Cache the AP delivery process

src/Protocol/ActivityPub/Transmitter.php

@@ -22,6 +22,7 @@ use Friendica\Model\Profile;
 use Friendica\Core\Config;
 use Friendica\Object\Image;
 use Friendica\Protocol\ActivityPub;
+use Friendica\Core\Cache;
 
 /**
  * @brief ActivityPub Transmitter Protocol class
@@ -480,6 +481,27 @@ class Transmitter
 		return $type;
 	}
 
+	/**
+	 * @brief Creates the activity or fetches it from the cache
+	 *
+	 * @param integer $item_id
+	 *
+	 * @return array with the activity
+	 */
+	public static function createCachedActivityFromItem($item_id)
+	{
+		$cachekey = "APDelivery:createActivity:".$item_id;
+		$data = Cache::get($cachekey);
+		if (!is_null($data)) {
+			return $data;
+		}
+
+		$data = ActivityPub\Transmitter::createActivityFromItem($item_id);
+
+		Cache::set($cachekey, $data, CACHE_QUARTER_HOUR);
+		return $data;
+	}
+
 	/**
 	 * @brief Creates an activity array for a given item id
 	 *

src/Worker/APDelivery.php

@@ -11,6 +11,14 @@ use Friendica\Util\HTTPSignature;
 
 class APDelivery extends BaseObject
 {
+	/**
+	 * @brief Delivers ActivityPub messages
+	 *
+	 * @param string $cmd
+	 * @param integer $item_id
+	 * @param string $inbox
+	 * @param integer $uid
+	 */
 	public static function execute($cmd, $item_id, $inbox, $uid)
 	{
 		logger('Invoked: ' . $cmd . ': ' . $item_id . ' to ' . $inbox, LOGGER_DEBUG);
@@ -23,12 +31,10 @@ class APDelivery extends BaseObject
 		} elseif ($cmd == Delivery::PROFILEUPDATE) {
 			ActivityPub\Transmitter::sendProfileUpdate($uid, $inbox);
 		} else {
-			$data = ActivityPub\Transmitter::createActivityFromItem($item_id);
+			$data = ActivityPub\Transmitter::createCachedActivityFromItem($item_id);
 			if (!empty($data)) {
 				HTTPSignature::transmit($data, $inbox, $uid);
 			}
 		}
-
-		return;
 	}
 }

src/Worker/Notifier.php

@@ -433,6 +433,9 @@ class Notifier
 			$inboxes = array_merge($inboxes, $parent_inboxes);
 		}
 
+		// Fill the item cache
+		ActivityPub\Transmitter::createCachedActivityFromItem($item_id);
+
 		foreach ($inboxes as $inbox) {
 			logger('Deliver ' . $item_id .' to ' . $inbox .' via ActivityPub', LOGGER_DEBUG);