListIterator {
-	protected function listFromShard( $container ) {
-		$list = $this->backend->getFileListInternal(
-			$container, $this->directory, $this->params );
-		if ( $list === null ) {
-			return new ArrayIterator( [] );
-		} else {
-			return is_array( $list ) ? new ArrayIterator( $list ) : $list;
-		}
-	}
-}
diff --git a/includes/filebackend/FileOp.php b/includes/filebackend/FileOp.php
deleted file mode 100644
index 8207b124b2d7..000000000000
--- a/includes/filebackend/FileOp.php
+++ /dev/null
@@ -1,855 +0,0 @@
-<?php
-/**
- * Helper class for representing operations with transaction support.
- *
- * 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
- * @ingroup FileBackend
- * @author Aaron Schulz
- */
-use Psr\Log\LoggerInterface;
-
-/**
- * FileBackend helper class for representing operations.
- * Do not use this class from places outside FileBackend.
- *
- * Methods called from FileOpBatch::attempt() should avoid throwing
- * exceptions at all costs. FileOp objects should be lightweight in order
- * to support large arrays in memory and serialization.
- *
- * @ingroup FileBackend
- * @since 1.19
- */
-abstract class FileOp {
-	/** @var array */
-	protected $params = [];
-
-	/** @var FileBackendStore */
-	protected $backend;
-	/** @var LoggerInterface */
-	protected $logger;
-
-	/** @var int */
-	protected $state = self::STATE_NEW;
-
-	/** @var bool */
-	protected $failed = false;
-
-	/** @var bool */
-	protected $async = false;
-
-	/** @var string */
-	protected $batchId;
-
-	/** @var bool Operation is not a no-op */
-	protected $doOperation = true;
-
-	/** @var string */
-	protected $sourceSha1;
-
-	/** @var bool */
-	protected $overwriteSameCase;
-
-	/** @var bool */
-	protected $destExists;
-
-	/* Object life-cycle */
-	const STATE_NEW = 1;
-	const STATE_CHECKED = 2;
-	const STATE_ATTEMPTED = 3;
-
-	/**
-	 * Build a new batch file operation transaction
-	 *
-	 * @param FileBackendStore $backend
-	 * @param array $params
-	 * @param LoggerInterface $logger PSR logger instance
-	 * @throws FileBackendError
-	 */
-	final public function __construct(
-		FileBackendStore $backend, array $params, LoggerInterface $logger
-	) {
-		$this->backend = $backend;
-		$this->logger = $logger;
-		list( $required, $optional, $paths ) = $this->allowedParams();
-		foreach ( $required as $name ) {
-			if ( isset( $params[$name] ) ) {
-				$this->params[$name] = $params[$name];
-			} else {
-				throw new InvalidArgumentException( "File operation missing parameter '$name'." );
-			}
-		}
-		foreach ( $optional as $name ) {
-			if ( isset( $params[$name] ) ) {
-				$this->params[$name] = $params[$name];
-			}
-		}
-		foreach ( $paths as $name ) {
-			if ( isset( $this->params[$name] ) ) {
-				// Normalize paths so the paths to the same file have the same string
-				$this->params[$name] = self::normalizeIfValidStoragePath( $this->params[$name] );
-			}
-		}
-	}
-
-	/**
-	 * Normalize a string if it is a valid storage path
-	 *
-	 * @param string $path
-	 * @return string
-	 */
-	protected static function normalizeIfValidStoragePath( $path ) {
-		if ( FileBackend::isStoragePath( $path ) ) {
-			$res = FileBackend::normalizeStoragePath( $path );
-
-			return ( $res !== null ) ? $res : $path;
-		}
-
-		return $path;
-	}
-
-	/**
-	 * Set the batch UUID this operation belongs to
-	 *
-	 * @param string $batchId
-	 */
-	final public function setBatchId( $batchId ) {
-		$this->batchId = $batchId;
-	}
-
-	/**
-	 * Get the value of the parameter with the given name
-	 *
-	 * @param string $name
-	 * @return mixed Returns null if the parameter is not set
-	 */
-	final public function getParam( $name ) {
-		return isset( $this->params[$name] ) ? $this->params[$name] : null;
-	}
-
-	/**
-	 * Check if this operation failed precheck() or attempt()
-	 *
-	 * @return bool
-	 */
-	final public function failed() {
-		return $this->failed;
-	}
-
-	/**
-	 * Get a new empty predicates array for precheck()
-	 *
-	 * @return array
-	 */
-	final public static function newPredicates() {
-		return [ 'exists' => [], 'sha1' => [] ];
-	}
-
-	/**
-	 * Get a new empty dependency tracking array for paths read/written to
-	 *
-	 * @return array
-	 */
-	final public static function newDependencies() {
-		return [ 'read' => [], 'write' => [] ];
-	}
-
-	/**
-	 * Update a dependency tracking array to account for this operation
-	 *
-	 * @param array $deps Prior path reads/writes; format of FileOp::newPredicates()
-	 * @return array
-	 */
-	final public function applyDependencies( array $deps ) {
-		$deps['read'] += array_fill_keys( $this->storagePathsRead(), 1 );
-		$deps['write'] += array_fill_keys( $this->storagePathsChanged(), 1 );
-
-		return $deps;
-	}
-
-	/**
-	 * Check if this operation changes files listed in $paths
-	 *
-	 * @param array $deps Prior path reads/writes; format of FileOp::newPredicates()
-	 * @return bool
-	 */
-	final public function dependsOn( array $deps ) {
-		foreach ( $this->storagePathsChanged() as $path ) {
-			if ( isset( $deps['read'][$path] ) || isset( $deps['write'][$path] ) ) {
-				return true; // "output" or "anti" dependency
-			}
-		}
-		foreach ( $this->storagePathsRead() as $path ) {
-			if ( isset( $deps['write'][$path] ) ) {
-				return true; // "flow" dependency
-			}
-		}
-
-		return false;
-	}
-
-	/**
-	 * Get the file journal entries for this file operation
-	 *
-	 * @param array $oPredicates Pre-op info about files (format of FileOp::newPredicates)
-	 * @param array $nPredicates Post-op info about files (format of FileOp::newPredicates)
-	 * @return array
-	 */
-	final public function getJournalEntries( array $oPredicates, array $nPredicates ) {
-		if ( !$this->doOperation ) {
-			return []; // this is a no-op
-		}
-		$nullEntries = [];
-		$updateEntries = [];
-		$deleteEntries = [];
-		$pathsUsed = array_merge( $this->storagePathsRead(), $this->storagePathsChanged() );
-		foreach ( array_unique( $pathsUsed ) as $path ) {
-			$nullEntries[] = [ // assertion for recovery
-				'op' => 'null',
-				'path' => $path,
-				'newSha1' => $this->fileSha1( $path, $oPredicates )
-			];
-		}
-		foreach ( $this->storagePathsChanged() as $path ) {
-			if ( $nPredicates['sha1'][$path] === false ) { // deleted
-				$deleteEntries[] = [
-					'op' => 'delete',
-					'path' => $path,
-					'newSha1' => ''
-				];
-			} else { // created/updated
-				$updateEntries[] = [
-					'op' => $this->fileExists( $path, $oPredicates ) ? 'update' : 'create',
-					'path' => $path,
-					'newSha1' => $nPredicates['sha1'][$path]
-				];
-			}
-		}
-
-		return array_merge( $nullEntries, $updateEntries, $deleteEntries );
-	}
-
-	/**
-	 * Check preconditions of the operation without writing anything.
-	 * This must update $predicates for each path that the op can change
-	 * except when a failing StatusValue object is returned.
-	 *
-	 * @param array $predicates
-	 * @return StatusValue
-	 */
-	final public function precheck( array &$predicates ) {
-		if ( $this->state !== self::STATE_NEW ) {
-			return StatusValue::newFatal( 'fileop-fail-state', self::STATE_NEW, $this->state );
-		}
-		$this->state = self::STATE_CHECKED;
-		$status = $this->doPrecheck( $predicates );
-		if ( !$status->isOK() ) {
-			$this->failed = true;
-		}
-
-		return $status;
-	}
-
-	/**
-	 * @param array $predicates
-	 * @return StatusValue
-	 */
-	protected function doPrecheck( array &$predicates ) {
-		return StatusValue::newGood();
-	}
-
-	/**
-	 * Attempt the operation
-	 *
-	 * @return StatusValue
-	 */
-	final public function attempt() {
-		if ( $this->state !== self::STATE_CHECKED ) {
-			return StatusValue::newFatal( 'fileop-fail-state', self::STATE_CHECKED, $this->state );
-		} elseif ( $this->failed ) { // failed precheck
-			return StatusValue::newFatal( 'fileop-fail-attempt-precheck' );
-		}
-		$this->state = self::STATE_ATTEMPTED;
-		if ( $this->doOperation ) {
-			$status = $this->doAttempt();
-			if ( !$status->isOK() ) {
-				$this->failed = true;
-				$this->logFailure( 'attempt' );
-			}
-		} else { // no-op
-			$status = StatusValue::newGood();
-		}
-
-		return $status;
-	}
-
-	/**
-	 * @return StatusValue
-	 */
-	protected function doAttempt() {
-		return StatusValue::newGood();
-	}
-
-	/**
-	 * Attempt the operation in the background
-	 *
-	 * @return StatusValue
-	 */
-	final public function attemptAsync() {
-		$this->async = true;
-		$result = $this->attempt();
-		$this->async = false;
-
-		return $result;
-	}
-
-	/**
-	 * Get the file operation parameters
-	 *
-	 * @return array (required params list, optional params list, list of params that are paths)
-	 */
-	protected function allowedParams() {
-		return [ [], [], [] ];
-	}
-
-	/**
-	 * Adjust params to FileBackendStore internal file calls
-	 *
-	 * @param array $params
-	 * @return array (required params list, optional params list)
-	 */
-	protected function setFlags( array $params ) {
-		return [ 'async' => $this->async ] + $params;
-	}
-
-	/**
-	 * Get a list of storage paths read from for this operation
-	 *
-	 * @return array
-	 */
-	public function storagePathsRead() {
-		return [];
-	}
-
-	/**
-	 * Get a list of storage paths written to for this operation
-	 *
-	 * @return array
-	 */
-	public function storagePathsChanged() {
-		return [];
-	}
-
-	/**
-	 * Check for errors with regards to the destination file already existing.
