ParsoidOutputAccess.php

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<?php
namespace MediaWiki\Parser\Parsoid;
 
use Config;
use HashConfig;
use IBufferingStatsdDataFactory;
use InvalidArgumentException;
use Liuggio\StatsdClient\Factory\StatsdDataFactory;
use MediaWiki\Config\ServiceOptions;
use MediaWiki\Content\IContentHandlerFactory;
use MediaWiki\Logger\LoggerFactory;
use MediaWiki\MainConfigNames;
use MediaWiki\Page\PageIdentity;
use MediaWiki\Page\PageLookup;
use MediaWiki\Page\PageRecord;
use MediaWiki\Parser\ParserCacheFactory;
use MediaWiki\Parser\Parsoid\Config\PageConfigFactory;
use MediaWiki\Parser\RevisionOutputCache;
use MediaWiki\Revision\RevisionAccessException;
use MediaWiki\Revision\RevisionLookup;
use MediaWiki\Revision\RevisionRecord;
use MediaWiki\Revision\SlotRecord;
use MWUnknownContentModelException;
use ParserCache;
use ParserOptions;
use ParserOutput;
use Status;
use Wikimedia\Parsoid\Config\PageConfig;
use Wikimedia\Parsoid\Config\SiteConfig;
use Wikimedia\Parsoid\Core\ClientError;
use Wikimedia\Parsoid\Core\ResourceLimitExceededException;
use Wikimedia\Parsoid\Parsoid;
use Wikimedia\UUID\GlobalIdGenerator;
 
class ParsoidOutputAccess {
    public const PARSOID_PARSER_CACHE_NAME = 'parsoid';
 
    private const RENDER_ID_KEY = 'parsoid-render-id';
 
    public const OPT_FORCE_PARSE = 1;
 
    public const OPT_NO_UPDATE_CACHE = 2;
 
    public const OPT_LOG_LINT_DATA = 64;
 
    public const CONSTRUCTOR_OPTIONS = [
        MainConfigNames::ParsoidCacheConfig,
        MainConfigNames::ParsoidSettings,
        'ParsoidWikiID'
    ];
 
    private $revisionOutputCache;
 
    private $parserCache;
 
    private $globalIdGenerator;
 
    private $stats;
 
    private $parsoidCacheConfig;
 
    private $parsoid;
 
    private $parsoidPageConfigFactory;
 
    private $pageLookup;
 
    private $revisionLookup;
 
    private $siteConfig;
 
    private $options;
 
    private $parsoidWikiId;
 
    private $contentHandlerFactory;
 
    public function __construct(
        ServiceOptions $options,
        ParserCacheFactory $parserCacheFactory,
        PageLookup $pageLookup,
        RevisionLookup $revisionLookup,
        GlobalIdGenerator $globalIdGenerator,
        IBufferingStatsdDataFactory $stats,
        Parsoid $parsoid,
        SiteConfig $siteConfig,
        PageConfigFactory $parsoidPageConfigFactory,
        IContentHandlerFactory $contentHandlerFactory
    ) {
        $options->assertRequiredOptions( self::CONSTRUCTOR_OPTIONS );
        $this->options = $options;
        $this->parsoidCacheConfig = new HashConfig( $options->get( MainConfigNames::ParsoidCacheConfig ) );
        $this->revisionOutputCache = $parserCacheFactory
            ->getRevisionOutputCache( self::PARSOID_PARSER_CACHE_NAME );
        $this->parserCache = $parserCacheFactory->getParserCache( self::PARSOID_PARSER_CACHE_NAME );
        $this->pageLookup = $pageLookup;
        $this->revisionLookup = $revisionLookup;
        $this->globalIdGenerator = $globalIdGenerator;
        $this->stats = $stats;
        $this->parsoid = $parsoid;
        $this->siteConfig = $siteConfig;
        $this->parsoidPageConfigFactory = $parsoidPageConfigFactory;
        $this->contentHandlerFactory = $contentHandlerFactory;
 
        // NOTE: This is passed as the "prefix" option to parsoid, which it uses
        //       to locate wiki specific configuration in the baseconfig directory.
        //       This should probably be managed by SiteConfig instead, so
        //       we hopefully will not need it here in the future.
        $this->parsoidWikiId = $options->get( 'ParsoidWikiID' );
    }
 
    public function supportsContentModel( string $model ): bool {
        if ( $model === CONTENT_MODEL_WIKITEXT ) {
            return true;
        }
 
        // Check if the content model serializes to wikitext.
        // NOTE: We could use isSupportedFormat( CONTENT_FORMAT_WIKITEXT ) if PageContent::getContent()
        //       would specify the format when calling serialize().
        try {
            $handler = $this->contentHandlerFactory->getContentHandler( $model );
            if ( $handler->getDefaultFormat() === CONTENT_FORMAT_WIKITEXT ) {
                return true;
            }
        } catch ( MWUnknownContentModelException $ex ) {
            // If the content model is not known, it can't be supported.
            return false;
        }
 
        return $this->siteConfig->getContentModelHandler( $model ) !== null;
    }
 
    public function getParserOutput(
        PageIdentity $page,
        ParserOptions $parserOpts,
        $revision = null,
        int $options = 0
    ): Status {
        [ $page, $revision ] = $this->resolveRevision( $page, $revision );
        $isOld = $revision->getId() !== $page->getLatest();
 
