1797 

  1797         streamclone.maybeperformstreamclone(self, remote, heads, stream)

  1798         # now, all clients that can request uncompressed clones can

  1799         # read repo formats supported by all servers that can serve

  1800         # them.

  1801 

  1802         # if revlog format changes, client will have to check version

  1803         # and format flags on "stream" capability, and use

  1804         # uncompressed only if compatible.

  1805 

  1806         if stream is None:

  1807             # if the server explicitly prefers to stream (for fast LANs)

  1808             stream = remote.capable('stream-preferred')

  1809 

  1810         if stream and not heads:

  1811             # 'stream' means remote revlog format is revlogv1 only

  1812             if remote.capable('stream'):

  1813                 streamclone.streamin(self, remote, set(('revlogv1',)))

  1814             else:

  1815                 # otherwise, 'streamreqs' contains the remote revlog format

  1816                 streamreqs = remote.capable('streamreqs')

  1817                 if streamreqs:

  1818                     streamreqs = set(streamreqs.split(','))

  1819                     # if we support it, stream in and adjust our requirements

  1820                     if not streamreqs - self.supportedformats:

  1821                         streamclone.streamin(self, remote, streamreqs)