* Introduce `should_include_local_users_in_dir`

We exclude three kinds of local users from the user_directory tables. At
present we don't consistently exclude all three in the same places. This
commit introduces a new function to gather those exclusion conditions
together. Because we have to handle local and remote users in different
ways, I've made that function only consider the case of remote users.
It's the caller's responsibility to make the local versus remote
distinction clear and correct.

A test fixup is required. The test now hits a path which makes db
queries against the users table. The expected rows were missing, because
we were using a dummy user that hadn't actually been registered.

We also add new test cases to covert the exclusion logic.

----

By my reading this makes these changes:

* When an app service user registers or changes their profile, they will
  _not_ be added to the user directory. (Previously only support and
  deactivated users were excluded). This is consistent with the logic that
  rebuilds the user directory. See also [the discussion
  here](https://github.com/matrix-org/synapse/pull/10914#discussion_r716859548

).
* When rebuilding the directory, exclude support and disabled users from
  room sharing tables. Previously only appservice users were excluded.
* Exclude all three categories of local users when rebuilding the
  directory. Previously `_populate_user_directory_process_users` didn't do
  any exclusion.

Co-authored-by: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>

This fixes a "Event not signed by authorising server" error when
transition room member from join -> join, e.g. when updating a
display name or avatar URL for restricted rooms.

* type-hint `HomeserverTestcase.setup_test_homeserver`

For better IDE completion. A small drive-by.

Uses `override_config` and fixes test_auto_create_auto_join_where_no_consent
to properly configure auto-join rooms.

This fixes a "Event not signed by authorising server" error when
transition room member from join -> join, e.g. when updating a
display name or avatar URL for restricted rooms.

Fix some harmless errors from background processes (mostly
due to awaiting Mock objects) that occurred in the Synapse
logs during unit tests.

Synapse 1.44.0rc2 (2021-09-30)
==============================

Bugfixes
--------

- Fix a bug introduced in v1.44.0rc1 which caused the experimental [MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716) `/batch_send` endpoint to return a 500 error. ([\#10938](https://github.com/matrix-org/synapse/issues/10938))
- Fix a bug introduced in v1.44.0rc1 which prevented sending presence events to application services. ([\#10944](https://github.com/matrix-org/synapse/issues/10944))

Improved Documentation
----------------------

- Minor updates to the installation instructions. ([\#10919](https://github.com/matrix-org/synapse/issues/10919))

`ttl` must be an integer according to the OpenAPI spec:
https://github.com/matrix-org/matrix-doc/blob/old_master/data/api/client-server/voip.yaml#L70



True division (`/`) returns a float instead (`"ttl": 7200.0`).
Floor division (`//`) returns an integer, so the response is spec compliant.

Signed-off-by: Lukas Lihotzki <lukas@lihotzki.de>

This follows a correction made in twisted/twisted#1664 and should fix our Twisted Trial CI job.

Until that change is in a twisted release, we'll have to ignore the type
of the `host` argument. I've raised #10899 to remind us to review the
issue in a few months' time.

Fix event context for outlier causing failures in all of the MSC2716
Complement tests.

The `EventContext.for_outlier` refactor happened in
https://github.com/matrix-org/synapse/pull/10883
and this spot was left out.

* Pull out GetUserDirectoryTables helper
* Don't rebuild the dir in tests that don't need it

In #10796 I changed registering a user to add directory entries under.
This means we don't have to force a directory regbuild in to tests of
the user directory search.

* Move test_initial to tests/storage
* Add type hints to both test_user_directory files

Co-authored-by: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>

Broadly, the existing `event_auth.check` function has two parts:
 * a validation section: checks that the event isn't too big, that it has the rught signatures, etc. 
   This bit is independent of the rest of the state in the room, and so need only be done once 
   for each event.
 * an auth section: ensures that the event is allowed, given the rest of the state in the room.
   This gets done multiple times, against various sets of room state, because it forms part of
   the state res algorithm.