-	 * Also set the destExists, overwriteSameCase and sourceSha1 member variables.
-	 * A bad StatusValue will be returned if there is no chance it can be overwritten.
-	 *
-	 * @param array $predicates
-	 * @return StatusValue
-	 */
-	protected function precheckDestExistence( array $predicates ) {
-		$status = StatusValue::newGood();
-		// Get hash of source file/string and the destination file
-		$this->sourceSha1 = $this->getSourceSha1Base36(); // FS file or data string
-		if ( $this->sourceSha1 === null ) { // file in storage?
-			$this->sourceSha1 = $this->fileSha1( $this->params['src'], $predicates );
-		}
-		$this->overwriteSameCase = false;
-		$this->destExists = $this->fileExists( $this->params['dst'], $predicates );
-		if ( $this->destExists ) {
-			if ( $this->getParam( 'overwrite' ) ) {
-				return $status; // OK
-			} elseif ( $this->getParam( 'overwriteSame' ) ) {
-				$dhash = $this->fileSha1( $this->params['dst'], $predicates );
-				// Check if hashes are valid and match each other...
-				if ( !strlen( $this->sourceSha1 ) || !strlen( $dhash ) ) {
-					$status->fatal( 'backend-fail-hashes' );
-				} elseif ( $this->sourceSha1 !== $dhash ) {
-					// Give an error if the files are not identical
-					$status->fatal( 'backend-fail-notsame', $this->params['dst'] );
-				} else {
-					$this->overwriteSameCase = true; // OK
-				}
-
-				return $status; // do nothing; either OK or bad status
-			} else {
-				$status->fatal( 'backend-fail-alreadyexists', $this->params['dst'] );
-
-				return $status;
-			}
-		}
-
-		return $status;
-	}
-
-	/**
-	 * precheckDestExistence() helper function to get the source file SHA-1.
-	 * Subclasses should overwride this if the source is not in storage.
-	 *
-	 * @return string|bool Returns false on failure
-	 */
-	protected function getSourceSha1Base36() {
-		return null; // N/A
-	}
-
-	/**
-	 * Check if a file will exist in storage when this operation is attempted
-	 *
-	 * @param string $source Storage path
-	 * @param array $predicates
-	 * @return bool
-	 */
-	final protected function fileExists( $source, array $predicates ) {
-		if ( isset( $predicates['exists'][$source] ) ) {
-			return $predicates['exists'][$source]; // previous op assures this
-		} else {
-			$params = [ 'src' => $source, 'latest' => true ];
-
-			return $this->backend->fileExists( $params );
-		}
-	}
-
-	/**
-	 * Get the SHA-1 of a file in storage when this operation is attempted
-	 *
-	 * @param string $source Storage path
-	 * @param array $predicates
-	 * @return string|bool False on failure
-	 */
-	final protected function fileSha1( $source, array $predicates ) {
-		if ( isset( $predicates['sha1'][$source] ) ) {
-			return $predicates['sha1'][$source]; // previous op assures this
-		} elseif ( isset( $predicates['exists'][$source] ) && !$predicates['exists'][$source] ) {
-			return false; // previous op assures this
-		} else {
-			$params = [ 'src' => $source, 'latest' => true ];
-
-			return $this->backend->getFileSha1Base36( $params );
-		}
-	}
-
-	/**
-	 * Get the backend this operation is for
-	 *
-	 * @return FileBackendStore
-	 */
-	public function getBackend() {
-		return $this->backend;
-	}
-
-	/**
-	 * Log a file operation failure and preserve any temp files
-	 *
-	 * @param string $action
-	 */
-	final public function logFailure( $action ) {
-		$params = $this->params;
-		$params['failedAction'] = $action;
-		try {
-			$this->logger->error( get_class( $this ) .
-				" failed (batch #{$this->batchId}): " . FormatJson::encode( $params ) );
-		} catch ( Exception $e ) {
-			// bad config? debug log error?
-		}
-	}
-}
-
-/**
- * Create a file in the backend with the given content.
- * Parameters for this operation are outlined in FileBackend::doOperations().
- */
-class CreateFileOp extends FileOp {
-	protected function allowedParams() {
-		return [
-			[ 'content', 'dst' ],
-			[ 'overwrite', 'overwriteSame', 'headers' ],
-			[ 'dst' ]
-		];
-	}
-
-	protected function doPrecheck( array &$predicates ) {
-		$status = StatusValue::newGood();
-		// Check if the source data is too big
-		if ( strlen( $this->getParam( 'content' ) ) > $this->backend->maxFileSizeInternal() ) {
-			$status->fatal( 'backend-fail-maxsize',
-				$this->params['dst'], $this->backend->maxFileSizeInternal() );
-			$status->fatal( 'backend-fail-create', $this->params['dst'] );
-
-			return $status;
-		// Check if a file can be placed/changed at the destination
-		} elseif ( !$this->backend->isPathUsableInternal( $this->params['dst'] ) ) {
-			$status->fatal( 'backend-fail-usable', $this->params['dst'] );
-			$status->fatal( 'backend-fail-create', $this->params['dst'] );
-
-			return $status;
-		}
-		// Check if destination file exists
-		$status->merge( $this->precheckDestExistence( $predicates ) );
-		$this->params['dstExists'] = $this->destExists; // see FileBackendStore::setFileCache()
-		if ( $status->isOK() ) {
-			// Update file existence predicates
-			$predicates['exists'][$this->params['dst']] = true;
-			$predicates['sha1'][$this->params['dst']] = $this->sourceSha1;
-		}
-
-		return $status; // safe to call attempt()
-	}
-
-	protected function doAttempt() {
-		if ( !$this->overwriteSameCase ) {
-			// Create the file at the destination
-			return $this->backend->createInternal( $this->setFlags( $this->params ) );
-		}
-
-		return StatusValue::newGood();
-	}
-
-	protected function getSourceSha1Base36() {
-		return Wikimedia\base_convert( sha1( $this->params['content'] ), 16, 36, 31 );
-	}
-
-	public function storagePathsChanged() {
-		return [ $this->params['dst'] ];
-	}
-}
-
-/**
- * Store a file into the backend from a file on the file system.
- * Parameters for this operation are outlined in FileBackend::doOperations().
- */
-class StoreFileOp extends FileOp {
-	protected function allowedParams() {
-		return [
-			[ 'src', 'dst' ],
-			[ 'overwrite', 'overwriteSame', 'headers' ],
-			[ 'src', 'dst' ]
-		];
-	}
-
-	protected function doPrecheck( array &$predicates ) {
-		$status = StatusValue::newGood();
-		// Check if the source file exists on the file system
-		if ( !is_file( $this->params['src'] ) ) {
-			$status->fatal( 'backend-fail-notexists', $this->params['src'] );
-
-			return $status;
-		// Check if the source file is too big
-		} elseif ( filesize( $this->params['src'] ) > $this->backend->maxFileSizeInternal() ) {
-			$status->fatal( 'backend-fail-maxsize',
-				$this->params['dst'], $this->backend->maxFileSizeInternal() );
-			$status->fatal( 'backend-fail-store', $this->params['src'], $this->params['dst'] );
-
-			return $status;
-		// Check if a file can be placed/changed at the destination
-		} elseif ( !$this->backend->isPathUsableInternal( $this->params['dst'] ) ) {
-			$status->fatal( 'backend-fail-usable', $this->params['dst'] );
-			$status->fatal( 'backend-fail-store', $this->params['src'], $this->params['dst'] );
-
-			return $status;
-		}
-		// Check if destination file exists
-		$status->merge( $this->precheckDestExistence( $predicates ) );
-		$this->params['dstExists'] = $this->destExists; // see FileBackendStore::setFileCache()
-		if ( $status->isOK() ) {
-			// Update file existence predicates
-			$predicates['exists'][$this->params['dst']] = true;
-			$predicates['sha1'][$this->params['dst']] = $this->sourceSha1;
-		}
-
-		return $status; // safe to call attempt()
-	}
-
-	protected function doAttempt() {
-		if ( !$this->overwriteSameCase ) {
-			// Store the file at the destination
-			return $this->backend->storeInternal( $this->setFlags( $this->params ) );
-		}
-
-		return StatusValue::newGood();
-	}
-
-	protected function getSourceSha1Base36() {
-		MediaWiki\suppressWarnings();
-		$hash = sha1_file( $this->params['src'] );
-		MediaWiki\restoreWarnings();
-		if ( $hash !== false ) {
-			$hash = Wikimedia\base_convert( $hash, 16, 36, 31 );
-		}
-
-		return $hash;
-	}
-
-	public function storagePathsChanged() {
-		return [ $this->params['dst'] ];
-	}
-}
-
-/**
- * Copy a file from one storage path to another in the backend.
