fix two errors in lpt rebalancing

xtreemfs_client/dataDistribution.py

@@ -268,6 +268,7 @@ class DataDistribution(object):
                 processing time than the average processing time of this distribution multiplied by rebalance_factor.
                 2. reassign the removed folders using the LPT strategy.
         """
+        total_folder_size = self.get_total_folder_size()
         movements = {}
         folders_to_be_reassigned = []
 
@@ -276,7 +277,7 @@ class DataDistribution(object):
         for osd in self.OSDs.values():
             # self.get_total_folder_size / self.get_total_bandwidth() is the optimal processing time for each OSD:
             # this value is a lower bound for the makespan
-            reassignment_limit = osd.bandwidth * (self.get_total_folder_size() / self.get_total_bandwidth())
+            reassignment_limit = self.get_rebalance_limit(rebalance_factor, total_folder_size)
             while osd.get_processing_time() > reassignment_limit:
                 folder_id, folder_size = osd.get_smallest_folder()
                 folders_to_be_reassigned.append(folder.Folder(folder_id, folder_size, None))
@@ -291,6 +292,9 @@ class DataDistribution(object):
 
         return movements
 
+    def get_rebalance_limit(self, factor, total_folder_size):
+        return factor * (total_folder_size / self.get_total_bandwidth())
+
     def rebalance_one_folder(self):
         """
         rebalance folders to OSDs by assigning folders to new OSDs using the following strategy: