initial

wp-content/plugins/jetpack-boost/app/lib/critical-css/class-admin-bar-compatibility.php

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+<?php
+namespace Automattic\Jetpack_Boost\Lib\Critical_CSS;
+
+class Admin_Bar_Compatibility {
+
+	/**
+	 * Enforces the admin bar stylesheet to load late and synchronously
+	 * when the admin bar is present on the page.
+	 */
+	public static function init() {
+
+		// Force the Admin Bar to render in the footer.
+		remove_action( 'wp_body_open', 'wp_admin_bar_render', '0' );
+
+		add_filter( 'jetpack_boost_async_style', array( __CLASS__, 'enable_asynchronous_admin_bar' ), 10, 2 );
+		add_action( 'wp_before_admin_bar_render', array( __CLASS__, 'force_admin_bar_stylesheet' ) );
+		add_action( 'wp_head', array( __CLASS__, 'dequeue_admin_bar' ), 0 );
+	}
+
+	/**
+	 * Load the admin bar CSS synchronously.
+	 *
+	 * @param bool   $is_async Whether admin bar is async.
+	 * @param string $handle   Asset handle.
+	 *
+	 * @return bool
+	 */
+	public static function enable_asynchronous_admin_bar( $is_async, $handle ) {
+
+		if ( 'admin-bar' === $handle ) {
+			$is_async = false;
+		}
+
+		return $is_async;
+	}
+
+	/**
+	 * Dequeue the admin bar stylesheet, so that it's not printed early.
+	 *
+	 * @see     wp_head
+	 */
+	public static function dequeue_admin_bar() {
+		wp_dequeue_style( 'admin-bar' );
+	}
+
+	/**
+	 * Force the admin bar stylesheet to print right before the admin bar markup.
+	 *
+	 * @see     wp_before_admin_bar_render
+	 */
+	public static function force_admin_bar_stylesheet() {
+		wp_print_styles( 'admin-bar' );
+	}
+}

wp-content/plugins/jetpack-boost/app/lib/critical-css/class-critical-css-invalidator.php

@@ -0,0 +1,84 @@
+<?php
+/**
+ * Critical CSS Invalidator
+ *
+ * Reset critical CSS when existing critical css values are stale.
+ */
+
+namespace Automattic\Jetpack_Boost\Lib\Critical_CSS;
+
+use Automattic\Jetpack_Boost\Admin\Regenerate_Admin_Notice;
+use Automattic\Jetpack_Boost\Lib\Boost_Health;
+use Automattic\Jetpack_Boost\Lib\Critical_CSS\Source_Providers\Source_Providers;
+use Automattic\Jetpack_Boost\Modules\Modules_Setup;
+use Automattic\Jetpack_Boost\Modules\Optimizations\Cloud_CSS\Cloud_CSS;
+use Automattic\Jetpack_Boost\Modules\Optimizations\Cloud_CSS\Cloud_CSS_Followup;
+
+/**
+ * Handler for invalidating Critical CSS; both Cloud and Local. Watches relevant
+ * hooks and clears data when necessary. Also sends out its own action
+ * (after_critical_css_invalidate) so that the Cloud or Local implementations of
+ * Critical CSS can respond to the invalidation.
+ */
+class Critical_CSS_Invalidator {
+	public static function init() {
+		add_action( 'jetpack_boost_deactivate', array( __CLASS__, 'reset_data' ) );
+		add_action( 'jetpack_boost_environment_changed', array( __CLASS__, 'handle_environment_change' ) );
+		add_filter( 'jetpack_boost_total_problem_count', array( __CLASS__, 'update_boost_problem_count' ) );
+	}
+
+	/**
+	 * Reset Critical CSS data.
+	 * For Cloud CSS, we need to make sure there are providers in the state,
+	 * otherwise Cloud CSS cannot be stored after it is generated by the cloud.
+	 */
+	public static function reset_data() {
+		$storage = new Critical_CSS_Storage();
+		$storage->clear();
+
+		$state = new Critical_CSS_State();
+		$state->clear();
+
+		if ( self::is_cloud_css() ) {
+			$state->prepare_for_generation( ( new Source_Providers() )->get_provider_sources() );
+			$state->save();
+
+			// Clear the regenerate flag so things are nice and tidy.
+			jetpack_boost_ds_delete( 'critical_css_suggest_regenerate' );
+			// Also clear the admin notice flag, so the notice doesn't show up in case
+			// the user is reverted to free Boost.
+			Regenerate_Admin_Notice::dismiss();
+
+		}
+
+		Cloud_CSS_Followup::unschedule();
+	}
+
+	/**
+	 * Respond to environment changes; deciding whether or not to clear Critical CSS data.
+	 */
+	public static function handle_environment_change( $is_major_change ) {
+		if ( $is_major_change ) {
+			self::reset_data();
+
+			/**
+			 * Indicate that all existing critical CSS has been invalidated.
+			 */
+			do_action( 'jetpack_boost_critical_css_invalidated' );
+		}
+	}
+
+	public static function update_boost_problem_count( $count ) {
+		$css_needs_regeneration = Boost_Health::critical_css_needs_regeneration();
+		if ( $css_needs_regeneration ) {
+			++$count;
+		}
+
+		return $count;
+	}
+
+	public static function is_cloud_css() {
+		$optimizations = ( new Modules_Setup() )->get_status();
+		return isset( $optimizations[ Cloud_CSS::get_slug() ] ) && $optimizations[ Cloud_CSS::get_slug() ];
+	}
+}

wp-content/plugins/jetpack-boost/app/lib/critical-css/class-critical-css-state.php