- * Parameters for this operation are outlined in FileBackend::doOperations().
- */
-class CopyFileOp extends FileOp {
-	protected function allowedParams() {
-		return [
-			[ 'src', 'dst' ],
-			[ 'overwrite', 'overwriteSame', 'ignoreMissingSource', 'headers' ],
-			[ 'src', 'dst' ]
-		];
-	}
-
-	protected function doPrecheck( array &$predicates ) {
-		$status = StatusValue::newGood();
-		// Check if the source file exists
-		if ( !$this->fileExists( $this->params['src'], $predicates ) ) {
-			if ( $this->getParam( 'ignoreMissingSource' ) ) {
-				$this->doOperation = false; // no-op
-				// Update file existence predicates (cache 404s)
-				$predicates['exists'][$this->params['src']] = false;
-				$predicates['sha1'][$this->params['src']] = false;
-
-				return $status; // nothing to do
-			} else {
-				$status->fatal( 'backend-fail-notexists', $this->params['src'] );
-
-				return $status;
-			}
-			// Check if a file can be placed/changed at the destination
-		} elseif ( !$this->backend->isPathUsableInternal( $this->params['dst'] ) ) {
-			$status->fatal( 'backend-fail-usable', $this->params['dst'] );
-			$status->fatal( 'backend-fail-copy', $this->params['src'], $this->params['dst'] );
-
-			return $status;
-		}
-		// Check if destination file exists
-		$status->merge( $this->precheckDestExistence( $predicates ) );
-		$this->params['dstExists'] = $this->destExists; // see FileBackendStore::setFileCache()
-		if ( $status->isOK() ) {
-			// Update file existence predicates
-			$predicates['exists'][$this->params['dst']] = true;
-			$predicates['sha1'][$this->params['dst']] = $this->sourceSha1;
-		}
-
-		return $status; // safe to call attempt()
-	}
-
-	protected function doAttempt() {
-		if ( $this->overwriteSameCase ) {
-			$status = StatusValue::newGood(); // nothing to do
-		} elseif ( $this->params['src'] === $this->params['dst'] ) {
-			// Just update the destination file headers
-			$headers = $this->getParam( 'headers' ) ?: [];
-			$status = $this->backend->describeInternal( $this->setFlags( [
-				'src' => $this->params['dst'], 'headers' => $headers
-			] ) );
-		} else {
-			// Copy the file to the destination
-			$status = $this->backend->copyInternal( $this->setFlags( $this->params ) );
-		}
-
-		return $status;
-	}
-
-	public function storagePathsRead() {
-		return [ $this->params['src'] ];
-	}
-
-	public function storagePathsChanged() {
-		return [ $this->params['dst'] ];
-	}
-}
-
-/**
- * Move a file from one storage path to another in the backend.
- * Parameters for this operation are outlined in FileBackend::doOperations().
