backup historical predictions pickle and load the backup in case of corruption

freqtrade/freqai/data_drawer.py

@@ -76,6 +76,8 @@ class FreqaiDataDrawer:
             self.full_path / f"follower_dictionary-{self.follower_name}.json"
         )
         self.historic_predictions_path = Path(self.full_path / "historic_predictions.pkl")
+        self.historic_predictions_bkp_path = Path(
+            self.full_path / "historic_predictions.backup.pkl")
         self.pair_dictionary_path = Path(self.full_path / "pair_dictionary.json")
         self.follow_mode = follow_mode
         if follow_mode:
@@ -118,6 +120,7 @@ class FreqaiDataDrawer:
         """
         exists = self.historic_predictions_path.is_file()
         if exists:
+            try:
                 with open(self.historic_predictions_path, "rb") as fp:
                     self.historic_predictions = cloudpickle.load(fp)
                 logger.info(
@@ -125,6 +128,13 @@ class FreqaiDataDrawer:
                     "that statistics may be inaccurate if the bot has been offline for "
                     "an extended period of time."
                 )
+            except EOFError:
+                logger.warning(
+                    'Historical prediction file was corrupted. Trying to load backup file.')
+                with open(self.historic_predictions_bkp_path, "rb") as fp:
+                    self.historic_predictions = cloudpickle.load(fp)
+                logger.warning('FreqAI successfully loaded the backup historical predictions file.')
+
         elif not self.follow_mode:
             logger.info("Could not find existing historic_predictions, starting from scratch")
         else:
@@ -142,6 +152,9 @@ class FreqaiDataDrawer:
         with open(self.historic_predictions_path, "wb") as fp:
             cloudpickle.dump(self.historic_predictions, fp, protocol=cloudpickle.DEFAULT_PROTOCOL)
 
+        # create a backup
+        shutil.copy(self.historic_predictions_path, self.historic_predictions_bkp_path)
+
     def save_drawer_to_disk(self):
         """
         Save data drawer full of all pair model metadata in present model folder.