diff --git a/synapse/types.py b/synapse/types.py
index fd6a3d1d72..baec8a6002 100644
--- a/synapse/types.py
+++ b/synapse/types.py
@@ -92,3 +92,77 @@ class RoomAlias(DomainSpecificString):
class RoomID(DomainSpecificString):
"""Structure representing a room id. """
SIGIL = "!"
+
+
+class StreamToken(
+ namedtuple(
+ "Token",
+ ("events_type", "topological_key", "stream_key", "presence_key")
+ )
+):
+ _SEPARATOR = "_"
+
+ _TOPOLOGICAL_PREFIX = "t"
+ _STREAM_PREFIX = "s"
+
+ _TOPOLOGICAL_SEPERATOR = "-"
+
+ TOPOLOGICAL_TYPE = "topo"
+ STREAM_TYPE = "stream"
+
+ @classmethod
+ def from_string(cls, string):
+ try:
+ events_part, presence_part = string.split(cls._SEPARATOR)
+
+ presence_key = int(presence_part)
+
+ topo_length = len(cls._TOPOLOGICAL_PREFIX)
+ stream_length = len(cls._STREAM_PREFIX)
+ if events_part[:topo_length] == cls._TOPOLOGICAL_PREFIX:
+ # topological event token
+ topo_tok = events_part[topo_length:]
+ topo_key, stream_key = topo_tok.split(
+ cls._TOPOLOGICAL_SEPERATOR, 1
+ )
+
+ topo_key = int(topo_key)
+ stream_key = int(stream_key)
+
+ events_type = cls.TOPOLOGICAL_TYPE
+ elif events_part[:stream_length] == cls._STREAM_PREFIX:
+ topo_key = None
+ stream_key = int(events_part[stream_length:])
+
+ events_type = cls.STREAM_TYPE
+ else:
+ raise
+
+ return cls(
+ events_type=events_type,
+ topological_key=topo_key,
+ stream_key=stream_key,
+ presence_key=presence_key,
+ )
+ except:
+ raise SynapseError(400, "Invalid Token")
+
+ def to_string(self):
+ if self.events_type == self.TOPOLOGICAL_TYPE:
+ return "".join([
+ self._TOPOLOGICAL_PREFIX,
+ str(self.topological_key),
+ self._TOPOLOGICAL_SEPERATOR,
+ str(self.stream_key),
+ self._SEPARATOR,
+ str(self.presence_key),
+ ])
+ elif self.events_type == self.STREAM_TYPE:
+ return "".join([
+ self._STREAM_PREFIX,
+ str(self.stream_key),
+ self._SEPARATOR,
+ str(self.presence_key),
+ ])
+
+ raise RuntimeError("Unrecognized event type: %s", self.events_type)
|
