diff options
Diffstat (limited to 'synapse/replication/tcp/streams/_base.py')
| -rw-r--r-- | synapse/replication/tcp/streams/_base.py | 61 |
1 files changed, 26 insertions, 35 deletions
diff --git a/synapse/replication/tcp/streams/_base.py b/synapse/replication/tcp/streams/_base.py index abf5c6c6a8..99cef97532 100644 --- a/synapse/replication/tcp/streams/_base.py +++ b/synapse/replication/tcp/streams/_base.py @@ -14,10 +14,9 @@ # See the License for the specific language governing permissions and # limitations under the License. -import itertools import logging from collections import namedtuple -from typing import Any, List, Optional, Tuple +from typing import Any, List, Optional, Tuple, Union import attr @@ -153,61 +152,53 @@ class Stream(object): """ self.last_token = self.current_token() - async def get_updates(self): + async def get_updates(self) -> Tuple[List[Tuple[int, JsonDict]], int, bool]: """Gets all updates since the last time this function was called (or since the stream was constructed if it hadn't been called before). 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, limited)`, where + `updates` is a list of `(token, row)` entries, `new_last_token` is + the new position in stream, and `limited` is whether there are + more updates to fetch. """ - updates, current_token = await self.get_updates_since(self.last_token) + current_token = self.current_token() + updates, current_token, limited = await self.get_updates_since( + self.last_token, current_token + ) self.last_token = current_token - return updates, current_token + return updates, current_token, limited async def get_updates_since( - self, from_token: int - ) -> Tuple[List[Tuple[int, JsonDict]], int]: + self, from_token: Union[int, str], upto_token: int, limit: int = 100 + ) -> Tuple[List[Tuple[int, JsonDict]], int, bool]: """Like get_updates except allows specifying from when we should stream updates Returns: - 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. + Resolves to a pair `(updates, new_last_token, limited)`, where + `updates` is a list of `(token, row)` entries, `new_last_token` is + the new position in stream, and `limited` is whether there are + more updates to fetch. """ if from_token in ("NOW", "now"): - return [], self.current_token() - - current_token = self.current_token() + return [], upto_token, False from_token = int(from_token) - if from_token == current_token: - return [], current_token - - 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) + if from_token == upto_token: + return [], upto_token, False + limited = False + rows = await self.update_function(from_token, upto_token, limit=limit) updates = [(row[0], row[1:]) for row in rows] + if len(updates) == limit: + upto_token = rows[-1][0] + limited = True - # check we didn't get more rows than the limit. - # doing it like this allows the update_function to be a generator. - 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 + return updates, upto_token, limited def current_token(self): """Gets the current token of the underlying streams. Should be provided |