Merge "SpecialBlock: Scroll to the error's fieldset instead of field"

[mediawiki.git] / includes / libs / filebackend / FSFileBackend.php

<?php
/**
 * 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
 */

/**
 * File system based backend.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 * @ingroup FileBackend
 */

namespace Wikimedia\FileBackend;

use MapCacheLRU;
use Shellbox\Command\BoxedCommand;
use Shellbox\Shellbox;
use StatusValue;
use Wikimedia\AtEase\AtEase;
use Wikimedia\FileBackend\FileIteration\FSFileBackendDirList;
use Wikimedia\FileBackend\FileIteration\FSFileBackendFileList;
use Wikimedia\FileBackend\FileOpHandle\FSFileOpHandle;
use Wikimedia\FileBackend\FSFile\FSFile;
use Wikimedia\FileBackend\FSFile\TempFSFile;
use Wikimedia\Timestamp\ConvertibleTimestamp;

/**
 * @brief Class for a file system (FS) based file backend.
 *
 * All "containers" each map to a directory under the backend's base directory.
 * For backwards-compatibility, some container paths can be set to custom paths.
 * The domain ID will not be used in any custom paths, so this should be avoided.
 *
 * Having directories with thousands of files will diminish performance.
 * Sharding can be accomplished by using FileRepo-style hash paths.
 *
 * StatusValue messages should avoid mentioning the internal FS paths.
 * PHP warnings are assumed to be logged rather than output.
 *
 * @ingroup FileBackend
 * @since 1.19
 */
class FSFileBackend extends FileBackendStore {
        /** @var MapCacheLRU Cache for known prepared/usable directories */
        protected $usableDirCache;

        /** @var string|null Directory holding the container directories */
        protected $basePath;

        /** @var array<string,string> Map of container names to root paths for custom container paths */
        protected $containerPaths;

        /** @var int Directory permission mode */
        protected $dirMode;
        /** @var int File permission mode */
        protected $fileMode;
        /** @var string Required OS username to own files */
        protected $fileOwner;

        /** @var string Simpler version of PHP_OS_FAMILY */
        protected $os;
        /** @var string OS username running this script */
        protected $currentUser;

        /** @var bool[] Map of (stack index => whether a warning happened) */
        private $warningTrapStack = [];

        /**
         * @see FileBackendStore::__construct()
         * Additional $config params include:
         *   - basePath       : File system directory that holds containers.
         *   - containerPaths : Map of container names to custom file system directories.
         *                      This should only be used for backwards-compatibility.
         *   - fileMode       : Octal UNIX file permissions to use on files stored.
         *   - directoryMode  : Octal UNIX file permissions to use on directories created.
         * @param array $config
         */
        public function __construct( array $config ) {
                parent::__construct( $config );

                if ( PHP_OS_FAMILY === 'Windows' ) {
                        $this->os = 'Windows';
                } elseif ( PHP_OS_FAMILY === 'BSD' || PHP_OS_FAMILY === 'Darwin' ) {
                        $this->os = 'BSD';
                } else {
                        $this->os = 'Linux';
                }
                // Remove any possible trailing slash from directories
                if ( isset( $config['basePath'] ) ) {
                        $this->basePath = rtrim( $config['basePath'], '/' ); // remove trailing slash
                } else {
                        $this->basePath = null; // none; containers must have explicit paths
                }

                $this->containerPaths = [];
                foreach ( ( $config['containerPaths'] ?? [] ) as $container => $fsPath ) {
                        $this->containerPaths[$container] = rtrim( $fsPath, '/' ); // remove trailing slash
                }

                $this->fileMode = $config['fileMode'] ?? 0644;
                $this->dirMode = $config['directoryMode'] ?? 0777;
                if ( isset( $config['fileOwner'] ) && function_exists( 'posix_getuid' ) ) {
                        $this->fileOwner = $config['fileOwner'];
                        // Cache this, assuming it doesn't change
                        $this->currentUser = posix_getpwuid( posix_getuid() )['name'];
                }

                $this->usableDirCache = new MapCacheLRU( self::CACHE_CHEAP_SIZE );
        }

        public function getFeatures() {
                return self::ATTR_UNICODE_PATHS;
        }

        protected function resolveContainerPath( $container, $relStoragePath ) {
                // Check that container has a root directory
                if ( isset( $this->containerPaths[$container] ) || $this->basePath !== null ) {
                        // Check for sensible relative paths (assume the base paths are OK)
                        if ( $this->isLegalRelPath( $relStoragePath ) ) {
                                return $relStoragePath;
                        }
                }

                return null; // invalid
        }

        /**
         * Check a relative file system path for validity
         *
         * @param string $fsPath Normalized relative path
         * @return bool
         */
        protected function isLegalRelPath( $fsPath ) {
                // Check for file names longer than 255 chars
                if ( preg_match( '![^/]{256}!', $fsPath ) ) { // ext3/NTFS
                        return false;
                }
                if ( $this->os === 'Windows' ) { // NTFS
                        return !preg_match( '![:*?"<>|]!', $fsPath );
                } else {
                        return true;
                }
        }

