commit 53d7e471f77c44010161312de3f00f02ea301a28 Author: Dave Rolek <dmr-x@riseup.net> Date: Sun May 27 19:47:03 2018 +0000 Refactor circ_id Size determination into a @staticmethod --- stem/client/cell.py | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) diff --git a/stem/client/cell.py b/stem/client/cell.py index 61503c40..e2aba8b6 100644 --- a/stem/client/cell.py +++ b/stem/client/cell.py @@ -113,6 +113,22 @@ class Cell(object): raise ValueError("'%s' isn't a valid cell value" % value) + @staticmethod + def _get_circ_id_size(link_protocol): + """ + Gets the proper Size for the link_protocol. + + :param int link_protocol: link protocol version + + :returns: :class:`~stem.client.datatype.Size` + """ + + # per tor-spec section 3 + # CIRCID_LEN := + # 2 for link protocol versions 1, 2, and 3 + # 4 for link protocol versions 4+ + return Size.LONG if link_protocol >= 4 else Size.SHORT + def pack(self, link_protocol): raise NotImplementedError('Unpacking not yet implemented for %s cells' % type(self).NAME) @@ -150,7 +166,7 @@ class Cell(object): * NotImplementedError if unable to unpack this cell type """ - circ_id, content = Size.SHORT.pop(content) if link_protocol < 4 else Size.LONG.pop(content) + circ_id, content = Cell._get_circ_id_size(link_protocol).pop(content) command, content = Size.CHAR.pop(content) cls = Cell.by_value(command) @@ -191,7 +207,7 @@ class Cell(object): raise ValueError('%s cells require a circ_id' % cls.NAME) cell = bytearray() - cell += Size.LONG.pack(circ_id) if link_protocol > 3 else Size.SHORT.pack(circ_id) + cell += Cell._get_circ_id_size(link_protocol).pack(circ_id) cell += Size.CHAR.pack(cls.VALUE) cell += b'' if cls.IS_FIXED_SIZE else Size.SHORT.pack(len(payload)) cell += payload