Currently, this is implemented with `do_sig_check` and `do_size_check` parameters, but I think
that makes everything hard to follow. Instead, we split the function in two and call each part
separately where it is needed.

Synapse 1.44.0rc1 (2021-09-29)
==============================

Features
--------

- Only allow the
[MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716)
`/batch_send?chunk_id=xxx` endpoint to connect to an already existing
insertion event.
([\#10776](https://github.com/matrix-org/synapse/issues/10776))
- Improve oEmbed URL previews by processing the author name, photo, and
video information.
([\#10814](https://github.com/matrix-org/synapse/issues/10814),
[\#10819](https://github.com/matrix-org/synapse/issues/10819))
- Speed up responding with large JSON objects to requests.
([\#10868](https://github.com/matrix-org/synapse/issues/10868),
[\#10905](https://github.com/matrix-org/synapse/issues/10905))
- Add a `user_may_create_room_with_invites` spam checker callback to
allow modules to allow or deny a room creation request based on the
invites and/or 3PID invites it includes.
([\#10898](https://github.com/matrix-org/synapse/issues/10898))

Bugfixes
--------

- Fix a long-standing bug that caused an `AssertionError` when purging
history in certain rooms. Contributed by @Kokokokoka.
([\#10690](https://github.com/matrix-org/synapse/issues/10690))
- Fix a long-standing bug which caused deactivated users that were later
reactivated to be missing from the user directory.
([\#10782](https://github.com/matrix-org/synapse/issues/10782))
- Fix a long-standing bug that caused unbanning a user by sending a
membership event to fail. Contributed by @aaronraimist.
([\#10807](https://github.com/matrix-org/synapse/issues/10807))
- Fix a long-standing bug where logging contexts would go missing when
federation requests time out.
([\#10810](https://github.com/matrix-org/synapse/issues/10810))
- Fix a long-standing bug causing an error in the deprecated
`/initialSync` endpoint when using the undocumented `from` and `to`
parameters.
([\#10827](https://github.com/matrix-org/synapse/issues/10827))
- Fix a bug causing the `remove_stale_pushers` background job to
repeatedly fail and log errors. This bug affected Synapse servers that
had been upgraded from version 1.28 or older and are using SQLite.
([\#10843](https://github.com/matrix-org/synapse/issues/10843))
- Fix a long-standing bug in Unicode support of the room search admin
API breaking search for rooms with non-ASCII characters.
([\#10859](https://github.com/matrix-org/synapse/issues/10859))
- Fix a bug introduced in Synapse 1.37.0 which caused `knock` membership
events which we sent to remote servers to be incorrectly stored in the
local database.
([\#10873](https://github.com/matrix-org/synapse/issues/10873))
- Fix invalidating one-time key count cache after claiming keys. The bug
was introduced in Synapse v1.41.0. Contributed by Tulir at Beeper.
([\#10875](https://github.com/matrix-org/synapse/issues/10875))
- Fix a long-standing bug causing application service users to be
subject to MAU blocking if the MAU limit had been reached, even if
configured not to be blocked.
([\#10881](https://github.com/matrix-org/synapse/issues/10881))
- Fix a long-standing bug which could cause events pulled over
federation to be incorrectly rejected.
([\#10907](https://github.com/matrix-org/synapse/issues/10907))
- Fix a long-standing bug causing URL cache files to be stored in
storage providers. Server admins may safely delete the `url_cache/` and
`url_cache_thumbnails/` directories from any configured storage
providers to reclaim space.
([\#10911](https://github.com/matrix-org/synapse/issues/10911))
- Fix a long-standing bug leading to race conditions when creating media
store and config directories.
([\#10913](https://github.com/matrix-org/synapse/issues/10913))