        /**
         * Given the short (unresolved) and full (resolved) name of
         * a container, return the file system path of the container.
         *
         * @param string $shortCont
         * @param string $fullCont
         * @return string|null
         */
        protected function containerFSRoot( $shortCont, $fullCont ) {
                if ( isset( $this->containerPaths[$shortCont] ) ) {
                        return $this->containerPaths[$shortCont];
                } elseif ( $this->basePath !== null ) {
                        return "{$this->basePath}/{$fullCont}";
                }

                return null; // no container base path defined
        }

        /**
         * Get the absolute file system path for a storage path
         *
         * @param string $storagePath
         * @return string|null
         */
        protected function resolveToFSPath( $storagePath ) {
                [ $fullCont, $relPath ] = $this->resolveStoragePathReal( $storagePath );
                if ( $relPath === null ) {
                        return null; // invalid
                }
                [ , $shortCont, ] = FileBackend::splitStoragePath( $storagePath );
                $fsPath = $this->containerFSRoot( $shortCont, $fullCont ); // must be valid
                if ( $relPath != '' ) {
                        $fsPath .= "/{$relPath}";
                }

                return $fsPath;
        }

        public function isPathUsableInternal( $storagePath ) {
                $fsPath = $this->resolveToFSPath( $storagePath );
                if ( $fsPath === null ) {
                        return false; // invalid
                }

                if ( $this->fileOwner !== null && $this->currentUser !== $this->fileOwner ) {
                        trigger_error( __METHOD__ . ": PHP process owner is not '{$this->fileOwner}'." );
                        return false;
                }

                $fsDirectory = dirname( $fsPath );
                $usable = $this->usableDirCache->get( $fsDirectory, MapCacheLRU::TTL_PROC_SHORT );
                if ( $usable === null ) {
                        AtEase::suppressWarnings();
                        $usable = is_dir( $fsDirectory ) && is_writable( $fsDirectory );
                        AtEase::restoreWarnings();
                        $this->usableDirCache->set( $fsDirectory, $usable ? 1 : 0 );
                }

                return $usable;
        }

        protected function doCreateInternal( array $params ) {
                $status = $this->newStatus();

                $fsDstPath = $this->resolveToFSPath( $params['dst'] );
                if ( $fsDstPath === null ) {
                        $status->fatal( 'backend-fail-invalidpath', $params['dst'] );

                        return $status;
                }

                if ( !empty( $params['async'] ) ) { // deferred
                        $tempFile = $this->newTempFileWithContent( $params );
                        if ( !$tempFile ) {
                                $status->fatal( 'backend-fail-create', $params['dst'] );

                                return $status;
                        }
                        $cmd = $this->makeCopyCommand( $tempFile->getPath(), $fsDstPath, false );
                        $handler = function ( $errors, StatusValue $status, array $params, $cmd ) {
                                if ( $errors !== '' && !( $this->os === 'Windows' && $errors[0] === " " ) ) {
                                        $status->fatal( 'backend-fail-create', $params['dst'] );
                                        trigger_error( "$cmd\n$errors", E_USER_WARNING ); // command output
                                }
                        };
                        $status->value = new FSFileOpHandle( $this, $params, $handler, $cmd );
                        $tempFile->bind( $status->value );
                } else { // immediate write
                        $created = false;
                        // Use fwrite+rename since (a) this clears xattrs, (b) threads still reading the old
                        // inode are unaffected since it writes to a new inode, and (c) new threads reading
                        // the file will either totally see the old version or totally see the new version
                        $fsStagePath = $this->makeStagingPath( $fsDstPath );
                        $this->trapWarningsIgnoringNotFound();
                        $stageHandle = fopen( $fsStagePath, 'xb' );
                        if ( $stageHandle ) {
                                $bytes = fwrite( $stageHandle, $params['content'] );
                                $created = ( $bytes === strlen( $params['content'] ) );
                                fclose( $stageHandle );
                                $created = $created ? rename( $fsStagePath, $fsDstPath ) : false;
                        }
                        $hadError = $this->untrapWarnings();
                        if ( $hadError || !$created ) {
                                $status->fatal( 'backend-fail-create', $params['dst'] );

                                return $status;
                        }
                        $this->chmod( $fsDstPath );
                }

                return $status;
        }

        protected function doStoreInternal( array $params ) {
                $status = $this->newStatus();

                $fsSrcPath = $params['src']; // file system path
                $fsDstPath = $this->resolveToFSPath( $params['dst'] );
                if ( $fsDstPath === null ) {
                        $status->fatal( 'backend-fail-invalidpath', $params['dst'] );

                        return $status;
                }

                if ( $fsSrcPath === $fsDstPath ) {
                        $status->fatal( 'backend-fail-internal', $this->name );