- */
-class MoveFileOp extends FileOp {
-	protected function allowedParams() {
-		return [
-			[ 'src', 'dst' ],
-			[ 'overwrite', 'overwriteSame', 'ignoreMissingSource', 'headers' ],
-			[ 'src', 'dst' ]
-		];
-	}
-
-	protected function doPrecheck( array &$predicates ) {
-		$status = StatusValue::newGood();
-		// Check if the source file exists
-		if ( !$this->fileExists( $this->params['src'], $predicates ) ) {
-			if ( $this->getParam( 'ignoreMissingSource' ) ) {
-				$this->doOperation = false; // no-op
-				// Update file existence predicates (cache 404s)
-				$predicates['exists'][$this->params['src']] = false;
-				$predicates['sha1'][$this->params['src']] = false;
-
-				return $status; // nothing to do
-			} else {
-				$status->fatal( 'backend-fail-notexists', $this->params['src'] );
-
-				return $status;
-			}
-		// Check if a file can be placed/changed at the destination
-		} elseif ( !$this->backend->isPathUsableInternal( $this->params['dst'] ) ) {
-			$status->fatal( 'backend-fail-usable', $this->params['dst'] );
-			$status->fatal( 'backend-fail-move', $this->params['src'], $this->params['dst'] );
-
-			return $status;
-		}
-		// Check if destination file exists
-		$status->merge( $this->precheckDestExistence( $predicates ) );
-		$this->params['dstExists'] = $this->destExists; // see FileBackendStore::setFileCache()
-		if ( $status->isOK() ) {
-			// Update file existence predicates
-			$predicates['exists'][$this->params['src']] = false;
-			$predicates['sha1'][$this->params['src']] = false;
-			$predicates['exists'][$this->params['dst']] = true;
-			$predicates['sha1'][$this->params['dst']] = $this->sourceSha1;
-		}
-
-		return $status; // safe to call attempt()
-	}
-
-	protected function doAttempt() {
-		if ( $this->overwriteSameCase ) {
-			if ( $this->params['src'] === $this->params['dst'] ) {
-				// Do nothing to the destination (which is also the source)
-				$status = StatusValue::newGood();
-			} else {
-				// Just delete the source as the destination file needs no changes
-				$status = $this->backend->deleteInternal( $this->setFlags(
-					[ 'src' => $this->params['src'] ]
-				) );
-			}
-		} elseif ( $this->params['src'] === $this->params['dst'] ) {
-			// Just update the destination file headers
-			$headers = $this->getParam( 'headers' ) ?: [];
-			$status = $this->backend->describeInternal( $this->setFlags(
-				[ 'src' => $this->params['dst'], 'headers' => $headers ]
-			) );
-		} else {
-			// Move the file to the destination
-			$status = $this->backend->moveInternal( $this->setFlags( $this->params ) );
-		}
-
-		return $status;
-	}
-
-	public function storagePathsRead() {
-		return [ $this->params['src'] ];
-	}
-
-	public function storagePathsChanged() {
-		return [ $this->params['src'], $this->params['dst'] ];
-	}
-}
-
-/**
- * Delete a file at the given storage path from the backend.
- * Parameters for this operation are outlined in FileBackend::doOperations().
- */
-class DeleteFileOp extends FileOp {
-	protected function allowedParams() {
-		return [ [ 'src' ], [ 'ignoreMissingSource' ], [ 'src' ] ];
-	}
-
-	protected function doPrecheck( array &$predicates ) {
-		$status = StatusValue::newGood();
-		// Check if the source file exists
-		if ( !$this->fileExists( $this->params['src'], $predicates ) ) {
-			if ( $this->getParam( 'ignoreMissingSource' ) ) {
-				$this->doOperation = false; // no-op
-				// Update file existence predicates (cache 404s)
-				$predicates['exists'][$this->params['src']] = false;
-				$predicates['sha1'][$this->params['src']] = false;
-
-				return $status; // nothing to do
-			} else {
-				$status->fatal( 'backend-fail-notexists', $this->params['src'] );
-
-				return $status;
-			}
-		// Check if a file can be placed/changed at the source
-		} elseif ( !$this->backend->isPathUsableInternal( $this->params['src'] ) ) {
-			$status->fatal( 'backend-fail-usable', $this->params['src'] );
-			$status->fatal( 'backend-fail-delete', $this->params['src'] );
-
-			return $status;
-		}
-		// Update file existence predicates
-		$predicates['exists'][$this->params['src']] = false;
-		$predicates['sha1'][$this->params['src']] = false;
-
-		return $status; // safe to call attempt()
-	}
-
-	protected function doAttempt() {
-		// Delete the source file
-		return $this->backend->deleteInternal( $this->setFlags( $this->params ) );
-	}
-
-	public function storagePathsChanged() {
-		return [ $this->params['src'] ];
-	}
-}
-
-/**
- * Change metadata for a file at the given storage path in the backend.
- * Parameters for this operation are outlined in FileBackend::doOperations().
