diff --git a/synapse/types.py b/synapse/types.py
index cc7c182a78..1ff71aa4e2 100644
--- a/synapse/types.py
+++ b/synapse/types.py
@@ -306,7 +306,7 @@ StreamToken.START = StreamToken(
)
-class RoomStreamToken(namedtuple("_StreamToken", "topological stream")):
+class RoomStreamToken(namedtuple("_StreamToken", ("chunk", "topological", "stream"))):
"""Tokens are positions between events. The token "s1" comes after event 1.
s0 s1
@@ -319,14 +319,18 @@ class RoomStreamToken(namedtuple("_StreamToken", "topological stream")):
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".
+ When traversing historic events the events are ordered by the topological
+ ordering of the room graph. This is done using event chunks and the
+ `topological_ordering` column.
- 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, followed by "-",
- followed by the "stream_ordering" id of the event it comes after.
+ Live tokens start with an 's' and include the stream_ordering of the event
+ it comes after. Historic tokens start with a 'c' and include the chunk ID,
+ topological ordering and stream ordering of the event it comes after.
+
+ (In previous versions, when chunks were not implemented, the historic tokens
+ started with 't' and included the topological and stream ordering. These
+ tokens can be roughly converted to the new format by looking up the chunk
+ and topological ordering of the event with the same stream ordering).
"""
__slots__ = []
@@ -334,10 +338,19 @@ class RoomStreamToken(namedtuple("_StreamToken", "topological stream")):
def parse(cls, string):
try:
if string[0] == 's':
- return cls(topological=None, stream=int(string[1:]))
- if string[0] == 't':
+ return cls(chunk=None, topological=None, stream=int(string[1:]))
+ if string[0] == 't': # For backwards compat with older tokens.
parts = string[1:].split('-', 1)
- return cls(topological=int(parts[0]), stream=int(parts[1]))
+ return cls(chunk=None, topological=int(parts[0]), stream=int(parts[1]))
+ if string[0] == 'c':
+ # We use '~' as both stream ordering and topological ordering
+ # can be negative, so we can't use '-'
+ parts = string[1:].split('~', 2)
+ return cls(
+ chunk=int(parts[0]),
+ topological=int(parts[1]),
+ stream=int(parts[2]),
+ )
except Exception:
pass
raise SynapseError(400, "Invalid token %r" % (string,))
@@ -346,12 +359,16 @@ class RoomStreamToken(namedtuple("_StreamToken", "topological stream")):
def parse_stream_token(cls, string):
try:
if string[0] == 's':
- return cls(topological=None, stream=int(string[1:]))
+ return cls(chunk=None, topological=None, stream=int(string[1:]))
except Exception:
pass
raise SynapseError(400, "Invalid token %r" % (string,))
def __str__(self):
+ if self.chunk is not None:
+ # We use '~' as both stream ordering and topological ordering
+ # can be negative, so we can't use '-'
+ return "c%d~%d~%d" % (self.chunk, self.topological, self.stream)
if self.topological is not None:
return "t%d-%d" % (self.topological, self.stream)
else:
|