@@ -0,0 +1,248 @@
+<?php
+
+namespace Automattic\Jetpack_Boost\Lib\Critical_CSS;
+
+use WP_Error;
+
+class Critical_CSS_State {
+
+	const GENERATION_STATES = array(
+		'not_generated' => 'not_generated',
+		'pending'       => 'pending',
+		'generated'     => 'generated',
+		'error'         => 'error',
+	);
+
+	const PROVIDER_STATES = array(
+		'pending' => 'pending',
+		'success' => 'success',
+		'error'   => 'error',
+	);
+	public $state;
+
+	public function __construct() {
+		$this->state = jetpack_boost_ds_get( 'critical_css_state' );
+	}
+
+	public function clear() {
+		jetpack_boost_ds_delete( 'critical_css_state' );
+	}
+
+	public function save() {
+		$this->state['updated'] = microtime( true );
+		jetpack_boost_ds_set( 'critical_css_state', $this->state );
+
+		if ( $this->is_generated() ) {
+			/**
+			 * Fires when critical CSS has successfully been generated.
+			 */
+			do_action( 'jetpack_boost_critical_css_generated' );
+		}
+	}
+
+	public function set_error( $message ) {
+		if ( empty( $message ) ) {
+			error_log( // phpcs:ignore WordPress.PHP.DevelopmentFunctions.error_log_error_log
+				'Critical CSS: set_error() called with empty message'
+			);
+			return $this;
+		}
+
+		$this->state['status_error'] = $message;
+		$this->state['status']       = self::GENERATION_STATES['error'];
+
+		return $this;
+	}
+
+	public function set_provider_error_dismissed( $provider_key, $error_type, $dismissed ) {
+		if ( empty( $this->state['providers'] ) ) {
+			return new WP_Error( 'invalid_provider_key', 'No providers exist' );
+		}
+
+		$provider_index = array_search( $provider_key, array_column( $this->state['providers'], 'key' ), true );
+		if ( $provider_index === false ) {
+			return new WP_Error( 'invalid_provider_key', 'Invalid provider key' );
+		}
+
+		if ( ! isset( $this->state['providers'][ $provider_index ]['dismissed_errors'] ) ) {
+			$this->state['providers'][ $provider_index ]['dismissed_errors'] = array();
+		}
+
+		if ( $dismissed ) {
+			if ( ! in_array( $error_type, $this->state['providers'][ $provider_index ]['dismissed_errors'], true ) ) {
+				$this->state['providers'][ $provider_index ]['dismissed_errors'][] = $error_type;
+			}
+		} else {
+			$key = array_search( $error_type, $this->state['providers'][ $provider_index ]['dismissed_errors'], true );
+			if ( $key !== false ) {
+				unset( $this->state['providers'][ $provider_index ]['dismissed_errors'][ $key ] );
+				$this->state['providers'][ $provider_index ]['dismissed_errors'] = array_values( $this->state['providers'][ $provider_index ]['dismissed_errors'] );
+			}
+		}
+
+		return true;
+	}
+
+	/**
+	 * Update a provider's state. The provider must already exist in the state to be updated.
+	 *
+	 * @param string $provider_key The provider key.
+	 * @param array  $state        An array to overlay over the current state.
+	 * @return bool|WP_Error True on success, WP_Error on failure.
+	 */
+	private function update_provider_state( $provider_key, $state ) {
+		if ( empty( $this->state['providers'] ) ) {
+			return new WP_Error( 'invalid_provider_key', 'No providers exist' );
+		}
+
+		$provider_index = array_search( $provider_key, array_column( $this->state['providers'], 'key' ), true );
+		if ( $provider_index === false ) {
+			return new WP_Error( 'invalid_provider_key', 'Invalid provider key' );
+		}
+
+		$this->state['providers'][ $provider_index ] = array_merge(
+			$this->state['providers'][ $provider_index ],
+			$state
+		);
+
+		$this->maybe_set_generated();
+
+		return true;
+	}
+
+	/**
+	 * Set a provider's state to error.
+	 *
+	 * @param string $provider_key The provider key.
+	 * @param array  $errors        A list of errors to store with this provider.
+	 * @return bool|WP_Error True on success, WP_Error on failure.
+	 */
+	public function set_provider_errors( $provider_key, $errors ) {
+		return $this->update_provider_state(
+			$provider_key,
+			array(
+				'status' => self::PROVIDER_STATES['error'],
+				'errors' => $errors,
+			)
+		);
+	}
+
+	/**
+	 * Set a provider's state to success.
+	 *
+	 * @param string $provider_key The provider key.
+	 * @return bool|WP_Error True on success, WP_Error on failure.
+	 */
+	public function set_provider_success( $provider_key ) {
+		return $this->update_provider_state(
+			$provider_key,
+			array(
+				'status' => self::PROVIDER_STATES['success'],
+			)
+		);
+	}
+
+	/**
+	 * Set the state to generated if all providers are done. Should be called wherever
+	 * a provider's state is updated.
+	 */
+	private function maybe_set_generated() {
+		if ( empty( $this->state['providers'] ) ) {
+			return;
+		}
+
+		$provider_states = array_column( $this->state['providers'], 'status' );
+		$is_done         = ! in_array( self::GENERATION_STATES['pending'], $provider_states, true );
+
+		if ( $is_done ) {
+			$this->state['status'] = self::GENERATION_STATES['generated'];
+		}
+	}
+
+	public function has_errors() {
+		// Check if any of the providers have errors as well.
+		$any_provider_has_error = in_array(
+			'error',
+			array_unique(
+				wp_list_pluck(
+					$this->state['providers'],
+					'status'
+				)
+			),
+			true
+		);
+
+		return self::GENERATION_STATES['error'] === $this->state['status'] || $any_provider_has_error;
+	}
+
+	public function get_error_message() {
+		return $this->state['status_error'] ?? null;
+	}
+
+	public function is_generated() {
+		return self::GENERATION_STATES['generated'] === $this->state['status'];
+	}
+
+	public function is_requesting() {
+		return self::GENERATION_STATES['pending'] === $this->state['status'];
+	}
+
+	public function prepare_request() {
+		$this->state = array(
+			'status'    => self::GENERATION_STATES['pending'],
+			'providers' => array(),
+			'created'   => microtime( true ),
+			'updated'   => microtime( true ),
+		);
+
+		return $this;
+	}
+
+	public function set_pending_providers( $providers ) {
+		foreach ( $providers as $key => $provider ) {
+			$providers[ $key ]['status'] = self::PROVIDER_STATES['pending'];
+		}
+		$this->state['providers'] = $providers;
+		return $this;
+	}
+
+	/**
+	 * Add providers to the state, sets their status to pending
+	 * and sets the generation status to pending.
+	 *
+	 * @param array $providers The providers to include in the state and set as pending.
+	 * @return $this
+	 */
+	public function prepare_for_generation( $providers ) {
+		$this->set_pending_providers( $providers );
+		$this->state['status'] = self::GENERATION_STATES['pending'];
+		return $this;
+	}
+
+	/**
+	 * Get fresh state
+	 */
+	public function get() {
+		$this->state = jetpack_boost_ds_get( 'critical_css_state' );
+		return $this->state;
+	}
+
+	public function has_pending_provider( $needles = array() ) {
+		if ( empty( $this->state['providers'] ) ) {
+			return false;
+		}
+
+		$providers = $this->state['providers'];
+		foreach ( $providers as $provider ) {
+			if (
+				! empty( $provider['key'] )
+				&& ! empty( $provider['status'] )
+				&& self::PROVIDER_STATES['pending'] === $provider['status']
+				&& in_array( $provider['key'], $needles, true )
+			) {
+				return true;
+			}
+		}
+		return false;
+	}
+}

wp-content/plugins/jetpack-boost/app/lib/critical-css/class-critical-css-storage.php

@@ -0,0 +1,75 @@
+<?php
+/**
+ * Critical CSS storage.
+ *
+ * @link       https://automattic.com
+ * @since      1.0.0
+ * @package    automattic/jetpack-boost
+ */
+
+namespace Automattic\Jetpack_Boost\Lib\Critical_CSS;
+
+use Automattic\Jetpack_Boost\Lib\Storage_Post_Type;
+
+/**
+ * Critical CSS Storage class
+ */
+class Critical_CSS_Storage {
+
+	/**
+	 * Storage post type.
+	 *
+	 * @var Storage_Post_Type
+	 */
+	protected $storage;
+
+	/**
+	 * Critical_CSS_Storage constructor.
+	 */
+	public function __construct() {
+		$this->storage = new Storage_Post_Type( 'css' );
+	}
+
+	/**
+	 * Store Critical CSS for a specific provider.
+	 *
+	 * @param string $key   Provider key.
+	 * @param string $value Critical CSS.
+	 */
+	public function store_css( $key, $value ) {
+		$this->storage->set(
+			$key,
+			array(
+				'css' => $value,
+			)
+		);
+	}
+
+	/**
+	 * Clear the whole Critical CSS storage.
+	 */
+	public function clear() {
+		$this->storage->clear();
+	}
+
+	/**
+	 * Get Critical CSS for specific provider keys.
+	 *
+	 * @param array $provider_keys Provider keys.
+	 *
+	 * @return array|false
+	 */
+	public function get_css( $provider_keys ) {
+		foreach ( $provider_keys as $key ) {
+			$data = $this->storage->get( $key, false );
+			if ( $data && $data['css'] ) {
+				return array(
+					'key' => $key,
+					'css' => $data['css'],
+				);
+			}
+		}
+
+		return false;
+	}
+}

wp-content/plugins/jetpack-boost/app/lib/critical-css/class-display-critical-css.php

