copyFileBackend.php

Go to the documentation of this file.

<?php
use MediaWiki\Maintenance\Maintenance;
use Wikimedia\FileBackend\FileBackend;
 
// @codeCoverageIgnoreStart
require_once __DIR__ . '/Maintenance.php';
// @codeCoverageIgnoreEnd
 
class CopyFileBackend extends Maintenance {
    protected $statCache = null;
 
    public function __construct() {
        parent::__construct();
        $this->addDescription( 'Copy files in one backend to another.' );
        $this->addOption( 'src', 'Backend containing the source files', true, true );
        $this->addOption( 'dst', 'Backend where files should be copied to', true, true );
        $this->addOption( 'containers', 'Pipe separated list of containers', true, true );
        $this->addOption( 'subdir', 'Only do items in this child directory', false, true );
        $this->addOption( 'ratefile', 'File to check periodically for batch size', false, true );
        $this->addOption( 'prestat', 'Stat the destination files first (try to use listings)' );
        $this->addOption( 'skiphash', 'Skip SHA-1 sync checks for files' );
        $this->addOption( 'missingonly', 'Only copy files missing from destination listing' );
        $this->addOption( 'syncviadelete', 'Delete destination files missing from source listing' );
        $this->addOption( 'utf8only', 'Skip source files that do not have valid UTF-8 names' );
        $this->setBatchSize( 50 );
    }
 
    public function execute() {
        $backendGroup = $this->getServiceContainer()->getFileBackendGroup();
        $src = $backendGroup->get( $this->getOption( 'src' ) );
        $dst = $backendGroup->get( $this->getOption( 'dst' ) );
        $containers = explode( '|', $this->getOption( 'containers' ) );
        $subDir = rtrim( $this->getOption( 'subdir', '' ), '/' );
 
        $rateFile = $this->getOption( 'ratefile' );
 
        foreach ( $containers as $container ) {
            if ( $subDir != '' ) {
                $backendRel = "$container/$subDir";
                $this->output( "Doing container '$container', directory '$subDir'...\n" );
            } else {
                $backendRel = $container;
                $this->output( "Doing container '$container'...\n" );
            }
 
            if ( $this->hasOption( 'missingonly' ) ) {
                $this->output( "\tBuilding list of missing files..." );
                $srcPathsRel = $this->getListingDiffRel( $src, $dst, $backendRel );
                $this->output( count( $srcPathsRel ) . " file(s) need to be copied.\n" );
            } else {
                $srcPathsRel = $src->getFileList( [
                    'dir' => $src->getRootStoragePath() . "/$backendRel",
                    'adviseStat' => true // avoid HEADs
                ] );
                if ( $srcPathsRel === null ) {
                    $this->fatalError( "Could not list files in $container." );
                }
            }
 
            if ( $this->getOption( 'prestat' ) && !$this->hasOption( 'missingonly' ) ) {
                // Build the stat cache for the destination files
                $this->output( "\tBuilding destination stat cache..." );
                $dstPathsRel = $dst->getFileList( [
                    'dir' => $dst->getRootStoragePath() . "/$backendRel",
                    'adviseStat' => true // avoid HEADs
                ] );
                if ( $dstPathsRel === null ) {
                    $this->fatalError( "Could not list files in $container." );
                }
                $this->statCache = [];
                foreach ( $dstPathsRel as $dstPathRel ) {
                    $path = $dst->getRootStoragePath() . "/$backendRel/$dstPathRel";
                    $this->statCache[sha1( $path )] = $dst->getFileStat( [ 'src' => $path ] );
                }
                $this->output( "done [" . count( $this->statCache ) . " file(s)]\n" );
            }
 
            $this->output( "\tCopying file(s)...\n" );
            $count = 0;
            $batchPaths = [];
            foreach ( $srcPathsRel as $srcPathRel ) {
                // Check up on the rate file periodically to adjust the concurrency
                if ( $rateFile && ( !$count || ( $count % 500 ) == 0 ) ) {
                    $this->setBatchSize( max( 1, (int)file_get_contents( $rateFile ) ) );
                    $this->output( "\tBatch size is now {$this->getBatchSize()}.\n" );
                }
                $batchPaths[$srcPathRel] = 1; // remove duplicates
                if ( count( $batchPaths ) >= $this->getBatchSize() ) {
                    $this->copyFileBatch( array_keys( $batchPaths ), $backendRel, $src, $dst );
                    $batchPaths = []; // done
                }
                ++$count;
            }
            if ( count( $batchPaths ) ) { // left-overs
                $this->copyFileBatch( array_keys( $batchPaths ), $backendRel, $src, $dst );
            }
            $this->output( "\tCopied $count file(s).\n" );
 
            if ( $this->hasOption( 'syncviadelete' ) ) {
                $this->output( "\tBuilding list of excess destination files..." );
                $delPathsRel = $this->getListingDiffRel( $dst, $src, $backendRel );
                $this->output( count( $delPathsRel ) . " file(s) need to be deleted.\n" );
 