                        return $status;
                }

                if ( !empty( $params['async'] ) ) { // deferred
                        $cmd = $this->makeCopyCommand( $fsSrcPath, $fsDstPath, false );
                        $handler = function ( $errors, StatusValue $status, array $params, $cmd ) {
                                if ( $errors !== '' && !( $this->os === 'Windows' && $errors[0] === " " ) ) {
                                        $status->fatal( 'backend-fail-store', $params['src'], $params['dst'] );
                                        trigger_error( "$cmd\n$errors", E_USER_WARNING ); // command output
                                }
                        };
                        $status->value = new FSFileOpHandle( $this, $params, $handler, $cmd );
                } else { // immediate write
                        $stored = false;
                        // Use fwrite+rename since (a) this clears xattrs, (b) threads still reading the old
                        // inode are unaffected since it writes to a new inode, and (c) new threads reading
                        // the file will either totally see the old version or totally see the new version
                        $fsStagePath = $this->makeStagingPath( $fsDstPath );
                        $this->trapWarningsIgnoringNotFound();
                        $srcHandle = fopen( $fsSrcPath, 'rb' );
                        if ( $srcHandle ) {
                                $stageHandle = fopen( $fsStagePath, 'xb' );
                                if ( $stageHandle ) {
                                        $bytes = stream_copy_to_stream( $srcHandle, $stageHandle );
                                        $stored = ( $bytes !== false && $bytes === fstat( $srcHandle )['size'] );
                                        fclose( $stageHandle );
                                        $stored = $stored ? rename( $fsStagePath, $fsDstPath ) : false;
                                }
                                fclose( $srcHandle );
                        }
                        $hadError = $this->untrapWarnings();
                        if ( $hadError || !$stored ) {
                                $status->fatal( 'backend-fail-store', $params['src'], $params['dst'] );

                                return $status;
                        }
                        $this->chmod( $fsDstPath );
                }

                return $status;
        }

        protected function doCopyInternal( array $params ) {
                $status = $this->newStatus();

                $fsSrcPath = $this->resolveToFSPath( $params['src'] );
                if ( $fsSrcPath === null ) {
                        $status->fatal( 'backend-fail-invalidpath', $params['src'] );

                        return $status;
                }

                $fsDstPath = $this->resolveToFSPath( $params['dst'] );
                if ( $fsDstPath === null ) {
                        $status->fatal( 'backend-fail-invalidpath', $params['dst'] );

                        return $status;
                }

                if ( $fsSrcPath === $fsDstPath ) {
                        return $status; // no-op
                }

                $ignoreMissing = !empty( $params['ignoreMissingSource'] );

                if ( !empty( $params['async'] ) ) { // deferred
                        $cmd = $this->makeCopyCommand( $fsSrcPath, $fsDstPath, $ignoreMissing );
                        $handler = function ( $errors, StatusValue $status, array $params, $cmd ) {
                                if ( $errors !== '' && !( $this->os === 'Windows' && $errors[0] === " " ) ) {
                                        $status->fatal( 'backend-fail-copy', $params['src'], $params['dst'] );
                                        trigger_error( "$cmd\n$errors", E_USER_WARNING ); // command output
                                }
                        };
                        $status->value = new FSFileOpHandle( $this, $params, $handler, $cmd );
                } else { // immediate write
                        $copied = false;
                        // Use fwrite+rename since (a) this clears xattrs, (b) threads still reading the old
                        // inode are unaffected since it writes to a new inode, and (c) new threads reading
                        // the file will either totally see the old version or totally see the new version
                        $fsStagePath = $this->makeStagingPath( $fsDstPath );
                        $this->trapWarningsIgnoringNotFound();
                        $srcHandle = fopen( $fsSrcPath, 'rb' );
                        if ( $srcHandle ) {
                                $stageHandle = fopen( $fsStagePath, 'xb' );
                                if ( $stageHandle ) {
                                        $bytes = stream_copy_to_stream( $srcHandle, $stageHandle );
                                        $copied = ( $bytes !== false && $bytes === fstat( $srcHandle )['size'] );
                                        fclose( $stageHandle );
                                        $copied = $copied ? rename( $fsStagePath, $fsDstPath ) : false;
                                }
                                fclose( $srcHandle );
                        }
                        $hadError = $this->untrapWarnings();
                        if ( $hadError || ( !$copied && !$ignoreMissing ) ) {
                                $status->fatal( 'backend-fail-copy', $params['src'], $params['dst'] );

                                return $status;
                        }
                        if ( $copied ) {
                                $this->chmod( $fsDstPath );
                        }
                }

                return $status;
        }

        protected function doMoveInternal( array $params ) {
                $status = $this->newStatus();

                $fsSrcPath = $this->resolveToFSPath( $params['src'] );
                if ( $fsSrcPath === null ) {
                        $status->fatal( 'backend-fail-invalidpath', $params['src'] );

                        return $status;
                }

                $fsDstPath = $this->resolveToFSPath( $params['dst'] );
                if ( $fsDstPath === null ) {
                        $status->fatal( 'backend-fail-invalidpath', $params['dst'] );

                        return $status;
                }

                if ( $fsSrcPath === $fsDstPath ) {
                        return $status; // no-op
                }