@@ -0,0 +1,188 @@
+<?php
+/**
+ * Class that's responsible for rendering
+ * Critical CSS on the site front-end.
+ */
+
+namespace Automattic\Jetpack_Boost\Lib\Critical_CSS;
+
+class Display_Critical_CSS {
+
+	/**
+	 * @var string The Critical CSS to display.
+	 */
+	protected $css;
+
+	/**
+	 * @param string $css
+	 */
+	public function __construct( $css ) {
+		$this->css = $css;
+	}
+
+	/**
+	 * Converts existing screen CSS to be asynchronously loaded.
+	 *
+	 * @param string $html   The link tag for the enqueued style.
+	 * @param string $handle The style's registered handle.
+	 * @param string $href   The stylesheet's source URL.
+	 * @param string $media  The stylesheet's media attribute.
+	 *
+	 * @return string
+	 * @see style_loader_tag
+	 */
+	public function asynchronize_stylesheets(
+		$html,
+		$handle,
+		$href,
+		$media
+	) {
+		// If there is no critical CSS, do not alter the stylesheet loading.
+		if ( ! $this->css ) {
+			return $html;
+		}
+
+		$supported_loading_methods = array( 'async', 'deferred' );
+
+		/**
+		 * Loading method for stylesheets.
+		 *
+		 * Filter the loading method for each stylesheet for the screen with following values:
+		 *     async    - Stylesheets are loaded asynchronously.
+		 *                Styles are applied once the stylesheet is loaded completely without render blocking.
+		 *     deferred - Loading of stylesheets are deferred until the window load event.
+		 *                Styles from all the stylesheets are applied at once after the page load.
+		 *
+		 * Stylesheet loading behaviour is not altered for any other value such as false or 'default'.
+		 * Stylesheet loading is instant and the process blocks the page rendering.
+		 *     Eg: add_filter( 'jetpack_boost_async_style', '__return_false' );
+		 *
+		 * @param string $handle The style's registered handle.
+		 * @param string $media  The stylesheet's media attribute.
+		 *
+		 * @see   onload_flip_stylesheets for how stylesheets loading is deferred.
+		 *
+		 * @todo  Retrieve settings from database, either via auto-configuration or UI option.
+		 */
+		$method = apply_filters( 'jetpack_boost_async_style', 'async', $handle, $media );
+
+		// If the loading method is not supported, do not alter the stylesheet loading.
+		if ( ! in_array( $method, $supported_loading_methods, true ) ) {
+			return $html;
+		}
+
+		// Update the stylesheet markup for supported loading methods using WordPress HTML API.
+		$processor = new \WP_HTML_Tag_Processor( $html );
+		if ( ! $processor->next_tag( 'link' ) ) {
+			return $html;
+		}
+
+		// Only process if this is a stylesheet link tag.
+		if ( 'stylesheet' !== $processor->get_attribute( 'rel' ) ) {
+			return $html;
+		}
+
+		// Set the new attributes based on the selected method.
+		$processor->set_attribute( 'media', 'not all' );
+		$processor->set_attribute( 'data-media', $media );
+		if ( 'async' === $method ) {
+			$processor->set_attribute( 'onload', "this.media=this.dataset.media; delete this.dataset.media; this.removeAttribute( 'onload' );" );
+		}
+
+		// Prepend the original HTML stylesheet tag within the noscript tag
+		// to support the rendering of the stylesheet when JavaScript is disabled.
+		return '<noscript>' . $html . '</noscript>' . $processor->get_updated_html();
+	}
+
+	/**
+	 * Prints the critical CSS to the page.
+	 */
+	public function display_critical_css() {
+		$critical_css = $this->css;
+
+		if ( ! $critical_css ) {
+			return false;
+		}
+
+		echo '<style id="jetpack-boost-critical-css">';
+
+		// Ensure the CSS cannot terminate the style element early.
+		// phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped
+		echo self::neutralize_style_closing_tags( $critical_css );
+
+		echo '</style>';
+	}
+
+	/**
+	 * Neutralize any closing </style tag so CSS can be printed inside a <style>
+	 * element without breaking out of it.
+	 *
+	 * This is NOT a general-purpose CSS sanitizer: it does exactly one thing,
+	 * which is to stop the CSS from terminating the surrounding <style> element.
+	 * It deliberately avoids wp_strip_all_tags(), which corrupts valid CSS values
+	 * that contain markup - e.g. `background-image: url("data:image/svg+xml,<svg ...></svg>")`.
+	 *
+	 * Per the HTML rawtext tokenizer, a <style> element can only be terminated by
+	 * the literal sequence `</style` (case-insensitive). Escaping its forward slash
+	 * to `<\/style` defeats the tokenizer - `</` must be immediately followed by the
+	 * tag name, and `<\` is treated as literal text - so the markup stays inert. The
+	 * replacement string contains no `</style` substring, so a single left-to-right
+	 * pass cannot reconstruct the sequence (including from nested input like
+	 * `<</style/style`), and the transform is idempotent.
+	 *
+	 * Inside CSS strings and url() tokens `\/` is a valid escape for `/`, so
+	 * legitimate quoted values keep their meaning. (A literal `</style` outside a
+	 * quoted string does not occur in well-formed CSS; the security guarantee takes
+	 * priority there regardless.)
+	 *
+	 * @param string $css CSS to neutralize.
+	 * @return string CSS that cannot terminate the surrounding <style> element.
+	 */
+	public static function neutralize_style_closing_tags( $css ) {
+		return str_ireplace( '</style', '<\/style', $css );
+	}
+
+	/**
+	 * Add a small piece of JavaScript to the footer, which on load flips all
+	 * linked stylesheets from media="not all" to "all", and switches the
+	 * Critical CSS <style> block to media="not all" to deactivate it.
+	 */
+	public function onload_flip_stylesheets() {
+		/*
+			Unminified version of footer script.
+
+		?>
+			<script>
+				window.addEventListener( 'load', function() {
+
+					// Flip all media="not all" links to media="all".
+					document.querySelectorAll( 'link' ).forEach(
+						function( link ) {
+							if ( link.media === 'not all' && link.dataset.media ) {
+								link.media = link.dataset.media;
+								delete link.dataset.media;
+							}
+						}
+					);
+
+					// Turn off Critical CSS style block with media="not all".
+					var element = document.getElementById( 'jetpack-boost-critical-css' );
+					if ( element ) {
+						element.media = 'not all';
+					}
+
+				} );
+			</script>
+		<?php
+		*/
+
+		// Minified version of footer script. See above comment for unminified version.
+		?>
+		<script>window.addEventListener( 'load', function() {
+				document.querySelectorAll( 'link' ).forEach( function( e ) {'not all' === e.media && e.dataset.media && ( e.media = e.dataset.media, delete e.dataset.media );} );
+				var e = document.getElementById( 'jetpack-boost-critical-css' );
+				e && ( e.media = 'not all' );
+			} );</script>
+		<?php
+	}
+}

wp-content/plugins/jetpack-boost/app/lib/critical-css/class-generator.php

@@ -0,0 +1,66 @@
+<?php
+
+namespace Automattic\Jetpack_Boost\Lib\Critical_CSS;
+
+use Automattic\Jetpack_Boost\Modules\Optimizations\Critical_CSS\CSS_Proxy;
+
+class Generator {
+
+	const GENERATE_QUERY_ACTION = 'jb-generate-critical-css';
+
+	public static function init() {
+		$generator = new static();
+		if ( static::is_generating_critical_css() ) {
+			add_action( 'wp_head', array( $generator, 'display_generate_meta' ), 0 );
+			$generator->force_logged_out_render();
+		}
+	}
+
+	/**
+	 * Force the current page to render as viewed by a logged out user. Useful when generating
+	 * Critical CSS.
+	 */
+	private function force_logged_out_render() {
+		$current_user_id = get_current_user_id();
+
+		if ( 0 !== $current_user_id ) {
+			// Force current user to 0 to ensure page is rendered as a non-logged-in user.
+			wp_set_current_user( 0 );
+
+			// Turn off display of admin bar.
+			add_filter( 'show_admin_bar', '__return_false', PHP_INT_MAX );
+		}
+	}
+
+	/**
+	 * Return true if page is loaded to generate critical CSS
+	 *
+	 * phpcs:disable WordPress.Security.NonceVerification.Recommended
+	 */
+	public static function is_generating_critical_css() {
+		return isset( $_GET[ self::GENERATE_QUERY_ACTION ] );
+	}
+
+	/**
+	 * Get a Critical CSS status block, adding in local generation nonces (if applicable).
+	 * i.e.: Call this method to supply enough Critical CSS status to kick off local generation,
+	 * such as in response to a request-generate API call or during page initialization.
+	 */
+	public function get_generation_metadata() {
+		$status = array();
+
+		// Add a user-bound nonce to use when proxying CSS for Critical CSS generation.
+		$status['proxy_nonce'] = wp_create_nonce( CSS_Proxy::NONCE_ACTION );
+
+		return $status;
+	}
+
+	/**
+	 * Renders a <meta> tag used to verify this is a valid page to generate Critical CSS with.
+	 */
+	public function display_generate_meta() {
+		?>
+		<meta name="<?php echo esc_attr( self::GENERATE_QUERY_ACTION ); ?>" content="true"/>
+		<?php
+	}
+}

wp-content/plugins/jetpack-boost/app/lib/critical-css/class-regenerate.php

@@ -0,0 +1,56 @@
+<?php
+
+namespace Automattic\Jetpack_Boost\Lib\Critical_CSS;
+
+use Automattic\Jetpack_Boost\Admin\Regenerate_Admin_Notice;
+use Automattic\Jetpack_Boost\Lib\Critical_CSS\Source_Providers\Source_Providers;
+use Automattic\Jetpack_Boost\Modules\Modules_Setup;
+use Automattic\Jetpack_Boost\Modules\Optimizations\Cloud_CSS\Cloud_CSS;
+use Automattic\Jetpack_Boost\Modules\Optimizations\Cloud_CSS\Cloud_CSS_Followup;
+
+class Regenerate {
+	/** @var Critical_CSS_State */
+	private $state;
+
+	public function is_cloud_css() {
+		$optimizations = ( new Modules_Setup() )->get_status();
+		return isset( $optimizations[ Cloud_CSS::get_slug() ] ) && $optimizations[ Cloud_CSS::get_slug() ];
+	}
+
+	public function start() {
+		// Get Critical CSS Source URLs
+		$source_providers = new Source_Providers();
+		$providers        = $source_providers->get_provider_sources();
+
+		// Store those URLs in the Critical CSS State
+		$this->state = new Critical_CSS_State();
+		$this->state->prepare_request()
+				->set_pending_providers( $providers )
+				->save();
+
+		// Get the data
+		$data = $this->state->get();
+
+		if ( $this->is_cloud_css() ) {
+			// If this is a cloud CSS request, we need to trigger the generation
+			// of the CSS and return the URL to the CSS file.
+			$cloud_css = new Cloud_CSS();
+			$cloud_css->regenerate_cloud_css( Cloud_CSS::REGENERATE_REASON_USER_REQUEST, $cloud_css->get_all_providers() );
+			Cloud_CSS_Followup::schedule();
+		}
+
+		// Clear previous Critical CSS From storage
+		$storage = new Critical_CSS_Storage();
+		$storage->clear();
+
+		// Dismiss admin notices
+		Regenerate_Admin_Notice::dismiss();
+		jetpack_boost_ds_delete( 'critical_css_suggest_regenerate' );
+
+		return $data;
+	}
+
+	public function get_state() {
+		return $this->state;
+	}
+}

wp-content/plugins/jetpack-boost/app/lib/critical-css/data-sync-actions/class-regenerate-css.php