- */
-class DescribeFileOp extends FileOp {
-	protected function allowedParams() {
-		return [ [ 'src' ], [ 'headers' ], [ 'src' ] ];
-	}
-
-	protected function doPrecheck( array &$predicates ) {
-		$status = StatusValue::newGood();
-		// Check if the source file exists
-		if ( !$this->fileExists( $this->params['src'], $predicates ) ) {
-			$status->fatal( 'backend-fail-notexists', $this->params['src'] );
-
-			return $status;
-		// Check if a file can be placed/changed at the source
-		} elseif ( !$this->backend->isPathUsableInternal( $this->params['src'] ) ) {
-			$status->fatal( 'backend-fail-usable', $this->params['src'] );
-			$status->fatal( 'backend-fail-describe', $this->params['src'] );
-
-			return $status;
-		}
-		// Update file existence predicates
-		$predicates['exists'][$this->params['src']] =
-			$this->fileExists( $this->params['src'], $predicates );
-		$predicates['sha1'][$this->params['src']] =
-			$this->fileSha1( $this->params['src'], $predicates );
-
-		return $status; // safe to call attempt()
-	}
-
-	protected function doAttempt() {
-		// Update the source file's metadata
-		return $this->backend->describeInternal( $this->setFlags( $this->params ) );
-	}
-
-	public function storagePathsChanged() {
-		return [ $this->params['src'] ];
-	}
-}
-
-/**
- * Placeholder operation that has no params and does nothing
- */
-class NullFileOp extends FileOp {
-}
diff --git a/includes/filebackend/FileOpBatch.php b/includes/filebackend/FileOpBatch.php
deleted file mode 100644
index 71b5c7d575bf..000000000000
--- a/includes/filebackend/FileOpBatch.php
+++ /dev/null
@@ -1,205 +0,0 @@
-<?php
-/**
- * Helper class for representing batch file operations.
- *
- * 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
- * @ingroup FileBackend
- * @author Aaron Schulz
- */
-
-/**
- * Helper class for representing batch file operations.
- * Do not use this class from places outside FileBackend.
- *
- * Methods should avoid throwing exceptions at all costs.
- *
- * @ingroup FileBackend
- * @since 1.20
- */
-class FileOpBatch {
-	/* Timeout related parameters */
-	const MAX_BATCH_SIZE = 1000; // integer
-
-	/**
-	 * Attempt to perform a series of file operations.
-	 * Callers are responsible for handling file locking.
-	 *
-	 * $opts is an array of options, including:
-	 *   - force        : Errors that would normally cause a rollback do not.
-	 *                    The remaining operations are still attempted if any fail.
-	 *   - nonJournaled : Don't log this operation batch in the file journal.
-	 *   - concurrency  : Try to do this many operations in parallel when possible.
-	 *
-	 * The resulting StatusValue will be "OK" unless:
-	 *   - a) unexpected operation errors occurred (network partitions, disk full...)
-	 *   - b) significant operation errors occurred and 'force' was not set
-	 *
-	 * @param FileOp[] $performOps List of FileOp operations
-	 * @param array $opts Batch operation options
-	 * @param FileJournal $journal Journal to log operations to
-	 * @return StatusValue
-	 */
-	public static function attempt( array $performOps, array $opts, FileJournal $journal ) {
-		$status = StatusValue::newGood();
-
-		$n = count( $performOps );
-		if ( $n > self::MAX_BATCH_SIZE ) {
-			$status->fatal( 'backend-fail-batchsize', $n, self::MAX_BATCH_SIZE );
-
-			return $status;
-		}
-
-		$batchId = $journal->getTimestampedUUID();
-		$ignoreErrors = !empty( $opts['force'] );
-		$journaled = empty( $opts['nonJournaled'] );
-		$maxConcurrency = isset( $opts['concurrency'] ) ? $opts['concurrency'] : 1;
-
-		$entries = []; // file journal entry list
-		$predicates = FileOp::newPredicates(); // account for previous ops in prechecks
-		$curBatch = []; // concurrent FileOp sub-batch accumulation
-		$curBatchDeps = FileOp::newDependencies(); // paths used in FileOp sub-batch
-		$pPerformOps = []; // ordered list of concurrent FileOp sub-batches
-		$lastBackend = null; // last op backend name
-		// Do pre-checks for each operation; abort on failure...
-		foreach ( $performOps as $index => $fileOp ) {
-			$backendName = $fileOp->getBackend()->getName();
-			$fileOp->setBatchId( $batchId ); // transaction ID
-			// Decide if this op can be done concurrently within this sub-batch
-			// or if a new concurrent sub-batch must be started after this one...
-			if ( $fileOp->dependsOn( $curBatchDeps )
-				|| count( $curBatch ) >= $maxConcurrency
-				|| ( $backendName !== $lastBackend && count( $curBatch ) )
-			) {
-				$pPerformOps[] = $curBatch; // push this batch
-				$curBatch = []; // start a new sub-batch
-				$curBatchDeps = FileOp::newDependencies();
-			}
-			$lastBackend = $backendName;
-			$curBatch[$index] = $fileOp; // keep index
-			// Update list of affected paths in this batch
-			$curBatchDeps = $fileOp->applyDependencies( $curBatchDeps );
-			// Simulate performing the operation...
