ExternalStoreMwstore.php

Go to the documentation of this file.

<?php
use MediaWiki\FileBackend\FileBackendGroup;
use MediaWiki\WikiMap\WikiMap;
use Wikimedia\FileBackend\FileBackend;
 
class ExternalStoreMwstore extends ExternalStoreMedium {
    private $fbGroup;
 
    public function __construct( array $params ) {
        parent::__construct( $params );
        if ( !isset( $params['fbGroup'] ) || !( $params['fbGroup'] instanceof FileBackendGroup ) ) {
            throw new InvalidArgumentException( "FileBackendGroup required in 'fbGroup' field." );
        }
        $this->fbGroup = $params['fbGroup'];
    }
 
    public function fetchFromURL( $url ) {
        $be = $this->fbGroup->backendFromPath( $url );
        if ( $be instanceof FileBackend ) {
            // We don't need "latest" since objects are immutable and
            // backends should at least have "read-after-create" consistency.
            return $be->getFileContents( [ 'src' => $url ] );
        }
 
        return false;
    }
 
    public function batchFetchFromURLs( array $urls ) {
        $pathsByBackend = [];
        foreach ( $urls as $url ) {
            $be = $this->fbGroup->backendFromPath( $url );
            if ( $be instanceof FileBackend ) {
                $pathsByBackend[$be->getName()][] = $url;
            }
        }
        $blobs = [];
        foreach ( $pathsByBackend as $backendName => $paths ) {
            $be = $this->fbGroup->get( $backendName );
            $blobs += $be->getFileContentsMulti( [ 'srcs' => $paths ] );
        }
 
        return $blobs;
    }
 
    public function store( $backend, $data ) {
        $be = $this->fbGroup->get( $backend );
        // Get three random base 36 characters to act as shard directories
        $rand = Wikimedia\base_convert( (string)mt_rand( 0, 46655 ), 10, 36, 3 );
        // Make sure ID is roughly lexicographically increasing for performance
        $id = str_pad( UIDGenerator::newTimestampedUID128( 32 ), 26, '0', STR_PAD_LEFT );
        // Segregate items by DB domain ID for the sake of bookkeeping
        $domain = $this->isDbDomainExplicit
            ? $this->dbDomain
            // @FIXME: this does not include the schema for b/c but it ideally should
            : WikiMap::getWikiIdFromDbDomain( $this->dbDomain );
        $url = $be->getContainerStoragePath( 'data' ) . '/' . rawurlencode( $domain );
        // Use directory/container sharding
        $url .= ( $be instanceof FSFileBackend )
            ? "/{$rand[0]}/{$rand[1]}/{$rand[2]}/{$id}" // keep directories small
            : "/{$rand[0]}/{$rand[1]}/{$id}"; // container sharding is only 2-levels
 
        $be->prepare( [ 'dir' => dirname( $url ), 'noAccess' => 1, 'noListing' => 1 ] );
        $status = $be->create( [ 'dst' => $url, 'content' => $data ] );
 
        if ( $status->isOK() ) {
            return $url;
        }
 
        throw new ExternalStoreException( __METHOD__ . ": operation failed: $status" );
    }
 
    public function isReadOnly( $backend ) {
        if ( parent::isReadOnly( $backend ) ) {
            return true;
        }
 
        $be = $this->fbGroup->get( $backend );
 
        return $be->isReadOnly();
    }
}