Improved Documentation
----------------------

- Fix some crashes in the Module API example code, by adding JSON
encoding/decoding.
([\#10845](https://github.com/matrix-org/synapse/issues/10845))
- Add developer documentation about experimental configuration flags.
([\#10865](https://github.com/matrix-org/synapse/issues/10865))
- Properly remove deleted files from GitHub pages when generating the
documentation.
([\#10869](https://github.com/matrix-org/synapse/issues/10869))

Internal Changes
----------------

- Fix GitHub Actions config so we can run sytest on synapse from
parallel branches.
([\#10659](https://github.com/matrix-org/synapse/issues/10659))
- Split out
[MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716) meta
events to their own fields in the `/batch_send` response.
([\#10777](https://github.com/matrix-org/synapse/issues/10777))
- Add missing type hints to REST servlets.
([\#10785](https://github.com/matrix-org/synapse/issues/10785),
[\#10817](https://github.com/matrix-org/synapse/issues/10817))
- Simplify the internal logic which maintains the user directory
database tables.
([\#10796](https://github.com/matrix-org/synapse/issues/10796))
- Use direct references to config flags.
([\#10812](https://github.com/matrix-org/synapse/issues/10812),
[\#10885](https://github.com/matrix-org/synapse/issues/10885),
[\#10893](https://github.com/matrix-org/synapse/issues/10893),
[\#10897](https://github.com/matrix-org/synapse/issues/10897))
- Specify the type of token in generic "Invalid token" error messages.
([\#10815](https://github.com/matrix-org/synapse/issues/10815))
- Make `StateFilter` frozen so it is hashable.
([\#10816](https://github.com/matrix-org/synapse/issues/10816))
- Fix a long-standing bug where an `m.room.message` event containing a
null byte would cause an internal server error.
([\#10820](https://github.com/matrix-org/synapse/issues/10820))
- Add type hints to the state database.
([\#10823](https://github.com/matrix-org/synapse/issues/10823))
- Opt out of cache expiry for `get_users_who_share_room_with_user`, to
hopefully improve `/sync` performance when you
haven't synced recently.
([\#10826](https://github.com/matrix-org/synapse/issues/10826))
- Track cache eviction rates more finely in Prometheus's monitoring.
([\#10829](https://github.com/matrix-org/synapse/issues/10829))
- Add missing type hints to `synapse.handlers`.
([\#10831](https://github.com/matrix-org/synapse/issues/10831),
[\#10856](https://github.com/matrix-org/synapse/issues/10856))
- Extend the Module API to let plug-ins check whether an ID is local and
to access IP + User Agent data.
([\#10833](https://github.com/matrix-org/synapse/issues/10833))
- Factor out PNG image data to a constant to be used in several tests.
([\#10834](https://github.com/matrix-org/synapse/issues/10834))
- Add a test to ensure state events sent by modules get persisted
correctly.
([\#10835](https://github.com/matrix-org/synapse/issues/10835))
- Rename [MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716)
fields and event types from `chunk` to `batch` to match the
`/batch_send` endpoint.
([\#10838](https://github.com/matrix-org/synapse/issues/10838))
- Rename [MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716)
`/batch_send` query parameter from `?prev_event` to more obvious usage
with `?prev_event_id`.
([\#10839](https://github.com/matrix-org/synapse/issues/10839))
- Add type hints to `synapse.http.site`.
([\#10867](https://github.com/matrix-org/synapse/issues/10867))
- Include outlier status when we log V2 or V3 events.
([\#10879](https://github.com/matrix-org/synapse/issues/10879))
- Break down Grafana's cache expiry time series based on reason for
eviction, c.f.
[\#10829](https://github.com/matrix-org/synapse/issues/10829).
([\#10880](https://github.com/matrix-org/synapse/issues/10880))
- Clean up some of the federation event authentication code for clarity.
([\#10883](https://github.com/matrix-org/synapse/issues/10883),
[\#10884](https://github.com/matrix-org/synapse/issues/10884),
[\#10896](https://github.com/matrix-org/synapse/issues/10896),
[\#10901](https://github.com/matrix-org/synapse/issues/10901))
- Allow the `.` and `~` characters when creating registration tokens as
per the change to
[MSC3231](https://github.com/matrix-org/matrix-doc/pull/3231).
([\#10887](https://github.com/matrix-org/synapse/issues/10887))
- Clean up some unnecessary parentheses in places around the codebase.
([\#10889](https://github.com/matrix-org/synapse/issues/10889))
- Improve type hinting in the user directory code.
([\#10891](https://github.com/matrix-org/synapse/issues/10891))
- Update development testing script `test_postgresql.sh` to use a
supported Python version and make re-runs quicker.
([\#10906](https://github.com/matrix-org/synapse/issues/10906))
- Document and summarize changes in schema version `61` – `64`.
([\#10917](https://github.com/matrix-org/synapse/issues/10917))
- Update release script to sign the newly created git tags.
([\#10925](https://github.com/matrix-org/synapse/issues/10925))
- Fix Debian builds due to `dh-virtualenv` no longer being able to build
their docs.
([\#10931](https://github.com/matrix-org/synapse/issues/10931))

