Allows delegating the password auth to an external module. This also
moves the LDAP auth to using this system, allowing it to be removed from
the synapse tree entirely in the future.
Some streams will occaisonally advance their positions without actually
having any new rows to send over federation. Currently this means that
the token will not advance on the workers, leading to them repeatedly
sending a slightly out of date token. This in turns requires the master
to hit the DB to check if there are any new rows, rather than hitting
the no op logic where we check if the given token matches the current
token.
This commit changes the API to always return an entry if the position
for a stream has changed, allowing workers to advance their tokens
correctly.
This is for two reasons:
1. Suppresses duplicates correctly, as the notifier doesn't do any
duplicate suppression.
2. Makes it easier to connect the AppserviceHandler to the replication
stream.
This includes:
- Splitting out methods of a class into stand alone functions, to make
them easier to test.
- Adding unit tests to split out functions, testing HTML -> preview.
- Handle the fact that elements in lxml may have tail text.
In the situation where all of a user's devices get deleted, we want to
indicate this to a client, so we want to return an empty dictionary, rather
than nothing at all.
for the email and http pushers rather than trying to make a single
method that will work with their conflicting requirements.
The http pusher needs to get the messages in ascending stream order, and
doesn't want to miss a message.
The email pusher needs to get the messages in descending timestamp order,
and doesn't mind if it misses messages.
1. Give the handler used for logging in unit tests a formatter, so that the
output is slightly more meaningful
2. Log some synapse.storage stuff, because it's useful.