@@ -0,0 +1,31 @@
+<?php
+
+namespace Automattic\Jetpack_Boost\Lib\Critical_CSS\Data_Sync_Actions;
+
+use Automattic\Jetpack\WP_JS_Data_Sync\Contracts\Data_Sync_Action;
+use Automattic\Jetpack_Boost\Lib\Critical_CSS\Regenerate;
+
+/**
+ * Critical CSS Action: request regeneration.
+ */
+class Regenerate_CSS implements Data_Sync_Action {
+
+	/**
+	 * Handles the action logic.
+	 *
+	 * @param mixed            $_data    JSON Data passed to the action.
+	 * @param \WP_REST_Request $_request The request object.
+	 */
+	public function handle( $_data, $_request ) {
+		$regenerate = new Regenerate();
+		$regenerate->start();
+
+		$state = $regenerate->get_state();
+
+		return array(
+			'success' => ! $state->has_errors(),
+			'state'   => $state->get(),
+			'errors'  => $state->get_error_message(),
+		);
+	}
+}

wp-content/plugins/jetpack-boost/app/lib/critical-css/data-sync-actions/class-set-provider-css.php

@@ -0,0 +1,55 @@
+<?php
+
+namespace Automattic\Jetpack_Boost\Lib\Critical_CSS\Data_Sync_Actions;
+
+use Automattic\Jetpack\WP_JS_Data_Sync\Contracts\Data_Sync_Action;
+use Automattic\Jetpack_Boost\Lib\Critical_CSS\Critical_CSS_State;
+use Automattic\Jetpack_Boost\Lib\Critical_CSS\Critical_CSS_Storage;
+
+/**
+ * Critical CSS Action: Set CSS for a provider.
+ */
+class Set_Provider_CSS implements Data_Sync_Action {
+
+	/**
+	 * Handles the action logic.
+	 *
+	 * @param mixed            $data     JSON Data passed to the action.
+	 * @param \WP_REST_Request $_request The request object.
+	 */
+	public function handle( $data, $_request ) {
+		$state = new Critical_CSS_State();
+
+		if ( empty( $data['key'] ) || empty( $data['css'] ) ) {
+			return array(
+				'success' => false,
+				'state'   => $state->get(),
+				'error'   => 'Invalid data',
+			);
+		}
+
+		$provider_key = sanitize_key( $data['key'] );
+		$css          = $this->unmask_content( $data['css'] );
+
+		$storage = new Critical_CSS_Storage();
+		$storage->store_css( $provider_key, $css );
+
+		$state->set_provider_success( $provider_key );
+		$state->save();
+
+		return array(
+			'success' => true,
+			'state'   => $state->get(),
+		);
+	}
+
+	/**
+	 * Unmasks the content.
+	 *
+	 * @param string $content The content to unmask.
+	 * @return string The unmasked content.
+	 */
+	private function unmask_content( $content ) {
+		return str_replace( '__JB_XMLNS__', 'xmlns', $content );
+	}
+}

wp-content/plugins/jetpack-boost/app/lib/critical-css/data-sync-actions/class-set-provider-error-dismissed.php

@@ -0,0 +1,43 @@
+<?php
+
+namespace Automattic\Jetpack_Boost\Lib\Critical_CSS\Data_Sync_Actions;
+
+use Automattic\Jetpack\WP_JS_Data_Sync\Contracts\Data_Sync_Action;
+use Automattic\Jetpack_Boost\Lib\Critical_CSS\Critical_CSS_State;
+
+/**
+ * Critical CSS Action: Update whether or not to show a provider which is in an error state.
+ */
+class Set_Provider_Error_Dismissed implements Data_Sync_Action {
+	/**
+	 * Handles the action logic.
+	 *
+	 * @param mixed            $data     JSON Data passed to the action.
+	 * @param \WP_REST_Request $_request The request object.
+	 */
+	public function handle( $data, $_request ) {
+		$state = new Critical_CSS_State();
+
+		foreach ( $data as $item ) {
+			if ( empty( $item['provider'] ) ) {
+				return array(
+					'success' => false,
+					'state'   => $state->get(),
+					'error'   => 'Invalid data',
+				);
+			}
+
+			$provider_key = sanitize_key( $item['provider'] );
+			$dismissed    = ! empty( $item['dismissed'] );
+
+			$state->set_provider_error_dismissed( $provider_key, $item['error_type'], $dismissed );
+		}
+
+		$state->save();
+
+		return array(
+			'success' => true,
+			'state'   => $state->get(),
+		);
+	}
+}

wp-content/plugins/jetpack-boost/app/lib/critical-css/data-sync-actions/class-set-provider-errors.php

@@ -0,0 +1,40 @@
+<?php
+
+namespace Automattic\Jetpack_Boost\Lib\Critical_CSS\Data_Sync_Actions;
+
+use Automattic\Jetpack\WP_JS_Data_Sync\Contracts\Data_Sync_Action;
+use Automattic\Jetpack_Boost\Lib\Critical_CSS\Critical_CSS_State;
+
+/**
+ * Critical CSS Action: Store errors for a provider.
+ */
+class Set_Provider_Errors implements Data_Sync_Action {
+	/**
+	 * Handles the action logic.
+	 *
+	 * @param mixed            $data     JSON Data passed to the action.
+	 * @param \WP_REST_Request $_request The request object.
+	 */
+	public function handle( $data, $_request ) {
+		$state = new Critical_CSS_State();
+
+		if ( empty( $data['key'] ) || empty( $data['errors'] ) ) {
+			return array(
+				'success' => false,
+				'state'   => $state->get(),
+				'error'   => 'Invalid data',
+			);
+		}
+
+		$provider_key = sanitize_key( $data['key'] );
+		$errors       = $data['errors'];
+
+		$state->set_provider_errors( $provider_key, $errors );
+		$state->save();
+
+		return array(
+			'success' => true,
+			'state'   => $state->get(),
+		);
+	}
+}

wp-content/plugins/jetpack-boost/app/lib/critical-css/data-sync/class-data-sync-schema.php

@@ -0,0 +1,115 @@
+<?php
+
+namespace Automattic\Jetpack_Boost\Lib\Critical_CSS\Data_Sync;
+
+use Automattic\Jetpack\Schema\Schema;
+
+/**
+ * Registers data sync for both the Critical CSS module and the Cloud CSS module. Both of these modules cannot be available at the same time.
+ */
+class Data_Sync_Schema {
+	/**
+	 * Represents a set of errors that can be stored for a single Provider Key in a Critical CSS state block.
+	 */
+	public static function critical_css_provider_error() {
+		return Schema::as_array(
+			Schema::as_assoc_array(
+				array(
+					'url'     => Schema::as_string(),
+					'message' => Schema::as_string(),
+					'type'    => Schema::as_string(),
+					'meta'    => Schema::any_json_data()->nullable(),
+				)
+			)->fallback(
+				array(
+					'url'     => '',
+					'message' => '',
+					'type'    => '',
+				)
+			)
+		);
+	}
+
+	public static function critical_css_state() {
+		return Schema::as_assoc_array(
+			array(
+				'providers'    => Schema::as_array(
+					Schema::as_assoc_array(
+						array(
+							'key'              => Schema::as_string(),
+							'label'            => Schema::as_string(),
+							'urls'             => Schema::as_array( Schema::as_string() ),
+							'success_ratio'    => Schema::as_float(),
+							'status'           => Schema::enum( array( 'success', 'pending', 'error', 'validation-error' ) )->fallback( 'validation-error' ),
+							'dismissed_errors' => Schema::as_array( Schema::as_string() )->nullable(),
+							'errors'           => self::critical_css_provider_error()->nullable(),
+						)
+					)
+				)->nullable(),
+				'status'       => Schema::enum( array( 'not_generated', 'generated', 'pending', 'error' ) )->fallback( 'not_generated' ),
+				'created'      => Schema::as_float()->nullable(),
+				'updated'      => Schema::as_float()->nullable(),
+				'status_error' => Schema::as_string()->nullable(),
+			)
+		)->fallback(
+			array(
+				'providers' => array(),
+				'status'    => 'not_generated',
+				'created'   => null,
+				'updated'   => null,
+			)
+		);
+	}
+
+	public static function critical_css_meta() {
+		return Schema::as_assoc_array(
+			array(
+				'proxy_nonce' => Schema::as_string()->nullable(),
+			)
+		);
+	}
+
+	public static function critical_css_suggest_regenerate() {
+		return Schema::enum(
+			array(
+				'1', // Old versions of Boost stored a boolean in the DB.
+				'page_saved',
+				'post_saved',
+				'switched_theme',
+				'plugin_change',
+				'cornerstone_page_saved',
+				'cornerstone_pages_list_updated',
+			)
+		)->nullable();
+	}
+
+	public static function critical_css_set_provider() {
+		return Schema::as_assoc_array(
+			array(
+				'key' => Schema::as_string(),
+				'css' => Schema::as_string(),
+			)
+		);
+	}
+
+	public static function critical_css_set_provider_errors() {
+		return Schema::as_assoc_array(
+			array(
+				'key'    => Schema::as_string(),
+				'errors' => self::critical_css_provider_error(),
+			)
+		);
+	}
+
+	public static function critical_css_set_provider_errors_dismissed() {
+		return Schema::as_array(
+			Schema::as_assoc_array(
+				array(
+					'provider'   => Schema::as_string(),
+					'error_type' => Schema::as_string(),
+					'dismissed'  => Schema::as_boolean(),
+				)
+			)
+		);
+	}
+}

wp-content/plugins/jetpack-boost/app/lib/critical-css/source-providers/class-source-providers.php