                $this->output( "\tDeleting file(s)...\n" );
                $count = 0;
                $batchPaths = [];
                foreach ( $delPathsRel as $delPathRel ) {
                    // Check up on the rate file periodically to adjust the concurrency
                    if ( $rateFile && ( !$count || ( $count % 500 ) == 0 ) ) {
                        $this->setBatchSize( max( 1, (int)file_get_contents( $rateFile ) ) );
                        $this->output( "\tBatch size is now {$this->getBatchSize()}.\n" );
                    }
                    $batchPaths[$delPathRel] = 1; // remove duplicates
                    if ( count( $batchPaths ) >= $this->getBatchSize() ) {
                        $this->delFileBatch( array_keys( $batchPaths ), $backendRel, $dst );
                        $batchPaths = []; // done
                    }
                    ++$count;
                }
                if ( count( $batchPaths ) ) { // left-overs
                    $this->delFileBatch( array_keys( $batchPaths ), $backendRel, $dst );
                }
 
                $this->output( "\tDeleted $count file(s).\n" );
            }
 
            if ( $subDir != '' ) {
                $this->output( "Finished container '$container', directory '$subDir'.\n" );
            } else {
                $this->output( "Finished container '$container'.\n" );
            }
        }
 
        $this->output( "Done.\n" );
    }
 
    protected function getListingDiffRel( FileBackend $src, FileBackend $dst, $backendRel ) {
        $srcPathsRel = $src->getFileList( [
            'dir' => $src->getRootStoragePath() . "/$backendRel" ] );
        if ( $srcPathsRel === null ) {
            $this->fatalError( "Could not list files in source container." );
        }
        $dstPathsRel = $dst->getFileList( [
            'dir' => $dst->getRootStoragePath() . "/$backendRel" ] );
        if ( $dstPathsRel === null ) {
            $this->fatalError( "Could not list files in destination container." );
        }
        // Get the list of destination files
        $relFilesDstSha1 = [];
        foreach ( $dstPathsRel as $dstPathRel ) {
            $relFilesDstSha1[sha1( $dstPathRel )] = 1;
        }
        unset( $dstPathsRel ); // free
        // Get the list of missing files
        $missingPathsRel = [];
        foreach ( $srcPathsRel as $srcPathRel ) {
            if ( !isset( $relFilesDstSha1[sha1( $srcPathRel )] ) ) {
                $missingPathsRel[] = $srcPathRel;
            }
        }
        unset( $srcPathsRel ); // free
 
        return $missingPathsRel;
    }
 
    protected function copyFileBatch(
        array $srcPathsRel, $backendRel, FileBackend $src, FileBackend $dst
    ) {
        $ops = [];
        $fsFiles = [];
        $copiedRel = []; // for output message
        $domainId = $src->getDomainId();
 
        // Download the batch of source files into backend cache...
        if ( $this->hasOption( 'missingonly' ) ) {
            $srcPaths = [];
            foreach ( $srcPathsRel as $srcPathRel ) {
                $srcPaths[] = $src->getRootStoragePath() . "/$backendRel/$srcPathRel";
            }
            $t_start = microtime( true );
            $fsFiles = $src->getLocalReferenceMulti( [ 'srcs' => $srcPaths, 'latest' => 1 ] );
            $elapsed_ms = floor( ( microtime( true ) - $t_start ) * 1000 );
            $this->output( "\n\tDownloaded these file(s) [{$elapsed_ms}ms]:\n\t" .
                implode( "\n\t", $srcPaths ) . "\n\n" );
        }
 
        // Determine what files need to be copied over...
        foreach ( $srcPathsRel as $srcPathRel ) {
            $srcPath = $src->getRootStoragePath() . "/$backendRel/$srcPathRel";
            $dstPath = $dst->getRootStoragePath() . "/$backendRel/$srcPathRel";
            if ( $this->hasOption( 'utf8only' ) && !mb_check_encoding( $srcPath, 'UTF-8' ) ) {
                $this->error( "$domainId: Detected illegal (non-UTF8) path for $srcPath." );
                continue;
            } elseif ( !$this->hasOption( 'missingonly' )
                && $this->filesAreSame( $src, $dst, $srcPath, $dstPath )
            ) {
                $this->output( "\tAlready have $srcPathRel.\n" );
                continue; // assume already copied...
            }
            $fsFile = array_key_exists( $srcPath, $fsFiles )
                ? $fsFiles[$srcPath]
                : $src->getLocalReference( [ 'src' => $srcPath, 'latest' => 1 ] );
            if ( !$fsFile ) {
                $src->clearCache( [ $srcPath ] );
                if ( $src->fileExists( [ 'src' => $srcPath, 'latest' => 1 ] ) === false ) {
                    $this->error( "$domainId: File '$srcPath' was listed but does not exist." );
                } else {
                    $this->error( "$domainId: Could not get local copy of $srcPath." );
                }
                continue;
            } elseif ( !$fsFile->exists() ) {
                // FSFileBackends just return the path for getLocalReference() and paths with
                // illegal slashes may get normalized to a different path. This can cause the
                // local reference to not exist...skip these broken files.
                $this->error( "$domainId: Detected possible illegal path for $srcPath." );
                continue;
            }
            $fsFiles[] = $fsFile; // keep TempFSFile objects alive as needed
            // Note: prepare() is usually fast for key/value backends
            $status = $dst->prepare( [ 'dir' => dirname( $dstPath ), 'bypassReadOnly' => true ] );
            if ( !$status->isOK() ) {
                $this->error( $status );
                $this->fatalError( "$domainId: Could not copy $srcPath to $dstPath." );
            }
            $ops[] = [ 'op' => 'store',
                'src' => $fsFile->getPath(), 'dst' => $dstPath, 'overwrite' => true ];
            $copiedRel[] = $srcPathRel;
        }
 
