ExtensionRegistry.php

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<?php
 
use Composer\Semver\Semver;
use MediaWiki\Settings\SettingsBuilder;
use MediaWiki\Shell\Shell;
use MediaWiki\ShellDisabledError;
use Wikimedia\ScopedCallback;
 
class ExtensionRegistry {
 
    public const MEDIAWIKI_CORE = 'MediaWiki';
 
    public const MANIFEST_VERSION = 2;
 
    public const MANIFEST_VERSION_MW_VERSION = '>= 1.29.0';
 
    public const OLDEST_MANIFEST_VERSION = 1;
 
    private const CACHE_VERSION = 8;
 
    private const CACHE_EXPIRY = 60 * 60 * 24;
 
    public const MERGE_STRATEGY = '_merge_strategy';
 
    private const LAZY_LOADED_ATTRIBUTES = [
        'TrackingCategories',
        'QUnitTestModules',
        'SkinLessImportPaths',
    ];
 
    private $loaded = [];
 
    protected $queued = [];
 
    private $finished = false;
 
    protected $attributes = [];
 
    protected $testAttributes = [];
 
    protected $lazyAttributes = [];
 
    private $varyHash;
 
    protected $checkDev = false;
 
    protected $loadTestClassesAndNamespaces = false;
 
    private static $instance;
 
    private $cache = null;
 
    private ?SettingsBuilder $settingsBuilder = null;
 
    private static bool $accessDisabledForUnitTests = false;
 
    public static function getInstance() {
        if ( self::$accessDisabledForUnitTests ) {
            throw new RuntimeException( 'Access is disabled in unit tests' );
        }
        if ( self::$instance === null ) {
            self::$instance = new self();
        }
 
        return self::$instance;
    }
 
    public static function disableForTest(): void {
        if ( !defined( 'MW_PHPUNIT_TEST' ) ) {
            throw new RuntimeException( 'Can only be called in tests' );
        }
        self::$accessDisabledForUnitTests = true;
    }
 
    public static function enableForTest(): void {
        if ( !defined( 'MW_PHPUNIT_TEST' ) ) {
            throw new RuntimeException( 'Can only be called in tests' );
        }
        self::$accessDisabledForUnitTests = false;
    }
 
    public function setCache( BagOStuff $cache ): void {
        $this->cache = $cache;
    }
 
    public function setCheckDevRequires( $check ) {
        $this->checkDev = $check;
        $this->invalidateProcessCache();
    }
 
    public function setLoadTestClassesAndNamespaces( $load ) {
        $this->loadTestClassesAndNamespaces = $load;
    }
 
    public function queue( $path ) {
        global $wgExtensionInfoMTime;
 
        $mtime = $wgExtensionInfoMTime;
        if ( $mtime === false ) {
            // phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged
            $mtime = @filemtime( $path );
            // @codeCoverageIgnoreStart
            if ( $mtime === false ) {
                $err = error_get_last();
                throw new MissingExtensionException( $path, $err['message'] );
                // @codeCoverageIgnoreEnd
            }
        }
        $this->queued[$path] = $mtime;
        $this->invalidateProcessCache();
    }
 
    private function getCache(): BagOStuff {
        if ( !$this->cache ) {
            // Can't call MediaWikiServices here, as we must not cause services
            // to be instantiated before extensions have loaded.
            return ObjectCache::makeLocalServerCache();
        }
 
        return $this->cache;
    }
 
    private function makeCacheKey( BagOStuff $cache, $component, ...$extra ) {
        // Allow reusing cached ExtensionRegistry metadata between wikis (T274648)
        return $cache->makeGlobalKey(
            "registration-$component",
            $this->getVaryHash(),
            ...$extra
        );
    }
 
    private function getVaryHash() {
        if ( $this->varyHash === null ) {
            // We vary the cache on the current queue (what will be or already was loaded)
            // plus various versions of stuff for VersionChecker
            $vary = [
                'registration' => self::CACHE_VERSION,
                'mediawiki' => MW_VERSION,
                'abilities' => $this->getAbilities(),
                'checkDev' => $this->checkDev,
                'queue' => $this->queued,
            ];
            $this->varyHash = md5( json_encode( $vary ) );
        }
        return $this->varyHash;
    }
 
    private function invalidateProcessCache() {
        $this->varyHash = null;
        $this->lazyAttributes = [];
    }
 
    public function loadFromQueue() {
        if ( !$this->queued ) {
            return;
        }
 
        if ( $this->finished ) {
            throw new MWException(
                "The following paths tried to load late: "
                . implode( ', ', array_keys( $this->queued ) )
            );
        }
 