@@ -0,0 +1,211 @@
+<?php
+
+namespace Automattic\Jetpack_Boost\Lib\Critical_CSS\Source_Providers;
+
+use Automattic\Jetpack_Boost\Lib\Critical_CSS\Critical_CSS_Storage;
+use Automattic\Jetpack_Boost\Lib\Critical_CSS\Source_Providers\Providers\Archive_Provider;
+use Automattic\Jetpack_Boost\Lib\Critical_CSS\Source_Providers\Providers\Cornerstone_Provider;
+use Automattic\Jetpack_Boost\Lib\Critical_CSS\Source_Providers\Providers\Post_ID_Provider;
+use Automattic\Jetpack_Boost\Lib\Critical_CSS\Source_Providers\Providers\Provider;
+use Automattic\Jetpack_Boost\Lib\Critical_CSS\Source_Providers\Providers\Singular_Post_Provider;
+use Automattic\Jetpack_Boost\Lib\Critical_CSS\Source_Providers\Providers\Taxonomy_Provider;
+use Automattic\Jetpack_Boost\Lib\Critical_CSS\Source_Providers\Providers\WP_Core_Provider;
+
+class Source_Providers {
+
+	/**
+	 * Variable used to cache the CSS string during the page request.
+	 * This is here because `get_critical_css` is called multiple
+	 * times in `style_loader_tag` hook (on each CSS file).
+	 *
+	 * @var null|false|string
+	 */
+	protected $request_cached_css;
+
+	/**
+	 * Stores the Critical CSS key used for rendering the current page if any.
+	 *
+	 * @var null|string
+	 */
+	protected $current_critical_css_key;
+
+	/**
+	 * List of all the Critical CSS Types.
+	 *
+	 * The order is important because searching for critical CSS will stop as soon as a value is found.
+	 * So finding Critical CSS by post ID is attempted before searching for a common Singular Post critical CSS.
+	 *
+	 * @var Provider[]
+	 */
+	protected $providers = array(
+		Cornerstone_Provider::class,
+		Post_ID_Provider::class,
+		WP_Core_Provider::class,
+		Singular_Post_Provider::class,
+		Archive_Provider::class,
+		Taxonomy_Provider::class,
+	);
+
+	public function get_providers() {
+		return $this->providers;
+	}
+
+	/**
+	 * Returns the Provider which controls a given key.
+	 */
+	public function get_provider_for_key( $key ) {
+		foreach ( $this->providers as $provider ) {
+			if ( $provider::owns_key( $key ) ) {
+				return $provider;
+			}
+		}
+
+		return null;
+	}
+
+	/**
+	 * Get all critical CSS storage keys that are available for the current request.
+	 * Caches the result.
+	 *
+	 * @return array
+	 */
+	public function get_current_request_css_keys() {
+		static $keys = null;
+		if ( null !== $keys ) {
+			return $keys;
+		}
+
+		$keys = array();
+
+		foreach ( $this->providers as $provider ) {
+			$provider_keys = $provider::get_current_storage_keys();
+			if ( empty( $provider_keys ) ) {
+				continue;
+			}
+			$keys = array_merge( $keys, $provider_keys );
+		}
+
+		return $keys;
+	}
+
+	/**
+	 * Get critical CSS for the current request.
+	 *
+	 * @return string|false
+	 */
+	public function get_current_request_css() {
+		if ( null !== $this->request_cached_css ) {
+			return $this->request_cached_css;
+		}
+
+		$storage = new Critical_CSS_Storage();
+		$data    = $storage->get_css( $this->get_current_request_css_keys() );
+		if ( false === $data ) {
+			return false;
+		}
+
+		$this->request_cached_css       = $data['css'];
+		$this->current_critical_css_key = $data['key'];
+
+		return $this->request_cached_css;
+	}
+
+	public function get_current_critical_css_key() {
+		return $this->current_critical_css_key;
+	}
+
+	/**
+	 * Get providers sources.
+	 *
+	 * @return array
+	 */
+	public function get_provider_sources( $context_posts = array() ) {
+		$sources                        = array();
+		$flat_core_and_cornerstone_urls = array();
+
+		$wp_core_provider_urls = WP_Core_Provider::get_critical_source_urls( $context_posts );
+		foreach ( $wp_core_provider_urls as $urls ) {
+			$flat_core_and_cornerstone_urls = array_merge( $flat_core_and_cornerstone_urls, $urls );
+		}
+		$cornerstone_provider_urls = Cornerstone_Provider::get_critical_source_urls( $context_posts );
+		foreach ( $cornerstone_provider_urls as $urls ) {
+			$flat_core_and_cornerstone_urls = array_merge( $flat_core_and_cornerstone_urls, $urls );
+		}
+		$flat_core_and_cornerstone_urls = array_values( array_unique( $flat_core_and_cornerstone_urls ) );
+
+		foreach ( $this->get_providers() as $provider ) {
+			$provider_name = $provider::get_provider_name();
+
+			// For each provider,
+			// Gather a list of URLs that are going to be used as Critical CSS source.
+			foreach ( $provider::get_critical_source_urls( $context_posts ) as $group => $urls ) {
+				if ( empty( $urls ) ) {
+					continue;
+				}
+
+				// This removes core and cornerstone URLs from the list of URLs,
+				// so they don't belong to two separate groups.
+				if ( ! in_array( $provider, array( WP_Core_Provider::class, Cornerstone_Provider::class ), true ) ) {
+					$urls = array_values( array_diff( $urls, $flat_core_and_cornerstone_urls ) );
+				}
+
+				if ( empty( $urls ) ) {
+					continue;
+				}
+
+				$urls = $this->make_absolute_urls( $urls );
+
+				$key = $provider_name . '_' . $group;
+
+				// For each provider
+				// Track the state and errors in a state array.
+				$sources[] = array(
+					'key'           => $key,
+					'label'         => $provider::describe_key( $key ),
+					/**
+					 * Filters the URLs used by Critical CSS for each provider.
+					 *
+					 * @param array $urls The list of URLs to be used to generate critical CSS
+					 * @param string $provider The provider name.
+					 * @since   1.0.0
+					 */
+					'urls'          => apply_filters( 'jetpack_boost_critical_css_urls', $urls, $provider ),
+					'success_ratio' => $provider::get_success_ratio(),
+				);
+			}
+		}
+
+		/**
+		 * Filters the list of Critical CSS source providers.
+		 *
+		 * @param array $sources The list of Critical CSS source providers.
+		 * @since 3.6.0
+		 */
+		return apply_filters( 'jetpack_boost_critical_css_providers', $sources );
+	}
+
+	/**
+	 * Make URLs absolute.
+	 *
+	 * @param array $urls The list of URLs to make absolute.
+	 *
+	 * @return array
+	 */
+	private function make_absolute_urls( $urls ) {
+		$absolute_urls = array();
+		foreach ( $urls as $url ) {
+			if ( class_exists( '\WP_Http' ) && method_exists( '\WP_Http', 'make_absolute_url' ) ) {
+				$absolute_urls[] = \WP_Http::make_absolute_url( $url, home_url() );
+				continue;
+			}
+
+			if ( stripos( $url, home_url() ) === 0 ) {
+				$absolute_urls[] = $url;
+			} else {
+				$absolute_urls[] = home_url( $url );
+			}
+		}
+
+		return $absolute_urls;
+	}
+}

wp-content/plugins/jetpack-boost/app/lib/critical-css/source-providers/providers/class-archive-provider.php

