make ReplayBuffer.load() compatible with v0.2.0.

chainerrl/replay_buffer.py

@@ -10,6 +10,7 @@
 from abc import ABCMeta
 from abc import abstractmethod
 from abc import abstractproperty
+import collections
 
 import numpy as np
 import six.moves.cPickle as pickle
@@ -153,6 +154,10 @@ def save(self, filename):
     def load(self, filename):
         with open(filename, 'rb') as f:
             self.memory = pickle.load(f)
+        if isinstance(self.memory, collections.deque):
+            # Load v0.2
+            self.memory = RandomAccessQueue(
+                self.memory, maxlen=self.memory.maxlen)
 
     def stop_current_episode(self):
         pass
@@ -281,7 +286,23 @@ def save(self, filename):
 
     def load(self, filename):
         with open(filename, 'rb') as f:
-            self.memory, self.episodic_memory = pickle.load(f)
+            memory = pickle.load(f)
+        if isinstance(memory, tuple):
+            self.memory, self.episodic_memory = memory
+        else:
+            # Load v0.2
+            # FIXME: The code works with EpisodicReplayBuffer
+            # but not with PrioritizedEpisodicReplayBuffer
+            self.memory = RandomAccessQueue(memory)
+            self.episodic_memory = RandomAccessQueue()
+
+            # Recover episodic_memory with best effort.
+            episode = []
+            for item in self.memory:
+                episode.append(item)
+                if item['is_state_terminal']:
+                    self.episodic_memory.append(episode)
+                    episode = []
 
     def stop_current_episode(self):
         if self.current_episode: