There's no guarantee that module callbacks will handle cancellation
appropriately. Protect module callbacks with read semantics from
cancellation and avoid swallowing `CancelledError`s that arise.
Other module callbacks, such as the `on_*` callbacks, are presumed to
live on code paths that involve writes and aren't cancellation-friendly.
These module callbacks have been left alone.
Signed-off-by: Sean Quah <seanq@element.io>
Part of #9744
Removes all redundant `# -*- coding: utf-8 -*-` lines from files, as python 3 automatically reads source code as utf-8 now.
`Signed-off-by: Jonathan de Jong <jonathan@automatia.nl>`
At the moment, if you'd like to share presence between local or remote users, those users must be sharing a room together. This isn't always the most convenient or useful situation though.
This PR adds a module to Synapse that will allow deployments to set up extra logic on where presence updates should be routed. The module must implement two methods, `get_users_for_states` and `get_interested_users`. These methods are given presence updates or user IDs and must return information that Synapse will use to grant passing presence updates around.
A method is additionally added to `ModuleApi` which allows triggering a set of users to receive the current, online presence information for all users they are considered interested in. This is the equivalent of that user receiving presence information during an initial sync.
The goal of this module is to be fairly generic and useful for a variety of applications, with hard requirements being:
* Sending state for a specific set or all known users to a defined set of local and remote users.
* The ability to trigger an initial sync for specific users, so they receive all current state.
