diff options
Diffstat (limited to 'synapse/replication/tcp/streams/_base.py')
| -rw-r--r-- | synapse/replication/tcp/streams/_base.py | 66 |
1 files changed, 26 insertions, 40 deletions
diff --git a/synapse/replication/tcp/streams/_base.py b/synapse/replication/tcp/streams/_base.py index 7a8b6e9df1..abf5c6c6a8 100644 --- a/synapse/replication/tcp/streams/_base.py +++ b/synapse/replication/tcp/streams/_base.py @@ -17,10 +17,12 @@ import itertools import logging from collections import namedtuple -from typing import Any, List, Optional +from typing import Any, List, Optional, Tuple import attr +from synapse.types import JsonDict + logger = logging.getLogger(__name__) @@ -119,13 +121,12 @@ class Stream(object): """Base class for the streams. Provides a `get_updates()` function that returns new updates since the last - time it was called up until the point `advance_current_token` was called. + time it was called. """ NAME = None # type: str # The name of the stream # The type of the row. Used by the default impl of parse_row. ROW_TYPE = None # type: Any - _LIMITED = True # Whether the update function takes a limit @classmethod def parse_row(cls, row): @@ -146,26 +147,15 @@ class Stream(object): # The token from which we last asked for updates self.last_token = self.current_token() - # The token that we will get updates up to - self.upto_token = self.current_token() - - def advance_current_token(self): - """Updates `upto_token` to "now", which updates up until which point - get_updates[_since] will fetch rows till. - """ - self.upto_token = self.current_token() - def discard_updates_and_advance(self): """Called when the stream should advance but the updates would be discarded, e.g. when there are no currently connected workers. """ - self.upto_token = self.current_token() - self.last_token = self.upto_token + self.last_token = self.current_token() async def get_updates(self): """Gets all updates since the last time this function was called (or - since the stream was constructed if it hadn't been called before), - until the `upto_token` + since the stream was constructed if it hadn't been called before). Returns: Deferred[Tuple[List[Tuple[int, Any]], int]: @@ -178,44 +168,45 @@ class Stream(object): return updates, current_token - async def get_updates_since(self, from_token): + async def get_updates_since( + self, from_token: int + ) -> Tuple[List[Tuple[int, JsonDict]], int]: """Like get_updates except allows specifying from when we should stream updates Returns: - Deferred[Tuple[List[Tuple[int, Any]], int]: - Resolves to a pair ``(updates, current_token)``, where ``updates`` is a - list of ``(token, row)`` entries. ``row`` will be json-serialised and - sent over the replication steam. + Resolves to a pair `(updates, new_last_token)`, where `updates` is + a list of `(token, row)` entries and `new_last_token` is the new + position in stream. """ + if from_token in ("NOW", "now"): - return [], self.upto_token + return [], self.current_token() - current_token = self.upto_token + current_token = self.current_token() from_token = int(from_token) if from_token == current_token: return [], current_token - logger.info("get_updates_since: %s", self.__class__) - if self._LIMITED: - rows = await self.update_function( - from_token, current_token, limit=MAX_EVENTS_BEHIND + 1 - ) + rows = await self.update_function( + from_token, current_token, limit=MAX_EVENTS_BEHIND + 1 + ) - # never turn more than MAX_EVENTS_BEHIND + 1 into updates. - rows = itertools.islice(rows, MAX_EVENTS_BEHIND + 1) - else: - rows = await self.update_function(from_token, current_token) + # never turn more than MAX_EVENTS_BEHIND + 1 into updates. + rows = itertools.islice(rows, MAX_EVENTS_BEHIND + 1) updates = [(row[0], row[1:]) for row in rows] # check we didn't get more rows than the limit. # doing it like this allows the update_function to be a generator. - if self._LIMITED and len(updates) >= MAX_EVENTS_BEHIND: + if len(updates) >= MAX_EVENTS_BEHIND: raise Exception("stream %s has fallen behind" % (self.NAME)) + # The update function didn't hit the limit, so we must have got all + # the updates to `current_token`, and can return that as our new + # stream position. return updates, current_token def current_token(self): @@ -227,9 +218,8 @@ class Stream(object): """ raise NotImplementedError() - def update_function(self, from_token, current_token, limit=None): - """Get updates between from_token and to_token. If Stream._LIMITED is - True then limit is provided, otherwise it's not. + def update_function(self, from_token, current_token, limit): + """Get updates between from_token and to_token. Returns: Deferred(list(tuple)): the first entry in the tuple is the token for @@ -257,7 +247,6 @@ class BackfillStream(Stream): class PresenceStream(Stream): NAME = "presence" - _LIMITED = False ROW_TYPE = PresenceStreamRow def __init__(self, hs): @@ -272,7 +261,6 @@ class PresenceStream(Stream): class TypingStream(Stream): NAME = "typing" - _LIMITED = False ROW_TYPE = TypingStreamRow def __init__(self, hs): @@ -372,7 +360,6 @@ class DeviceListsStream(Stream): """ NAME = "device_lists" - _LIMITED = False ROW_TYPE = DeviceListsStreamRow def __init__(self, hs): @@ -462,7 +449,6 @@ class UserSignatureStream(Stream): """ NAME = "user_signature" - _LIMITED = False ROW_TYPE = UserSignatureStreamRow def __init__(self, hs): |