Chatroom lines are deleted after MAX_CHATROOM_HOURS or the chat becomes slow to load

boot.php

@@ -358,6 +358,11 @@ define ( 'MAX_LIKERS',    10);
 
 define ( 'ZCURL_TIMEOUT' , (-1));
 
+/**
+ * Hours before chat lines are deleted
+ */
+
+define ( 'MAX_CHATROOM_HOURS' , 36);
 
 /**
  * email notification options

include/chat.php

@@ -152,6 +152,8 @@ function chatroom_enter($observer_xchan,$room_id,$status,$client) {
 		dbesc($status),
 		dbesc($client)
 	);
+	
+	chatroom_flush($room_id,$xchan);
 	return $r;
 }
 
@@ -224,5 +226,18 @@ function chat_message($uid,$room_id,$xchan,$text) {
 	);
 
 	$ret['success'] = true;
+	chatroom_flush($room_id,$xchan);
 	return $ret;
 }
+
+/**
+ * Reduces the number of lines shown in chat by removing those older than MAX_CHATROOM_HOURS
+ */
+
+function chatroom_flush($room_id,$xchan) {
+	$d = q("delete from chat where chat_room = %d and chat_xchan = '%s' and created < '%s'",
+		intval($room_id),
+		dbesc($xchan),
+		datetime_convert('','', $date_limit));
+	return true;
+}