diff --git a/synapse/types.py b/synapse/types.py
index f6a1b0bbcf..0f16867d75 100644
--- a/synapse/types.py
+++ b/synapse/types.py
@@ -121,4 +121,56 @@ class StreamToken(
return StreamToken(**d)
+class RoomStreamToken(namedtuple("_StreamToken", "topological stream")):
+ """Tokens are positions between events. The token "s1" comes after event 1.
+
+ s0 s1
+ | |
+ [0] V [1] V [2]
+
+ Tokens can either be a point in the live event stream or a cursor going
+ through historic events.
+
+ When traversing the live event stream events are ordered by when they
+ arrived at the homeserver.
+
+ When traversing historic events the events are ordered by their depth in
+ the event graph "topological_ordering" and then by when they arrived at the
+ homeserver "stream_ordering".
+
+ Live tokens start with an "s" followed by the "stream_ordering" id of the
+ event it comes after. Historic tokens start with a "t" followed by the
+ "topological_ordering" id of the event it comes after, follewed by "-",
+ followed by the "stream_ordering" id of the event it comes after.
+ """
+ __slots__ = []
+
+ @classmethod
+ def parse(cls, string):
+ try:
+ if string[0] == 's':
+ return cls(topological=None, stream=int(string[1:]))
+ if string[0] == 't':
+ parts = string[1:].split('-', 1)
+ return cls(topological=int(parts[0]), stream=int(parts[1]))
+ except:
+ pass
+ raise SynapseError(400, "Invalid token %r" % (string,))
+
+ @classmethod
+ def parse_stream_token(cls, string):
+ try:
+ if string[0] == 's':
+ return cls(topological=None, stream=int(string[1:]))
+ except:
+ pass
+ raise SynapseError(400, "Invalid token %r" % (string,))
+
+ def __str__(self):
+ if self.topological is not None:
+ return "t%d-%d" % (self.topological, self.stream)
+ else:
+ return "s%d" % (self.stream,)
+
+
ClientInfo = namedtuple("ClientInfo", ("device_id", "token_id"))
|