                $ignoreMissing = !empty( $params['ignoreMissingSource'] );

                if ( !empty( $params['async'] ) ) { // deferred
                        $cmd = $this->makeMoveCommand( $fsSrcPath, $fsDstPath, $ignoreMissing );
                        $handler = function ( $errors, StatusValue $status, array $params, $cmd ) {
                                if ( $errors !== '' && !( $this->os === 'Windows' && $errors[0] === " " ) ) {
                                        $status->fatal( 'backend-fail-move', $params['src'], $params['dst'] );
                                        trigger_error( "$cmd\n$errors", E_USER_WARNING ); // command output
                                }
                        };
                        $status->value = new FSFileOpHandle( $this, $params, $handler, $cmd );
                } else { // immediate write
                        // Use rename() here since (a) this clears xattrs, (b) any threads still reading the
                        // old inode are unaffected since it writes to a new inode, and (c) this is fast and
                        // atomic within a file system volume (as is normally the case)
                        $this->trapWarningsIgnoringNotFound();
                        $moved = rename( $fsSrcPath, $fsDstPath );
                        $hadError = $this->untrapWarnings();
                        if ( $hadError || ( !$moved && !$ignoreMissing ) ) {
                                $status->fatal( 'backend-fail-move', $params['src'], $params['dst'] );

                                return $status;
                        }
                }

                return $status;
        }

        protected function doDeleteInternal( array $params ) {
                $status = $this->newStatus();

                $fsSrcPath = $this->resolveToFSPath( $params['src'] );
                if ( $fsSrcPath === null ) {
                        $status->fatal( 'backend-fail-invalidpath', $params['src'] );

                        return $status;
                }

                $ignoreMissing = !empty( $params['ignoreMissingSource'] );

                if ( !empty( $params['async'] ) ) { // deferred
                        $cmd = $this->makeUnlinkCommand( $fsSrcPath, $ignoreMissing );
                        $handler = function ( $errors, StatusValue $status, array $params, $cmd ) {
                                if ( $errors !== '' && !( $this->os === 'Windows' && $errors[0] === " " ) ) {
                                        $status->fatal( 'backend-fail-delete', $params['src'] );
                                        trigger_error( "$cmd\n$errors", E_USER_WARNING ); // command output
                                }
                        };
                        $status->value = new FSFileOpHandle( $this, $params, $handler, $cmd );
                } else { // immediate write
                        $this->trapWarningsIgnoringNotFound();
                        $deleted = unlink( $fsSrcPath );
                        $hadError = $this->untrapWarnings();
                        if ( $hadError || ( !$deleted && !$ignoreMissing ) ) {
                                $status->fatal( 'backend-fail-delete', $params['src'] );

                                return $status;
                        }
                }

                return $status;
        }

        /**
         * @inheritDoc
         */
        protected function doPrepareInternal( $fullCont, $dirRel, array $params ) {
                $status = $this->newStatus();
                [ , $shortCont, ] = FileBackend::splitStoragePath( $params['dir'] );
                $contRoot = $this->containerFSRoot( $shortCont, $fullCont ); // must be valid
                $fsDirectory = ( $dirRel != '' ) ? "{$contRoot}/{$dirRel}" : $contRoot;
                // Create the directory and its parents as needed...
                $created = false;
                AtEase::suppressWarnings();
                $alreadyExisted = is_dir( $fsDirectory ); // already there?
                if ( !$alreadyExisted ) {
                        $created = mkdir( $fsDirectory, $this->dirMode, true );
                        if ( !$created ) {
                                $alreadyExisted = is_dir( $fsDirectory ); // another thread made it?
                        }
                }
                $isWritable = $created ?: is_writable( $fsDirectory ); // assume writable if created here
                AtEase::restoreWarnings();
                if ( !$alreadyExisted && !$created ) {
                        $this->logger->error( __METHOD__ . ": cannot create directory $fsDirectory" );
                        $status->fatal( 'directorycreateerror', $params['dir'] ); // fails on races
                } elseif ( !$isWritable ) {
                        $this->logger->error( __METHOD__ . ": directory $fsDirectory is read-only" );
                        $status->fatal( 'directoryreadonlyerror', $params['dir'] );
                }
                // Respect any 'noAccess' or 'noListing' flags...
                if ( $created ) {
                        $status->merge( $this->doSecureInternal( $fullCont, $dirRel, $params ) );
                }

                if ( $status->isGood() ) {
                        $this->usableDirCache->set( $fsDirectory, 1 );
                }

                return $status;
        }

        protected function doSecureInternal( $fullCont, $dirRel, array $params ) {
                $status = $this->newStatus();
                [ , $shortCont, ] = FileBackend::splitStoragePath( $params['dir'] );
                $contRoot = $this->containerFSRoot( $shortCont, $fullCont ); // must be valid
                $fsDirectory = ( $dirRel != '' ) ? "{$contRoot}/{$dirRel}" : $contRoot;
                // Seed new directories with a blank index.html, to prevent crawling...
                if ( !empty( $params['noListing'] ) && !is_file( "{$fsDirectory}/index.html" ) ) {
                        $this->trapWarnings();
                        $bytes = file_put_contents( "{$fsDirectory}/index.html", $this->indexHtmlPrivate() );
                        $this->untrapWarnings();
                        if ( $bytes === false ) {
                                $status->fatal( 'backend-fail-create', $params['dir'] . '/index.html' );
                        }
                }
                // Add a .htaccess file to the root of the container...
                if ( !empty( $params['noAccess'] ) && !is_file( "{$contRoot}/.htaccess" ) ) {
                        AtEase::suppressWarnings();
                        $bytes = file_put_contents( "{$contRoot}/.htaccess", $this->htaccessPrivate() );
                        AtEase::restoreWarnings();
                        if ( $bytes === false ) {
                                $storeDir = "mwstore://{$this->name}/{$shortCont}";
                                $status->fatal( 'backend-fail-create', "{$storeDir}/.htaccess" );
                        }
                }

                return $status;
        }

        protected function doPublishInternal( $fullCont, $dirRel, array $params ) {
                $status = $this->newStatus();
                [ , $shortCont, ] = FileBackend::splitStoragePath( $params['dir'] );
                $contRoot = $this->containerFSRoot( $shortCont, $fullCont ); // must be valid
                $fsDirectory = ( $dirRel != '' ) ? "{$contRoot}/{$dirRel}" : $contRoot;
                // Unseed new directories with a blank index.html, to allow crawling...
                if ( !empty( $params['listing'] ) && is_file( "{$fsDirectory}/index.html" ) ) {
                        $exists = ( file_get_contents( "{$fsDirectory}/index.html" ) === $this->indexHtmlPrivate() );
                        if ( $exists && !$this->unlink( "{$fsDirectory}/index.html" ) ) { // reverse secure()
                                $status->fatal( 'backend-fail-delete', $params['dir'] . '/index.html' );
                        }
                }
                // Remove the .htaccess file from the root of the container...
                if ( !empty( $params['access'] ) && is_file( "{$contRoot}/.htaccess" ) ) {
                        $exists = ( file_get_contents( "{$contRoot}/.htaccess" ) === $this->htaccessPrivate() );
                        if ( $exists && !$this->unlink( "{$contRoot}/.htaccess" ) ) { // reverse secure()
                                $storeDir = "mwstore://{$this->name}/{$shortCont}";
                                $status->fatal( 'backend-fail-delete', "{$storeDir}/.htaccess" );
                        }
                }

                return $status;
        }

        protected function doCleanInternal( $fullCont, $dirRel, array $params ) {
                $status = $this->newStatus();
                [ , $shortCont, ] = FileBackend::splitStoragePath( $params['dir'] );
                $contRoot = $this->containerFSRoot( $shortCont, $fullCont ); // must be valid
                $fsDirectory = ( $dirRel != '' ) ? "{$contRoot}/{$dirRel}" : $contRoot;

                $this->rmdir( $fsDirectory );

                return $status;
        }

        protected function doGetFileStat( array $params ) {
                $fsSrcPath = $this->resolveToFSPath( $params['src'] );
                if ( $fsSrcPath === null ) {
                        return self::RES_ERROR; // invalid storage path
                }

                $this->trapWarnings(); // don't trust 'false' if there were errors
                $stat = is_file( $fsSrcPath ) ? stat( $fsSrcPath ) : false; // regular files only
                $hadError = $this->untrapWarnings();

                if ( is_array( $stat ) ) {
                        $ct = new ConvertibleTimestamp( $stat['mtime'] );

                        return [
                                'mtime' => $ct->getTimestamp( TS_MW ),
                                'size' => $stat['size']
                        ];
                }

                return $hadError ? self::RES_ERROR : self::RES_ABSENT;
        }

        protected function doClearCache( ?array $paths = null ) {
                if ( is_array( $paths ) ) {
                        foreach ( $paths as $path ) {
                                $fsPath = $this->resolveToFSPath( $path );
                                if ( $fsPath !== null ) {
                                        clearstatcache( true, $fsPath );
                                        $this->usableDirCache->clear( $fsPath );
                                }
                        }
                } else {
                        clearstatcache( true ); // clear the PHP file stat cache
                        $this->usableDirCache->clear();
                }
        }

        protected function doDirectoryExists( $fullCont, $dirRel, array $params ) {
                [ , $shortCont, ] = FileBackend::splitStoragePath( $params['dir'] );
                $contRoot = $this->containerFSRoot( $shortCont, $fullCont ); // must be valid
                $fsDirectory = ( $dirRel != '' ) ? "{$contRoot}/{$dirRel}" : $contRoot;

                $this->trapWarnings(); // don't trust 'false' if there were errors
                $exists = is_dir( $fsDirectory );
                $hadError = $this->untrapWarnings();

                return $hadError ? self::RES_ERROR : $exists;
        }

        /**
         * @see FileBackendStore::getDirectoryListInternal()
         * @param string $fullCont
         * @param string $dirRel
         * @param array $params
         * @return array|FSFileBackendDirList|null
         */
        public function getDirectoryListInternal( $fullCont, $dirRel, array $params ) {
                [ , $shortCont, ] = FileBackend::splitStoragePath( $params['dir'] );
                $contRoot = $this->containerFSRoot( $shortCont, $fullCont ); // must be valid
                $fsDirectory = ( $dirRel != '' ) ? "{$contRoot}/{$dirRel}" : $contRoot;

