An error occured if a filter was supplied with `event_fields` which did not include
`unsigned`.

In that case, bundled aggregations are still added as the spec states it is allowed
for servers to add additional fields.

To handle cancellation, we ensure that `after_callback`s and
`exception_callback`s are always run, since the transaction will
complete on another thread regardless of cancellation.

We also wait until everything is done before releasing the
`CancelledError`, so that logging contexts won't get used after they
have been finished.

Signed-off-by: Sean Quah <seanq@element.io>

Adds a handler layer between the REST and datastore layers for relations.

* Moves the relation pagination tests to a separate class.
* Move the assertion of the response code into the `_send_relation` helper.
* Moves some helpers into the base-class.

By using urljoin from the standard library and reducing the number
of places URLs are rebased.

Instead of fetching the raw account data and re-parsing it. The
ignored_users table is a denormalised version of the account data
for quick searching.

Signed-off-by: Sean Quah <seanq@element.io>

These decorators mostly support cancellation already. Add cancellation
tests and fix use of finished logging contexts by delaying cancellation,
as suggested by @erikjohnston.

Signed-off-by: Sean Quah <seanq@element.io>

Also convert `ReadWriteLock` to use async context managers.

Signed-off-by: Sean Quah <seanq@element.io>

Signed-off-by: Sean Quah <seanq@element.io>

`delay_cancellation` behaves like `stop_cancellation`, except it
delays `CancelledError`s until the original `Deferred` resolves.
This is handy for unifying cleanup paths and ensuring that uncancelled
coroutines don't use finished logcontexts.

Signed-off-by: Sean Quah <seanq@element.io>

And rename the field used for caching from _id to _cache_key.

Fixes https://github.com/matrix-org/synapse/issues/12205

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

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

This test was relying on poking events which weren't in the database into
filter_events_for_client.

This includes the `typing`, `to_device`, `account_data`, `receipts`, and `presence`
streams (really anything except the `events` stream).

Remove workaround introduced in Synapse v1.50.0rc1 for Mjolnir compatibility. Breaks compatibility with Mjolnir v1.3.1 and earlier. (#11700)

The unstable identifiers are still supported if the experimental configuration
flag is enabled. The unstable identifiers will be removed in a future release.

Some stuff that came up while we were talking about #12173.

This is allowed per MSC2675, although the original implementation did
not allow for it and would return an empty chunk / not bundle aggregations.

The main thing to improve is that the various caches get cleared properly
when an event is redacted, and that edits must not leak if the original
event is redacted (as that would presumably leak something similar to
the original event content).

Since the object it returns is a ReplicationCommandHandler.

This is clean-up from adding support to Redis where the command handler
was added as an additional layer of abstraction from the TCP protocol.

Signed-off-by: Sean Quah <seanq@element.io>

Add third_party module callbacks to check if a user can delete a room and deactivate a user (#12028)

* Add check_can_deactivate_user

* Add check_can_shutdown_rooms

* Documentation

* callbacks, not functions

* Various suggested tweaks

* Add tests for test_check_can_shutdown_room and test_check_can_deactivate_user

* Update check_can_deactivate_user to not take a Requester

* Fix check_can_shutdown_room docs

* Renegade and use `by_admin` instead of `admin_user_id`

* fix lint

* Update docs/modules/third_party_rules_callbacks.md

Co-authored-by: Brendan Abolivier <babolivier@matrix.org>

* Update docs/modules/third_party_rules_callbacks.md

Co-authored-by: Brendan Abolivier <babolivier@matrix.org>

* Update docs/modules/third_party_rules_callbacks.md

Co-authored-by: Brendan Abolivier <babolivier@matrix.org>

* Update docs/modules/third_party_rules_callbacks.md

Co-authored-by: Brendan Abolivier <babolivier@matrix.org>

Co-authored-by: Brendan Abolivier <babolivier@matrix.org>