F124520CEEE062448FE1C8442D2EFA2F32FBE047
<olivier@librepush.net>" [ultimate]

Various updates to the install docs.

Various refactors to use `RoomVersion` objects instead of room version identifiers.

Ensure `(room_id, next_batch_id)` is unique to avoid cross-talk/conflicts between batches (MSC2716) (#10877)

Part of [MSC2716](https://github.com/matrix-org/matrix-doc/pull/2716)

Part of https://github.com/matrix-org/synapse/issues/10737

* update _handle_frozendict to work with c implementations of frozen dict

* add changelog

* add clarifying comment to _handle_frozendict

Before Synapse 1.31 (#9411), we relied on `outlier` being stored in the
`internal_metadata` column. We can now assume nobody will roll back their
deployment that far and drop the legacy support.

* Inline `_check_event_auth` for outliers

When we are persisting an outlier, most of `_check_event_auth` is redundant:

 * `_update_auth_events_and_context_for_auth` does nothing, because the
   `input_auth_events` are (now) exactly the event's auth_events,
   which means that `missing_auth` is empty.

 * we don't care about soft-fail, kicking guest users or `send_on_behalf_of`
   for outliers

... so the only thing that matters is the auth itself, so let's just do that.

* `_auth_and_persist_fetched_events_inner`: de-async `prep`

`prep` no longer calls any `async` methods, so let's make it synchronous.

* Simplify `_check_event_auth`

We no longer need to support outliers here, which makes things rather simpler.

* changelog

* lint

Introduced in #10905

By using attrs instead of dicts to store configuration.

Also updates some of the attrs classes to use proper type
hints and auto_attribs.

Otherwise the presence of a (bogus, unused) field could cause
auth checks to fail.

This was due to dh-virtualenv builds being broken due to Shpinx removing
deprecated APIs.

Currently we use `JsonEncoder.iterencode` to write JSON responses, which ensures that we don't block the main reactor thread when encoding huge objects. The downside to this is that `iterencode` falls back to using a pure Python encoder that is *much* less efficient and can easily burn a lot of CPU for huge responses. To fix this, while still ensuring we don't block the reactor loop, we encode the JSON on a threadpool using the standard `JsonEncoder.encode` functions, which is backed by a C library.

Doing so, however, requires `respond_with_json` to have access to the reactor, which it previously didn't. There are two ways of doing this:

1. threading through the reactor object, which is a bit fiddly as e.g. `DirectServeJsonResource` doesn't currently take a reactor, but is exposed to modules and so is a PITA to change; or
2. expose the reactor in `SynapseRequest`, which requires updating a bunch of servlet types.

I went with the latter as that is just a mechanical change, and I think makes sense as a request already has a reactor associated with it (via its http channel).