                $list = new FSFileBackendDirList( $fsDirectory, $params );
                $error = $list->getLastError();
                if ( $error !== null ) {
                        if ( $this->isFileNotFoundError( $error ) ) {
                                $this->logger->info( __METHOD__ . ": non-existant directory: '$fsDirectory'" );

                                return []; // nothing under this dir
                        } elseif ( is_dir( $fsDirectory ) ) {
                                $this->logger->warning( __METHOD__ . ": unreadable directory: '$fsDirectory'" );

                                return self::RES_ERROR; // bad permissions?
                        } else {
                                $this->logger->warning( __METHOD__ . ": unreachable directory: '$fsDirectory'" );

                                return self::RES_ERROR;
                        }
                }

                return $list;
        }

        /**
         * @see FileBackendStore::getFileListInternal()
         * @param string $fullCont
         * @param string $dirRel
         * @param array $params
         * @return array|FSFileBackendFileList|null
         */
        public function getFileListInternal( $fullCont, $dirRel, array $params ) {
                [ , $shortCont, ] = FileBackend::splitStoragePath( $params['dir'] );
                $contRoot = $this->containerFSRoot( $shortCont, $fullCont ); // must be valid
                $fsDirectory = ( $dirRel != '' ) ? "{$contRoot}/{$dirRel}" : $contRoot;

                $list = new FSFileBackendFileList( $fsDirectory, $params );
                $error = $list->getLastError();
                if ( $error !== null ) {
                        if ( $this->isFileNotFoundError( $error ) ) {
                                $this->logger->info( __METHOD__ . ": non-existent directory: '$fsDirectory'" );

                                return []; // nothing under this dir
                        } elseif ( is_dir( $fsDirectory ) ) {
                                $this->logger->warning( __METHOD__ .
                                        ": unreadable directory: '$fsDirectory': $error" );

                                return self::RES_ERROR; // bad permissions?
                        } else {
                                $this->logger->warning( __METHOD__ .
                                        ": unreachable directory: '$fsDirectory': $error" );

                                return self::RES_ERROR;
                        }
                }

                return $list;
        }

        protected function doGetLocalReferenceMulti( array $params ) {
                $fsFiles = []; // (path => FSFile)

                foreach ( $params['srcs'] as $src ) {
                        $source = $this->resolveToFSPath( $src );
                        if ( $source === null ) {
                                $fsFiles[$src] = self::RES_ERROR; // invalid path
                                continue;
                        }

                        $this->trapWarnings(); // don't trust 'false' if there were errors
                        $isFile = is_file( $source ); // regular files only
                        $hadError = $this->untrapWarnings();

                        if ( $isFile ) {
                                $fsFiles[$src] = new FSFile( $source );
                        } elseif ( $hadError ) {
                                $fsFiles[$src] = self::RES_ERROR;
                        } else {
                                $fsFiles[$src] = self::RES_ABSENT;
                        }
                }

                return $fsFiles;
        }

        protected function doGetLocalCopyMulti( array $params ) {
                $tmpFiles = []; // (path => TempFSFile)

                foreach ( $params['srcs'] as $src ) {
                        $source = $this->resolveToFSPath( $src );
                        if ( $source === null ) {
                                $tmpFiles[$src] = self::RES_ERROR; // invalid path
                                continue;
                        }
                        // Create a new temporary file with the same extension...
                        $ext = FileBackend::extensionFromPath( $src );
                        $tmpFile = $this->tmpFileFactory->newTempFSFile( 'localcopy_', $ext );
                        if ( !$tmpFile ) {
                                $tmpFiles[$src] = self::RES_ERROR;
                                continue;
                        }

                        $tmpPath = $tmpFile->getPath();
                        // Copy the source file over the temp file
                        $this->trapWarnings(); // don't trust 'false' if there were errors
                        $isFile = is_file( $source ); // regular files only
                        $copySuccess = $isFile ? copy( $source, $tmpPath ) : false;
                        $hadError = $this->untrapWarnings();

                        if ( $copySuccess ) {
                                $this->chmod( $tmpPath );
                                $tmpFiles[$src] = $tmpFile;
                        } elseif ( $hadError ) {
                                $tmpFiles[$src] = self::RES_ERROR; // copy failed
                        } else {
                                $tmpFiles[$src] = self::RES_ABSENT;
                        }
                }

                return $tmpFiles;
        }

        public function addShellboxInputFile( BoxedCommand $command, string $boxedName,
                array $params
        ) {
                $path = $this->resolveToFSPath( $params['src'] );
                if ( $path === null ) {
                        return $this->newStatus( 'backend-fail-invalidpath', $params['src'] );
                }
                $command->inputFileFromFile( $boxedName, $path );
                return $this->newStatus();
        }

        protected function directoriesAreVirtual() {
                return false;
        }

        /**
         * @param FSFileOpHandle[] $fileOpHandles
         *
         * @return StatusValue[]
         */
        protected function doExecuteOpHandlesInternal( array $fileOpHandles ) {
                $statuses = [];

                $pipes = [];
                foreach ( $fileOpHandles as $index => $fileOpHandle ) {
                        $pipes[$index] = popen( $fileOpHandle->cmd, 'r' );
                }

