Don't save duplicate messages into a user's packed inbox. We've already got the packed box loaded at insert time, so we can simply unpack it and check before doing the update query.

Should help with dupes that come in when inbox distrib jobs die and get restarted, etc.

1 files changed, 37 insertions, 2 deletions

diff --git a/classes/Inbox.php b/classes/Inbox.php
index 014ba3d82..2533210b7 100644
--- a/classes/Inbox.php
+++ b/classes/Inbox.php
@@ -96,12 +96,23 @@ class Inbox extends Memcached_DataObject
         $inbox = new Inbox();
 
         $inbox->user_id = $user_id;
-        $inbox->notice_ids = call_user_func_array('pack', array_merge(array('N*'), $ids));
+        $inbox->pack($ids);
         $inbox->fake = true;
 
         return $inbox;
     }
 
+    /**
+     * Append the given notice to the given user's inbox.
+     * Caching updates are managed for the inbox itself.
+     *
+     * If the notice is already in this inbox, the second
+     * add will be silently dropped.
+     *
+     * @param int @user_id
+     * @param int $notice_id
+     * @return boolean success
+     */
     static function insertNotice($user_id, $notice_id)
     {
         $inbox = DB_DataObject::staticGet('inbox', 'user_id', $user_id);
@@ -114,6 +125,13 @@ class Inbox extends Memcached_DataObject
             return false;
         }
 
+        $ids = $inbox->unpack();
+        if (in_array(intval($notice_id), $ids)) {
+            // Already in there, we probably re-ran some inbox adds
+            // due to an error. Skip the dupe silently.
+            return true;
+        }
+
         $result = $inbox->query(sprintf('UPDATE inbox '.
                                         'set notice_ids = concat(cast(0x%08x as binary(4)), '.
                                         'substr(notice_ids, 1, %d)) '.
@@ -150,7 +168,7 @@ class Inbox extends Memcached_DataObject
             }
         }
 
-        $ids = unpack('N*', $inbox->notice_ids);
+        $ids = $inbox->unpack();
 
         if (!empty($since_id)) {
             $newids = array();
@@ -229,4 +247,21 @@ class Inbox extends Memcached_DataObject
         }
         return new ArrayWrapper($items);
     }
+
+    /**
+     * Saves a list of integer notice_ids into a packed blob in this object.
+     * @param array $ids list of integer notice_ids
+     */
+    protected function pack(array $ids)
+    {
+        $this->notice_ids = call_user_func_array('pack', array_merge(array('N*'), $ids));
+    }
+
+    /**
+     * @return array of integer notice_ids
+     */
+    protected function unpack()
+    {
+        return unpack('N*', $this->notice_ids);
+    }
 }