-			$oldPredicates = $predicates;
-			$subStatus = $fileOp->precheck( $predicates ); // updates $predicates
-			$status->merge( $subStatus );
-			if ( $subStatus->isOK() ) {
-				if ( $journaled ) { // journal log entries
-					$entries = array_merge( $entries,
-						$fileOp->getJournalEntries( $oldPredicates, $predicates ) );
-				}
-			} else { // operation failed?
-				$status->success[$index] = false;
-				++$status->failCount;
-				if ( !$ignoreErrors ) {
-					return $status; // abort
-				}
-			}
-		}
-		// Push the last sub-batch
-		if ( count( $curBatch ) ) {
-			$pPerformOps[] = $curBatch;
-		}
-
-		// Log the operations in the file journal...
-		if ( count( $entries ) ) {
-			$subStatus = $journal->logChangeBatch( $entries, $batchId );
-			if ( !$subStatus->isOK() ) {
-				$status->merge( $subStatus );
-
-				return $status; // abort
-			}
-		}
-
-		if ( $ignoreErrors ) { // treat precheck() fatals as mere warnings
-			$status->setResult( true, $status->value );
-		}
-
-		// Attempt each operation (in parallel if allowed and possible)...
-		self::runParallelBatches( $pPerformOps, $status );
-
-		return $status;
-	}
-
-	/**
-	 * Attempt a list of file operations sub-batches in series.
-	 *
-	 * The operations *in* each sub-batch will be done in parallel.
-	 * The caller is responsible for making sure the operations
-	 * within any given sub-batch do not depend on each other.
-	 * This will abort remaining ops on failure.
-	 *
-	 * @param array $pPerformOps Batches of file ops (batches use original indexes)
-	 * @param StatusValue $status
-	 */
-	protected static function runParallelBatches( array $pPerformOps, StatusValue $status ) {
-		$aborted = false; // set to true on unexpected errors
-		foreach ( $pPerformOps as $performOpsBatch ) {
-			/** @var FileOp[] $performOpsBatch */
-			if ( $aborted ) { // check batch op abort flag...
-				// We can't continue (even with $ignoreErrors) as $predicates is wrong.
-				// Log the remaining ops as failed for recovery...
-				foreach ( $performOpsBatch as $i => $fileOp ) {
-					$status->success[$i] = false;
-					++$status->failCount;
-					$performOpsBatch[$i]->logFailure( 'attempt_aborted' );
-				}
-				continue;
-			}
-			/** @var StatusValue[] $statuses */
-			$statuses = [];
-			$opHandles = [];
-			// Get the backend; all sub-batch ops belong to a single backend
-			/** @var FileBackendStore $backend */
-			$backend = reset( $performOpsBatch )->getBackend();
-			// Get the operation handles or actually do it if there is just one.
-			// If attemptAsync() returns a StatusValue, it was either due to an error
-			// or the backend does not support async ops and did it synchronously.
-			foreach ( $performOpsBatch as $i => $fileOp ) {
-				if ( !isset( $status->success[$i] ) ) { // didn't already fail in precheck()
-					// Parallel ops may be disabled in config due to missing dependencies,
-					// (e.g. needing popen()). When they are, $performOpsBatch has size 1.
-					$subStatus = ( count( $performOpsBatch ) > 1 )
-						? $fileOp->attemptAsync()
-						: $fileOp->attempt();
-					if ( $subStatus->value instanceof FileBackendStoreOpHandle ) {
-						$opHandles[$i] = $subStatus->value; // deferred
-					} else {
-						$statuses[$i] = $subStatus; // done already
-					}
-				}
-			}
-			// Try to do all the operations concurrently...
-			$statuses = $statuses + $backend->executeOpHandlesInternal( $opHandles );
-			// Marshall and merge all the responses (blocking)...
-			foreach ( $performOpsBatch as $i => $fileOp ) {
-				if ( !isset( $status->success[$i] ) ) { // didn't already fail in precheck()
-					$subStatus = $statuses[$i];
-					$status->merge( $subStatus );
-					if ( $subStatus->isOK() ) {
-						$status->success[$i] = true;
-						++$status->successCount;
-					} else {
-						$status->success[$i] = false;
-						++$status->failCount;
-						$aborted = true; // set abort flag; we can't continue
-					}
-				}
-			}
-		}
-	}
-}