call on_access in _MemoryFile next and readlines methods

Author: nwh

fs/memoryfs.py

@@ -108,6 +108,7 @@ def __iter__(self):
     def next(self):
         # type: () -> bytes
         with self._seek_lock():
+            self.on_access()
             return next(self._bytes_io)
 
     __next__ = next
@@ -148,6 +149,7 @@ def readinto(self, b):
     def readlines(self, hint=-1):
         # type: (int) -> List[bytes]
         with self._seek_lock():
+            self.on_access()
             return self._bytes_io.readlines(hint)
 
     def seekable(self):