Cache response status and headers when fetching external stylesheets

includes/validation/class-amp-validation-error-taxonomy.php

@@ -3344,6 +3344,10 @@ public static function get_source_key_label( $key, $validation_error ) {
 				return __( 'Invalid attribute', 'amp' );
 			case 'required_attr_value':
 				return __( 'Required attribute value', 'amp' );
+			case 'url':
+				return __( 'URL', 'amp' );
+			case 'message':
+				return __( 'Message', 'amp' );
 			default:
 				return $key;
 		}

lib/common/phpstan.neon.dist

@@ -8,3 +8,5 @@ parameters:
 		- %currentWorkingDirectory%/src/
 	autoload_files:
 		- %currentWorkingDirectory%/vendor/autoload.php
+	ignoreErrors:
+		- '#^PHPDoc tag @throws with type AmpProject\\Exception\\FailedRemoteRequest is not subtype of Throwable$#'

lib/common/src/Exception/FailedRemoteRequest.php

@@ -0,0 +1,13 @@
+<?php
+
+namespace AmpProject\Exception;
+
+/**
+ * Marker interface to enable consumers to catch all exceptions for failed remote requests.
+ *
+ * @package ampproject/common
+ */
+interface FailedRemoteRequest extends AmpException
+{
+
+}

lib/common/src/Exception/FailedToGetCachedResponse.php

@@ -0,0 +1,27 @@
+<?php
+
+namespace AmpProject\Exception;
+
+use RuntimeException;
+
+/**
+ * Exception thrown when a cached remote response could not be retrieved.
+ *
+ * @package ampproject/common
+ */
+final class FailedToGetCachedResponse extends RuntimeException implements FailedRemoteRequest
+{
+
+    /**
+     * Instantiate a FailedToGetCachedResponseData exception for a URL if the cached response data could not be retrieved.
+     *
+     * @param string $url URL that failed to be fetched.
+     * @return self
+     */
+    public static function withUrl($url)
+    {
+        $message = "Failed to retrieve the cached response for the URL '{$url}'.";
+
+        return new self($message);
+    }
+}

lib/common/src/Exception/FailedToGetFromRemoteUrl.php

@@ -10,7 +10,7 @@
  *
  * @package ampproject/common
  */
-final class FailedToGetFromRemoteUrl extends RuntimeException implements AmpException
+final class FailedToGetFromRemoteUrl extends RuntimeException implements FailedRemoteRequest
 {
 
     /**

lib/common/src/RemoteGetRequest.php

@@ -2,7 +2,7 @@
 
 namespace AmpProject;
 
-use AmpProject\Exception\FailedToGetFromRemoteUrl;
+use AmpProject\Exception\FailedRemoteRequest;
 
 /**
  * Interface for abstracting away the transport that is being used for making remote requests.
@@ -19,7 +19,7 @@ interface RemoteGetRequest
      *
      * @param string $url URL to get.
      * @return Response Response for the executed request.
-     * @throws FailedToGetFromRemoteUrl If retrieving the contents from the URL failed.
+     * @throws FailedRemoteRequest If retrieving the contents from the URL failed.
      */
     public function get($url);
 }

lib/common/src/RemoteRequest/CurlRemoteGetRequest.php

@@ -2,6 +2,7 @@
 
 namespace AmpProject\RemoteRequest;
 
+use AmpProject\Exception\FailedRemoteRequest;
 use AmpProject\Exception\FailedToGetFromRemoteUrl;
 use AmpProject\RemoteGetRequest;
 use AmpProject\Response;
@@ -92,7 +93,7 @@ public function __construct($sslVerify = true, $timeout = self::DEFAULT_TIMEOUT,
      *
      * @param string $url URL to get.
      * @return Response Response for the executed request.
-     * @throws FailedToGetFromRemoteUrl If retrieving the contents from the URL failed.
+     * @throws FailedRemoteRequest If retrieving the contents from the URL failed.
      */
     public function get($url)
     {

lib/common/src/RemoteRequest/FallbackRemoteGetRequest.php

@@ -2,7 +2,7 @@
 
 namespace AmpProject\RemoteRequest;
 
-use AmpProject\Exception\FailedToGetFromRemoteUrl;
+use AmpProject\Exception\FailedRemoteRequest;
 use AmpProject\RemoteGetRequest;
 use AmpProject\Response;
 use Exception;
@@ -55,7 +55,7 @@ private function addRemoteGetRequestInstance(RemoteGetRequest $remoteGetRequest)
      *
      * @param string $url URL to get.
      * @return Response Response for the executed request.
-     * @throws FailedToGetFromRemoteUrl If retrieving the contents from the URL failed.
+     * @throws FailedRemoteRequest If retrieving the contents from the URL failed.
      */
     public function get($url)
     {

lib/common/src/RemoteRequest/FilesystemRemoteGetRequest.php

@@ -2,6 +2,7 @@
 
 namespace AmpProject\RemoteRequest;
 
+use AmpProject\Exception\FailedRemoteRequest;
 use AmpProject\Exception\FailedToGetFromRemoteUrl;
 use AmpProject\RemoteGetRequest;
 use AmpProject\Response;
@@ -40,7 +41,7 @@ public function __construct($argumentMap)
      *
      * @param string $url URL to get.
      * @return Response Response for the executed request.
-     * @throws FailedToGetFromRemoteUrl If retrieving the contents from the URL failed.
+     * @throws FailedRemoteRequest If retrieving the contents from the URL failed.
      */
     public function get($url)
     {

lib/common/src/RemoteRequest/StubbedRemoteGetRequest.php

@@ -2,7 +2,7 @@
 
 namespace AmpProject\RemoteRequest;
 
-use AmpProject\Exception\FailedToGetFromRemoteUrl;
+use AmpProject\Exception\FailedRemoteRequest;
 use AmpProject\RemoteGetRequest;
 use AmpProject\Response;
 use LogicException;
@@ -37,7 +37,7 @@ public function __construct($argumentMap)
      *
      * @param string $url URL to get.
      * @return Response Response for the executed request.
-     * @throws FailedToGetFromRemoteUrl If retrieving the contents from the URL failed.
+     * @throws FailedRemoteRequest If retrieving the contents from the URL failed.
      */
     public function get($url)
     {

src/RemoteRequest/CachedRemoteGetRequest.php

@@ -7,6 +7,8 @@
 
 namespace AmpProject\AmpWP\RemoteRequest;
 
+use AmpProject\Exception\FailedRemoteRequest;
+use AmpProject\Exception\FailedToGetCachedResponse;
 use AmpProject\Exception\FailedToGetFromRemoteUrl;
 use AmpProject\RemoteGetRequest;
 use AmpProject\RemoteRequest\RemoteGetRequestResponse;
@@ -28,7 +30,7 @@ final class CachedRemoteGetRequest implements RemoteGetRequest {
 	 *
 	 * @var string
 	 */
-	const TRANSIENT_PREFIX = 'amp_remote_request_';
+	const TRANSIENT_PREFIX = 'amp_remote_request_v2_';
 
 	/**
 	 * Cache control header directive name.
@@ -101,42 +103,48 @@ public function __construct(
 	 *
 	 * @param string $url URL to get.
 	 * @return Response Response for the executed request.
-	 * @throws FailedToGetFromRemoteUrl If retrieving the contents from the URL failed.
+	 * @throws FailedRemoteRequest If retrieving the contents from the URL failed.
 	 */
 	public function get( $url ) {
-		$cache_key   = self::TRANSIENT_PREFIX . md5( __CLASS__ . $url );
-		$cached_data = get_transient( $cache_key );
-		$headers     = [];
-		$status      = null;
+		$cache_key       = self::TRANSIENT_PREFIX . md5( __CLASS__ . $url );
+		$cached_response = get_transient( $cache_key );
+		$headers         = [];
 
-		if ( false !== $cached_data ) {
+		if ( false !== $cached_response ) {
 			if ( PHP_MAJOR_VERSION >= 7 ) {
-				$cached_data = unserialize( $cached_data, [ CachedData::class, DateTimeImmutable::class ] ); // phpcs:ignore WordPress.PHP.DiscouragedPHPFunctions.serialize_unserialize,PHPCompatibility.FunctionUse.NewFunctionParameters.unserialize_optionsFound
+				$cached_response = unserialize( $cached_response, [ CachedResponse::class, DateTimeImmutable::class ] ); // phpcs:ignore WordPress.PHP.DiscouragedPHPFunctions.serialize_unserialize,PHPCompatibility.FunctionUse.NewFunctionParameters.unserialize_optionsFound
 			} else {
 				// PHP 5.6 does not provide the second $options argument yet.
-				$cached_data = unserialize( $cached_data ); // phpcs:ignore WordPress.PHP.DiscouragedPHPFunctions.serialize_unserialize
+				$cached_response = unserialize( $cached_response ); // phpcs:ignore WordPress.PHP.DiscouragedPHPFunctions.serialize_unserialize
 			}
 		}
 
-		if ( false === $cached_data || $cached_data->is_expired() ) {
+		if ( false === $cached_response || $cached_response->is_expired() ) {
 			try {
 				$response = $this->remote_request->get( $url );
 				$status   = $response->getStatusCode();
 				$expiry   = $this->get_expiry_time( $response );
 				$headers  = $response->getHeaders();
 				$body     = $response->getBody();
 			} catch ( FailedToGetFromRemoteUrl $exception ) {
-				$status = $exception->getStatusCode();
-				$expiry = new DateTimeImmutable( "+ {$this->min_expiry} seconds" );
-				$body   = $exception->getMessage();
+				$status   = $exception->getStatusCode();
+				$expiry   = new DateTimeImmutable( "+ {$this->min_expiry} seconds" );
+				$body     = $exception->getMessage();
+				$response = new RemoteGetRequestResponse( $body, $headers, $status );
 			}
 
-			$cached_data = new CachedData( $body, $expiry );
+			$cached_response = new CachedResponse( $body, $headers, $status, $expiry );
 
-			set_transient( $cache_key, serialize( $cached_data ) ); // phpcs:ignore WordPress.PHP.DiscouragedPHPFunctions.serialize_serialize
+			set_transient( $cache_key, serialize( $cached_response ) ); // phpcs:ignore WordPress.PHP.DiscouragedPHPFunctions.serialize_serialize
+
+			return $response;
+		}
+
+		if ( ! $cached_response->is_valid() ) {
+			throw new FailedToGetCachedResponse( $url );
 		}
 
-		return new RemoteGetRequestResponse( $cached_data->get_value(), $headers, $status );
+		return new RemoteGetRequestResponse( $cached_response->get_body(), $cached_response->get_headers(), $cached_response->get_status_code() );
 	}
 
 	/**