        $statsKey = $isOld ? 'ParsoidOutputAccess.Cache.revision' : 'ParsoidOutputAccess.Cache.parser';
 
        if ( !( $options & self::OPT_FORCE_PARSE ) ) {
            $parserOutput = $this->getCachedParserOutputInternal(
                $page,
                $parserOpts,
                $revision,
                $isOld,
                $statsKey
            );
 
            if ( $parserOutput ) {
                return Status::newGood( $parserOutput );
            }
        }
 
        $parsoidOptions = [];
 
        if ( $options & self::OPT_LOG_LINT_DATA ) {
            $parsoidOptions += [
                'logLinterData' => true
            ];
        }
 
        $mainSlot = $revision->getSlot( SlotRecord::MAIN );
 
        $startTime = microtime( true );
        $status = $this->parse( $page, $parserOpts, $parsoidOptions, $revision );
        $time = microtime( true ) - $startTime;
 
        if ( !$status->isOK() ) {
            $this->stats->increment( $statsKey . '.save.notok' );
        } elseif ( $options & self::OPT_NO_UPDATE_CACHE ) {
            $this->stats->increment( $statsKey . '.save.disabled' );
        } elseif ( !$this->supportsContentModel( $mainSlot->getModel() ) ) {
            // TODO: We really want to cache for all supported content models.
            // But supportsContentModels() lies, because of T324711.
            // This causes us to render garbage output for all content models, which we shouldn't cache.
            // NOTE: this will become irrelevant when we implement T311648.
            $this->stats->increment( $statsKey . '.save.badmodel' );
        } else {
            if ( $time > $this->parsoidCacheConfig->get( 'CacheThresholdTime' ) ) {
                $parserOutput = $status->getValue();
                $now = $parserOutput->getCacheTime();
 
                if ( $isOld ) {
                    $this->revisionOutputCache->save( $parserOutput, $revision, $parserOpts, $now );
                } else {
                    $this->parserCache->save( $parserOutput, $page, $parserOpts, $now );
                }
                $this->stats->increment( $statsKey . '.save.ok' );
            } else {
                $this->stats->increment( $statsKey . '.save.skipfast' );
            }
        }
 
        return $status;
    }
 
    private function parseInternal(
        PageConfig $pageConfig,
        array $parsoidOptions
    ): Status {
        $defaultOptions = [
            'pageBundle' => true,
            'prefix' => $this->parsoidWikiId,
            'pageName' => $pageConfig->getTitle(),
            'htmlVariantLanguage' => $pageConfig->getPageLanguage(),
            'outputContentVersion' => Parsoid::defaultHTMLVersion(),
        ];
 
        try {
            $startTime = microtime( true );
            $parserOutput = new ParserOutput();
            $pageBundle = $this->parsoid->wikitext2html(
                $pageConfig,
                $parsoidOptions + $defaultOptions,
                $headers,
                $parserOutput
            );
 
            $parserOutput = PageBundleParserOutputConverter::parserOutputFromPageBundle( $pageBundle, $parserOutput );
            $time = microtime( true ) - $startTime;
            if ( $time > 3 ) {
                LoggerFactory::getInstance( 'slow-parsoid' )
                    ->info( 'Parsing {title} was slow, took {time} seconds', [
                        'time' => number_format( $time, 2 ),
                        'title' => $pageConfig->getTitle(),
                    ] );
            }
            return Status::newGood( $parserOutput );
        } catch ( ClientError $e ) {
            return Status::newFatal( 'parsoid-client-error', $e->getMessage() );
        } catch ( ResourceLimitExceededException $e ) {
            return Status::newFatal( 'parsoid-resource-limit-exceeded', $e->getMessage() );
        }
    }
 
    public function getParsoidRenderID( ParserOutput $parserOutput ): ParsoidRenderID {
        // XXX: ParserOutput may be coming from the parser cache, so we need to be careful
        // when we change how we store the render key in the ParserOutput object.
        $renderId = $parserOutput->getExtensionData( self::RENDER_ID_KEY );
        if ( !$renderId ) {
            throw new InvalidArgumentException( 'ParserOutput does not have a render ID' );
        }
 
        return ParsoidRenderID::newFromKey( $renderId );
    }
 
    public function getCachedParserOutput(
        PageIdentity $page,
        ParserOptions $parserOpts,
        $revision = null
    ): ?ParserOutput {
        [ $page, $revision ] = $this->resolveRevision( $page, $revision );
        $isOld = $revision->getId() !== $page->getLatest();
 
        $statsKey = $isOld ? 'ParsoidOutputAccess.Cache.revision' : 'ParsoidOutputAccess.Cache.parser';
 
        return $this->getCachedParserOutputInternal(
            $page,
            $parserOpts,
            $revision,
            $isOld,
            $statsKey
        );
    }
 
    protected function getCachedParserOutputInternal(
        PageRecord $page,
        ParserOptions $parserOpts,
        ?RevisionRecord $revision,
        bool $isOld,
        string $statsKey
    ): ?ParserOutput {
        if ( $isOld ) {
            $parserOutput = $this->revisionOutputCache->get( $revision, $parserOpts );
        } else {
            $parserOutput = $this->parserCache->get( $page, $parserOpts );
        }
 
        if ( $parserOutput ) {
            // Ignore cached ParserOutput if it is incomplete,
            // because it was stored by an old version of the code.
            if ( !$parserOutput->getExtensionData( PageBundleParserOutputConverter::PARSOID_PAGE_BUNDLE_KEY )
                || !$parserOutput->getExtensionData( self::RENDER_ID_KEY )
            ) {
                $parserOutput = null;
            }
        }
 
        if ( $parserOutput ) {
            $this->stats->increment( $statsKey . '.get.hit' );
            return $parserOutput;
        } else {
            $this->stats->increment( $statsKey . '.get.miss' );
            return null;
        }
    }
 
    private function makeDummyParserOutput( string $contentModel ): Status {
        $msg = "Dummy output. Parsoid does not support content model $contentModel. See T324711.";
        $output = new ParserOutput( $msg );
 
        // This is fast to generate so it's fine not to write this to parser cache.
        $output->updateCacheExpiry( 0 );
        // The render ID is required for rendering of dummy output: T311728.
        $output->setExtensionData( self::RENDER_ID_KEY, '0/dummy-output' );
 
        return Status::newGood( $output );
    }
 
    public function parse(
        PageIdentity $page,
        ParserOptions $parserOpts,
        array $parsoidOptions,
        $revision
    ): Status {
        // NOTE: If we have a RevisionRecord already, just use it, there is no need to resolve $page to
        //       a PageRecord (and it may not be possible if the page doesn't exist).
        if ( !$revision instanceof RevisionRecord ) {
            [ $page, $revision ] = $this->resolveRevision( $page, $revision );
        }
 
        $mainSlot = $revision->getSlot( SlotRecord::MAIN );
        $contentModel = $mainSlot->getModel();
        if ( !$this->supportsContentModel( $contentModel ) ) {
            // This is a messy fix for T324711. The real solution is T311648.
            // For now, just return dummy parser output.
            return $this->makeDummyParserOutput( $contentModel );
 
            // TODO: go back to throwing, once RESTbase no longer expects to get a parsoid rendering for
            //any kind of content (T324711).
            /*
                // TODO: throw an internal exception here, convert to HttpError in HtmlOutputRendererHelper.
                throw new HttpException( 'Parsoid does not support content model ' . $mainSlot->getModel(), 400 );
            }
            */
        }
 
        $languageOverride = $parserOpts->getTargetLanguage();
        $pageConfig = $this->parsoidPageConfigFactory->create(
            $page,
            null,
            $revision,
            null,
            $languageOverride,
            $this->options->get( MainConfigNames::ParsoidSettings )
        );
 
        $status = $this->parseInternal( $pageConfig, $parsoidOptions );
 
        if ( !$status->isOK() ) {
            return $status;
        }
 
        $parserOutput = $status->getValue();
 
        // TODO: when we make tighter integration with Parsoid, render ID should become
        // a standard ParserOutput property. Nothing else needs it now, so don't generate
        // it in ParserCache just yet.
        $revId = $revision->getId();
        $parsoidRenderId = new ParsoidRenderID( $revId, $this->globalIdGenerator->newUUIDv1() );
        $parserOutput->setExtensionData( self::RENDER_ID_KEY, $parsoidRenderId->getKey() );
 
        // XXX: ParserOutput should just always record the revision ID and timestamp
        $now = wfTimestampNow();
        $parserOutput->setCacheRevisionId( $revId );
        $parserOutput->setCacheTime( $now );
 
        return $status;
    }
 
    private function resolveRevision( PageIdentity $page, $revision ): array {
        if ( !$page instanceof PageRecord ) {
            $name = "$page";
            $page = $this->pageLookup->getPageByReference( $page );
            if ( !$page ) {
                throw new RevisionAccessException(
                    'Page {name} not found',
                    [ 'name' => $name ]
                );
            }
        }
 
        if ( $revision === null ) {
            $revision = $page->getLatest();
        }
 
        if ( is_int( $revision ) ) {
            $revId = $revision;
            $revision = $this->revisionLookup->getRevisionById( $revId );
 
            if ( !$revision ) {
                throw new RevisionAccessException(
                    'Revision {revId} not found',
                    [ 'revId' => $revId ]
                );
            }
        }
 
        return [ $page, $revision ];
    }
}