                $errs = [];
                foreach ( $pipes as $index => $pipe ) {
                        // Result will be empty on success in *NIX. On Windows,
                        // it may be something like "        1 file(s) [copied|moved].".
                        $errs[$index] = stream_get_contents( $pipe );
                        fclose( $pipe );
                }

                foreach ( $fileOpHandles as $index => $fileOpHandle ) {
                        $status = $this->newStatus();
                        $function = $fileOpHandle->callback;
                        $function( $errs[$index], $status, $fileOpHandle->params, $fileOpHandle->cmd );
                        $statuses[$index] = $status;
                }

                return $statuses;
        }

        /**
         * @param string $fsPath Absolute file system path
         * @return string Absolute file system path on the same device
         */
        private function makeStagingPath( $fsPath ) {
                $time = dechex( time() ); // make it easy to find old orphans
                $hash = \Wikimedia\base_convert( md5( basename( $fsPath ) ), 16, 36, 25 );
                $unique = \Wikimedia\base_convert( bin2hex( random_bytes( 16 ) ), 16, 36, 25 );

                return dirname( $fsPath ) . "/.{$time}_{$hash}_{$unique}.tmpfsfile";
        }

        /**
         * @param string $fsSrcPath Absolute file system path
         * @param string $fsDstPath Absolute file system path
         * @param bool $ignoreMissing Whether to no-op if the source file is non-existent
         * @return string Command
         */
        private function makeCopyCommand( $fsSrcPath, $fsDstPath, $ignoreMissing ) {
                // Use copy+rename since (a) this clears xattrs, (b) threads still reading the old
                // inode are unaffected since it writes to a new inode, and (c) new threads reading
                // the file will either totally see the old version or totally see the new version
                $fsStagePath = $this->makeStagingPath( $fsDstPath );
                $encSrc = Shellbox::escape( $this->cleanPathSlashes( $fsSrcPath ) );
                $encStage = Shellbox::escape( $this->cleanPathSlashes( $fsStagePath ) );
                $encDst = Shellbox::escape( $this->cleanPathSlashes( $fsDstPath ) );
                if ( $this->os === 'Windows' ) {
                        // https://docs.microsoft.com/en-us/windows-server/administration/windows-commands/copy
                        // https://docs.microsoft.com/en-us/windows-server/administration/windows-commands/move
                        $cmdWrite = "COPY /B /Y $encSrc $encStage 2>&1 && MOVE /Y $encStage $encDst 2>&1";
                        $cmd = $ignoreMissing ? "IF EXIST $encSrc $cmdWrite" : $cmdWrite;
                } else {
                        // https://manpages.debian.org/buster/coreutils/cp.1.en.html
                        // https://manpages.debian.org/buster/coreutils/mv.1.en.html
                        $cmdWrite = "cp $encSrc $encStage 2>&1 && mv $encStage $encDst 2>&1";
                        $cmd = $ignoreMissing ? "test -f $encSrc && $cmdWrite" : $cmdWrite;
                        // Clean up permissions on any newly created destination file
                        $octalPermissions = '0' . decoct( $this->fileMode );
                        if ( strlen( $octalPermissions ) == 4 ) {
                                $cmd .= " && chmod $octalPermissions $encDst 2>/dev/null";
                        }
                }

                return $cmd;
        }

        /**
         * @param string $fsSrcPath Absolute file system path
         * @param string $fsDstPath Absolute file system path
         * @param bool $ignoreMissing Whether to no-op if the source file is non-existent
         * @return string Command
         */
        private function makeMoveCommand( $fsSrcPath, $fsDstPath, $ignoreMissing = false ) {
                // https://manpages.debian.org/buster/coreutils/mv.1.en.html
                // https://docs.microsoft.com/en-us/windows-server/administration/windows-commands/move
                $encSrc = Shellbox::escape( $this->cleanPathSlashes( $fsSrcPath ) );
                $encDst = Shellbox::escape( $this->cleanPathSlashes( $fsDstPath ) );
                if ( $this->os === 'Windows' ) {
                        $writeCmd = "MOVE /Y $encSrc $encDst 2>&1";
                        $cmd = $ignoreMissing ? "IF EXIST $encSrc $writeCmd" : $writeCmd;
                } else {
                        $writeCmd = "mv -f $encSrc $encDst 2>&1";
                        $cmd = $ignoreMissing ? "test -f $encSrc && $writeCmd" : $writeCmd;
                }

                return $cmd;
        }

        /**
         * @param string $fsPath Absolute file system path
         * @param bool $ignoreMissing Whether to no-op if the file is non-existent
         * @return string Command
         */
        private function makeUnlinkCommand( $fsPath, $ignoreMissing = false ) {
                // https://manpages.debian.org/buster/coreutils/rm.1.en.html
                // https://docs.microsoft.com/en-us/windows-server/administration/windows-commands/del
                $encSrc = Shellbox::escape( $this->cleanPathSlashes( $fsPath ) );
                if ( $this->os === 'Windows' ) {
                        $writeCmd = "DEL /Q $encSrc 2>&1";
                        $cmd = $ignoreMissing ? "IF EXIST $encSrc $writeCmd" : $writeCmd;
                } else {
                        $cmd = $ignoreMissing ? "rm -f $encSrc 2>&1" : "rm $encSrc 2>&1";
                }

                return $cmd;
        }

        /**
         * Chmod a file, suppressing the warnings
         *
         * @param string $fsPath Absolute file system path
         * @return bool Success
         */
        protected function chmod( $fsPath ) {
                if ( $this->os === 'Windows' ) {
                        return true;
                }

