1 files changed, 106 insertions, 0 deletions
diff --git a/plugins/jetpack/sync/class.jetpack-sync-server.php b/plugins/jetpack/sync/class.jetpack-sync-server.php
new file mode 100644
index 00000000..752aa666
--- /dev/null
+++ b/plugins/jetpack/sync/class.jetpack-sync-server.php
@@ -0,0 +1,106 @@
+<?php
+
+require_once dirname( __FILE__ ) . '/class.jetpack-sync-json-deflate-codec.php';
+
+/**
+ * Simple version of a Jetpack Sync Server - just receives arrays of events and
+ * issues them locally with the 'jetpack_sync_remote_action' action.
+ */
+class Jetpack_Sync_Server {
+	private $codec;
+	const MAX_TIME_PER_REQUEST_IN_SECONDS = 15;
+	const BLOG_LOCK_TRANSIENT_PREFIX = 'jp_sync_req_lock_';
+	const BLOG_LOCK_TRANSIENT_EXPIRY = 60; // seconds
+
+	// this is necessary because you can't use "new" when you declare instance properties >:(
+	function __construct() {
+		$this->codec = new Jetpack_Sync_JSON_Deflate_Codec();
+	}
+
+	function set_codec( iJetpack_Sync_Codec $codec ) {
+		$this->codec = $codec;
+	}
+
+	function attempt_request_lock( $blog_id, $expiry = self::BLOG_LOCK_TRANSIENT_EXPIRY ) {
+		$transient_name = $this->get_concurrent_request_transient_name( $blog_id );
+		$locked_time    = get_site_transient( $transient_name );
+		if ( $locked_time ) {
+			return false;
+		}
+		set_site_transient( $transient_name, microtime( true ), $expiry );
+
+		return true;
+	}
+
+	private function get_concurrent_request_transient_name( $blog_id ) {
+		return self::BLOG_LOCK_TRANSIENT_PREFIX . $blog_id;
+	}
+
+	function remove_request_lock( $blog_id ) {
+		delete_site_transient( $this->get_concurrent_request_transient_name( $blog_id ) );
+	}
+
+	function receive( $data, $token = null, $sent_timestamp = null, $queue_id = null ) {
+		$start_time = microtime( true );
+		if ( ! is_array( $data ) ) {
+			return new WP_Error( 'action_decoder_error', 'Events must be an array' );
+		}
+
+		if ( $token && ! $this->attempt_request_lock( $token->blog_id ) ) {
+			/**
+			 * Fires when the server receives two concurrent requests from the same blog
+			 *
+			 * @since 4.2.0
+			 *
+			 * @param token The token object of the misbehaving site
+			 */
+			do_action( 'jetpack_sync_multi_request_fail', $token );
+
+			return new WP_Error( 'concurrent_request_error', 'There is another request running for the same blog ID' );
+		}
+
+		$events           = wp_unslash( array_map( array( $this->codec, 'decode' ), $data ) );
+		$events_processed = array();
+
+		/**
+		 * Fires when an array of actions are received from a remote Jetpack site
+		 *
+		 * @since 4.2.0
+		 *
+		 * @param array Array of actions received from the remote site
+		 */
+		do_action( 'jetpack_sync_remote_actions', $events, $token );
+
+		foreach ( $events as $key => $event ) {
+			list( $action_name, $args, $user_id, $timestamp, $silent ) = $event;
+
+			/**
+			 * Fires when an action is received from a remote Jetpack site
+			 *
+			 * @since 4.2.0
+			 *
+			 * @param string $action_name The name of the action executed on the remote site
+			 * @param array $args The arguments passed to the action
+			 * @param int $user_id The external_user_id who did the action
+			 * @param bool $silent Whether the item was created via import
+			 * @param double $timestamp Timestamp (in seconds) when the action occurred
+			 * @param double $sent_timestamp Timestamp (in seconds) when the action was transmitted
+			 * @param string $queue_id ID of the queue from which the event was sent (sync or full_sync)
+			 * @param array $token The auth token used to invoke the API
+			 */
+			do_action( 'jetpack_sync_remote_action', $action_name, $args, $user_id, $silent, $timestamp, $sent_timestamp, $queue_id, $token );
+
+			$events_processed[] = $key;
+
+			if ( microtime( true ) - $start_time > self::MAX_TIME_PER_REQUEST_IN_SECONDS ) {
+				break;
+			}
+		}
+
+		if ( $token ) {
+			$this->remove_request_lock( $token->blog_id );
+		}
+
+		return $events_processed;
+	}
+}