diff options
| -rw-r--r-- | synapse/types.py | 24 |
1 files changed, 16 insertions, 8 deletions
diff --git a/synapse/types.py b/synapse/types.py index 27f204ce79..1ff71aa4e2 100644 --- a/synapse/types.py +++ b/synapse/types.py @@ -306,7 +306,7 @@ StreamToken.START = StreamToken( ) -class RoomStreamToken(namedtuple("_StreamToken", "chunk 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", "chunk 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__ = [] @@ -339,6 +343,8 @@ class RoomStreamToken(namedtuple("_StreamToken", "chunk topological stream")): parts = string[1:].split('-', 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]), @@ -360,6 +366,8 @@ class RoomStreamToken(namedtuple("_StreamToken", "chunk topological stream")): 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) |