        // Copy in the batch of source files...
        $t_start = microtime( true );
        $status = $dst->doQuickOperations( $ops, [ 'bypassReadOnly' => true ] );
        if ( !$status->isOK() ) {
            sleep( 10 ); // wait and retry copy again
            $status = $dst->doQuickOperations( $ops, [ 'bypassReadOnly' => true ] );
        }
        $elapsed_ms = floor( ( microtime( true ) - $t_start ) * 1000 );
        if ( !$status->isOK() ) {
            $this->error( $status );
            $this->fatalError( "$domainId: Could not copy file batch." );
        } elseif ( count( $copiedRel ) ) {
            $this->output( "\n\tCopied these file(s) [{$elapsed_ms}ms]:\n\t" .
                implode( "\n\t", $copiedRel ) . "\n\n" );
        }
    }
 
    protected function delFileBatch(
        array $dstPathsRel, $backendRel, FileBackend $dst
    ) {
        $ops = [];
        $deletedRel = []; // for output message
        $domainId = $dst->getDomainId();
 
        // Determine what files need to be copied over...
        foreach ( $dstPathsRel as $dstPathRel ) {
            $dstPath = $dst->getRootStoragePath() . "/$backendRel/$dstPathRel";
            $ops[] = [ 'op' => 'delete', 'src' => $dstPath ];
            $deletedRel[] = $dstPathRel;
        }
 
        // Delete the batch of source files...
        $t_start = microtime( true );
        $status = $dst->doQuickOperations( $ops, [ 'bypassReadOnly' => true ] );
        if ( !$status->isOK() ) {
            sleep( 10 ); // wait and retry copy again
            $status = $dst->doQuickOperations( $ops, [ 'bypassReadOnly' => true ] );
        }
        $elapsed_ms = floor( ( microtime( true ) - $t_start ) * 1000 );
        if ( !$status->isOK() ) {
            $this->error( $status );
            $this->fatalError( "$domainId: Could not delete file batch." );
        } elseif ( count( $deletedRel ) ) {
            $this->output( "\n\tDeleted these file(s) [{$elapsed_ms}ms]:\n\t" .
                implode( "\n\t", $deletedRel ) . "\n\n" );
        }
    }
 
    protected function filesAreSame( FileBackend $src, FileBackend $dst, $sPath, $dPath ) {
        $skipHash = $this->hasOption( 'skiphash' );
        $srcStat = $src->getFileStat( [ 'src' => $sPath ] );
        $dPathSha1 = sha1( $dPath );
        if ( $this->statCache !== null ) {
            // All dst files are already in stat cache
            $dstStat = $this->statCache[$dPathSha1] ?? false;
        } else {
            $dstStat = $dst->getFileStat( [ 'src' => $dPath ] );
        }
        // Initial fast checks to see if files are obviously different
        $sameFast = (
            is_array( $srcStat )
            && is_array( $dstStat ) // dest exists
            && $srcStat['size'] === $dstStat['size']
        );
        // More thorough checks against files
        if ( !$sameFast ) {
            $same = false; // no need to look farther
        } elseif ( isset( $srcStat['md5'] ) && isset( $dstStat['md5'] ) ) {
            // If MD5 was already in the stat info, just use it.
            // This is useful as many objects stores can return this in object listing,
            // so we can use it to avoid slow per-file HEADs.
            $same = ( $srcStat['md5'] === $dstStat['md5'] );
        } elseif ( $skipHash ) {
            // This mode is good for copying to a backup location or resyncing clone
            // backends in FileBackendMultiWrite (since they get writes second, they have
            // higher timestamps). However, when copying the other way, this hits loads of
            // false positives (possibly 100%) and wastes a bunch of time on GETs/PUTs.
            // @phan-suppress-next-line PhanTypeArraySuspiciousNullable
            $same = ( $srcStat['mtime'] <= $dstStat['mtime'] );
        } else {
            // This is the slowest method which does many per-file HEADs (unless an object
            // store tracks SHA-1 in listings).
            $same = ( $src->getFileSha1Base36( [ 'src' => $sPath, 'latest' => 1 ] )
                === $dst->getFileSha1Base36( [ 'src' => $dPath, 'latest' => 1 ] ) );
        }
 
        return $same;
    }
}
 
// @codeCoverageIgnoreStart
$maintClass = CopyFileBackend::class;
require_once RUN_MAINTENANCE_IF_MAIN;
// @codeCoverageIgnoreEnd