@@ -0,0 +1,128 @@
+<?php
+/**
+ * Archive provider class.
+ *
+ * @package automattic/jetpack-boost
+ */
+
+namespace Automattic\Jetpack_Boost\Lib\Critical_CSS\Source_Providers\Providers;
+
+/**
+ * Class Archive_Provider
+ *
+ * @package Automattic\Jetpack_Boost\Modules\Critical_CSS\Providers
+ */
+class Archive_Provider extends Provider {
+
+	/**
+	 * Provider name.
+	 *
+	 * @var string
+	 */
+	protected static $name = 'archive';
+
+	/** @inheritdoc */
+	public static function get_critical_source_urls( $context_posts = array() ) {
+		$links              = array();
+		$context_post_types = wp_list_pluck( $context_posts, 'post_type' );
+
+		$post_types = self::get_post_types();
+		if ( ! empty( $context_post_types ) ) {
+			$post_types = array_intersect( $post_types, $context_post_types );
+		}
+		foreach ( $post_types as $post_type ) {
+			$link = get_post_type_archive_link( $post_type );
+
+			if ( ! empty( $link ) ) {
+				$links[ $post_type ][] = $link;
+			}
+		}
+
+		return $links;
+	}
+
+	/** @inheritdoc */
+	public static function get_current_storage_keys() {
+		if ( ! is_archive() ) {
+			return array();
+		}
+
+		// For example: "archive_post".
+		return array( self::$name . '_' . get_post_type() );
+	}
+
+	/** @inheritdoc */
+	public static function get_keys() {
+		return self::get_post_types();
+	}
+
+	/** @inheritdoc */
+	public static function get_edit_url( $_provider_key ) {
+		return null;
+	}
+
+	/** @inheritdoc */
+	public static function describe_key( $provider_key ) {
+		$post_type = substr( $provider_key, strlen( static::$name ) + 1 );
+
+		switch ( $post_type ) {
+			case 'post':
+				return __( 'Post archive view', 'jetpack-boost' );
+
+			case 'page':
+				return __( 'Page archive view', 'jetpack-boost' );
+
+			default:
+				return __( 'Archive page for custom post type', 'jetpack-boost' );
+		}
+	}
+
+	/**
+	 * Get post types that need Critical CSS.
+	 *
+	 * @return mixed|void
+	 */
+	public static function get_post_types() {
+		$post_types = get_post_types(
+			array(
+				'public'      => true,
+				'has_archive' => true,
+			),
+			'objects'
+		);
+		unset( $post_types['attachment'] );
+
+		$post_types = array_filter( $post_types, 'is_post_type_viewable' );
+
+		$provider_post_types = array();
+		// Generate a name => name array for backwards compatibility.
+		foreach ( $post_types as $post_type ) {
+			$provider_post_types[ $post_type->name ] = $post_type->name;
+		}
+
+		/**
+		 * Filters the post types used for Critical CSS
+		 *
+		 * @param array $post_types The array of post types to be used
+		 *
+		 * @since   1.0.0
+		 */
+		return apply_filters(
+			'jetpack_boost_critical_css_post_types_archives',
+			apply_filters_deprecated(
+				'jetpack_boost_critical_css_post_types',
+				array(
+					$provider_post_types,
+				),
+				'3.4.0',
+				'jetpack_boost_critical_css_post_types_archives'
+			),
+			$post_types
+		);
+	}
+
+	/** @inheritdoc */
+	public static function get_success_ratio() {
+		return 1;
+	}
+}

wp-content/plugins/jetpack-boost/app/lib/critical-css/source-providers/providers/class-cornerstone-provider.php

@@ -0,0 +1,129 @@
+<?php
+/**
+ * Provider for the cornerstone pages
+ *
+ * @package automattic/jetpack-boost
+ */
+
+namespace Automattic\Jetpack_Boost\Lib\Critical_CSS\Source_Providers\Providers;
+
+use Automattic\Jetpack_Boost\Lib\Cornerstone\Cornerstone_Utils;
+
+/**
+ * Class Cornerstone_Provider
+ *
+ * @package Automattic\Jetpack_Boost\Lib\Critical_CSS\Source_Providers\Providers
+ */
+class Cornerstone_Provider extends Provider {
+
+	/**
+	 * @var string
+	 */
+	protected static $name = 'cornerstone';
+
+	/**
+	 * Get the providers for cornerstone pages.
+	 *
+	 * @param array $_context_posts Context posts, not used. Cornerstone pages are always available.
+	 * @return array
+	 */
+	public static function get_critical_source_urls( $_context_posts = array() ) {
+		$urls = Cornerstone_Utils::get_list();
+
+		$groups = array();
+		foreach ( $urls as $url ) {
+			$groups[ self::get_hash_for_url( $url ) ] = array( $url );
+		}
+
+		return $groups;
+	}
+
+	public static function get_provider_key( $url ) {
+		return self::$name . '_' . self::get_hash_for_url( $url );
+	}
+
+	/**
+	 * Get the current storage keys for cornerstone pages.
+	 *
+	 * @return array
+	 */
+	public static function get_current_storage_keys() {
+		$current_url = self::get_request_url();
+		return array( self::get_provider_key( $current_url ) );
+	}
+
+	public static function get_request_url() {
+		global $wp;
+
+		// If pretty parmalinks are enabled, use the request. Otherwise, use the query vars.
+		if ( get_option( 'permalink_structure' ) ) {
+			return home_url( $wp->request );
+		}
+
+		return add_query_arg( $wp->query_vars, home_url() );
+	}
+
+	/**
+	 * Get the keys for cornerstone pages.
+	 *
+	 * @return array
+	 */
+	public static function get_keys() {
+		$urls = Cornerstone_Utils::get_list();
+
+		return array_map( array( __CLASS__, 'get_hash_for_url' ), $urls );
+	}
+
+	/**
+	 * @inheritdoc
+	 */
+	public static function get_hash_for_url( $url ) {
+		// Remove the home_url from the beginning of the URL.
+		$home_url = home_url();
+		if ( stripos( $url, $home_url ) === 0 ) {
+			$url = substr( $url, strlen( $home_url ) );
+		}
+
+		$url = ltrim( $url, '/' );
+		$url = untrailingslashit( $url );
+
+		$hash = hash( 'md5', $url );
+
+		return substr( $hash, 0, 8 );
+	}
+
+	/**
+	 * @inheritdoc
+	 */
+	public static function describe_key( $_key ) {
+		return __( 'Cornerstone page', 'jetpack-boost' );
+	}
+
+	/**
+	 * @inheritdoc
+	 */
+	public static function get_edit_url( $key ) {
+		$hash = substr( $key, strlen( self::$name ) + 1 );
+
+		$source_urls = self::get_critical_source_urls();
+
+		if ( ! isset( $source_urls[ $hash ] ) ) {
+			return null;
+		}
+
+		$post_id = url_to_postid( $source_urls[ $hash ][0] );
+
+		if ( ! $post_id ) {
+			return null;
+		}
+
+		return get_edit_post_link( $post_id );
+	}
+
+	/**
+	 * @inheritdoc
+	 */
+	public static function get_success_ratio() {
+		return 1;
+	}
+}

wp-content/plugins/jetpack-boost/app/lib/critical-css/source-providers/providers/class-post-id-provider.php

@@ -0,0 +1,162 @@
+<?php
+/**
+ * The Post ID provider class.
+ *
+ * @package automattic/jetpack-boost
+ */
+
+namespace Automattic\Jetpack_Boost\Lib\Critical_CSS\Source_Providers\Providers;
+
+/**
+ * Class Post_ID_Provider
+ *
+ * @package Automattic\Jetpack_Boost\Modules\Critical_CSS\Providers
+ */
+class Post_ID_Provider extends Provider {
+
+	/**
+	 * Post Ids storage key.
+	 *
+	 * @var string
+	 */
+	const STORAGE_KEY = 'jetpack_boost_critical_css_post_ids';
+
+	/**
+	 * Provider name.
+	 *
+	 * @var string
+	 */
+	protected static $name = 'post_id';
+
+	/** @inheritdoc */
+	public static function get_critical_source_urls( $context_posts = array() ) {
+		$results          = array();
+		$query            = self::get_posts();
+		$context_post_ids = wp_list_pluck( $context_posts, 'ID' );
+
+		if ( false === $query ) {
+			return array();
+		}
+
+		foreach ( $query->posts as $post ) {
+			if ( empty( $context_post_ids ) || in_array( $post->ID, $context_post_ids, true ) ) {
+				$url = get_permalink( $post );
+				if ( ! empty( $url ) ) {
+					$results[ $post->ID ] = array( $url );
+				}
+			}
+		}
+
+		return $results;
+	}
+
+	/** @inheritdoc */
+	public static function get_current_storage_keys() {
+		if ( ! is_singular() ) {
+			return array();
+		}
+
+		// For example: "post_id_123".
+		return array( self::$name . '_' . get_the_ID() );
+	}
+
+	/** @inheritdoc */
+	public static function describe_key( $provider_key ) {
+		$post_id = (int) substr( $provider_key, strlen( self::$name ) + 1 );
+
+		$post = get_post( $post_id );
+		if ( ! $post ) {
+			/* translators: %d is the id of a post which cannot be found. */
+			return sprintf( __( 'Post %d', 'jetpack-boost' ), $post_id );
+		}
+
+		return $post->post_title;
+	}
+
+	/** @inheritdoc */
+	public static function get_edit_url( $provider_key ) {
+		$post_id = (int) substr( $provider_key, strlen( self::$name ) + 1 );
+
+		return get_edit_post_link( $post_id, 'link' );
+	}
+
+	/**
+	 * Returns a key that can be used to identify the current page, if any exists.
+	 *
+	 * @return string|null
+	 */
+	public static function get_current_page_key() {
+		$keys = static::get_current_storage_keys();
+
+		if ( count( $keys ) > 0 ) {
+			return $keys[0];
+		} else {
+			return null;
+		}
+	}
+
+	/**
+	 * Get post ids.
+	 *
+	 * @return array
+	 */
+	public static function get_post_ids() {
+		// Store the IDs somewhere.
+		return get_option( self::STORAGE_KEY, array() );
+	}
+
+	/**
+	 * Add post id to storage.
+	 *
+	 * @param int $post_id Post Id.
+	 *
+	 * @return bool
+	 */
+	public static function add_post_id( $post_id ) {
+		$post_ids = static::get_post_ids();
+
+		if ( in_array( $post_id, $post_ids, true ) ) {
+			return false;
+		}
+
+		$post_ids[] = (int) $post_id;
+
+		return update_option( self::STORAGE_KEY, $post_ids );
+	}
+
+	/** @inheritdoc */
+	public static function get_keys() {
+		return self::get_post_ids();
+	}
+
+	/**
+	 * Create a new WP_Query to gather sample posts.
+	 *
+	 * @return false|\WP_Query
+	 */
+	public static function get_posts() {
+		$ids = self::get_post_ids();
+
+		if ( ! $ids ) {
+			return false;
+		}
+
+		return new \WP_Query(
+			array(
+				'post__in'               => $ids,
+				'posts_per_page'         => count( $ids ),
+				'post_status'            => array( 'publish' ),
+				'post_type'              => 'any',
+				'no_found_rows'          => true,
+				'ignore_sticky_posts'    => true,
+				'update_post_term_cache' => false,
+				'update_post_meta_cache' => false,
+			)
+		);
+	}
+
+	/** @inheritdoc */
+	public static function get_success_ratio() {
+		return 1;
+	}
+}

