+global\ResourceLoader::respond()

Complexity

Conditions	20
Paths	1568

Size

Total Lines	118
Code Lines	61

Duplication

Lines	0
Ratio	0 %

Importance

Changes

0

<?php
	public function respond( ResourceLoaderContext $context ) {
		// Buffer output to catch warnings. Normally we'd use ob_clean() on the
		// top-level output buffer to clear warnings, but that breaks when ob_gzhandler
		// is used: ob_clean() will clear the GZIP header in that case and it won't come
		// back for subsequent output, resulting in invalid GZIP. So we have to wrap
		// the whole thing in our own output buffer to be sure the active buffer
		// doesn't use ob_gzhandler.
		// See http://bugs.php.net/bug.php?id=36514
		ob_start();

		// Find out which modules are missing and instantiate the others
		$modules = [];
		$missing = [];
		foreach ( $context->getModules() as $name ) {
			$module = $this->getModule( $name );
			if ( $module ) {
				// Do not allow private modules to be loaded from the web.
				// This is a security issue, see bug 34907.
				if ( $module->getGroup() === 'private' ) {
					$this->logger->debug( "Request for private module '$name' denied" );
					$this->errors[] = "Cannot show private module \"$name\"";
					continue;
				}
				$modules[$name] = $module;
			} else {
				$missing[] = $name;
			}
		}

		try {
			// Preload for getCombinedVersion() and for batch makeModuleResponse()
			$this->preloadModuleInfo( array_keys( $modules ), $context );
		} catch ( Exception $e ) {
			MWExceptionHandler::logException( $e );
			$this->logger->warning( 'Preloading module info failed: {exception}', [
				'exception' => $e
			] );
			$this->errors[] = self::formatExceptionNoComment( $e );
		}

		// Combine versions to propagate cache invalidation
		$versionHash = '';
		try {
			$versionHash = $this->getCombinedVersion( $context, array_keys( $modules ) );
		} catch ( Exception $e ) {
			MWExceptionHandler::logException( $e );
			$this->logger->warning( 'Calculating version hash failed: {exception}', [
				'exception' => $e
			] );
			$this->errors[] = self::formatExceptionNoComment( $e );
		}

		// See RFC 2616 § 3.11 Entity Tags
		// http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.11
		$etag = 'W/"' . $versionHash . '"';

		// Try the client-side cache first
		if ( $this->tryRespondNotModified( $context, $etag ) ) {
			return; // output handled (buffers cleared)
		}

		// Use file cache if enabled and available...
		if ( $this->config->get( 'UseFileCache' ) ) {
			$fileCache = ResourceFileCache::newFromContext( $context );
			if ( $this->tryRespondFromFileCache( $fileCache, $context, $etag ) ) {
				return; // output handled
			}
		}

		// Generate a response
		$response = $this->makeModuleResponse( $context, $modules, $missing );

		// Capture any PHP warnings from the output buffer and append them to the
		// error list if we're in debug mode.
		if ( $context->getDebug() ) {
			$warnings = ob_get_contents();
			if ( strlen( $warnings ) ) {
				$this->errors[] = $warnings;
			}
		}

		// Save response to file cache unless there are errors
		if ( isset( $fileCache ) && !$this->errors && !count( $missing ) ) {
			// Cache single modules and images...and other requests if there are enough hits
			if ( ResourceFileCache::useFileCache( $context ) ) {
				if ( $fileCache->isCacheWorthy() ) {
					$fileCache->saveText( $response );
				} else {
					$fileCache->incrMissesRecent( $context->getRequest() );
				}
			}
		}

		$this->sendResponseHeaders( $context, $etag, (bool)$this->errors );

		// Remove the output buffer and output the response
		ob_end_clean();

		if ( $context->getImageObj() && $this->errors ) {
			// We can't show both the error messages and the response when it's an image.
			$response = implode( "\n\n", $this->errors );
		} elseif ( $this->errors ) {
			$errorText = implode( "\n\n", $this->errors );
			$errorResponse = self::makeComment( $errorText );
			if ( $context->shouldIncludeScripts() ) {
				$errorResponse .= 'if (window.console && console.error) {'
					. Xml::encodeJsCall( 'console.error', [ $errorText ] )
					. "}\n";
			}

			// Prepend error info to the response
			$response = $errorResponse . $response;
		}

		$this->errors = [];
		echo $response;

	}