added checkpoint reader private function

solver.py

@@ -279,9 +279,44 @@ class Solver():
 
         """
 
-    def _load_checkpoint_file(self):
-        # Name is private = can't be called outisde of this module
-        pass
+        if epoch is None:
+            checkpoint_file_path = os.path.join(self.experiment_directory_path, checkpoint_directory, 'checkpoint_epoch_' + str(epoch) + '.' + checkpoint_extension)
+            self._checkpoint_reader(checkpoint_file_path)
+        else:
+            pizdetz! 
+    
+    
+    def _checkpoint_reader(self, checkpoint_file_path):
+        """Checkpoint Reader
+
+        This private function reads a checkpoint file and then loads the relevant variables
+
+        Args:
+            checkpoint_file_path (str): path to checkpoint file
+
+        Returns:
+            None
+        
+        Raises:
+            None
+        """
+
+        self.LogWriter.log("Loading Checkpoint {}".format(checkpoint_file_path))
+
+        checkpoint = torch.load(checkpoint_file_path)
+        self.start_epoch = checkpoint['epoch']
+        self.start_iteration = checkpoint['start_iteration']
+        # We are not loading the model_name as we might want to pre-train a model and then use it. 
+        self.model.load_state_dict = checkpoint['state_dict']
+        self.optimizer.load_state_dict = checkpoint['optimizer']
+        self.scheduler.load_state_dict = checkpoint['scheduler']
+
+        for state in self.optimizer.state.values():
+            for key, value in state.items{}:
+                if torch.is_tensor(value):
+                    state[key] = value.to(self.device)
+
+        self.LogWriter.log("Checkpoint Loaded {} - epoch {}".format(checkpoint_file_path, checkpoint['epoch']))
 
     def save_model(self):
         pass