wp-content/plugins/jetpack-boost/app/lib/critical-css/source-providers/providers/class-provider.php

@@ -0,0 +1,88 @@
+<?php
+/**
+ * Abstract Critical CSS provider class.
+ *
+ * @package automattic/jetpack-boost
+ */
+
+namespace Automattic\Jetpack_Boost\Lib\Critical_CSS\Source_Providers\Providers;
+
+/**
+ * Class Provider
+ *
+ * @package Automattic\Jetpack_Boost\Modules\Critical_CSS\Providers
+ */
+abstract class Provider {
+
+	/**
+	 * The name of the provider.
+	 *
+	 * @since    1.0.0
+	 * @access   protected
+	 * @var      string $name The name of the provider
+	 */
+	protected static $name;
+
+	/**
+	 * Each provider must return a list of URLs to generate CSS from.
+	 *
+	 * @param \WP_Post[] $context_posts The posts to generate CSS from.
+	 * @return array
+	 */
+	abstract public static function get_critical_source_urls( $context_posts = array() );
+
+	/**
+	 * What key should this provider look for during the current request?
+	 * Used in the front-end to determine where the CSS
+	 * might be stored for the current request.
+	 *
+	 * @return array
+	 */
+	abstract public static function get_current_storage_keys();
+
+	/**
+	 * Returns a list of all keys that this provider can provide, regardless
+	 * of the current URL.
+	 */
+	abstract public static function get_keys();
+
+	/**
+	 * Get a human-displayable string describing the given provider key.
+	 *
+	 * @param string $provider_key the key to describe.
+	 */
+	abstract public static function describe_key( $provider_key );
+
+	/**
+	 * Get the URL of the edit page for the given provider key.
+	 *
+	 * @param string $provider_key the key to edit.
+	 */
+	abstract public static function get_edit_url( $provider_key );
+
+	/**
+	 * Returns true if the key looks like it belongs to this provider.
+	 *
+	 * @param string $key The key.
+	 */
+	public static function owns_key( $key ) {
+		return strncmp( static::$name, $key, strlen( static::$name ) ) === 0;
+	}
+
+	/**
+	 * Get the name of the provider.
+	 *
+	 * @return string
+	 */
+	public static function get_provider_name() {
+		return static::$name;
+	}
+
+	/**
+	 * Returns the ratio of valid urls from the provider source urls
+	 * for the Critical CSS generation to be considered successful.
+	 *
+	 * @return float|int
+	 */
+	abstract public static function get_success_ratio();
+}

wp-content/plugins/jetpack-boost/app/lib/critical-css/source-providers/providers/class-singular-post-provider.php

@@ -0,0 +1,178 @@
+<?php
+/**
+ * Critical CSS Provider for singular posts.
+ *
+ * @package automattic/jetpack-boost
+ */
+
+namespace Automattic\Jetpack_Boost\Lib\Critical_CSS\Source_Providers\Providers;
+
+/**
+ * Class Singular_Post_Provider
+ *
+ * @package Automattic\Jetpack_Boost\Modules\Critical_CSS\Providers
+ */
+class Singular_Post_Provider extends Provider {
+
+	/**
+	 * Provider name.
+	 *
+	 * @var string
+	 */
+	protected static $name = 'singular';
+
+	/**
+	 * Max number of posts to query.
+	 *
+	 * @var integer
+	 */
+	const MAX_URLS = 10;
+
+	/**
+	 * Minimum number of posts to have Critical CSS generated in order for the whole process to be successful.
+	 *
+	 * @var integer
+	 */
+	const MIN_SUCCESS_URLS = 5;
+
+	/** @inheritdoc */
+	public static function get_critical_source_urls( $context_posts = array() ) {
+		$links              = array();
+		$context_post_types = wp_list_pluck( $context_posts, 'post_type' );
+
+		$post_types = self::get_post_types();
+		if ( ! empty( $context_post_types ) ) {
+			$post_types = array_intersect( $post_types, $context_post_types );
+		}
+		foreach ( $post_types as $post_type ) {
+			$query = self::post_type_query( $post_type );
+
+			foreach ( $query->posts as $post ) {
+				$url = get_permalink( $post );
+				if ( ! empty( $url ) ) {
+					$links[ $post_type ][] = $url;
+				}
+			}
+		}
+
+		return $links;
+	}
+
+	/** @inheritdoc */
+	public static function get_current_storage_keys() {
+		if ( ! is_singular() ) {
+			return array();
+		}
+
+		// For example: "singular_post".
+		return array( self::$name . '_' . get_post_type() );
+	}
+
+	/** @inheritdoc */
+	public static function get_keys() {
+		return array_keys( self::get_post_types() );
+	}
+
+	/** @inheritdoc */
+	public static function get_edit_url( $_provider_key ) {
+		return null;
+	}
+
+	/** @inheritdoc */
+	public static function describe_key( $provider_key ) {
+		$post_type = substr( $provider_key, strlen( static::$name ) + 1 );
+
+		switch ( $post_type ) {
+			case 'post':
+				return __( 'Single post view', 'jetpack-boost' );
+
+			case 'page':
+				return __( 'Single page view', 'jetpack-boost' );
+
+			case 'product':
+				return __( 'Single product view', 'jetpack-boost' );
+
+			default:
+				return __( 'Custom post type', 'jetpack-boost' );
+		}
+	}
+
+	/**
+	 * Get post types that need Critical CSS.
+	 *
+	 * @return mixed|void
+	 */
+	public static function get_post_types() {
+		$post_types = get_post_types(
+			array(
+				'public' => true,
+			),
+			'objects'
+		);
+		unset( $post_types['attachment'] );
+
+		$post_types = array_filter( $post_types, 'is_post_type_viewable' );
+
+		$provider_post_types = array();
+		// Generate a name => name array for backwards compatibility.
+		foreach ( $post_types as $post_type ) {
+			$provider_post_types[ $post_type->name ] = $post_type->name;
+		}
+
+		/**
+		 * Filters the post types used for Critical CSS
+		 *
+		 * @param array $post_types The array of post types to be used
+		 *
+		 * @since   1.0.0
+		 */
+		return apply_filters(
+			'jetpack_boost_critical_css_post_types_singular',
+			apply_filters_deprecated(
+				'jetpack_boost_critical_css_post_types',
+				array(
+					$provider_post_types,
+				),
+				'3.4.0',
+				'jetpack_boost_critical_css_post_types_singular'
+			),
+			$post_types
+		);
+	}
+
+	/**
+	 * Create a new WP_Query to gather sample posts.
+	 *
+	 * @param string $post_type post type.
+	 *
+	 * @return \WP_Query
+	 */
+	public static function post_type_query( $post_type ) {
+		/**
+		 * Filters the WP_Query parameters used to gather sample posts
+		 *
+		 * @param array $args The arguments that will be used by WP_Query
+		 *
+		 * @since   1.0.0
+		 */
+		$args = apply_filters(
+			'jetpack_boost_critical_css_post_type_query',
+			array(
+				'orderby'                => 'ID',
+				'post_type'              => $post_type,
+				'posts_per_page'         => static::MAX_URLS,
+				'post_status'            => array( 'publish' ),
+				'no_found_rows'          => true,
+				'update_post_term_cache' => false,
+				'update_post_meta_cache' => false,
+			)
+		);
+
+		return new \WP_Query( $args );
+	}
+
+	/** @inheritdoc */
+	public static function get_success_ratio() {
+		return static::MIN_SUCCESS_URLS / static::MAX_URLS;
+	}
+}

wp-content/plugins/jetpack-boost/app/lib/critical-css/source-providers/providers/class-taxonomy-provider.php

