This bumps us closer to current Python without going all the way to 3.9.

Fixes #8674

Signed-off-by: Dan Callahan <danc@element.io>

We do a `SELECT MAX(stream_id) FROM e2e_cross_signing_keys` on startup.

Fix serialisation errors when using third-party event rules.

* Tie together matches_user_in_member_list and get_users_in_room

* changelog

* Remove type to fix mypy

* Add `on_invalidate` to the function signature in the hopes that may make things work well

* Remove **kwargs

* Update 8676.bugfix

We don't always need the full power of a DeferredCache.

Fixes #6755

Missed in #8671.

* Fix unit tests

* Newsfile

* Tie together matches_user_in_member_list and get_users_in_room

* changelog

* Remove type to fix mypy

* Add `on_invalidate` to the function signature in the hopes that may make things work well

* Remove **kwargs

* Update 8676.bugfix

We do it this way round so that only the "owner" can delete the access token (i.e. `/logout/all` by the "owner" also deletes that token, but `/logout/all` by the "target user" doesn't).

A future PR will add an API for creating such a token.

When the target user and authenticated entity are different the `Processed request` log line will be logged with a: `{@admin:server as @bob:server} ...`. I'm not convinced by that format (especially since it adds spaces in there, making it harder to use `cut -d ' '` to chop off the start of log lines). Suggestions welcome.

Cached functions accept an `on_invalidate` function, which we failed to add to the type signature. It's rarely used in the files that we have typed, which is why we haven't noticed it before.

otherwise non-state events get written as `<FrozenEvent ... state_key='None'>`
which is indistinguishable from state events with the actual state_key `None`.

By not dropping the membership lock between invites, we can stop joins from
grabbing the lock when we're half-done and slowing the whole thing down.

This modifies the configuration of structured logging to be usable from
the standard Python logging configuration.

This also separates the formatting of logs from the transport allowing
JSON logs to files or standard logs to sockets.

Fix serialisation errors when using third-party event rules.

Not being able to serialise `frozendicts` is fragile, and it's annoying to have
to think about which serialiser you want. There's no real downside to
supporting frozendicts, so let's just have one json encoder.

Add an admin API `GET /_synapse/admin/v1/users/<user_id>/pushers` like https://matrix.org/docs/spec/client_server/latest#get-matrix-client-r0-pushers

I was trying to make it so that we didn't have to start a background task when handling RDATA, but that is a bigger job (due to all the code in `generic_worker`). However I still think not pulling the event from the DB may help reduce some DB usage due to replication, even if most workers will simply go and pull that event from the DB later anyway.

Co-authored-by: Patrick Cloke <clokep@users.noreply.github.com>

This allows trailing commas in multi-line arg lists.

Minor, but we might as well keep our formatting current with regard to
our minimum supported Python version.

Signed-off-by: Dan Callahan <danc@element.io>

The test runner isn't present in the `[all]` set of extras, so the
previous instructions did not work without also installing `[test]`.

Note that this does not include the `[lint]` extras, since those do not
install on all supported Python versions (specifically, isort 5.x
requires Python 3.6, while we still support 3.5). Instructions for that
are included in our pull request template, so we should be fine there.

I've also dropped the `--no-use-pep517` arg to `pip install` since it
seems to have been added to address a temporary regression in pip 19.1
which was fixed in pip 19.1.1 the following month.

Lastly, updated the example output of the test suite to set more
realistic expectations around run time.

Signed-off-by: Dan Callahan <danc@element.io>

As expected, all tests pass locally without modification.

Signed-off-by: Dan Callahan <danc@element.io>

This is a requirement for [knocking](https://github.com/matrix-org/synapse/pull/6739), and is abstracting some code that was originally used by the invite flow. I'm separating it out into this PR as it's a fairly contained change.

For a bit of context: when you invite a user to a room, you send them [stripped state events](https://matrix.org/docs/spec/server_server/unstable#put-matrix-federation-v2-invite-roomid-eventid) as part of `invite_room_state`. This is so that their client can display useful information such as the room name and avatar. The same requirement applies to knocking, as it would be nice for clients to be able to display a list of rooms you've knocked on - room name and avatar included.

The reason we're sending membership events down as well is in the case that you are invited to a room that does not have an avatar or name set. In that case, the client should use the displayname/avatar of the inviter. That information is located in the inviter's membership event.

This is optional as knocks don't really have any user in the room to link up to. When you knock on a room, your knock is sent by you and inserted into the room. It wouldn't *really* make sense to show the avatar of a random user - plus it'd be a data leak. So I've opted not to send membership events to the client here. The UX on the client for when you knock on a room without a name/avatar is a separate problem.

In essence this is just moving some inline code to a reusable store method.