613         # 2-tuple of (offset, data) of raw data from the revlog at an offset.

   613         # 2-tuple of (offset, data) of raw data from the revlog at an offset.

   614         self._chunkcache = (0, '')

   614         self._chunkcache = (0, '')

   615         # How much data to read and cache into the raw revlog data cache.

   615         # How much data to read and cache into the raw revlog data cache.

   616         self._chunkcachesize = 65536

   616         self._chunkcachesize = 65536

   617         self._maxchainlen = None

   617         self._maxchainlen = None

   619         self.index = []

   619         self.index = []

   620         # Mapping of partial identifiers to full nodes.

   620         # Mapping of partial identifiers to full nodes.

   621         self._pcache = {}

   621         self._pcache = {}

   622         # Mapping of revision integer to full node.

   622         # Mapping of revision integer to full node.

   623         self._nodecache = {nullid: nullrev}

   623         self._nodecache = {nullid: nullrev}