@@ -0,0 +1,171 @@
+<?php
+/**
+ * Provides taxonomy support for critical CSS
+ *
+ * @package automattic/jetpack-boost
+ */
+
+namespace Automattic\Jetpack_Boost\Lib\Critical_CSS\Source_Providers\Providers;
+
+/**
+ * Class Taxonomy_Provider
+ *
+ * @package Automattic\Jetpack_Boost\Modules\Critical_CSS\Providers
+ */
+class Taxonomy_Provider extends Provider {
+
+	/**
+	 * Provider name.
+	 *
+	 * @var string
+	 */
+	protected static $name = 'taxonomy';
+
+	/**
+	 * Max number of posts to query.
+	 *
+	 * @var integer
+	 */
+	const MAX_URLS = 10;
+
+	/**
+	 * Minimum number of posts to have Critical CSS generated in order for the whole process to be successful.
+	 *
+	 * @var integer
+	 */
+	const MIN_SUCCESS_URLS = 5;
+
+	/** @inheritdoc */
+	public static function get_critical_source_urls( $context_posts = array() ) {
+		$results = array();
+
+		$taxonomies = self::get_available_taxonomies();
+		if ( ! empty( $context_posts ) ) {
+			$context_post_types = array_unique( wp_list_pluck( $context_posts, 'post_type' ) );
+			$context_taxonomies = get_object_taxonomies( $context_post_types, 'names' );
+			$taxonomies         = array_intersect( $taxonomies, $context_taxonomies );
+		}
+
+		foreach ( $taxonomies as $taxonomy ) {
+			$terms = self::get_terms( $taxonomy );
+
+			if ( ! $terms ) {
+				continue;
+			}
+
+			foreach ( $terms as $term ) {
+				$url = get_term_link( $term, $taxonomy );
+				if ( ! is_wp_error( $url ) && ! empty( $url ) ) {
+					$results[ $taxonomy ][] = $url;
+				}
+			}
+		}
+
+		return $results;
+	}
+
+	/** @inheritdoc */
+	public static function get_current_storage_keys() {
+		if ( ! is_category() && ! is_tax() ) {
+			return array();
+		}
+
+		if ( ! get_queried_object() ) {
+			return array();
+		}
+
+		// For example: "taxonomy_category".
+		return array( self::$name . '_' . get_queried_object()->taxonomy );
+	}
+
+	/** @inheritdoc */
+	public static function get_keys() {
+		return array_keys(
+			array_filter(
+				self::get_available_taxonomies(),
+				function ( $taxonomy ) {
+					return ! empty( Taxonomy_Provider::get_terms( $taxonomy ) );
+				}
+			)
+		);
+	}
+
+	/** @inheritdoc */
+	public static function describe_key( $provider_key ) {
+		$taxonomy = substr( $provider_key, strlen( static::$name ) + 1 );
+
+		switch ( $taxonomy ) {
+			case 'category':
+				return __( 'Category view', 'jetpack-boost' );
+
+			default:
+				return __( 'View for custom taxonomy', 'jetpack-boost' );
+		}
+	}
+
+	/** @inheritdoc */
+	public static function get_edit_url( $_provider_key ) {
+		return null;
+	}
+
+	/**
+	 * Which taxonomies should Critical CSS be generated for.
+	 *
+	 * @return array
+	 */
+	public static function get_available_taxonomies() {
+		$taxonomies = get_taxonomies(
+			array(
+				'public'       => true,
+				'show_in_rest' => true,
+			),
+			'objects'
+		);
+
+		$taxonomies = array_filter( $taxonomies, 'is_taxonomy_viewable' );
+
+		$provider_taxonomies = array();
+		// Generate a name => name array for backwards compatibility.
+		foreach ( $taxonomies as $taxonomy ) {
+			$provider_taxonomies[ $taxonomy->name ] = $taxonomy->name;
+		}
+
+		return $provider_taxonomies;
+	}
+
+	/**
+	 * Get a couple sample terms for a taxonomy.
+	 *
+	 * @param string $taxonomy Taxonomy.
+	 *
+	 * @return array
+	 */
+	public static function get_terms( $taxonomy ) {
+		/**
+		 * Filters the WP_Term_Query args to get a sample of terms for a taxonomy
+		 *
+		 * @param array $args The arguments that will be used by WP_Term_Query
+		 *
+		 * @since   1.0.0
+		 */
+		$args = apply_filters(
+			'jetpack_boost_critical_css_terms_query',
+			array(
+				'fields'                 => 'ids',
+				'taxonomy'               => $taxonomy,
+				'orderby'                => 'term_order',
+				'number'                 => static::MAX_URLS,
+				'hide_empty'             => true,
+				'hierarchical'           => false,
+				'update_term_meta_cache' => false,
+			)
+		);
+
+		return ( new \WP_Term_Query( $args ) )->terms;
+	}
+
+	/** @inheritdoc */
+	public static function get_success_ratio() {
+		return static::MIN_SUCCESS_URLS / static::MAX_URLS;
+	}
+}

wp-content/plugins/jetpack-boost/app/lib/critical-css/source-providers/providers/class-wp-core-provider.php

@@ -0,0 +1,118 @@
+<?php
+/**
+ * Provides core support for critical CSS
+ *
+ * @package automattic/jetpack-boost
+ */
+
+namespace Automattic\Jetpack_Boost\Lib\Critical_CSS\Source_Providers\Providers;
+
+/**
+ * Class WP_Core_Provider.
+ *
+ * @package Automattic\Jetpack_Boost\Modules\Critical_CSS\Providers
+ */
+class WP_Core_Provider extends Provider {
+
+	/**
+	 * Provider name.
+	 *
+	 * @var string
+	 */
+	protected static $name = 'core';
+
+	/** @inheritdoc */
+	public static function get_critical_source_urls( $context_posts = array() ) {
+		$urls = array();
+
+		$front_page = (int) get_option( 'page_on_front' );
+		$posts_page = (int) get_option( 'page_for_posts' );
+
+		if ( ! empty( $front_page ) && empty( $context_posts ) ) {
+			$permalink = get_permalink( $front_page );
+			if ( ! empty( $permalink ) ) {
+				$urls['front_page'] = array( $permalink );
+			}
+		}
+
+		$context_post_types = wp_list_pluck( $context_posts, 'post_type' );
+		$context_post_ids   = wp_list_pluck( $context_posts, 'ID' );
+
+		// The blog page is only in context if the context posts include a 'post' post_type.
+		// Or, if the blog page itself is in context.
+		if ( empty( $context_post_types ) || in_array( 'post', $context_post_types, true ) || in_array( $posts_page, $context_post_ids, true ) ) {
+			if ( ! empty( $posts_page ) ) {
+				$permalink = get_permalink( $posts_page );
+				if ( ! empty( $permalink ) ) {
+					$urls['posts_page'] = array( $permalink );
+				}
+			}
+		}
+
+		if ( ! $front_page && ! isset( $urls['posts_page'] ) ) {
+			$urls['posts_page'] = array( home_url( '/' ) );
+		}
+
+		return $urls;
+	}
+
+	/** @inheritdoc */
+	public static function get_keys() {
+		$keys = array( 'posts_page' );
+
+		if ( ! empty( get_option( 'page_on_front' ) ) ) {
+			$keys[] = 'front_page';
+		}
+
+		return $keys;
+	}
+
+	/** @inheritdoc */
+	public static function get_current_storage_keys() {
+		if ( is_home() ) {
+			$key = 'posts_page';
+		} elseif ( is_front_page() ) {
+			$key = 'front_page';
+		}
+
+		if ( ! isset( $key ) ) {
+			return array();
+		}
+
+		// For example: "core_posts_page".
+		return array( self::$name . '_' . $key );
+	}
+
+	/** @inheritdoc */
+	public static function get_edit_url( $provider_key ) {
+		if ( $provider_key === 'core_front_page' ) {
+			$front_page_id = get_option( 'page_on_front' );
+			if ( ! empty( $front_page_id ) ) {
+				return get_edit_post_link( $front_page_id, 'link' );
+			}
+		}
+
+		return null;
+	}
+
+	/** @inheritdoc */
+	public static function describe_key( $provider_key ) {
+		$page = substr( $provider_key, strlen( static::$name ) + 1 );
+
+		switch ( $page ) {
+			case 'posts_page':
+				return __( 'Posts page', 'jetpack-boost' );
+
+			case 'front_page':
+				return __( 'Front page', 'jetpack-boost' );
+
+			default:
+				return $provider_key;
+		}
+	}
+
+	/** @inheritdoc */
+	public static function get_success_ratio() {
+		return 1;
+	}
+}