        $cache = $this->getCache();
        // See if this queue is in APC
        $key = $this->makeCacheKey( $cache, 'main' );
        $data = $cache->get( $key );
        if ( !$data ) {
            $data = $this->readFromQueue( $this->queued );
            $this->saveToCache( $cache, $data );
        }
        $this->exportExtractedData( $data );
    }
 
    protected function saveToCache( BagOStuff $cache, array $data ) {
        global $wgDevelopmentWarnings;
        if ( $data['warnings'] && $wgDevelopmentWarnings ) {
            // If warnings were shown, don't cache it
            return;
        }
        $lazy = [];
        // Cache lazy-loaded attributes separately
        foreach ( self::LAZY_LOADED_ATTRIBUTES as $attrib ) {
            if ( isset( $data['attributes'][$attrib] ) ) {
                $lazy[$attrib] = $data['attributes'][$attrib];
                unset( $data['attributes'][$attrib] );
            }
        }
        $mainKey = $this->makeCacheKey( $cache, 'main' );
        $cache->set( $mainKey, $data, self::CACHE_EXPIRY );
        foreach ( $lazy as $attrib => $value ) {
            $cache->set(
                $this->makeCacheKey( $cache, 'lazy-attrib', $attrib ),
                $value,
                self::CACHE_EXPIRY
            );
        }
    }
 
    public function getQueue() {
        return $this->queued;
    }
 
    public function clearQueue() {
        $this->queued = [];
        $this->invalidateProcessCache();
    }
 
    public function finish() {
        $this->finished = true;
    }
 
    private function getAbilities() {
        return [
            'shell' => !Shell::isDisabled(),
        ];
    }
 
    private function buildVersionChecker() {
        // array to optionally specify more verbose error messages for
        // missing abilities
        $abilityErrors = [
            'shell' => ( new ShellDisabledError() )->getMessage(),
        ];
 
        return new VersionChecker(
            MW_VERSION,
            PHP_MAJOR_VERSION . '.' . PHP_MINOR_VERSION . '.' . PHP_RELEASE_VERSION,
            get_loaded_extensions(),
            $this->getAbilities(),
            $abilityErrors
        );
    }
 
    public function readFromQueue( array $queue ) {
        $processor = new ExtensionProcessor();
        $versionChecker = $this->buildVersionChecker();
        $extDependencies = [];
        $warnings = false;
        foreach ( $queue as $path => $mtime ) {
            $json = file_get_contents( $path );
            if ( $json === false ) {
                throw new Exception( "Unable to read $path, does it exist?" );
            }
            $info = json_decode( $json, /* $assoc = */ true );
            if ( !is_array( $info ) ) {
                throw new Exception( "$path is not a valid JSON file." );
            }
 
            $version = $info['manifest_version'];
            if ( $version < self::OLDEST_MANIFEST_VERSION || $version > self::MANIFEST_VERSION ) {
                throw new Exception( "$path: unsupported manifest_version: {$version}" );
            }
 
            // get all requirements/dependencies for this extension
            $requires = $processor->getRequirements( $info, $this->checkDev );
 
            // validate the information needed and add the requirements
            if ( is_array( $requires ) && $requires && isset( $info['name'] ) ) {
                $extDependencies[$info['name']] = $requires;
            }
 
            // Compatible, read and extract info
            $processor->extractInfo( $path, $info, $version );
        }
        $data = $processor->getExtractedInfo( $this->loadTestClassesAndNamespaces );
        $data['warnings'] = $warnings;
 
        // check for incompatible extensions
        $incompatible = $versionChecker
            ->setLoadedExtensionsAndSkins( $data['credits'] )
            ->checkArray( $extDependencies );
 
        if ( $incompatible ) {
            throw new ExtensionDependencyError( $incompatible );
        }
 
        return $data;
    }
 
    protected function exportExtractedData( array $info ) {
        foreach ( $info['globals'] as $key => $val ) {
            // If a merge strategy is set, read it and remove it from the value
            // so it doesn't accidentally end up getting set.
            if ( is_array( $val ) && isset( $val[self::MERGE_STRATEGY] ) ) {
                $mergeStrategy = $val[self::MERGE_STRATEGY];
                unset( $val[self::MERGE_STRATEGY] );
            } else {
                $mergeStrategy = 'array_merge';
            }
 
            if ( $mergeStrategy === 'provide_default' ) {
                if ( !array_key_exists( $key, $GLOBALS ) ) {
                    $GLOBALS[$key] = $val;
                }
                continue;
            }
 
            // Optimistic: If the global is not set, or is an empty array, replace it entirely.
            // Will be O(1) performance.
            if ( !array_key_exists( $key, $GLOBALS ) || ( is_array( $GLOBALS[$key] ) && !$GLOBALS[$key] ) ) {
                $GLOBALS[$key] = $val;
                continue;
            }
 
            if ( !is_array( $GLOBALS[$key] ) || !is_array( $val ) ) {
                // config setting that has already been overridden, don't set it
                continue;
            }
 
            switch ( $mergeStrategy ) {
                case 'array_merge_recursive':
                    $GLOBALS[$key] = array_merge_recursive( $GLOBALS[$key], $val );
                    break;
                case 'array_replace_recursive':
                    $GLOBALS[$key] = array_replace_recursive( $val, $GLOBALS[$key] );
                    break;
                case 'array_plus_2d':
                    $GLOBALS[$key] = wfArrayPlus2d( $GLOBALS[$key], $val );
                    break;
                case 'array_plus':
                    $GLOBALS[$key] += $val;
                    break;
                case 'array_merge':
                    $GLOBALS[$key] = array_merge( $val, $GLOBALS[$key] );
                    break;
                default:
                    throw new UnexpectedValueException( "Unknown merge strategy '$mergeStrategy'" );
            }
        }
 
        if ( isset( $info['autoloaderNS'] ) ) {
            AutoLoader::registerNamespaces( $info['autoloaderNS'] );
        }
 
        if ( isset( $info['autoloaderClasses'] ) ) {
            AutoLoader::registerClasses( $info['autoloaderClasses'] );
        }
 
        foreach ( $info['defines'] as $name => $val ) {
            if ( !defined( $name ) ) {
                define( $name, $val );
            } elseif ( constant( $name ) !== $val ) {
                throw new UnexpectedValueException(
                    "$name cannot be re-defined with $val it has already been set with " . constant( $name )
                );
            }
        }
 
        if ( isset( $info['autoloaderPaths'] ) ) {
            AutoLoader::loadFiles( $info['autoloaderPaths'] );
        }
 
        $this->loaded += $info['credits'];
        if ( $info['attributes'] ) {
            if ( !$this->attributes ) {
                $this->attributes = $info['attributes'];
            } else {
                $this->attributes = array_merge_recursive( $this->attributes, $info['attributes'] );
            }
        }
 
        // XXX: SettingsBuilder should really be a parameter to this method.
        $settings = $this->getSettingsBuilder();
 
        foreach ( $info['callbacks'] as $name => $cb ) {
            if ( !is_callable( $cb ) ) {
                if ( is_array( $cb ) ) {
                    $cb = '[ ' . implode( ', ', $cb ) . ' ]';
                }
                throw new UnexpectedValueException( "callback '$cb' is not callable" );
            }
            $cb( $info['credits'][$name], $settings );
        }
    }
 
    public function isLoaded( $name, $constraint = '*' ) {
        $isLoaded = isset( $this->loaded[$name] );
        if ( $constraint === '*' || !$isLoaded ) {
            return $isLoaded;
        }
        // if a specific constraint is requested, but no version is set, throw an exception
        if ( !isset( $this->loaded[$name]['version'] ) ) {
            $msg = "{$name} does not expose its version, but an extension or a skin"
                    . " requires: {$constraint}.";
            throw new LogicException( $msg );
        }
 
        return Semver::satisfies( $this->loaded[$name]['version'], $constraint );
    }
 
    public function getAttribute( $name ) {
        if ( isset( $this->testAttributes[$name] ) ) {
            return $this->testAttributes[$name];
        }
 
        if ( in_array( $name, self::LAZY_LOADED_ATTRIBUTES, true ) ) {
            return $this->getLazyLoadedAttribute( $name );
        }
 
        return $this->attributes[$name] ?? [];
    }
 
    protected function getLazyLoadedAttribute( $name ) {
        if ( isset( $this->testAttributes[$name] ) ) {
            return $this->testAttributes[$name];
        }
        if ( isset( $this->lazyAttributes[$name] ) ) {
            return $this->lazyAttributes[$name];
        }
 
        // See if it's in the cache
        $cache = $this->getCache();
        $key = $this->makeCacheKey( $cache, 'lazy-attrib', $name );
        $data = $cache->get( $key );
        if ( $data !== false ) {
            $this->lazyAttributes[$name] = $data;
            return $data;
        }
 
        $paths = [];
        foreach ( $this->loaded as $info ) {
            // mtime (array value) doesn't matter here since
            // we're skipping cache, so use a dummy time
            $paths[$info['path']] = 1;
        }
 
        $result = $this->readFromQueue( $paths );
        $data = $result['attributes'][$name] ?? [];
        $this->saveToCache( $cache, $result );
        $this->lazyAttributes[$name] = $data;
 
        return $data;
    }
 
    public function setAttributeForTest( $name, array $value ) {
        // @codeCoverageIgnoreStart
        if ( !defined( 'MW_PHPUNIT_TEST' ) ) {
            throw new LogicException( __METHOD__ . ' can only be used in tests' );
        }
        // @codeCoverageIgnoreEnd
        if ( isset( $this->testAttributes[$name] ) ) {
            throw new Exception( "The attribute '$name' has already been overridden" );
        }
        $this->testAttributes[$name] = $value;
        return new ScopedCallback( function () use ( $name ) {
            unset( $this->testAttributes[$name] );
        } );
    }
 
    public function getAllThings() {
        return $this->loaded;
    }
 
    protected static function processAutoLoader( $dir, array $files ) {
        // Make paths absolute, relative to the JSON file
        foreach ( $files as &$file ) {
            $file = "$dir/$file";
        }
        return $files;
    }
 
    public function setSettingsBuilder( SettingsBuilder $settingsBuilder ) {
        $this->settingsBuilder = $settingsBuilder;
    }
 
    private function getSettingsBuilder(): SettingsBuilder {
        if ( $this->settingsBuilder === null ) {
            $this->settingsBuilder = SettingsBuilder::getInstance();
        }
        return $this->settingsBuilder;
    }
}