                AtEase::suppressWarnings();
                $ok = chmod( $fsPath, $this->fileMode );
                AtEase::restoreWarnings();

                return $ok;
        }

        /**
         * Unlink a file, suppressing the warnings
         *
         * @param string $fsPath Absolute file system path
         * @return bool Success
         */
        protected function unlink( $fsPath ) {
                AtEase::suppressWarnings();
                $ok = unlink( $fsPath );
                AtEase::restoreWarnings();
                clearstatcache( true, $fsPath );

                return $ok;
        }

        /**
         * Remove an empty directory, suppressing the warnings
         *
         * @param string $fsDirectory Absolute file system path
         * @return bool Success
         */
        protected function rmdir( $fsDirectory ) {
                AtEase::suppressWarnings();
                $ok = rmdir( $fsDirectory ); // remove directory if empty
                AtEase::restoreWarnings();
                clearstatcache( true, $fsDirectory );

                return $ok;
        }

        /**
         * @param array $params Parameters for FileBackend 'create' operation
         * @return TempFSFile|null
         */
        protected function newTempFileWithContent( array $params ) {
                $tempFile = $this->tmpFileFactory->newTempFSFile( 'create_', 'tmp' );
                if ( !$tempFile ) {
                        return null;
                }

                AtEase::suppressWarnings();
                if ( file_put_contents( $tempFile->getPath(), $params['content'] ) === false ) {
                        $tempFile = null;
                }
                AtEase::restoreWarnings();

                return $tempFile;
        }

        /**
         * Return the text of an index.html file to hide directory listings
         *
         * @return string
         */
        protected function indexHtmlPrivate() {
                return '';
        }

        /**
         * Return the text of a .htaccess file to make a directory private
         *
         * @return string
         */
        protected function htaccessPrivate() {
                return "Require all denied\n";
        }

        /**
         * Clean up directory separators for the given OS
         *
         * @param string $fsPath
         * @return string
         */
        protected function cleanPathSlashes( $fsPath ) {
                return ( $this->os === 'Windows' ) ? strtr( $fsPath, '/', '\\' ) : $fsPath;
        }

        /**
         * Listen for E_WARNING errors and track whether any that happen
         *
         * @param string|null $regexIgnore Optional regex of errors to ignore
         */
        protected function trapWarnings( $regexIgnore = null ) {
                $this->warningTrapStack[] = false;
                set_error_handler( function ( $errno, $errstr ) use ( $regexIgnore ) {
                        if ( $regexIgnore === null || !preg_match( $regexIgnore, $errstr ) ) {
                                $this->logger->error( $errstr );
                                $this->warningTrapStack[count( $this->warningTrapStack ) - 1] = true;
                        }
                        return true; // suppress from PHP handler
                }, E_WARNING );
        }

        /**
         * Track E_WARNING errors but ignore any that correspond to ENOENT "No such file or directory"
         */
        protected function trapWarningsIgnoringNotFound() {
                $this->trapWarnings( $this->getFileNotFoundRegex() );
        }

        /**
         * Stop listening for E_WARNING errors and get whether any happened
         *
         * @return bool Whether any warnings happened
         */
        protected function untrapWarnings() {
                restore_error_handler();

                return array_pop( $this->warningTrapStack );
        }

        /**
         * Get a regex matching file not found errors
         *
         * @return string
         */
        protected function getFileNotFoundRegex() {
                static $regex;
                if ( $regex === null ) {
                        // "No such file or directory": string literal in spl_directory.c etc.
                        $alternatives = [ ': No such file or directory' ];
                        if ( $this->os === 'Windows' ) {
                                // 2 = The system cannot find the file specified.
                                // 3 = The system cannot find the path specified.
                                $alternatives[] = ' \(code: [23]\)';
                        }
                        if ( function_exists( 'pcntl_strerror' ) ) {
                                $alternatives[] = preg_quote( ': ' . pcntl_strerror( 2 ), '/' );
                        } elseif ( function_exists( 'socket_strerror' ) && defined( 'SOCKET_ENOENT' ) ) {
                                $alternatives[] = preg_quote( ': ' . socket_strerror( SOCKET_ENOENT ), '/' );
                        }
                        $regex = '/(' . implode( '|', $alternatives ) . ')$/';
                }
                return $regex;
        }

        /**
         * Determine whether a given error message is a file not found error.
         *
         * @param string $error
         * @return bool
         */
        protected function isFileNotFoundError( $error ) {
                return (bool)preg_match( $this->getFileNotFoundRegex(), $error );
        }
}

/** @deprecated class alias since 1.43 */
class_alias( FSFileBackend::class, 'FSFileBackend' );