Add method to get deduped track objects (only the most recent version…

… of each row)

SSL/SSLHistoryDom.php

@@ -51,7 +51,42 @@ public function getTracks()
  }
  return $tracks;
  }
-
+
+ /**
+ * @return array of SSLTrack
+ */
+ public function getDedupedTracks()
+ {
+ $tracks = $this->getTracks();
+
+ // raw session files are append-only when in use, and often contain multiple entries
+ // for the same track written at different points in the lifecycle (e.g. deck load / 
+ // deck eject). Newer versions of Serato clean these up when you end the session,
+ // but it can still happen if you crash etc.
+
+ $seen_ids = array();
+ $positions_to_filter = array();
+
+ $ptr = count($tracks);
+ while($ptr > 0)
+ {
+ // work backward through the array removing younger dupes
+
+ $ptr--;
+ $row_id = $tracks[$ptr]->getRow();
+ if(isset($seen_ids[$row_id]))
+ {
+ $tracks[$ptr] = null;
+ }
+ else
+ {
+ $seen_ids[$row_id] = true;
+ }
+ }
+
+ return array_filter($tracks);
+ }
+
  /**
  * @return array of SSLAdatChunk
  */